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Earth and Moon as Viewed fro
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| Title |
Earth and Moon as Viewed from Mars |
| Description |
This is the first image of Earth ever taken from another planet that actually shows our home as a planetary disk. Because Earth and the Moon are closer to the Sun than Mars, they exhibit phases, just as the Moon, Venus, and Mercury do when viewed from Earth. As seen from Mars by the NASA Mars Global Surveyor on May 8, 2003, at 13:00 GMT (6:00 a.m. PDT), Earth and the Moon appeared in the evening sky. This Earth/Moon image has been specially processed to allow both Earth (with an apparent magnitude of -2.5) and the much darker Moon (with an apparent magnitude of +0.9) to be visible together. The bright area at the top of the image of Earth is cloud cover over central and eastern North America. Below that, a darker area includes Central America and the Gulf of Mexico. The bright feature near the center right of the crescent Earth consists of clouds over northern South America. The image also shows the Earth-facing hemisphere of the Moon, since the Moon was on the far side of Earth as viewed from Mars. The slightly lighter tone of the lower portion of the image of the Moon results from the large and conspicuous ray system associated with the crater Tycho. A note about the coloring process: The Mars Global Surveyor Mars Orbital Camera (MOC, a high-resolution camera) only takes grayscale (black-and-white) images. To "colorize" the image, a Mariner 10 Earth/Moon image taken in 1973 was used to color this Earth and Moon picture. The procedure used was as follows: the Mariner 10 image was converted from 24-bit color to 8-bit color using a JPEG to GIF conversion program. The 8-bit color image was converted to 8-bit grayscale and an associated lookup table mapping each gray value of the image to a red-green-blue color triplet (RGB). Each color triplet was root-sum-squared (RSS), and sorted in increasing RSS values. These sorted lists were brightness-to-color maps for the images. Each brightness-to-color map was then used to convert the 8-bit grayscale MOC image to an 8-bit color image. This 8-bit color image was then converted to a 24-bit color image. The color image was edited to return the background to black. Image courtesy NASA/JPL/Malin Space Science Systems [ http://www.msss.com/ ] |
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Sky and Planets
| Title |
Sky and Planets |
| Explanation |
On February 10th, an evocative [ http://www.jps.net/ssumner/ ] evening sky above Rocklin, California, USA inspired astrophotographer Steve Sumner to record this remarkable sight - five planets and the Moon. Near its first quarter phase, the bright Moon [ http://lunar.arc.nasa.gov/ ] was intentionally overexposed but Saturn [ http://www.jpl.nasa.gov/cassini/ ], Jupiter [ http://galileo.jpl.nasa.gov/ ], Mars [ http://mars.jpl.nasa.gov/ ], and Mercury [ http://sd-www.jhuapl.edu/MESSENGER/ ] (and, of course, planet Earth's [ http://www.earth.nasa.gov/ ] horizon) are all clearly visible in the deepening twilight. Notably absent in this grouping of naked-eye planets is Venus [ http://antwrp.gsfc.nasa.gov/apod/ap990903.html ] which is still putting in an early appearance as the morning star [ http://ispec.scibernet.com/station/morn_star.html ]. This month, Mercury has joined Venus in the dawn twilight while Saturn, Jupiter, and Mars still shine brightly in the western sky at nightfall [ http://www.skypub.com/sights/sights.shtml ] making another gorgeous close grouping with the crescent Moon [ http://www.inconstantmoon.com/ ]. |
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1006 AD: Supernova in the Sk
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| Title |
1006 AD: Supernova in the Sky |
| Explanation |
A new star, likely the brightest supernova [ http://antwrp.gsfc.nasa.gov/apod/ap030317.html ] in recorded human history [ http://www.seds.org/messier/more/mw_sn.html ], appeared in planet Earth's sky about 1,000 years ago today, in 1006 AD. The expanding debris cloud [ http://antwrp.gsfc.nasa.gov/apod/ap051226.html ] from the stellar explosion is still visible to modern [ http://antwrp.gsfc.nasa.gov/apod/ap001202.html ] astronomers, but what did the supernova look like in 1006? In celebration of the millennial anniversary of SN1006, astronomer Tunc Tezel offers this intriguing suggestion, based on a photograph he took on February 22, 1998 from a site overlooking the Mediterranean [ http://antwrp.gsfc.nasa.gov/apod/ap011207.html ] south of Antalya, Turkey. On that date, bright Venus and a waning crescent Moon shone in [ http://antwrp.gsfc.nasa.gov/apod/ap020619.html ] the early morning sky. Adopting calculations [ http://arxiv.org/abs/astro-ph/0208415 ] which put the supernova's apparent brightness [ http://www.noao.edu/outreach/press/pr03/pr0304.html ] between Venus and the crescent Moon, he digitally superposed an appropriate new star in the picture. He placed the star at the supernova's position in the southerly constellation of Lupus [ http://www.seasky.org/pictures/ sky7b06.html#Lupus ] and used the water's reflection of moonlight [ http://antwrp.gsfc.nasa.gov/apod/ap021122.html ] in the final image. |
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Venus, Moon, and Neighbors
| Title |
Venus, Moon, and Neighbors |
| Explanation |
Rising before the Sun on February 2nd, astrophotographer [ http://pages.prodigy.net/pam.orman/JoeGallery.html ] Joe Orman anticipated [ http://pages.prodigy.net/pam.orman/JoeAlmanac2000.html ] this apparition of the bright morning star [ http://ispec.scibernet.com/station/morn_star.html ] Venus near a lovely crescent Moon above a neighbor's house in suburban Phoenix, Arizona, USA. Fortunately, the alignment of bright planets and the Moon is one of the most inspiring sights in the night sky [ http://www.skypub.com/sights/skyevents/0004skyevents.html ] and one that is often easy to enjoy and share without any special equipment. Take tonight [ http://spacescience.com/headlines/y2000/ast30mar_1m.htm ], for example. Those blessed with clear skies can simply step outside near sunset and view a young crescent Moon very near three bright planets in the west Jupiter [ http://galileo.jpl.nasa.gov/ ], Mars [ http://mars.jpl.nasa.gov/mgs/ ], and Saturn [ http://www.jpl.nasa.gov/cassini/ ]. Jupiter will be the unmistakable brightest star near the Moon with a reddish Mars just to Jupiter's north and pale yellow Saturn directly above. Of course, these sky shows [ http://drumright.ossm.edu/astronomy/conjunctions.html ] create an evocative picture [ http://antwrp.gsfc.nasa.gov/apod/ap000310.html ] but the planets and Moon just appear to be near each other -- they are actually only approximately lined up and lie in widely separated orbits. Unfortunately, next month's highly publicized alignment of planets [ http://www.griffithobs.org/SkyAlignments.html ] on May 5th will be lost from view in the Sun's glare but such planetary alignments [ http://www.skypub.com/news/special/whypanic.html ] occur repeatedly and pose no danger [ http://www.badastronomy.com/bad/misc/planets.html ] to planet Earth. |
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The Belt of Venus over the V
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| Title |
The Belt of Venus over the Valley of the Moon |
| Explanation |
Although you've surely seen it, you might not have noticed it. During a cloudless twilight [ http://www.hyperdictionary.com/dictionary/twilight ], just before sunrise [ http://antwrp.gsfc.nasa.gov/apod/ap030320.html ] or after sunset [ http://antwrp.gsfc.nasa.gov/apod/ap030412.html ], part of the atmosphere above the horizon appears slightly off-color, slightly pink. Called the Belt of Venus [ http://www.weather-photography.com/Photos/gallery.php?cat=optics&subcat=venus_belt ], this off-color band between the dark eclipsed [ http://antwrp.gsfc.nasa.gov/apod/ap030822.html ] sky and the blue sky [ http://www.sciencemadesimple.com/sky_blue.html ] can be seen in nearly every direction including that opposite the Sun. Straight above, blue sky [ http://www.why-is-the-sky-blue.org/why-is-the-sky-blue.html ] is normal sunlight reflecting off the atmosphere. In the Belt of Venus [ http://epod.usra.edu/archive/epodviewer.php3?oid=158080 ], however, the atmosphere reflects light from the setting (or rising) Sun which appears more red. The Belt of Venus [ http://en.wikipedia.org/wiki/Belt_of_Venus ] can be seen from any location with a clear horizon. Pictured above, the Belt of Venus was photographed above morning fog [ http://antwrp.gsfc.nasa.gov/apod/ap021122.html ] in the Valley of the Moon [ http://www.vmoa.kenwood.ca.us/ ], a famous wine-producing region in northern California [ http://en.wikipedia.org/wiki/California ], USA [ http://www.cia.gov/cia/publications/factbook/geos/us.html ]. The belt is frequently [ http://antwrp.gsfc.nasa.gov/apod/ap011209.html ] caught [ http://antwrp.gsfc.nasa.gov/apod/ap010601.html ] by [ http://antwrp.gsfc.nasa.gov/apod/ap010308.html ] accident [ http://antwrp.gsfc.nasa.gov/apod/ap990418.html ] in [ http://antwrp.gsfc.nasa.gov/apod/ap990325.html ] other [ http://antwrp.gsfc.nasa.gov/apod/ap990308.html ] photographs [ http://antwrp.gsfc.nasa.gov/apod/ap010501.html ]. |
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Planets In The Sun
| Title |
Planets In The Sun |
| Explanation |
Today [ http://science.nasa.gov/headlines/y2000/ast02may_1.htm ], all five naked-eye planets [ http://www.seds.org/nineplanets/nineplanets/ ] (Mercury, Venus, Mars, Jupiter, Saturn) plus the Moon and the Sun [ http://helios.gsfc.nasa.gov/ sun.html ] will at least approximately line-up. As viewed [ http://drumright.ossm.edu/astronomy/conjunctions.html ] from planet Earth, they will be clustered within about 26 degrees, the closest alignment for all these celestial bodies [ http://science.nasa.gov/headlines/y2000/ ast30mar_1m.htm#alignments ] since February 1962, when there was a solar eclipse [ http://antwrp.gsfc.nasa.gov/apod/ap990818.html ]! Such planetary alignments [ http://www.griffithobs.org/SkyAlignments.html ] are not dangerous, except of course that the Sun might hurt your eyes when you look at it [ http://antwrp.gsfc.nasa.gov/apod/ap981212.html ]. So it might be easier [ http://sohowww.nascom.nasa.gov/hotshots/ ] to appreciate today's solar system [ http://space.jpl.nasa.gov/ ] spectacle if |
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Moon And Venus Share The Sky
| Title |
Moon And Venus Share The Sky |
| Explanation |
July is drawing to a close and in the past few days, some early morning risers [ http://antwrp.gsfc.nasa.gov/apod/ap990714.html ] could have looked east and seen a crescent Moon sharing the pre-dawn [ http://science.nasa.gov/headlines/y2000/ast25jul_1m.htm ] skies with planets Jupiter and Saturn. Planet Mercury will also pass about 2 degrees from the thin waning crescent Moon [ http://aa.usno.navy.mil/AA/faq/docs/moon_phases.html ] just before sunrise near the eastern horizon on Saturday, July 29. And finally, on the evening of July 31st, Venus will take its turn near the crescent Moon [ http://antwrp.gsfc.nasa.gov/apod/ap991108.html ]. But this time it will be a day-old crescent Moon near the western horizon, shortly after sunset [ http://antwrp.gsfc.nasa.gov/apod/ap000507.html ]. In fact [ http://pages.prodigy.net/pam.orman/JoeAlmanac2000.html ], on July 31 (August 1 Universal Time) the Moon will occult [ http://www.skypub.com/sights/occultations/lunar/ 0001lunarocc.html ] (pass in front of) Venus for northwestern observers [ http://www.skypub.com/sights/images2000/ 0008moonvenus_big.jpg ] in North America. This telescopic picture taken on 31 December 1997, shows a lovely young crescent Moon and brilliant crescent Venus in [ http://antwrp.gsfc.nasa.gov/apod/ap990903.html ] the early evening sky near Bursa, Turkey [ http://www.mersina.com/Turkey/Marmara/Bursa/index.html ]. And what about the Sun? On Sunday, July 30, a partial eclipse of the Sun [ http://sunearth.gsfc.nasa.gov/eclipse/extra/ PSE2000Jul31.html ] will be visible from some locations [ http://sunearth.gsfc.nasa.gov/eclipse/OH/ PSE2000Jul.gif ] in North America. |
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Crescent Venus and Moon
| Title |
Crescent Venus and Moon |
| Explanation |
There's something behind these clouds. Those faint graceful arcs, upon inspection, are actually far, far in the distance. They are the Earth's Moon [ http://antwrp.gsfc.nasa.gov/apod/ap060907.html ] and the planet Venus [ http://en.wikipedia.org/wiki/Planet_Venus ]. Both the Moon and Venus [ http://antwrp.gsfc.nasa.gov/apod/ap050913.html ] are bright enough to be seen during the day, and both are quite capable of showing a crescent phase [ http://antwrp.gsfc.nasa.gov/apod/ap060618.html ]. To see Venus, which appears quite small, in a crescent phase [ http://antwrp.gsfc.nasa.gov/apod/ap060110.html ] requires binoculars [ http://en.wikipedia.org/wiki/Binoculars ] or a telescope. In the above dramatic daytime image [ http://eder.csillagaszat.hu/digital/venus_fedes/Ven_fed.html ] taken from Budapest [ http://en.wikipedia.org/wiki/Budapest ], Hungary [ http://en.wikipedia.org/wiki/Hungary ], the Moon and Venus [ http://antwrp.gsfc.nasa.gov/apod/ap060723.html ] shared a similar crescent phase a few minutes before the Moon eclipsed [ http://www.astronomy.no/venus080604/venusocc/images.html ] the larger but more distant world. About an hour later, Venus reappeared. |
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Castle and Sky
| Title |
Castle and Sky |
| Explanation |
While Comet McNaught [ http://spaceweather.com/comets/ gallery_mcnaught_page18.php ] ruled southern skies, last week's conjunction [ http://en.wikipedia.org/wiki/ Astronomical_conjunction ] of the Moon and Venus could be enjoyed by denizens [ http://mizar.blogalia.com/ ] of both hemispheres of planet Earth. The two more commonly viewed celestial beacons produced this lovely twilight scene, recorded last Saturday in skies above Almodovar near Cordoba [ http://viajero.blogalia.com/historias/45824 ] in southern Spain. Brilliant Venus and [ http://antwrp.gsfc.nasa.gov/apod/ap061030.html ] a slender crescent Moon seem to overlook the small town, along with a well-lit Castle Almodovar [ http://www.castillodealmodovar.com/historia.htm ]. The impressive castle's [ http://antwrp.gsfc.nasa.gov/apod/ap050218.html ] construction began in the 700s on the strategic site of a Roman fort. It was extensively restored in the 20th century. |
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International Space Station
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| Title |
International Space Station Trail |
| Explanation |
Still under construction, the International Space Station [ http://spaceflight.nasa.gov/station/assembly/ ] is becoming one of the brightest [ http://science.nasa.gov/headlines/y2000/ast01dec_1.htm ], fastest moving "stars" in the heavens. Despite illuminated clouds and bright light from a nearly full moon (lower left), this 5 minute time exposure easily captures the Space Station's trail as it arcs through early evening skies above Palm Beach Gardens, Florida, USA on December 9 [ http://spaceflight.nasa.gov/spacenews/reports/sts97/ STS-97-18.html ]. At the time, the Space Shuttle Endeavour [ http://spaceflight.nasa.gov/shuttle/index.html ] had undocked [ http://antwrp.gsfc.nasa.gov/apod/ap001018.html ] and moved away from the orbiting platform, the shuttle crew having just completed the installation of large solar panels to power the Space Station's systems. Sunlight glinting off the large, shiny panels is likely the source of the brief flare [ http://antwrp.gsfc.nasa.gov/apod/ap991022.html ] visible along the track. Astrophotographer Doug Murray and colleague report that both Shuttle and Space Station were visible [ http://spaceflight.nasa.gov/realdata/sightings/index.html ] separately and on close inspection of this image they do produce distinct, parallel arcs. At the extreme right hand edge of the picture, the trails pass [ http://liftoff.msfc.nasa.gov/temp/StationLoc.html ] very near the brightest "star" in the night sky, Venus [ http://antwrp.gsfc.nasa.gov/apod/ap990903.html ]. |
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Lisbon Moonset
| Title |
Lisbon Moonset |
| Explanation |
Brilliant Venus [ http://antwrp.gsfc.nasa.gov/apod/ap061030.html ], a slender crescent Moon, and lights along the Ponte 25 de Abril [ http://en.wikipedia.org/wiki/25_de_Abril_Bridge ] glow against the western twilight in this lovely moonset scene from Lisbon, Portugal, recorded on March 20. In fact, such serene views were enjoyed across planet Earth this week, as the young Moon [ http://antwrp.gsfc.nasa.gov/apod/ap050513.html ] remained near the setting Sun following a partial solar eclipse, and Venus ruled as the evening star [ http://www.johnpratt.com/items/astronomy/eve_morn.html ]. Because of strong Earthshine [ http://science.nasa.gov/headlines/y2002/ 12apr_earthshine.htm ] - light from the sunlit Earth - even the Moon's night side is clearly visible in the picture. The Ponte 25 de Abril [ http://antwrp.gsfc.nasa.gov/apod/ap070324.html http://maps.google.com/maps?q=38.690066,-9.177017&ie=UTF8 &om=1&z=18&ll=38.685028,-9.17566&spn=0.002789,0.004292&t=k &iwloc=addr ] is a 2.3 kilometer long suspension bridge across the Tagus river, often compared to the Golden Gate [ http://antwrp.gsfc.nasa.gov/apod/ap030521.html ] bridge in San Francisco, USA. |
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Nashville Four Planet Skylin
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| Title |
Nashville Four Planet Skyline |
| Explanation |
So far this February, evening skies [ http://antwrp.gsfc.nasa.gov/apod/ap000504.html ] have been blessed with a glorious Moon and three bright planets, Venus [ http://www.library.utoronto.ca/utel/rp/poems/ longfe10.html ], Jupiter, and Saturn. But just last week, on January 30th, an extreme wide-angle lens allowed astrophotographer Larry Koehn to capture this twilight view of Moon and four planets above [ http://www.seds.org/nineplanets/nineplanets/ see.html ] Nashville, Tennessee, USA. These major solar system [ http://space.jpl.nasa.gov/ ] bodies lie along the ecliptic plane [ http://antwrp.gsfc.nasa.gov/apod/ap001014.html ] and so follow a diagonal line through the picture. Starting near the upper left corner is bright Jupiter [ http://starchild.gsfc.nasa.gov/docs/StarChild/ solar_system_level2/jupiter.html ], which takes on a slightly triangular shape due to the lens distortion. Just below and right of Jupiter is Saturn [ http://www.jpl.nasa.gov/cassini/english/kids/ saturn_in_sky.html ]. Continuing along the diagonal toward the lower right is an overexposed, six day old Moon [ http://www.inconstantmoon.com/ ] and brilliant Venus seemingly embedded in clouds. The fourth planet pictured is Mercury. Notoriously hard to see from planet Earth because it never wanders far from the Sun, Mercury is [ http://antwrp.gsfc.nasa.gov/apod/ap991111.html ] visible just above the lower right corner. The line from Jupiter to Mercury spans about 92 degrees across the Nashville sky. |
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Young Moon and Sister Stars
| Title |
Young Moon and Sister Stars |
| Explanation |
A young [ http://antwrp.gsfc.nasa.gov/apod/ap050513.html ] crescent Moon shared the western sky with thin clouds and the sister stars [ http://www.naic.edu/~gibson/pleiades/pleiades_myth.html ] of the Pleiades cluster in this early evening skyscape recorded on April 19th. Astronomical images of the well-known Pleiades [ http://antwrp.gsfc.nasa.gov/apod/ap060109.html ] often show the star cluster's alluring blue reflection nebulae, but they are washed-out here in the clouds and bright moonlight. While the 3-day old Moon is overexposed, surface features can be seen on the dim lunar night side, illuminated by earthshine [ http://antwrp.gsfc.nasa.gov/apod/ap020419.html ] - light from sunlit planet Earth. Only a week earlier [ http://antwrp.gsfc.nasa.gov/apod/ap070414.html ], brilliant Venus also posed near the sister stars. Of course, Venus has not yet wandered too far from the Pleiades and still rules western skies as the evening star [ http://www.baltastro.org/AstroPoetry.html#EveningStar ]. |
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Bright Venus
| Title |
Bright Venus |
| Explanation |
Have you seen a bright evening star [ http://antwrp.gsfc.nasa.gov/apod/ap990903.html ] in the western sky lately? That's no star, that's planet Venus the second "rock" from the Sun [ http://space.jpl.nasa.gov/ ]. Blazing at -4.6 magnitude [ http://liftoff.msfc.nasa.gov/academy/universe/ MAG.HTML ], Venus, after the Sun and Moon, is the third brightest celestial body in planet Earth's sky [ http://www.skypub.com/sights/sights.shtml ]. Venus is closer [ http://antwrp.gsfc.nasa.gov/apod/ap990612.html ] to the Sun than Earth and as Venus orbits [ http://astrosun.tn.cornell.edu/courses/astro201/ venus_phase.htm ] the Sun it is seen to go through phases [ http://euclid.sms.port.ac.uk/students/astrowise/ venus/demo1.html ] similar to the Moon. But unlike the Moon, as Venus waxes and wanes [ http://www.badastronomy.com/bitesize/ venus_phase.html ] its distance from Earth and hence its apparent size changes drastically. This causes Venus to look brighter [ http://www.science.nasa.gov/newhome/headlines/ ast14jun99_1.htm ] as it looms large in its crescent phases than when it is smaller and nearly full. Taken on January 28th, this dramatic picture finds a crescent Venus near its brightest to the right of a crescent Moon. The brilliant rivals seem poised above a satellite dish of the Scripps Satellite Oceanography Facility [ http://www.sio.ucsd.edu/about_scripps/scripps_tour/ siotour18.htm ]. Closer to the horizon, just below and to the right of the satellite dish, Mercury [ http://antwrp.gsfc.nasa.gov/apod/ap000320.html ] pierces the twilight glow. |
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Venus Near the Moon
| Title |
Venus Near the Moon |
| Explanation |
The two brightest objects in the night sky appeared to go right past each other last week. On the night of May 19, Earth's Moon [ http://antwrp.gsfc.nasa.gov/apod/ap051113.html ] and the planet Venus [ http://antwrp.gsfc.nasa.gov/apod/ap070501.html ] were visible in the same part of the sky, and at closest approach were less than one degree apart. The conjunction was captured in the above image taken from near Quebec City [ http://en.wikipedia.org/wiki/Quebec_City ], Quebec [ http://en.wikipedia.org/wiki/Quebec ], Canada [ http://en.wikipedia.org/wiki/Canada ]. Venus appears on the lower left of the above photo. The spires [ http://antwrp.gsfc.nasa.gov/apod/ap010415.html ] that appear to emanate from Venus [ http://en.wikipedia.org/wiki/Venus ] are diffraction spikes [ http://spider.ipac.caltech.edu/staff/kaspar/obs_mishaps/images/int_reflection2.html ] caused by the camera itself. The image is so clear that craters on the Moon [ http://antwrp.gsfc.nasa.gov/apod/ap060530.html ] are resolved. Of course, the real physical distance between the two heavenly bodies was not unusually small -- the apparent conjunction [ http://en.wikipedia.org/wiki/Conjunction_%28astronomy_and_astrology%29 ] was really just an illusion [ http://www.youtube.com/watch?v=rvY7NGncCgU ] of perspective [ http://antwrp.gsfc.nasa.gov/apod/ap050913.html ]. Although Earth's Moon passes Venus once each month, such a close passing [ http://antwrp.gsfc.nasa.gov/apod/ap061030.html ] visible in the evening sky [ http://antwrp.gsfc.nasa.gov/apod/ap020524.html ] is more rare. |
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The Moon's Saturn
| Title |
The Moon's Saturn |
| Explanation |
On May 22nd, just days after sharing the western evening sky with Venus [ http://antwrp.gsfc.nasa.gov/apod/ap070523.html ], the Moon moved on to Saturn [ http://saturn.jpl.nasa.gov/home/index.cfm ] - actually passing in front of the ringed planet when viewed in skies over Europe, northern Africa, and western Asia. Because the Moon and bright planets wander through the sky near the ecliptic plane [ http://antwrp.gsfc.nasa.gov/apod/ap050503.html ], such occultation events [ http://www.lunar-occultations.com/iota/planets/ planets.htm ] are not uncommon, but they are dramatic [ http://antwrp.gsfc.nasa.gov/apod/ap030724.html ], especially in telescopic views. For example, in this sharp image Saturn is captured emerging from [ http://www.tamanti.it/Solar%20Sys/SaturnOccultation.htm ] behind the Moon, giving the illusion that it lies just beyond the Moon's bright edge. Of course, the Moon is a mere 400 thousand kilometers away, compared to Saturn's distance of 1.4 billion [ http://kokogiak.com/megapenny/nine.asp ] kilometers. Taken with [ http://www.kopfgeist.com/besonderes.htm ] a digital camera and 20 inch diameter telescope at the Weikersheim Observatory [ http://www.sternwarte-weikersheim.de/about/ about_set.html ] in southern Germany, the picture is a single exposure adjusted to reduce the difference in brightness between Saturn and the cratered lunar surface. |
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Red, White, and Blue Sky
| Title |
Red, White, and Blue Sky |
| Explanation |
Contrasting colors in this beautiful sunset sky [ http://www.schursastrophotography.com/10dastro/ vensat070107.html ] were captured on June 30 from Clear Creek Canyon Observatory in central Arizona, USA. The twilight scene includes brilliant [ http://www.digitalsky.org.uk/venus/ shadow-of-venus.html ] Venus as the evening star [ http://www.johnpratt.com/items/astronomy/eve_morn.html ], with a bright Saturn just above it, shining through thin clouds. The two wandering [ http://antwrp.gsfc.nasa.gov/apod/ap070407.html ] planets [ http://antwrp.gsfc.nasa.gov/apod/ap010601.html ] were a mere 1 degree apart or so, about twice the width of the full Moon rising above the eastern horizon on the other side of the sky. In fact, such serene skyviews [ http://www.spaceweather.com/ ] were possible from all over planet Earth as Venus and Saturn approached a conjunction [ http://en.wikipedia.org/wiki/Astronomical_conjunction# Conjunctions_of_planets_in_right_ascension_2005-2020 ]. Regulus, alpha star of the constellation Leo [ http://en.wikipedia.org/wiki/Leo_(constellation) ], is above and to the left of the close planetary pairing. At dusk, lights in tonight's sky will also feature Venus and Saturn low in the west and separated by about 2 degrees. |
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A Daylight Eclipse of Venus
| Title |
A Daylight Eclipse of Venus |
| Explanation |
Something was about to happen. Just two days ago, two of the three celestial objects easily visible during the day appeared to collide. But actually, Earth's Moon [ http://en.wikipedia.org/wiki/Moon ] passed well in front of the distant planet Venus [ http://antwrp.gsfc.nasa.gov/apod/ap070501.html ]. The occultation [ http://www.spaceweather.com/eclipses/gallery_18jun07_page2.htm ] was caught from Switzerland [ http://en.wikipedia.org/wiki/Switzerland ] in the hours before sunset [ http://antwrp.gsfc.nasa.gov/apod/ap050620.html ]. Moments after this image was taken, the Moon, visible as the crescent on the right of the above image, eclipsed Venus [ http://antwrp.gsfc.nasa.gov/apod/ap061030.html ], appearing near half phase [ http://www.enchantedlearning.com/subjects/astronomy/moon/Phases.shtml ] on the lower left. Clouds [ http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/cld/cldtyp/home.rxml ] that once threatened to obscure the whole event [ http://www.skyandtelescope.com/observing/home/7957837.html ], were visible on the far left. About 90 minutes [ http://www.youtube.com/watch?v=co31wxGosN4 ] later, Venus re-appeared just to the right of the bright crescent [ http://antwrp.gsfc.nasa.gov/apod/ap060618.html ]. |
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Planets over Pony Express La
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| Title |
Planets over Pony Express Lake |
| Explanation |
Beautiful sunset sky colors [ http://webexhibits.org/causesofcolor/14B.html ] are reflected in Pony Express [ http://www.ponyexpress.org/history.htm ] Lake in this twilight skyview [ http://www.pbase.com/missouri_skies/image/82364390 ] from northern Missouri, USA, planet Earth. Recorded on Monday, a two day old crescent Moon and brilliant planet Venus shine through thin clouds. Joining the conjunction [ http://antwrp.gsfc.nasa.gov/apod/ap070704.html ] on the right of the Moon's sunlit crescent is fellow wanderer [ http://www.nasm.si.edu/ceps/etp/discovery/ disc_ancient.html ] Saturn, with Regulus, alpha star of the constellation Leo, above and right of Venus. Moonlight and Venus light [ http://www.digitalsky.org.uk/venus/shadow-of-venus.html ] streak the almost-calm lake waters. |
|
Solar System Web Cam
| Title |
Solar System Web Cam |
| Explanation |
Ranging throughout the solar system [ http://space.jpl.nasa.gov/ ], these pictures all have something in common. They were taken with an 8 inch diameter telescope, a size popular with amateur astronomy buffs, and slightly modified "web cam" of the type widely used to send images out over the internet. The results are clearly remarkable for [ http://www.djcash.demon.co.uk/astro/webcam/webcam.htm ] such inexpensive and readily available equipment. Each sharp image was produced from 20 to 30 frames which were digitally stacked and processed using free software [ http://utopia.ision.nl/users/rjstek/english/software/ index.htm ]. Until recently, digital imaging for amateur astronomers required a specialized camera [ http://www.wvi.com/~rberry/cookbook.htm ], but the advent of low-light video surveillance cameras and web cams now presents other options for relatively bright [ http://www.astrabio.demon.co.uk/QCUIAG/ac/3dmoon.htm ] solar system objects. Want to try some unconventional [ http://www.astrabio.demon.co.uk/QCUIAG/ ] web cam astronomy? Geoff Chester, Public Affairs Officer at the U.S. Naval Observatory [ http://www.usno.navy.mil ], offers these images and an account of his own adventures [ http://www.usno.navy.mil/pao/QuickCamAstro.shtml ] from a suburban front lawn near Washington D.C. |
|
Bright Planets, Crescent Moo
…
| Title |
Bright Planets, Crescent Moon |
| Explanation |
Early risers are currently enjoying the sight [ http://stardate.org/nightsky/planets/ ] of dazzling Venus [ http://www.nineplanets.org/venus.html ], near the eastern horizon as the morning star [ http://www.windows.ucar.edu/tour/link=/venus/ morning_star.html&edu=high ]. Recorded on October 7, this predawn skyview [ http://www.usno.navy.mil/pao/sky/sky_week.shtml ] does feature Venus at the upper right. It also includes a crescent Moon and Saturn (lower left). In fact, holding your fist at arms length would have easily covered [ http://chandra.harvard.edu/photo/scale.html ] both planets and the Moon in this 5 degree wide field. Earthshine [ http://antwrp.gsfc.nasa.gov/apod/ap020419.html ], sunlight reflected from planet Earth's dayside, illuminates features on the lunar nightside. A close inspection of Saturn itself reveals a nearby pinpoint of light corresponding to Saturn's [ http://saturn.jpl.nasa.gov/science/moons/index.cfm ] large moon Titan. Though the Moon has moved on, the tight triangle [ http://www.spaceweather.com/images2007/12oct07/ skymap_north.gif ] formed by Venus, Saturn, and Regulus (top), alpha star in the constellation Leo, will continue to look impressive in early morning skies over the next few days. Early bird astrophotographer Jay Ouellet also described Mars as [ http://www.spaceweather.com/images2007/11oct07/ skymap_north_mars.gif ] a "brilliant red diode" in his dark country sky east of Quebec City, Canada. Count the Stars: The Great World Wide Star Count [ http://www.windows.ucar.edu/citizen_science/starcount/ ] |
|
VERITAS and Venus
| Title |
VERITAS and Venus |
| Explanation |
Early morning risers and late to bed astronomers have recently enjoyed bright planets [ http://science.nasa.gov/headlines/y2007/02nov_nov5.htm ] in predawn skies, with brilliant Venus [ http://www.avertedimagination.com/img_pages/ morning_star.html ] above the eastern horizon. On November 5, Venus was joined by the waning crescent Moon. This self-portrait by astronomer Larry Ciupik captures the lovely pairing of the two brightest celestial beacons on the scene, though the Moon, right of Venus, is strongly over exposed. Included at the far left in the 30 second exposure is the bright streak of the International Space Station [ http://antwrp.gsfc.nasa.gov/apod/ap070625.html ] still docked with shuttle orbiter Discovery [ http://www.nasa.gov/mission_pages/shuttle/ main/index.html ]. Together in Earth orbit, the spacefaring [ http://antwrp.gsfc.nasa.gov/apod/ap070628.html ] combination was momentarily the third brightest sky light in view [ http://spaceflight.nasa.gov/realdata/sightings/index.html ]. In dim silhouette, a multi-mirrored unit of the Very Energetic Radiation Imaging Telescope Array System (VERITAS [ http://veritas.adlerplanetarium.org/home.shtml ]) is also visible in the foreground. VERITAS operates at the Whipple Observatory near Tucson, Arizona to detect high-energy gamma-rays from the cosmos [ http://veritas.adlerplanetarium.org/science/ ]. |
|
The Earth and Moon Planetary
…
| Title |
The Earth and Moon Planetary System |
| Explanation |
How similar in size are the Earth [ http://antwrp.gsfc.nasa.gov/apod/ap010204.html ] and the Moon [ http://antwrp.gsfc.nasa.gov/apod/ap000113.html ]? A dramatic visual answer [ http://photojournal.jpl.nasa.gov/cgi-bin/PIAGenCatalogPage.pl?PIA02441 ] to this question is found by combining photographs taken by the Mariner 10 spacecraft [ http://nssdc.gsfc.nasa.gov/nmc/tmp/1973-085A.html ] that headed out toward Venus [ http://www.nineplanets.org/venus.html ] and Mercury [ http://www.solarviews.com/eng/mercury.htm ] in 1973. The Moon [ http://www.nineplanets.org/luna.html ] can be seen to have a diameter over one quarter that of Earth [ http://antwrp.gsfc.nasa.gov/apod/earth.html ], relatively large compared to its planetary companion [ http://antwrp.gsfc.nasa.gov/apod/ap991231.html ]. In our Solar System [ http://www.nineplanets.org/overview.html ], only Pluto and Charon [ http://antwrp.gsfc.nasa.gov/apod/ap980708.html ] are closer together in size. Striking features of the Earth [ http://antwrp.gsfc.nasa.gov/apod/ap001127.html ] visible to the passing spacecraft include blue oceans [ http://seawifs.gsfc.nasa.gov/ocean_planet.html ] and white clouds [ http://vortex.plymouth.edu/clouds.html ], showing the Earth [ http://earthobservatory.nasa.gov/ ] to be truly a water world [ http://antwrp.gsfc.nasa.gov/apod/ap980530.html ]. |
|
Venus and Jupiter in Morning
…
| Title |
Venus and Jupiter in Morning Skies |
| Explanation |
These two celestial beacons shining brightly in the east before sunrise are actually children of the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap061116.html ], the planets Venus and Jupiter. The second and third brightest objects in the sky at Night [ http://www.twanight.org/ ] after the Moon, Venus and Jupiter [ http://www.earthsky.org/skywatching/ venus-and-jupiter-before-sunrise-february-1 ] appeared separated by about 2 degrees when this picture was taken on January 30th, but closed to within nearly half a degree early yesterday morning. In the serene foreground is the shoreline along the Miankaleh [ http://www.aliparsa.com/shipwreck/ship.html ] Peninsula and Gorgan Bay, an important bird and wildlife [ http://www.birdlife.org/datazone/sites/ index.html?action=SitHTMDetails.asp&sid=8085&m=0 ] refuge in the southeastern Caspian Sea [ http://antwrp.gsfc.nasa.gov/apod/ap060516.html ]. Over the next two days, early morning risers around the globe will be able to enjoy a close pairing of Venus and Jupiter with an old crescent Moon. |
|
Comet Ikeya-Zhang
| Title |
Comet Ikeya-Zhang |
| Explanation |
Comet Ikeya-Zhang [ http://cometography.com/lcomets/2002c1.html ] is presently heading north in planet Earth's sky [ http://encke.jpl.nasa.gov/images/02C1/ c2002c1chart.jpg ], framed by stars of the constellation Cetus. The comet was discovered [ http://cfa-www.harvard.edu/iauc/07800/ 07812.html ] as a faint, telescopic object [ http://encke.jpl.nasa.gov/RecentObs.html#02C1 ] near the western horizon on the evening of February 1st independently by Kaoru Ikeya [ http://comets.amsmeteors.org/comets/ lcomets/1965s1.html ] of Shizuoka prefecture, Japan, Daqing Zhang in Henan province, China, and later by [ http://cfa-www.harvard.edu/iauc/07800/07813.html ] observer Paulo Raymundo of Salvador, Brazil. But Ikeya-Zhang [ http://skyandtelescope.com/observing/objects/comets/ article_477_1.asp ] is expected to brighten significantly and in March and April could become visible to the unaided eye. This picture, taken near Tucson, Arizona, USA on the evening of February 9th, covers a field a bit less than the width of the full moon showing the comet's [ http://encke.jpl.nasa.gov/define.html ] condensed coma [ http://www.ifa.hawaii.edu/faculty/jewitt/ coma.html ] and narrow, developing tail [ http://antwrp.gsfc.nasa.gov/apod/ap001227.html ]. Ikeya-Zhang should pass closest to the Sun (perihelion) on March 18 at a point roughly midway [ http://encke.jpl.nasa.gov/images/02C1/ ikeyaorbit.jpg ] between the orbits of Mercury and Venus. Based on preliminary calculations of this comet's orbit, Ikeya-Zhang [ http://cfa-www.harvard.edu/iau/Ephemerides/Comets/ 2002C1.html ] is suspected of being a periodic comet, returning to the inner Solar System every 500 years or so. In fact, it is "speculated" that Ikeya-Zhang may be directly connected with a historic bright comet [ http://ssd.jpl.nasa.gov/great_comets.html ] seen in 1532. |
|
Venus: Earth's Sister Planet
| Title |
Venus: Earth's Sister Planet |
| Explanation |
This picture in visible light was taken by the Galileo [ http://nssdc.gsfc.nasa.gov/planetary/galileo.html ] spacecraft. Venus [ http://seds.lpl.arizona.edu/nineplanets/nineplanets/venus.html ] is very similar to Earth [ http://antwrp.gsfc.nasa.gov/apod/ap950622.html ] in size and mass - and so is sometimes referred to as Earth's sister planet - but Venus has a quite different climate. Venus' [ http://www.c3.lanl.gov/~cjhamil/SolarSystem/venus.html ] thick clouds and closeness to the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap950813.html ] (only Mercury [ http://antwrp.gsfc.nasa.gov/apod/ap950814.html ] is closer) make it the hottest planet - much hotter than the Earth. Humans could not survive there, and no life of any sort has ever been found. When Venus [ http://nssdc.gsfc.nasa.gov/photo_gallery/PhotoGallery-Venus.html ] is visible it is usually the brightest object in the sky after the Sun and the Moon. More than 20 spacecraft have visited Venus including Venera 9, which landed on the surface, and Magellan [ http://stardust.jpl.nasa.gov/mveg/guide.html ], which used radar to peer through the clouds and make a map of the surface. There are still many things about Venus's unusual atmosphere that astronomers don't understand. Tomorrow's picture: Uranus: The Tilted Planet |
|
Planets in the West
| Title |
Planets in the West |
| Explanation |
Have you seen any bright planets lately? Chances are if you've been outside under clear skies [ http://currentsky.com/ ] just after sunset, then you have. Now shining in the west as bright "stars [ http://nfo.edu/astro/planets.htm ]" in the night sky, are all five planets of the solar system known to [ http://www.nasm.si.edu/ceps/etp/discovery/ etpdiscovery.html ] ancient astronomers - Mercury, Venus, Mars [ http://mars.jpl.nasa.gov/ funzone.html ], Saturn, and Jupiter [ http://www.seds.org/nineplanets/nineplanets/ jupiter.html ]. Recorded from Holt, Michigan, USA about 40 minutes after sunset on April 14th, this digital image [ http://www.pa.msu.edu/people/frenchj/const/index2.html ] captures three of them, Venus, Mars, and Saturn [ http://www.jpl.nasa.gov/solar_system/planets/ saturn_index.html ], along with a young crescent Moon [ http://antwrp.gsfc.nasa.gov/apod/ap000728.html ]. Also indicated are the Pleiades [ http://antwrp.gsfc.nasa.gov/apod/ap010506.html ] star cluster and bright red giant star Aldebaran [ http://www.earthsky.com/Features/ Skywatching/pronounce.html ] in Taurus. Mercury [ http://www.psrd.hawaii.edu/Jan97/ MercuryUnveiled.html ], setting, is lost in the trees and glow along the horizon, while Jupiter is off the top of this view. The coming weeks [ http://www.darkhorizons.org/planets.htm ] will see photo opportunities galore as all five planets gradually move closer together, posing after sunset with the Moon and stars in the western sky [ http://www.skyviewcafe.com/skyview.shtml ]. Venus [ http://antwrp.gsfc.nasa.gov/apod/ap020330.html ], Mars, and Saturn will form the closest trio, drawing within a 5 degree circle (about the apparent size of your fist with arm extended) above Aldebaran by May 3rd. |
|
Dusk of the Planets
| Title |
Dusk of the Planets |
| Explanation |
A great grouping of planets [ http://www.nineplanets.org/ ] is now visible [ http://CarnegieScienceCenter.org/exhibits/planet_calendar.asp ] to the west just after sunset. Over the next two weeks, Mercury [ http://antwrp.gsfc.nasa.gov/apod/ap010819.html ], Venus [ http://antwrp.gsfc.nasa.gov/apod/ap010916.html ], Earth, Mars [ http://antwrp.gsfc.nasa.gov/apod/ap010628.html ], Jupiter [ http://antwrp.gsfc.nasa.gov/apod/ap020205.html ], and Saturn [ http://antwrp.gsfc.nasa.gov/apod/ap020215.html ] -- the innermost six planets of our Solar System [ http://www.nineplanets.org/overview.html ] -- can be seen in a single knowing glance. The image on the left [ http://www.astropix.com/HTML/H_OTHER/PLANETS.HTM ] captured them all in one frame. Connecting the planetary dots delineates the edge-on ecliptic [ http://antwrp.gsfc.nasa.gov/apod/ap990529.html ], the plane in which the planets orbit the Sun [ http://csep10.phys.utk.edu/astr161/lect/retrograde/copernican.html ]. The shot was taken on April 23 near Chatsworth, New Jersey [ http://www.state.nj.us/ ], USA [ http://www.cia.gov/cia/publications/factbook/geos/us.html ], and even includes scattered light from the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap000403.html ] and the Moon [ http://antwrp.gsfc.nasa.gov/apod/ap010218.html ]. Besides the planets, the Pleiades [ http://antwrp.gsfc.nasa.gov/apod/ap010506.html ] and Hyades [ http://www.astro.uiuc.edu/~kaler/sow/hyades-p.html ] open clusters [ http://www.seds.org/messier/open.html ] of stars are visible [ http://www.planetary.org/html/news/articlearchive/headlines/2002/alignment.htm ]. |
|
Moon and Planets by the Eiff
…
| Title |
Moon and Planets by the Eiffel Tower |
| Explanation |
The great evening grouping of planets [ http://antwrp.gsfc.nasa.gov/apod/ap020429.html ] is coming to an end. Before all the planets [ http://antwrp.gsfc.nasa.gov/apod/ap020510.html ] went their own separate directions [ http://CarnegieScienceCenter.org/exhibits/planet_calendar.asp ], however, the Moon [ http://antwrp.gsfc.nasa.gov/apod/ap010218.html ] was kind enough to pose [ http://science.nasa.gov/spaceweather/planets/gallery_may02.html ] with some of them. The planets [ http://www.nineplanets.org ] in the above picture [ http://perso.club-internet.fr/legault/planets.html ], taken last week, are Venus [ http://antwrp.gsfc.nasa.gov/apod/ap970507.html ] and Jupiter [ http://antwrp.gsfc.nasa.gov/apod/ap020205.html ]. Mars [ http://www.nineplanets.org/mars.html ], Saturn [ http://antwrp.gsfc.nasa.gov/apod/ap010702.html ], and even Mercury [ http://antwrp.gsfc.nasa.gov/apod/ap000320.html ] appear to the lower right of Venus [ http://nssdc.gsfc.nasa.gov/photo_gallery/photogallery-venus.html ] but are too dim to be seen. Over the next two weeks, the Moon will rise [ http://aa.usno.navy.mil/data/docs/RS_OneYear.html ] later and later passing a full phase [ http://antwrp.gsfc.nasa.gov/apod/ap990419.html ] on May 26. Venus and Jupiter will continue to shine, moving together [ http://SkyandTelescope.com/observing/objects/planets/article_572_4.asp ] until their closest approach on June 3. The Eiffel Tower [ http://www.tour-eiffel.fr/teiffel/uk/ ], however, is expected to remain right where it is. |
|
Love and War by Moonlight
| Title |
Love and War by Moonlight |
| Explanation |
Venus [ http://www.pantheon.org/articles/v/venus.html ], named for the Roman goddess of love, and Mars [ http://www.pantheon.org/articles/m/mars.html ], the war god's namesake, approach each other by moonlight [ http://www.thorstenkaye.com/tk_todayspoem3.htm#BM41 ] in this lovely sky view recorded on May 14th from Dunkirk, Maryland, USA. The four second time exposure made in twilight with a digital camera also records earthshine [ http://antwrp.gsfc.nasa.gov/apod/ap020419.html ] illuminating the otherwise dark surface of the young [ http://starchild.gsfc.nasa.gov/docs/StarChild/ StarChild.html ] crescent Moon. Venus shines as the third brightest object in Earth's sky, after the Sun and the Moon itself, and has been appearing as the brilliant evening star [ http://www.library.utoronto.ca/utel/rp/poems/ longfe10.html ] in the pantheon of planets [ http://www.seds.org/nineplanets/nineplanets/ nineplanets.html ] arrayed in the west during April and May. Here, Venus' light is so intense that it produces a noticeable spike in the sensitive camera's image. Much fainter Mars [ http://www-mgcm.arc.nasa.gov/mgcm/fun/ ancient_mars.html ] is lower in the picture, caught between tree limbs swaying in a gentle evening breeze. By early June, Mars will be harder to spot as it wanders toward the horizon, but Venus and father Jupiter [ http://www.pantheon.org/articles/j/jupiter.html ] will draw closer together, presenting a spectacular pair of bright planets in the west [ http://SkyandTelescope.com/observing/objects/planets/ article_572_1.asp ]. |
|
Planets Over Stonehenge
| Title |
Planets Over Stonehenge |
| Explanation |
Stonehenge [ http://antwrp.gsfc.nasa.gov/apod/ap990912.html ], four thousand year old [ http://antwrp.gsfc.nasa.gov/apod/ap980408.html ] monument to the Sun [ http://www.hao.ucar.edu/public/education/archeoslides/ index.html ], provides an appropriate setting for this delightful snapshot [ http://www.astrocruise.com/planets.htm ] of the Sun's children [ http://www.seds.org/nineplanets/nineplanets/ ] gathering in planet Earth's sky. While the massive stone [ http://www.amherst.edu/~ermace/sth/poetry.html ] structure dates from around 2000 B.C. [ http://mathforum.org/dr.math/problems/masell10.1.97.html ], this arrangement of the visible planets [ http://skyandtelescope.com/observing/objects/planets/ article_572_1.asp ] was recorded only a few days ago on the evening of May 4th, 2002 A.D. Bright Jupiter stands highest above the horizon at the upper left. A remarkable, almost equilateral triangle [ http://mathforum.org/dr.math/faq/formulas/ faq.triangle.html ] formed by Saturn (left), Mars (top), and Venus (right) is placed just above the stones near picture center. Fighting the glow of the setting sun, Mercury can be spotted closest to the horizon, below and right of the planetary triad. Still easy to enjoy [ http://science.nasa.gov/headlines/y2002/24apr_relax.htm ] for casual sky gazers, this photogenic and slowly shifting planetary grouping [ http://science.nasa.gov/spaceweather/planets/ gallery_may02.html ] will be joined by a young crescent [ http://antwrp.gsfc.nasa.gov/apod/ap020419.html ] Moon beginning Monday, May 13. |
|
An Atlas Centaur Rocket Laun
…
| Title |
An Atlas Centaur Rocket Launches |
| Explanation |
Atlas Centaur [ http://www.lerc.nasa.gov/Other_Groups/PAO/html/atlas2as.htm ] rockets have launched over 75 successful unmanned missions. These missions included the Surveyor [ http://antwrp.gsfc.nasa.gov/apod/ap951008.html ] series - the first vehicles to make soft landings on the Moon [ http://antwrp.gsfc.nasa.gov/apod/ap950903.html ], Pioneer [ http://pyroeis.arc.nasa.gov/pioneer/PNhome.html ] 10 and 11 - the first missions to fly by Jupiter [ http://antwrp.gsfc.nasa.gov/apod/ap951206.html ] and Saturn [ http://antwrp.gsfc.nasa.gov/apod/ap950705.html ] and the first man-made objects able to leave our Solar System [ http://antwrp.gsfc.nasa.gov/apod/ap950819.html ], the Viking missions [ http://antwrp.gsfc.nasa.gov/apod/ap950721.html ] which landed on Mars [ http://antwrp.gsfc.nasa.gov/apod/ap950716.html ], several satellites in the High Energy Astrophysics Observatory [ http://heasarc.gsfc.nasa.gov/ ] (HEAO) series, Pioneer Venus [ http://nssdc.gsfc.nasa.gov/planetary/pioneer_venus.html ] which circled and mapped the surface of Venus [ http://antwrp.gsfc.nasa.gov/apod/ap950822.html ], and numerous Intelsat [ http://www.intelsat.int:8080/info/html/is5.html ] satellites. Of recent scientific interest was the Atlas [ http://www.ksc.nasa.gov/elv/ATLAS_CENTAUR/atlcent.htm ] launched SOHO [ http://sohowww.nascom.nasa.gov/index-text.html ] mission which will continually observe the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap950813.html ]. Atlas rockets are manufactured by Lockheed Martin [ http://www.mmc.com/ ] Co. |
|
The Moon & Venus Over Geneva
| Title |
The Moon & Venus Over Geneva |
| Explanation |
The Moon, fresh from a biting encounter [ http://antwrp.gsfc.nasa.gov/apod/ap020612.html ] with the Sun last week [ http://antwrp.gsfc.nasa.gov/apod/ap020610.html ], appeared next to threaten Venus. The waxing Moon [ http://www.astro.wisc.edu/~dolan/java/MoonPhase.html ] appeared to glide right past, however, just a few degrees away [ http://science.nasa.gov/spaceweather/planets/gallery_june02_page2.html ]. Venus [ http://antwrp.gsfc.nasa.gov/apod/venus.html ], of course, is much further away from the Earth than the Moon, so the passing was really just an angular illusion [ http://antwrp.gsfc.nasa.gov/apod/ap020130.html ]. Pictured above [ http://science.nasa.gov/spaceweather/planets/gallery_june02_page2.html ] on June 13, a fading sunset finds the crescent Moon [ http://antwrp.gsfc.nasa.gov/apod/ap020225.html ] and Venus [ http://www.nineplanets.org/venus.html ] between clouds and above the city lights of Geneva [ http://www.geneva.ch/GenevaHistory.htm ], Switzerland [ http://www.cia.gov/cia/publications/factbook/geos/sz.html ]. |
|
Clearing Skies
| Title |
Clearing Skies |
| Explanation |
Clear evening skies are a welcome sight for stargazers [ http://antwrp.gsfc.nasa.gov/apod/ap000817.html ] worldwide, but clearing skies are good too. Just such a glorious occasion was recorded in this dramatic photo taken by [ http://www.skyphoto.homestead.com ] Dominic Cantin during a recent gathering of Canadian astronomers [ http://sracqc.com/ ] at St-Nérée Observatory [ http://sracqc.com/librairie/activit%C9soff.htm ], located about 60 kilometers southeast of the city of Quebec. Looking toward the west on July 13th [ http://stardate.org/radio/program.php?f=detail&id=2002-07-13 ], the exposure captured a distant lightning [ http://thunder.msfc.nasa.gov/primer/ ] flash from a passing thunderstorm at the far left. On the right, the storm clouds' retreat has uncovered an overexposed crescent Moon [ http://antwrp.gsfc.nasa.gov/apod/ap020419.html ] sharing the evening twilight with bright Venus [ http://science.nasa.gov/headlines/y2002/ 06may_pillar.htm ] only a few degrees away (below and far right). In the darkening sky above the young Moon is a familiar right triangle of stars in the constellation Leo [ http://www.astro.wisc.edu/~dolan/constellations/ constellations/Leo.html ]. Cantin reports that clear skies followed, all night long. |
|
The McMath-Pierce Solar Obse
…
| Title |
The McMath-Pierce Solar Observatory |
| Explanation |
This odd-looking structure silhouetted in the foreground houses the three largest solar telescopes in the world. Located in Kitt Peak [ http://argo.tuc.noao.edu/nsokp/nsokp.html ], Arizona, the largest telescope inside the McMath-Pierce Facility [ http://argo.tuc.noao.edu/nsokp/mp.html ] is 1.6-meters in diameter and contains only mirrors. The telescope contains no windows or lenses because focusing bright sunlight would overheat them. Visible in the background of this sunrise photo are the Moon [ http://antwrp.gsfc.nasa.gov/apod/ap960222.html ] and Venus [ http://antwrp.gsfc.nasa.gov/apod/ap950822.html ]. The telescopes are used in many research projects including determining the Sun's structure [ http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1993BAAS%2E%2E183%2E5902U&db_key=AST ], researching the cause of the solar corona [ http://antwrp.gsfc.nasa.gov/apod/ap951024.html ], monitoring Sun-spots [ http://www.hao.ucar.edu/public/slides/slide3.html ] and solar flares [ http://antwrp.gsfc.nasa.gov/apod/ap950813.html ], and observing bright planets and comets near the Sun [ http://www.dsi.unimi.it/Users/Students/amoroso/sun/list-e.html ]. The telescopes even help monitor the Earth's atmospheric content of ozone [ http://www.cis.ohio-state.edu/hypertext/faq/usenet/ozone-depletion/top.html ] and CFCs [ http://duckworth.rh.imsa.edu/~yensid/chem/ozonedepletion.html ]! |
|
Moon, Mars, Venus, and Spica
| Title |
Moon, Mars, Venus, and Spica |
| Explanation |
Gliding toward today's total eclipse [ http://sunearth.gsfc.nasa.gov/ eclipse/TSE2002/TSE2002.html ] of the Sun, the crescent Moon has been rising early, just before dawn. And as a prelude to its close solar alignment [ http://www.mreclipse.com/ Special/SEprimer.html ], the Moon also completed a lovely celestial triangle, closing with bright planets Mars and Venus [ http://antwrp.gsfc.nasa.gov/apod/ap020524.html ] on the morning of December 1. While [ http://antwrp.gsfc.nasa.gov/apod/ap021203.html ] the total solar eclipse can only [ http://profjohn.com/el/el2002/index.html ] be seen [ http://www.csiro.au/helix/eclipse/ ] from a [ http://astronomy.swin.edu.au/solar_eclipse_2002/ ] narrow corridor, skygazers around the globe could appreciate this [ http://www.spaceweather.com/planets/ gallery_01dec02.html ] lunar-planetary conjunction. This view is from near Nashville Tennessee, USA, and finds brilliant Venus at the lowest corner of the triangle with a much fainter Mars immediately to the right of the Moon. The Moon's sunlit crescent is overexposed, but details of the lunar night side are revealed by earthshine [ http://antwrp.gsfc.nasa.gov/apod/ap020419.html ]. Above and to the right of the trio is Spica [ http://www.astro.wisc.edu/~dolan/constellations/ hr/5056.html ], brightest star in the constellation Virgo. |
|
1006 AD: Supernova in the Sk
…
| Title |
1006 AD: Supernova in the Sky |
| Explanation |
A new star, likely the brightest supernova [ http://antwrp.gsfc.nasa.gov/apod/ap030317.html ] in recorded human history [ http://www.seds.org/messier/more/mw_sn.html ], appeared in planet Earth's sky in the year 1006 AD. The expanding debris cloud [ http://antwrp.gsfc.nasa.gov/apod/ap001202.html ] from the stellar explosion is still visible to modern astronomers, but what did the supernova look like in 1006? Astronomer Tunç Tezel offers this suggestion, based on a photograph he took on February 22, 1998 from a site overlooking the Mediterranean [ http://antwrp.gsfc.nasa.gov/apod/ap011207.html ] south of Antalya, Turkey. On that date, bright Venus and a waning crescent Moon shone in [ http://antwrp.gsfc.nasa.gov/apod/ap020619.html ] the early morning sky. Adopting recent calculations [ http://www.noao.edu/outreach/press/pr03/pr0304.html ] which put the supernova's apparent brightness between Venus and the crescent Moon, he digitally superposed an appropriate new star in the picture. He placed the star at the supernova's position in the southerly constellation of Lupus [ http://www.seasky.org/pictures/ sky7b06.html#Lupus ] and used the water's reflection of moonlight [ http://antwrp.gsfc.nasa.gov/apod/ap021122.html ] in the final image. Tezel hopes to view the total solar eclipse of 29 March 2006 [ http://newton.physics.metu.edu.tr/~aat/TSE2006/TSE2006.html ] from this same site -- on the 1,000th anniversary of Supernova 1006 [ http://www.seds.org/~spider/spider/Misc/sn1006.html ]. |
|
Mars Rising Behind Poodle Ro
…
| Title |
Mars Rising Behind Poodle Rock |
| Explanation |
Have you seen Mars lately? As Earth [ http://antwrp.gsfc.nasa.gov/apod/ap010204.html ] and Mars [ http://antwrp.gsfc.nasa.gov/apod/ap030728.html ] near their closest approach in nearly 60,000 years [ http://mars.jpl.nasa.gov/spotlight/marsClose01.html ] on August 27, the red planet [ http://www.nineplanets.org/mars.html ] has begun to appear dramatically bright and show interesting details [ http://antwrp.gsfc.nasa.gov/apod/ap030724.html ] through telescopes and binoculars. Although not yet visible at sunset, Mars [ http://www.tnni.net/~dustymars/2003_MARS.htm ] can be seen rising [ http://skyandtelescope.com/observing/ataglance/article_110_1.asp ] increasingly earlier in the evening. Once above the horizon, Mars is easy to spot [ http://skyandtelescope.com/observing/objects/planets/article_985_1.asp ], as it sports a distinct orange-red hue and it is the brightest object in the sky after the Sun [ http://antwrp.gsfc.nasa.gov/apod/sun.html ], the nearby Moon [ http://antwrp.gsfc.nasa.gov/apod/moon.html ], and Venus [ http://antwrp.gsfc.nasa.gov/apod/venus.html ]. After Earth overtakes Mars [ http://www.earthsky.com/2003/es030728.html ] in their respective solar orbits, Mars will be visible [ http://www.space.com/spacewatch/mars_preview_021108.html ] right from sunset, although its historic brightness will then begin to fade [ http://www.lpl.arizona.edu/~rhill/alpo/marstuff/ephems/ephem2003.html ]. Pictured above [ http://www.astropics.com/mars/index.htm ], Mars was captured rising in the south east next to Poodle Rock in Valley of Fire State Park [ http://parks.nv.gov/vf.htm ], Nevada [ http://quickfacts.census.gov/qfd/index.html ], USA [ http://www.cia.gov/cia/publications/factbook/geos/us.html ]. |
|
Shadow Rise
| Title |
Shadow Rise |
| Explanation |
As the Sun sets [ http://antwrp.gsfc.nasa.gov/apod/ap030424.html ], the Earth's shadow rises up from the east. The subtle beauty of this daily apparition [ http://webexhibits.org/causesofcolor/14E.html ] is often overlooked in favor of the brighter, more colorful [ http://antwrp.gsfc.nasa.gov/apod/ap021110.html ] western horizon. But while gazing toward a nearly full rising Moon on August 9, astronomer Steve Mandel admired the shadow rise from his driveway near Soquel, California, USA. His view looks east from the northern tip of Monterey Bay toward Fremont Peak, the highest point in the small mountain range on the horizon. The Earth's rising shadow [ http://www.galaxyimages.com/earthshadow.html ] is cast through the dense atmosphere and is seen in his picture as the dark blue band along the horizon, bounded above by a pinkish purple glow or antitwilight arch. Also known as the Belt of Venus [ http://antwrp.gsfc.nasa.gov/apod/ap011209.html ], the arch's lovely color is due to backscattering of reddened light [ http://www.exploratorium.edu/snacks/blue_sky.html ] from the setting Sun [ http://antwrp.gsfc.nasa.gov/apod/ap980526.html ]. |
|
The Belt of Venus over the V
…
| Title |
The Belt of Venus over the Valley of the Moon |
| Explanation |
Although you've surely seen it, you might not have noticed it. During a cloudless twilight [ http://www.hyperdictionary.com/dictionary/twilight ], just before sunrise [ http://antwrp.gsfc.nasa.gov/apod/ap030320.html ] or after sunset [ http://antwrp.gsfc.nasa.gov/apod/ap030412.html ], part of the atmosphere above the horizon appears slightly off-color, slightly pink. Called the Belt of Venus [ http://www.weather-photography.com/Photos/gallery.php?cat=optics&subcat=venus_belt ], this off-color band between the dark eclipsed [ http://antwrp.gsfc.nasa.gov/apod/ap030822.html ] sky and the blue sky [ http://www.sciencemadesimple.com/sky_blue.html ] can be seen in nearly every direction including that opposite the Sun. Straight above, blue sky [ http://www.why-is-the-sky-blue.org/why-is-the-sky-blue.html ] is normal sunlight reflecting off the atmosphere. In the Belt of Venus [ http://epod.usra.edu/archive/epodviewer.php3?oid=158080 ], however, the atmosphere reflects light from the setting (or rising) Sun which appears more red. The Belt of Venus [ http://home.iprimus.com.au/rsims/atmospheric01.htm ] can be seen from any location with a clear horizon. Pictured above, the Belt of Venus was photographed above morning fog [ http://antwrp.gsfc.nasa.gov/apod/ap021122.html ] in the Valley of the Moon [ http://www.vmoa.kenwood.ca.us/ ], a famous wine-producing region in northern California [ http://www.state.ca.us/ ], USA [ http://www.cia.gov/cia/publications/factbook/geos/us.html ]. The belt is frequently [ http://antwrp.gsfc.nasa.gov/apod/ap011209.html ] caught [ http://antwrp.gsfc.nasa.gov/apod/ap010601.html ] by [ http://antwrp.gsfc.nasa.gov/apod/ap010308.html ] accident [ http://antwrp.gsfc.nasa.gov/apod/ap990418.html ] in [ http://antwrp.gsfc.nasa.gov/apod/ap990325.html ] other [ http://antwrp.gsfc.nasa.gov/apod/ap990308.html ] photographs [ http://antwrp.gsfc.nasa.gov/apod/ap010501.html ]. |
|
New Horizons at Jupiter
| Title |
New Horizons at Jupiter |
| Explanation |
Headed for the first close-up exploration of the Pluto-Charon system [ http://www.plutoportal.net/ ] and the icy denizens of the Kuiper belt [ http://www.ifa.hawaii.edu/faculty/jewitt/kb.html ], NASA's New Horizons [ http://pluto.jhuapl.edu/mission.htm ] spacecraft is pictured here in an artist's vision of the robot probe outward bound. The dramatic scene [ http://www.swri.org/press/jest.htm ] depicts the 465 kilogram spacecraft about one year after a planned 2006 launch, following a flyby of gas giant Jupiter [ http://antwrp.gsfc.nasa.gov/apod/ap031114.html ]. While the Jupiter flyby [ http://www.swri.edu/9what/releases/ JEST.htm ] will be used as a gravity assist [ http://www.jpl.nasa.gov/basics/grav/primer.html ] maneuver to save fuel and cut travel time to the outer reaches of the Solar System [ http://www.seds.org/nineplanets/nineplanets/ nineplanets.html ], it will also provide an opportunity to test instruments and study the giant planet, its moons, and magnetic fields. The Sun is seen from eight hundred million kilometers away, with inner planets Earth, Venus, and Mercury aligned [ http://antwrp.gsfc.nasa.gov/apod/ap001014.html ] on the left. A dim crescent of outermost Galilean moon Callisto [ http://antwrp.gsfc.nasa.gov/apod/ap010731.html ], orbiting Jupiter just inside of the spacecraft's trajectory, appears to the upper right of the fading Sun. Left of Jupiter itself is Europa [ http://antwrp.gsfc.nasa.gov/apod/ap030919.html ] and in the distant background are the faint, unresolved stars and dust clouds of the Milky Way [ http://home.arcor-online.de/axel.mellinger/ ]. New Horizons' planned arrival at Pluto-Charon [ http://pluto.jhuapl.edu/plutocharon.htm ] is in the summer of 2015. |
|
Venus and the 37 Hour Moon
| Title |
Venus and the 37 Hour Moon |
| Explanation |
At Table Mountain Observatory [ http://tmf-web.jpl.nasa.gov/projects.html ], near Wrightwood California, USA on October 26, wild fires were [ http://antwrp.gsfc.nasa.gov/apod/ap030807.html ] approaching from the east. But looking toward the west just after sunset [ http://aa.usno.navy.mil/data/docs/RS_OneDay.html ], astronomer James Young could still enjoy this comforting view of a young crescent Moon [ http://aa.usno.navy.mil/faq/docs/islamic.html ] and brilliant Venus [ http://seds.lpl.arizona.edu/nineplanets/nineplanets/ venus.html ] through the the fading twilight. Setting over the horizon of Mt. Baden-Powell, the thin crescent was only about 37 hours "old", or 37 hours after its exact New Moon phase [ http://aa.usno.navy.mil/faq/docs/moon_phases.html ]. After disappearing from [ http://antwrp.gsfc.nasa.gov/apod/ap990903.html ] morning twilight in August, Venus [ http://www.transitofvenus.org/ ] was becoming prominent in its role in western skies as the evening star [ http://antwrp.gsfc.nasa.gov/apod/ap010601.html ]. A similar lovely pairing of thin crescent Moon and stunning evening star can be seen toward the west in today's evening twilight [ http://science.nasa.gov/headlines/y2003/ 09dec_sunset.htm ]. Happy Holidays and Best Wishes from APOD [ http://antwrp.gsfc.nasa.gov/apod/lib/ about_apod.html ]! |
|
Venus On The Horizon
| Title |
Venus On The Horizon |
| Explanation |
The month of October [ http://www.skypub.com/whatsup/oct97sky.html ] features a sky full of planets, including Venus as the brilliant evening star. Besides the sun and moon, Venus is the brightest object [ http://www.seds.org/billa/nineplanets/venus.html ] visible in Earth's sky. This month, Venus appears in early evening near the red planet Mars [ http://antwrp.gsfc.nasa.gov/apod/ap970528.html ] and Mars' red giant rival Antares [ http://antwrp.gsfc.nasa.gov/apod/ap970922.html ] above the southwestern horizon. Because it is closer to the sun than Earth, Venus never strays far from the sun in its apparent position [ http://quasar.as.utexas.edu/courses/ast309/misc/DresdenCodex.html ] and is seen during the year as either a bright morning or evening star [ http://rowlf.cc.wwu.edu:8080/~skywise/legends.html#Evening Star ]. This beautiful sunset imaged from low earth orbit by the Atlantis space shuttle [ http://www.ksc.nasa.gov/shuttle/resources/orbiters/atlantis.html ] crew in May 1989 also reveals the planet Venus blazing above Earth's horizon. It is a fitting image [ http://images.jsc.nasa.gov/images/pao/STS30/10063311.htm ] for this mission and crew [ http://www.ksc.nasa.gov/shuttle/missions/sts-30/sts-30-press-kit.txt ]. It was recorded following the successful release of the robot Venus-explorer Magellan [ http://nssdc.gsfc.nasa.gov/planetary/magellan.html ], the first planetary probe to be deployed from a space shuttle. |
|
Moon and Planets Sky Credit
…
| Title |
Moon and Planets Sky Credit & Copyright: Wojtek Rychlik [ http://www.pikespeakphoto.com ] |
| Explanation |
Look up into the sky tonight [ http://science.nasa.gov/headlines/y2004/ 19mar_planets.htm ] and without a telescope or binoculars you might have a view [ http://astronomy.swin.edu.au/staff/gmackie/billions.html ] like this one of Moon, planets and stars. The lovely photo [ http://www.pikespeakphoto.com/planets.html ] was taken on March 23rd, and captures the crescent Moon on the horizon with Venus above it. Both brilliant celestial bodies are over-exposed. Farther above Venus is the tinted glow of Mars with the Pleiades star cluster just to the red planet's right. The V-shaped arrangement of stars [ http://antwrp.gsfc.nasa.gov/apod/ap040304.html ] to the left of Mars is the Hydaes star cluster. Bright red giant Aldebaran [ http://www.astro.uiuc.edu/~kaler/sow/ aldebaran.html ], not itself a member of the Hyades cluster, marks the top left of the V. During the next week [ http://www.griffithobs.org/planetsgather.html ], all five naked-eye planets, Mercury, Venus, Mars, Jupiter, and Saturn, along with the Moon will grace the evening sky [ http://skyandtelescope.com/observing/objects/planets/ article_1226_1.asp ] together - a lunar and planetary spectacle that can be enjoyed by skygazers [ http://www.spaceweather.com/ ] around the world. But look just after sunset, low on the western horizon, to see Mercury [ http://antwrp.gsfc.nasa.gov/apod/ap030412.html ] before it sets. The next similar gathering [ http://antwrp.gsfc.nasa.gov/apod/ap000524.html ] of the planets will be in 2008. |
|
A Sky Full Of Planets
| Title |
A Sky Full Of Planets |
| Explanation |
Look up tonight [ http://www.cnn.com/TECH/9712/01/heavenly.show.ap/ ]. Just after sunset, the crescent moon and all five "naked-eye" planets (Mercury [ http://antwrp.gsfc.nasa.gov/apod/ap971130.html ], Venus [ http://antwrp.gsfc.nasa.gov/apod/ap971014.html ], Mars [ http://antwrp.gsfc.nasa.gov/apod/ap970528.html ], Jupiter [ http://antwrp.gsfc.nasa.gov/apod/ap971030.html ], and Saturn [ http://antwrp.gsfc.nasa.gov/apod/ap970829.html ]) will be visible (depending on your latitude), lying near our solar system's ecliptic plane [ http://antwrp.gsfc.nasa.gov/apod/ap970927.html ]. Venus and Jupiter will shine brilliantly as the brightest "stars" in the sky, but Mercury will be near the horizon and hard to see. A pair of binoculars will also reveal Uranus and Neptune and observers with a telescope and a good site may even be able to glimpse faint Pluto just above the Western horizon in the fading twilight (not shown on the chart above). Enjoy this lovely spectacle any clear night [ http://www.skypub.com/whatsup/dec97sky.html ] through about December 8. A similar gathering is expected in May 2000 [ http://www.skypub.com/special/alignmnt/whypanic.html ] but the planets will be hidden from view by the solar glare. A night sky as full of planets as this one will occur again though ... in about 100 years. |
|
Venus: Earth's Cloudy Twin C
…
| Title |
Venus: Earth's Cloudy Twin Credit: Galileo [ http://galileo.jpl.nasa.gov/ ] Spacecraft, JPL [ http://www.jpl.nasa.gov/ ], NASA [ http://www.nasa.gov/ ]; |
| Explanation |
This picture by the Galileo spacecraft [ http://nssdc.gsfc.nasa.gov/planetary/galileo.html ] shows just how cloudy Venus [ http://seds.lpl.arizona.edu/nineplanets/nineplanets/venus.html ] is. Venus [ http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=34067 ] is very similar to Earth [ http://antwrp.gsfc.nasa.gov/apod/ap010204.html ] in size and mass - and so is sometimes referred to as Earth's sister planet - but Venus [ http://pds.jpl.nasa.gov/planets/welcome/venus.htm ] has a quite different climate. Venus [ http://spacelink.nasa.gov/NASA.Projects/Space.Science/Solar.System/Pioneer.Venus/Venus.Discoveries ]' thick clouds and closeness to the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap980830.html ] (only Mercury [ http://antwrp.gsfc.nasa.gov/apod/ap010819.html ] is closer) make it the hottest planet - much hotter than the Earth [ http://antwrp.gsfc.nasa.gov/apod/earth.html ]. Humans could not survive there, and no life of any sort has ever been found. When Venus is visible [ http://www.space.com/spacewatch/venus_guide_031024.html ] it is usually the brightest object in the sky after the Sun and the Moon [ http://antwrp.gsfc.nasa.gov/apod/moon.html ]. More than 20 spacecraft have visited Venus [ http://nssdc.gsfc.nasa.gov/photo_gallery/PhotoGallery-Venus.html ] including Venera 9 [ http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=1975-050D ], which landed on the surface, and Magellan [ http://www.jpl.nasa.gov/magellan/ ], which used radar to peer through the clouds and make a map of the surface [ http://antwrp.gsfc.nasa.gov/apod/ap030427.html ]. This visible light picture of Venus [ http://antwrp.gsfc.nasa.gov/apod/venus.html ] was taken by the Galileo spacecraft [ http://antwrp.gsfc.nasa.gov/apod/ap951206.html ] that orbited Jupiter from 1995 to 2003. Many things about Venus remain unknown, including the cause of mysterious bursts of radio waves [ http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1995JATP...57..557S ]. |
|
A Western Sky at Twilight
| Title |
A Western Sky at Twilight |
| Explanation |
On April 23rd, the Moon along with planets Saturn, Mars, and Venus (and planet Earth of course ...) were all visible [ http://science.nasa.gov/headlines/y2004/ 21apr_planets2.htm ] in the west at twilight, captured here [ http://www.nightskyevents.com/ ] from a site near Saylorvillle Lake north of Des Moines, Iowa, USA. Putting your cursor [ http://www.fourmilab.ch/yoursky/ ] over the image will label our fellow solar system wanderers [ http://liftoff.msfc.nasa.gov/academy/time/ weekdays.html ] and also reveal the approximate trajectory of the ecliptic plane [ http://antwrp.gsfc.nasa.gov/apod/ap001014.html ] - defined by Earth's orbit around the Sun - angling above the western horizon. After sunset tonight, the western sky will present a similar arrangement of planets, although the Moon will have moved east out of the picture, passing bright Jupiter along the ecliptic and heading for May 4th's total lunar eclipse [ http://www.xs4all.nl/~carlkop/eclipsmaan/leclips2004.html ]. May could also [ http://skyandtelescope.com/observing/objects/comets/ article_1238_1.asp ] be a good month for comets [ http://skyandtelescope.com/observing/objects/comets/ article_1229_2.asp ]. |
|
Titan's X-Ray
| Title |
Titan's X-Ray |
| Explanation |
This June's rare and much heralded transit of Venus [ http://sunearth.gsfc.nasa.gov/eclipse/transit/ venus0412.html ] will feature our currently brilliant evening star [ http://antwrp.gsfc.nasa.gov/apod/ap040415.html ] in silhouette, as the inner planet glides across the face of the Sun. But on January 5, 2003 an even rarer transit took place. Titan, large moon [ http://www.nineplanets.org/titan.html ] of ringed gas giant Saturn, crossed in front of the Crab [ http://antwrp.gsfc.nasa.gov/apod/ap030110.html ] Nebula, a supernova remnant some 7,000 light-years away. During Titan's transit [ http://chandra.harvard.edu/press/04_releases/ press_040504.html ], the orbiting Chandra Observatory's [ http://chandra.harvard.edu/chronicle/0204/ solsys/index.html ] x-ray detectors recorded the shadowing of cosmic x-rays generated by the Crab's amazing pulsar nebula [ http://antwrp.gsfc.nasa.gov/apod/ap030904.html ], pictured above, in a situation analogous to a medical x-ray [ http://chandra.harvard.edu/xray_astro/medxray.html ]. The resulting image (inset at left) probes the extent of Titan's atmosphere [ http://arxiv.org/abs/astro-ph/?0403283 ]. So, how rare was Titan's transit of the Crab? While Saturn itself passes within a few degrees of the Crab Nebula every 30 years, the next similar transit is reportedly due in 2267. And since the stellar explosion which gave birth to the Crab was seen in 1054, the 2003 Titan transit may have been the first to occur ... ever. |
|
Planets Over Easter Island
| Title |
Planets Over Easter Island |
| Explanation |
It isn't every day that planets line up behind a stone giant. For one thing, it helps to have a good planet line-up [ http://antwrp.gsfc.nasa.gov/apod/ap040501.html ], such as occurred in the sky just last month. For another, it helps to be on Easter Island [ http://www.pbs.org/wgbh/nova/easter/ ], where over 800 large stone statues exist. The Easter Island statues [ http://www.pbs.org/wgbh/nova/easter/civilization/giants.html ], stand, on the average, over twice as tall as a person and have over 200 times as much mass. Few specifics are known about the history or meaning of the unusual statues [ http://www.sscnet.ucla.edu/ioa/eisp/ ], but many believe that they were created about 500 years ago in the images of local leaders of a lost civilization. Pictured above, the Moon [ http://antwrp.gsfc.nasa.gov/apod/ap030810.html ], Venus [ http://antwrp.gsfc.nasa.gov/apod/ap040516.html ], and Mars [ http://www.nineplanets.org/mars.html ] can be seen behind Ahu Tahai [ http://www.pbs.org/wgbh/nova/easter/explore/ahutahai.html ], a famous Easter Island statue. The bright star Aldebaran [ http://www.astro.uiuc.edu/~kaler/sow/aldebaran.html ] is also visible. |
|
Phases of Venus
| Title |
Phases of Venus |
| Explanation |
Venus is currently falling out [ http://antwrp.gsfc.nasa.gov/apod/ap990903.html ] of the western evening sky. Second planet [ http://nssdc.gsfc.nasa.gov/planetary/factsheet/ venusfact.html ] from the Sun and third brightest celestial object after the Sun and Moon, Venus has been appreciated by casual sky gazers as a brilliant beacon above the horizon after sunset. But telescopic [ http://csep10.phys.utk.edu/astr161/lect/history/ galileo.html ] images have also revealed its dramatic phases. In fact, this thoughtful composite [ http://webpages.charter.net/darksky25/Astronomy/ Planets/Venus/venus.html ] of telescopic views nicely illustrates the progression of phases [ http://csep10.phys.utk.edu/astr161/lect/celestial/ aspects.html ] and increase in apparent size undergone by Venus over the past few weeks. Gliding along [ http://www.venus-transit.de/PlanetPhases/ index.html ] its interior orbit, Venus has been catching up with planet Earth, growing larger as it draws near. At the same time, just as the Moon goes through phases [ http://www.souledout.org/nightsky/venusphases/ venusphases.html ], Venus' visible sunlit hemisphere has presented an increasingly slender, crescent shape [ http://imaginesoftworks.com/ astropage/venus/venus05052004-0258.html ]. Now sharing the sky [ http://skyandtelescope.com/observing/objects/planets/ article_1194_1.asp ] with a crescent Moon, on June 8th Venus [ http://sunearth.gsfc.nasa.gov/sunearthday/2004/ index_vthome.htm ] will actually cross the face of the Sun, the first such transit since 1882 [ http://canopus.saao.ac.za/%7Ewpk/tov1882/ tovwell.html ]. |
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![Moon and Planets Sky Credit & Copyright: Wojtek Rychlik [ http://www.pikespeakphoto.com ]](http://mm04.nasaimages.org/MediaManager/srvr?mediafile=/Size1/NVA2-4-NA/6310/moonplanets_rychlik_full.jpg&userid=1&username=admin&resolution=1&servertype=JVA&cid=4&iid=NVA2&vcid=NA&usergroup=NASA_Astronomy_Picture_of_the_Day_Collecti-4-Admin&profileid=16)
![Venus: Earth's Cloudy Twin Credit: Galileo [ http://galileo.jpl.nasa.gov/ ] Spacecraft, JPL [ http://www.jpl.nasa.gov/ ], NASA [ http://www.nasa.gov/ ];](http://mm04.nasaimages.org/MediaManager/srvr?mediafile=/Size1/NVA2-4-NA/6350/venus2_gal_big.jpg&userid=1&username=admin&resolution=1&servertype=JVA&cid=4&iid=NVA2&vcid=NA&usergroup=NASA_Astronomy_Picture_of_the_Day_Collecti-4-Admin&profileid=16)
