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Images of Venus and Jet Propulsion Laboratory (JPL)
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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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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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Pleiades, Planets, And Hot P
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| Title |
Pleiades, Planets, And Hot Plasma |
| Explanation |
Bright stars of the Pleiades, four planets, and erupting solar plasma are all captured in this spectacular image [ http://sohowww.nascom.nasa.gov/hotshots/ ] from the space-based SOlar and Heliospheric Observatory (SOHO). In the foreground of the 15 degree wide field of view, a bubble of hot plasma, called a Coronal Mass Ejection (CME [ http://antwrp.gsfc.nasa.gov/apod/ap000309.html ]), is blasting away from the active Sun [ http://www.spaceweather.com/ ] whose position and relative size is indicated by the central white circle. Beyond [ http://sohowww.nascom.nasa.gov/hotshots/2000_05_03/ diagram1.jpg ] appear four of the five [ http://antwrp.gsfc.nasa.gov/apod/ap000505.html ] naked-eye planets [ http://sse.jpl.nasa.gov/features/planets/ planetsfeat.html ] -- courtesy [ http://www.badastronomy.com/bad/misc/planets.html ] of the planetary alignment [ http://science.nasa.gov/headlines/y2000/ ast30mar_1m.htm#alignments ] which did not destroy the world! In the background are distant stars and the famous Pleiades [ http://www.seds.org/messier/m/m045.html ] star cluster, also easily visible to the unaided eye when it shines in the night sky [ http://antwrp.gsfc.nasa.gov/apod/ap000504.html ]. Distances for these familiar [ http://www.seds.org/nineplanets/nineplanets/ nineplanets.html ] celestial objects are, the Sun [ http://helios.gsfc.nasa.gov/sun.html ], 150 million kilometers away, Mercury, Venus, Jupiter, and Saturn, about 58, 110, 780, and 1,400 million kilometers beyond the Sun respectively, and the Pleiades [ http://www.ras.ucalgary.ca/~gibson/pleiades/ ] star cluster at a mere 3,800 trillion kilometers (400 light-years). SOHO itself orbits 1.5 million kilometers sunward of planet Earth. The image [ http://sohowww.nascom.nasa.gov/data/latestimages.html ] was recorded by the Large Angle and Spectrometric COronagraph (LASCO) instrument on board SOHO on Monday, May 15 at 10:42 UT. |
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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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Lightning on Earth
| Title |
Lightning on Earth |
| Explanation |
Nobody knows what causes lightning. It is known that charges [ http://physics.bu.edu/~duffy/PY106/Charge.html ] slowly separate in some clouds [ http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/cld/cldtyp/home.rxml ] causing rapid electrical discharges [ http://www.eng.tau.ac.il/Pages/Departments/Inter/edp_lab/ ] (lightning), but how electrical charges [ http://physicsstudio.indstate.edu/java/potential/ProyectI.html ] get separated in clouds [ http://www.geo.mtu.edu/department/classes/ge406/tjbrabec/cloud.html ] remains a topic of much research. Nevertheless, lightning [ http://wvlightning.com/info.html ] bolts are common in clouds during rainstorms, and on average 6000 lightning bolts occur between clouds and the Earth every minute. Above [ http://www.noao.edu/image_gallery/html/im0426.html ], several lightning strokes were photographed behind Kitt Peak National Observatory [ http://www.noao.edu/outreach/kpoutreach.html ] in Arizona [ http://www.state.az.us/ ]. Lightning [ http://bondo.wsc.mass.edu/dept/garp/faculty/lightn.htm ] has also been found on the planets Venus [ http://www.lpl.arizona.edu/~hansell/lightning/poster.html ], Jupiter [ http://antwrp.gsfc.nasa.gov/apod/ap971216.html ], Saturn [ http://learn.jpl.nasa.gov/projectspacef/bkg130b.html ], and Uranus [ http://www.spacetoday.org/SolSys/Uranus/Uranus.html ]. NASA [ http://www.nasa.gov/ ] launched the TRMM mission [ http://trmm.gsfc.nasa.gov/news.html ] in 1997 that continues to measure rainfall and lightning [ http://thunder.msfc.nasa.gov/primer/ ] on planet Earth [ http://antwrp.gsfc.nasa.gov/apod/ap990131.html ]. |
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Children of the Sun
| Title |
Children of the Sun |
| Explanation |
For a moment [ http://photojournal.jpl.nasa.gov/index.html ], planets Jupiter [ http://kids.nineplanets.org/jupiter.htm ], Venus [ http://kids.nineplanets.org/venus.htm ], Mars [ http://kids.nineplanets.org/mars.htm ], and Mercury [ http://kids.nineplanets.org/mercury.htm ] all posed near their parent star in this Sun-centered view, recorded on November 11. The picture, from a coronograph onboard the space-based SOlar Heliospheric Observatory [ http://sohowww.nascom.nasa.gov/ ], spans 15 degrees with the Sun's size and position indicated by the white circle. Background stars are also visible as the otherwise overwhelming sunlight is blocked by the coronograph's [ http://lasco-www.nrl.navy.mil/index.php?p=content/ about_lasco ] occulting disk. But the planets themselves, in particular Jupiter and Venus, are still bright enough to cause significant horizontal streaks in the image. Mercury is actually moving most rapidly (left to right) through the field and days earlier [ http://sohowww.nascom.nasa.gov/hotshots/2006_11_06/ ] was seen to cross in front [ http://www.spaceweather.com/eclipses/gallery_08nov06.htm ] of the solar disk. So what's that bright double star to the left of Mars? Zubenelgenubi [ http://antwrp.gsfc.nasa.gov/apod/ap040514.html ], of course. |
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October Skylights
| Title |
October Skylights |
| Explanation |
With brilliant Venus [ http://nssdc.gsfc.nasa.gov/planetary/factsheet/ venusfact.html ] above the western horizon at sunset and Jupiter [ http://galileo.jpl.nasa.gov/ ] and Saturn [ http://www.jpl.nasa.gov/cassini/ ] high in the east by early evening, November's night sky is filled with bright planets. October's sky featured bright planets as well and, triggered by the active Sun, some lovely auroral displays [ http://www.exploratorium.edu/learning_studio/ auroras/ ]. This colorful aurora was recorded by astrophotographer Wade Clark in skies above Hamilton, Washington, USA on the night of October 4th. Through the shimmering northern lights [ http://climate.gi.alaska.edu/Curtis/aurora/ aurora.html ] Jupiter and Saturn are easy to spot [ http://antwrp.gsfc.nasa.gov/apod/ap000929.html ] flanking the V-shaped head of Taurus [ http://server.remc12.k12.mi.us/csplanet/myth/ taurus.html ] the Bull. Of course, just above lies the lovely Pleiades star cluster. Solar activity [ http://spaceweather.com/ ] will also produce auroral shows in November, particularly at high northern and southern latitudes. Plus, November skygazers can certainly anticipate a celestial performance on the evening of the 17th/18th -- the moonlit Leonid meteor shower [ http://spacescience.com/headlines/y2000/ast10oct_1.htm ]. |
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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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Seven Dusty Sisters
| Title |
Seven Dusty Sisters |
| Explanation |
Hurtling through a cosmic dust cloud a mere 400 light-years away, the lovely Pleiades [ http://www.naic.edu/~gibson/pleiades/ ] or Seven Sisters star cluster is well-known in astronomical images for its striking blue reflection nebulae [ http://antwrp.gsfc.nasa.gov/apod/ap060109.html ]. At visible wavelengths, the starlight is scattered and reflected by the dust, but in this portrait [ http://www.spitzer.caltech.edu/Media/releases/ssc2007-07/ index.shtml ] in infrared light [ http://coolcosmos.ipac.caltech.edu/ ] by the Spitzer Space Telescope, the dust itself glows. The false color image spans about 1 degree or seven light-years at the distance of the Pleiades, with the densest regions of the dust cloud shown in yellow and red hues. Exploring this [ http://www.pleiade.org/pleiades_03.html ] young, nearby cluster, the Spitzer data have revealed many cool, low mass stars, brown dwarfs [ http://antwrp.gsfc.nasa.gov/apod/ap000713.html ] or failed stars, and possible planetary debris disks. Want to see the Pleiades tonight? Look near [ http://skytonight.com/observing/highlights/ VenusAndPleiades.html ] Venus, the brilliant evening star in the west just after sunset. |
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Jupiter, Saturn and Messier
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| Title |
Jupiter, Saturn and Messier 45 |
| Explanation |
Brilliant Venus falls out [ http://antwrp.gsfc.nasa.gov/apod/ap990903.html] of the evening sky as March ends, but Jupiter and Saturn remain well up above the western horizon. Jupiter [ http://www.jpl.nasa.gov/galileo/jupiter/jupiter.html ] blazes forth above and to the left of a slightly fainter Saturn [ http://antwrp.gsfc.nasa.gov/apod/ap000212.html ] in this telephoto picture taken on January 19th. Near the top lies the lovely Pleiades [ http://antwrp.gsfc.nasa.gov/apod/ap000227.html ] star cluster with suggestions of its characteristic blue reflection nebulae [ http://antwrp.gsfc.nasa.gov/cgi-bin/apod/ apod_search?reflection+nebula ]. These planets and the Pleiades have a similar, easily recognizable orientation in the Spring night sky. Also known as M45 [ http://www.seds.org/messier/m/m045.html ], the 45th object in French astronomer Charles Messier's [ http://antwrp.gsfc.nasa.gov/apod/ap960626.html ] famous catalog, the Pleiades will likely soon be checked off many stargazers' tally lists. For northern hemisphere observers this weekend offers a prime opportunity to complete a Messier Marathon [ http://www.seds.org/messier/xtra/marathon/ marathon.html ] -- the viewing of all 110 Messier catalog objects [ http://www.seds.org/messier/data2.html ] in one glorious [ http://antwrp.gsfc.nasa.gov/apod/ap000311.html ] dusk to dawn observing run. This weekend it will also be possible to complete an all-planet marathon, observing all the solar system's [ http://space.jpl.nasa.gov/ ] planets in a single night. And if you still need something to look at, the International Space Station [ http://www.hq.nasa.gov/osf/station/viewing/ issvis.html ] could also be visible arcing through the skies depending on your location, but Mir will not [ http://www.russianspaceweb.com/ ]. |
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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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The Iron Tail of Comet McNau
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| Title |
The Iron Tail of Comet McNaught |
| Explanation |
Outstanding in planet Earth's sky [ http://www.spaceweather.com/comets/ gallery_mcnaught_page23.php ] early this year, Comet McNaught [ http://en.wikipedia.org/wiki/Comet_McNaught ] is captured in this view from the STEREO [ http://stereo.gsfc.nasa.gov/ ] A spacecraft. McNaught's coma [ http://www.nasa.gov/worldbook/comet_worldbook.html ] is so bright, it blooms [ http://www.cs.duke.edu/~parr/photography/ faq.html#blooming ] into the long horizontal stripe at the bottom of the field. Brilliant Venus, near the top left corner, also produces a severe horizontal blemish in the digital image. But the sensitive camera does accurately record the striations in McNaught's famous dust tail [ http://antwrp.gsfc.nasa.gov/apod/ap070201.html ] along a region stretching over 30 million kilometers toward the top right of the field of view. A separate, fainter, arching tail just to the left of the dust tail was initially thought to be an example of a common ion tail [ http://www.ifa.hawaii.edu/~jewitt/tail.html ], formed by electrically charged atoms [ http://www.chem4kids.com/files/atom_ions.html ] carried away from the comet by the solar wind [ http://www.phy6.org/Education/wsolwind.html ]. However, detailed [ http://www.swisseduc.ch/stromboli/pdf/irontail.pdf ] modeling indicates that tail is actually due to neutral iron atoms pushed out by the pressure of sunlight [ http://www.phy6.org/stargaze/Solsail.htm ] -- the first ever detected neutral iron tail from a comet. The iron atoms are thought to originate in dust grains [ http://stardust.jpl.nasa.gov/home/index.html ] from the comet nucleus [ http://antwrp.gsfc.nasa.gov/apod/ap050915.html ] that contain the iron-sulfur mineral troilite [ http://www.mindat.org/min-4029.html ] (FeS). |
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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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One Hundred-Kilometer Terrai
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| Title |
One Hundred-Kilometer Terrain on Venus |
| Explanation |
Even the hot and cracked surface of Venus [ http://www.nineplanets.org/venus.html ] has rolling hills. Although never actually photographed from up-close, images of the Venusian surface [ http://csep10.phys.utk.edu/astr161/lect/venus/surface.html ] like that shown above have been constructed in recent years by digitally merging distant photographs from height-sensitive radar [ http://southport.jpl.nasa.gov/ ]. Isolated above [ http://photojournal.jpl.nasa.gov/cgi-bin/PIAGenCatalogPage.pl?PIA00150 ] is a 100-kilometer wide swath inside a volcanic region [ http://antwrp.gsfc.nasa.gov/apod/ap000326.html ] known as Yavine Corona. Visible in the frame [ http://photojournal.jpl.nasa.gov/cgi-bin/PIAGenCatalogPage.pl?PIA00150 ] are numerous fractures [ http://antwrp.gsfc.nasa.gov/apod/ap980120.html ] in the surface. Data is missing from the dark lane on the upper right. The surface of Venus [ http://nssdc.gsfc.nasa.gov/imgcat/html/object_page/v13_vg261_262.html ] is so hot and oppressive that robot spacecraft [ http://pds-geophys.wustl.edu/venera/ ] landed there [ http://antwrp.gsfc.nasa.gov/apod/ap990124.html ] have lasted for only a few hours. |
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A Radar Image of Venus
| Title |
A Radar Image of Venus |
| Explanation |
The largest radio telescopes in the world are working together to create a new map of the surface of Venus. The surface of Venus [ http://www.nineplanets.org/venus.html ] is unusually hidden by a thick atmosphere [ http://bigmac.civil.mtu.edu/public_html/classes/ce459/projects/t15/r15.html ] of mostly carbon dioxide [ http://scifun.chem.wisc.edu/chemweek/CO2/CO2.html ] gas. These thick clouds [ http://antwrp.gsfc.nasa.gov/apod/ap960923.html ] are transparent, however, to radar signals [ http://spaceplace.jpl.nasa.gov/srtm_makemap3.htm ] sent and received from Earth. The two radio telescopes [ http://www.setileague.org/otherweb/othrtele.htm ] generating the most powerful radar ever are the Arecibo Telescope [ http://antwrp.gsfc.nasa.gov/apod/ap981129.html ] in Puerto Rico [ http://www.cia.gov/cia/publications/factbook/geos/rq.html ] and the new Robert C. Byrd Green Bank Telescope [ http://www.gb.nrao.edu/GBT/GBT.html ] in West Virginia [ http://www.state.wv.us/ ]. The new survey will resolve details as fine a one-kilometer across, and will be inspected for changes since the last major radar map [ http://antwrp.gsfc.nasa.gov/apod/ap991128.html ] was made by NASA's Magellan spacecraft [ http://www.jpl.nasa.gov/magellan/ ] that orbited Venus [ http://antwrp.gsfc.nasa.gov/apod/venus.html ] from 1990 to 1994. Pictured above [ http://www.aoc.nrao.edu/pr/gbtfirstsci.html ] is part of a preliminary image showing details as small as five-kilometers across. |
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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. |
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Bright Planets, Crescent Moo
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| 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/ ] |
|
Uranus: The Tilted Planet
| Title |
Uranus: The Tilted Planet |
| Explanation |
Uranus is the third largest planet in our Solar System [ http://www.nineplanets.org/overview.html ] after Jupiter [ http://antwrp.gsfc.nasa.gov/apod/jupiter.html ] and Saturn [ http://antwrp.gsfc.nasa.gov/apod/ap010826.html http://www.solarviews.com/eng/saturn.htm ]. Uranus [ http://www.nineplanets.org/uranus.html ] is composed mostly of rock and ices, but with a thick hydrogen [ http://chemlab.pc.maricopa.edu/periodic/h.html ] and helium [ http://antwrp.gsfc.nasa.gov/apod/ap010120.html ] atmosphere. The blue hue of Uranus' atmosphere arises from the small amount of methane [ http://scifun.chem.wisc.edu/chemweek/methane/methane.html ] which preferentially absorbs red light. This picture [ http://photojournal.jpl.nasa.gov/cgi-bin/PIAGenCatalogPage.pl?PIA01360 ] was snapped by the Voyager 2 spacecraft [ http://nssdc.gsfc.nasa.gov/planetary/voyager.html ] in 1986 - the only spacecraft ever to visit Uranus. Uranus [ http://antwrp.gsfc.nasa.gov/apod/uranus.html ] has many moons [ http://antwrp.gsfc.nasa.gov/apod/ap990531.html ] and a ring system [ http://antwrp.gsfc.nasa.gov/apod/ap971126.html ]. Uranus, like Venus [ http://antwrp.gsfc.nasa.gov/apod/venus.html ], has a rotation axis that is greatly tilted and sometimes points near the Sun. It remains an astronomical mystery why Uranus' axis [ http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1991LPIP...22...59S ] is so tilted. Uranus and Neptune [ http://antwrp.gsfc.nasa.gov/apod/neptune.html ] are quite similar: Uranus is slightly larger but less massive. |
|
Venus' Once Molten Surface
| Title |
Venus' Once Molten Surface |
| Explanation |
If you could look at Venus with radar eyes - this is what you might see. This computer reconstruction of the surface of Venus [ http://www.nineplanets.org/venus.html ] was created from data from the Magellan spacecraft [ http://nssdc.gsfc.nasa.gov/planetary/magellan.html ]. Magellan orbited Venus [ http://antwrp.gsfc.nasa.gov/apod/venus.html ] and used radar to map our neighboring planet [ http://www.solarviews.com/eng/venus.htm ]'s surface between 1990 and 1994. Magellan [ http://www.jpl.nasa.gov/magellan/guide.html ] found many interesting surface features, including the large circular domes [ http://antwrp.gsfc.nasa.gov/apod/ap980120.html ], typically 25-kilometers across, that are depicted above [ http://nssdc.gsfc.nasa.gov/photo_gallery/caption/mgn_alpha_regio.txt ]. Volcanism [ http://www.geo.mtu.edu/volcanoes/ ] is thought to have created the domes [ http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1995GeoRL..22.2781B ], although the precise mechanism remains unknown. Venus [ http://www.solarviews.com/eng/venus.htm ]' surface is so hot and hostile that no surface probe [ http://antwrp.gsfc.nasa.gov/apod/ap990124.html ] has lasted more than a few minutes. |
|
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 ]. |
|
Sunbather
| Title |
Sunbather |
| Explanation |
Intense and overwhelming, the direct glare of the Sun [ http://www.michielb.nl/od95/ ] is blocked by the smooth disk centered in this image [ http://sohowww.nascom.nasa.gov/hotshots/2002_01_08/ ] from the sun-staring [ http://sohowww.nascom.nasa.gov/ freestuff/#SCREEN SAVER ] SOHO spacecraft. Taken on January 8, the picture shows streamers of solar wind [ http://science.nasa.gov/headlines/y2000/ ast12oct%5F1.htm ] billowing radially outward for millions of kilometers above the Sun's surface indicated by the white circle. Below and right is inner planet Venus [ http://antwrp.gsfc.nasa.gov/apod/ap011211.html ], so bright that its image is marred by a sharp horizontal stripe, a digital imaging artifact. Also impressively bright is a periodic visitor to the inner Solar System, sunbathing [ http://sci.esa.int/content/news/ index.cfm?aid=1&cid=1&oid=29213 ] comet 96/P Machholz 1 [ http://comets.amsmeteors.org/comets/pcomets/ 096p.html ] (above and left). This comet is definitely not a member of the more suicidal sungrazer [ http://antwrp.gsfc.nasa.gov/apod/ap000901.html ] comet family often spotted approaching [ http://www.lmsal.com/YPOP/Spotlight/Tour/ tour02.html ] the Sun by SOHO. Seen here only 18 million kilometers from the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap981212.html ] (about one eighth the Earth-Sun distance) with a substantial coma and [ http://starchild.gsfc.nasa.gov/docs/StarChild/questions/ question27.html ] foreshortened tail, Machholz 1 has now passed perihelion [ http://imagine.gsfc.nasa.gov/docs/ dictionary.html#perihelion ] and is outbound in its orbit [ http://neo.jpl.nasa.gov/cgi-bin/db?name= 96P%2FMachholz+1&group=all&search=Search ], to return again in just over 5 years. |
|
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. |
|
Mercury: Closest Planet to t
…
| Title |
Mercury: Closest Planet to the Sun |
| Explanation |
This picture was compiled from images taken by the NASA spacecraft Mariner 10 which flew by the planet three times in 1974. Mercury [ http://seds.lpl.arizona.edu/nineplanets/nineplanets/mercury.html ] is the closest planet to the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap950813.html ], the second hottest planet (Venus gets hotter), and the second smallest planet (Pluto is smaller). Mercury [ http://www.c3.lanl.gov/~cjhamil/SolarSystem/mercury.html ] rotates so slowly that one day there - "day" meaning the normal time it takes from sunset to sunset - lasts 176 days on Earth [ http://antwrp.gsfc.nasa.gov/apod/ap950622.html ]. It is difficult to see Mercury [ http://nssdc.gsfc.nasa.gov/photo_gallery/photogallery-mercury.html ] not because it is dim but because it always appears near the Sun, and is therefore only visible for a short time just after sunset or just before sunrise. Mercury is made of rocky material like Earth. No one knows why Mercury has the magnetic field that it does. Tomorrow's picture: Venus: Earth's Sister Planet |
|
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 |
|
A Radar Image of Planet Eart
…
| Title |
A Radar Image of Planet Earth |
| Explanation |
This image of Mt. Rainier, Washington USA, planet Earth [ http://volcano.und.nodak.edu/vwdocs/volc_images/img_rainier.html ], was produced by the Spaceborne Radar Laboratory [ http://southport.jpl.nasa.gov/desc/SIRCdesc.html ] which flew on the Space Shuttle Endeavour [ http://antwrp.gsfc.nasa.gov/apod/ap950807.html ] in 1994. Radar, short for RAdio Detection And Ranging, is a technique which coordinates the operation of a radio transmitter and receiver to measure the direction, strength, and timing of radio echos from the surface of distant objects. An actual image of an object can be constructed by recording and analyzing many echos. One advantage of using radar imaging in planetary studies is that images can be made regardless of cloud cover or lighting conditions. During the early 90s, NASA's Magellan spacecraft [ http://nssdc.gsfc.nasa.gov/planetary/magellan.html ] was able to use radar imaging to produce similar high resolution maps of the surface of Venus [ http://antwrp.gsfc.nasa.gov/apod/ap950822.html ]. For more information about the picture click here [ http://southport.jpl.nasa.gov/pio/volcanos/captions/srl2-rainier_cap.html ]. Tomorrow's picture: A World Explorer |
|
Venus UnVeiled
| Title |
Venus UnVeiled |
| Explanation |
The surface of Venus [ http://antwrp.gsfc.nasa.gov/apod/ap950815.html ] is perpetually covered by a veil of thick clouds and remains hidden from even the powerful telescopic eyes of earth-based astronomers. However, using an imaging radar [ http://southport.jpl.nasa.gov/ ] technique, the Magellan spacecraft [ http://nssdc.gsfc.nasa.gov/planetary/magellan.html ] was able to lift the veil from the Face of Venus [ http://www.eps.mcgill.ca/~bud/craters/first.html ] and produce spectacular high resolution images of the planet's surface. The bright area running across the middle of this picture represents the largest highland region of Venus known as Aphrodite [ http://info.desy.de/gna/interpedia/greek_myth/olympian.html#Aphrodite ] Terra. The large highland regions are analogous to continents on Earth. Scientists are particularly interested in exploring the geology of Venus because of its similarity to Earth. For more information about Venus and this image see the Overview of Venus [ http://www.eps.mcgill.ca/~bud/craters/venus_image.html ]. Tomorrow's picture: A Venusian Tick |
|
Atete Corona on Venus
| Title |
Atete Corona on Venus |
| Explanation |
What could cause a huge cylindrical mountain to rise from the surface of Venus [ http://www.nineplanets.org/venus.html ]? Such features that occur on Venus [ http://pdsmaps.wr.usgs.gov/PDS/public/explorer/html/fmapeasy.htm ] are known as coronas [ http://emma.la.asu.edu/~hamilton/abstracts/coronae.html ]. Pictured above [ http://photojournal.jpl.nasa.gov/cgi-bin/PIAGenCatalogPage.pl?PIA00096 ] in the foreground is 500-kilometer wide Atete Corona found in a region of Venus known as the Galindo [ http://wwwflag.wr.usgs.gov/USGSFlag/Space/GEOMAP/MapStatus/VenusStatus/V40.html ]. The image was created by combining multiple radar maps [ http://spaceplace.jpl.nasa.gov/srtm_makemap3.htm ] of the region to form a computer-generated three-dimensional perspective. The series of dark rectangles that crosses the image from top to bottom were created by the imaging procedure and are not real. The origin of massive coronas [ http://pds.jpl.nasa.gov/planets/captions/venus/vencor.htm ] remains a mystery although speculation [ http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1999Icar..139..100S ] holds they result from some form of volcanism [ http://www.usgs.gov/education/learnweb/volcano/ ]. Studying Venusian coronas [ http://www.star.ucl.ac.uk/~idh/geology/g3613.htm ] help scientists better understand the inner structure [ http://www.windows.ucar.edu/tour/link=/venus/interior.html ] of both Venus and Earth [ http://scign.jpl.nasa.gov/learn/plate1.htm ]. |
|
Venus Unveiled
| Title |
Venus Unveiled |
| Explanation |
The surface of Venus [ http://www.seds.org/nineplanets/nineplanets/ venus.html ] is perpetually covered by a veil of thick clouds [ http://antwrp.gsfc.nasa.gov/apod/ap970507.html ] and remains hidden from even the powerful telescopic eyes of earth-bound astronomers. But in the early 1990s, using imaging radar, the Venus orbiting Magellan spacecraft [ http://www.jpl.nasa.gov/magellan/guide.html ] was able to lift the veil from the face [ http://www.artchive.com/artchive/B/botticelli/ birth_of_venus_detail.jpg.html ] of Venus and produced spectacular high resolution images of the planet's surface [ http://earth.agu.org/revgeophys/bindsc01/ bindsc01.html ]. Colors used in this computer generated picture [ http://photojournal.jpl.nasa.gov/cgi-bin/ PIAGenCatalogPage.pl?PIA00104 ] of Magellan radar data are based on color images from the surface of Venus [ http://www.sciam.com/specialissues/0398cosmos/ 0398venus.html ] transmitted by the Soviet Venera [ http://nssdc.gsfc.nasa.gov/planetary/ venera.html ] 13 and 14 landers. The bright area running roughly across the middle represents the largest highland region of Venus [ http://pdsmaps.wr.usgs.gov/PDS/public/explorer/html/ fmappick.htm ] known as Aphrodite Terra [ http://starryskies.com/solar_system/venus_html/ surface.htm ]. |
|
A World Explorer
| Title |
A World Explorer |
| Explanation |
Ferdinand Magellan [ http://www.nortel.com/english/magellan/ferdinand/MagellanBio.html ] was a world explorer. Many consider him the greatest navigator of Europe's 16th century age of sea going exploration and credit his expedition with the first circumnavigation of planet Earth. NASA's Venus probe, the aptly named Magellan spacecraft [ http://nssdc.gsfc.nasa.gov/planetary/magellan.html ] shown above in an artist's conception, provided a global view of the poorly known surface of Venus [ http://antwrp.gsfc.nasa.gov/apod/ap950822.html ] - just as Magellan's expedition provided the beginnings of a global perspective of the Earth. Ferdinand Magellan's expedition of 5 ships and 265 men left Spain in 1519 in search of a western route to the Spice Islands of Indonesia. [ http://eduserv.rug.ac.be/~mbagus/ina.html ] In 1522 one ship and 17 men returned. NASA launched the Magellan probe on May 4, 1989. Placed in a polar orbit, Magellan's many circumnavigations resulted in a detailed radar mapping of 98% of the Venusian surface. [ http://www.jpl.nasa.gov/releases/mgnlpsc.html ] As pictured, the radar mapper's antenna resembles a large inverted bowl. Power for the radar was produced by the wing like solar panels. In October of 1994, the Magellan probe entered the Venusian atmosphere and ground controllers lost contact [ http://nssdc.gsfc.nasa.gov/planetary/mgn_rip.txt ] with the spacecraft. Tomorrow's picture: Two Tails of Comet West |
|
A Venus Landing
| Title |
A Venus Landing |
| Explanation |
This image is part of the first color panoramic view from Venus [ http://antwrp.gsfc.nasa.gov/apod/ap950815.html ]. It was transmitted by a TV camera on the Soviet Venera 13 lander which parachuted to the surface [ http://nssdc.gsfc.nasa.gov/photo_gallery/photogallery-venus.html #surface ] on March 1, 1982. Venus' [ http://antwrp.gsfc.nasa.gov/apod/ap950822.html ] clouds are composed of sulfuric acid droplets while its surface temperature is about 900 degrees Fahrenheit (482 degrees C) at an atmospheric pressure of 92 times that of sea-level on Earth. Despite these harsh conditions, the Venera 13 lander [ http://delcano.mit.edu/venera/ ] survived long enough to send back a series of images and perform an analysis of the Venusian soil. Part of the lander itself is visible in the lower right portion of the image. An earlier Soviet Venus lander, Venera 7 [ http://newproducts.jpl.nasa.gov/calendar/venera7.html ] (1970), was the first spacecraft to return data from the surface of another planet. |
|
A Venusian Landscape
| Title |
A Venusian Landscape |
| Explanation |
This computer generated view of a Venusian volcano was created using data from NASA's Magellan spacecraft [ http://antwrp.gsfc.nasa.gov/apod/ap950825.html ]. Magellan used its onboard radar to map the surface of Venus [ http://antwrp.gsfc.nasa.gov/apod/ap950822.html ] which is hidden from telescopic observations by a perpetual cloud cover. Using this radar data to provide three dimensional information, a computer was then able to produce this view of Maat Mons [ http://nssdc.gsfc.nasa.gov/photo_gallery/caption/mgn_maat_mons.txt ], a 5 mile high volcano, from a dramatic perspective. The colors used to render the surface are based on earlier color images transmitted by TV cameras on the Soviet Venera 13 [ http://antwrp.gsfc.nasa.gov/apod/ap950927.html ] and 14 Venus landers. |
|
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. |
|
Venus and Jupiter Over Belfa
…
| Title |
Venus and Jupiter Over Belfast |
| Explanation |
Venus and Jupiter appeared to glide right past each other earlier this month. In a slow day-by-day march, Jupiter [ http://www.nineplanets.org/jupiter.html ] sank into the sunset horizon while Venus remained high and bright. The conjunction [ http://science.nasa.gov/headlines/y2002/24may_duo.htm ] ended the five-planet party [ http://antwrp.gsfc.nasa.gov/apod/ap020429.html ] visible over the last two months. Jupiter [ http://antwrp.gsfc.nasa.gov/apod/jupiter.html ], of course, is much further away from the Earth and Sun [ http://antwrp.gsfc.nasa.gov/apod/ap010301.html ] than Venus [ http://pds.jpl.nasa.gov/planets/welcome/venus.htm ], 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 3, a fading sunset finds Venus shining over Jupiter above clouds, mountains, and the city lights of Belfast [ http://www.belfastcity.gov.uk/ ], Northern Ireland [ http://www.geographia.com/northern-ireland/default.htm ]. |
|
A View from Venus: Rift Vall
…
| Title |
A View from Venus: Rift Valley |
| Explanation |
Color information from the Soviet Venera landers [ http://antwrp.gsfc.nasa.gov/apod/ap950927.html ] and radar data from the Magellan spacecraft [ http://antwrp.gsfc.nasa.gov/apod/ap950825.html ] were used to construct this striking perspective view of the Venusian landscape [ http://antwrp.gsfc.nasa.gov/apod/ap950928.html ]. (In this computer generated image, the vertical scale has been exagerated.) In the foreground is the edge of a rift valley created by faulting in the crust of Venus [ http://bang.lanl.gov/solarsys/venus.htm ]. The valley runs all the way to the base of Gula Mons, a 2 mile high volcano seen here on the right, some 450 miles in the distance. On the left is another volcano, Sif Mons. Using radar to pierce the dense clouds continuously shrouding the Face of Venus [ http://stoner.eps.mcgill.ca/bud/first.html ], Magellan was able to explore [ http://www.jpl.nasa.gov/magellan/guide.html ] over 98% of the Venusian surface, revealing [ http://antwrp.gsfc.nasa.gov/apod/ap950822.html ] a a diverse and tantalizing topography. |
|
The North Pole of Venus
| Title |
The North Pole of Venus |
| Explanation |
If you could look down on the North Pole [ http://antwrp.gsfc.nasa.gov/apod/ap020818.html ] of Venus what would you see? The Magellan probe [ http://www.jpl.nasa.gov/magellan/fact.html ] that orbited Venus [ http://www.nineplanets.org/venus.html ] from 1990 to 1994 was able to peer through the thick Venusian clouds [ http://antwrp.gsfc.nasa.gov/apod/ap960923.html ] and build up the above image [ http://www.jpl.nasa.gov/magellan/image3.html ] by emitting and re-detecting cloud-penetrating radar [ http://spaceplace.jpl.nasa.gov/srtm_makemap3.htm ]. Visible as the bright patch below central North is Venus' highest mountain Maxwell Montes [ http://nssdc.gsfc.nasa.gov/imgcat/html/object_page/mgn_c260n033_2.html ]. Other notable features include numerous mountains, coronas [ http://antwrp.gsfc.nasa.gov/apod/ap020312.html ], impact craters [ http://antwrp.gsfc.nasa.gov/apod/ap990711.html ], tessera [ http://www.windows.ucar.edu/tour/link=/venus/interior/V_tessera.html&fr=t&edu=mid ], ridges, and lava flows. Although the size and mass of Venus [ http://archive.ncsa.uiuc.edu/Cyberia/Bima/venus.html ] are similar to the Earth [ http://antwrp.gsfc.nasa.gov/apod/ap010204.html ], its thick carbon-dioxide [ http://scifun.chem.wisc.edu/chemweek/CO2/CO2.html ] atmosphere has trapped heat [ http://www.epa.gov/globalwarming/kids/greenhouse.html ] so efficiently that surface temperature usually exceeds 700 kelvins [ http://inventors.about.com/library/inventors/blthermometer.htm ], hot enough to melt lead [ http://pearl1.lanl.gov/periodic/elements/82.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 ]. |
|
Lightning on Jupiter
| Title |
Lightning on Jupiter |
| Explanation |
Does lightning occur only on Earth? Spacecraft in our Solar System have detected radio signals consistent with lightning [ http://wwwghcc.msfc.nasa.gov/lisotd.html ] on other planets, including Venus [ http://www.seds.org/nineplanets/nineplanets/venus.html ], Jupiter [ http://www.seds.org/nineplanets/nineplanets/jupiter.html ], Saturn [ http://www.seds.org/nineplanets/nineplanets/saturn.html ], Uranus [ http://www.seds.org/nineplanets/nineplanets/uranus.html ], and Neptune [ http://www.seds.org/nineplanets/nineplanets/neptune.html ]. In the above photograph [ http://galileo.ivv.nasa.gov/callisto/050197.html ], optical flashes from Jupiter [ http://antwrp.gsfc.nasa.gov/apod/ap970109.html ] were photographed recently by the Galileo orbiter [ http://galileo.ivv.nasa.gov/mission.html ]. Each of the circled dots indicates lightning [ http://www.nofc.forestry.ca/~kanderso/ltgfaq.html ]. The numbers label lines of latitude [ http://www.met.fsu.edu/explores/latlon.html ]. The size of the largest spot is about 500 kilometers across and might be high clouds illuminated by several bright lightning strokes. |
|
An Auroral Ring on Jupiter
| Title |
An Auroral Ring on Jupiter |
| Explanation |
Do other planets have aurora? Terrestrial [ http://work.ucsd.edu:5141/cgi-bin/http_webster?terrestrial ] and spacecraft observations have found evidence for aurora on Venus [ http://www.seds.org/nineplanets/nineplanets/venus.html ], Mars [ http://antwrp.gsfc.nasa.gov/apod/ap970609.html http://www.seds.org/nineplanets/nineplanets/mars.html ], Jupiter [ http://www.seds.org/nineplanets/nineplanets/jupiter.html ], Saturn [ http://www.seds.org/nineplanets/nineplanets/saturn.html ], Uranus [ http://www.seds.org/nineplanets/nineplanets/uranus.html ], and Neptune [ http://www.seds.org/nineplanets/nineplanets/neptune.html ]. In the above false-color photograph [ http://galileo.ivv.nasa.gov/callisto/043097.html ], a good portion of an auroral ring [ http://antwrp.gsfc.nasa.gov/apod/ap970609.html http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1996BAAS%2E%2E%2E28%2E2123P&db_key=AST&nosetcookie=1 ] was captured recently in optical light by the Galileo spacecraft [ http://galileo.ivv.nasa.gov/spacecraft.html ] in orbit around Jupiter [ http://antwrp.gsfc.nasa.gov/apod/ap970609.html http://antwrp.gsfc.nasa.gov/cgi-bin/cossc/apod_search?jupiter ]. Auroral rings [ http://antwrp.gsfc.nasa.gov/apod/ap970609.html http://www.geo.mtu.edu/weather/aurora/ ] encircle a planet's magnetic pole, and result from charged particles spiraling down magnetic field lines. Although the surroundings near Jupiter [ http://antwrp.gsfc.nasa.gov/apod/ap960803.html ] are much different than Earth [ http://antwrp.gsfc.nasa.gov/apod/ap961230.html ], the auroral rings [ http://antwrp.gsfc.nasa.gov/apod/ap970402.html ] appear similar. |
|
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. |
|
A Venus Landing
| Title |
A Venus Landing |
| Explanation |
This image [ http://nssdc.gsfc.nasa.gov/imgcat/html/object_page/v13_vg261_262.html ] is part of the first color panoramic view from Venus [ http://www.nineplanets.org/venus.html ]. A TV camera on the Soviet Venera 13 [ http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=1981-106D ] lander that parachuted to the surface on 1982 March 1 transmitted it. Venus' [ http://sseforum.jpl.nasa.gov/planets/index.cfm?Display=Venus ] clouds are composed of sulfuric acid [ http://scifun.chem.wisc.edu/chemweek/Sulf&top/Sulf&Top.html ] droplets while its surface temperature is about 482 degrees Celsius [ http://www.astro.uu.se/history/celsius_scale.html ] at an atmospheric pressure of 92 times that of sea-level [ http://antwrp.gsfc.nasa.gov/apod/ap020527.html ] on Earth. Despite these harsh conditions, the Venera [ http://nssdc.gsfc.nasa.gov/planetary/venera.html ] 13 lander survived long enough to send back a series of images and perform an analysis of the Venusian soil [ http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1984pggp.rept...76G ]. Part of the lander itself is visible in the lower right portion of the image. An earlier Soviet [ http://memory.loc.gov/frd/cs/sutoc.html ] Venus lander, Venera 7 [ http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=1970-060A ] (1970), was the first spacecraft to return data from the surface of another planet. |
|
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 ]! |
|
Cassini To Venus
| Title |
Cassini To Venus |
| Explanation |
NASA's Saturn Explorer Cassini [ http://www.jpl.nasa.gov/cassini/ ] with ESA's Titan Probe Huygens [ http://www.estec.esa.nl/spdwww/huygens/html/ ] attached successfully rocketed into the skies [ http://www.ksc.nasa.gov/payload/missions/cassini/movies/movies.html ] early yesterday morning. The mighty Titan 4B Centaur rocket is seen here [ http://www-pao.ksc.nasa.gov/kscpao/captions/1997/oct/97pc1543.htm ] across the water gracefully arcing away from Launch Complex 40 [ http://www.ksc.nasa.gov/payload/missions/cassini/ ] at Cape Canaveral Air Station. Cassini, a sophisticated, bus-sized robot spacecraft [ http://www.jpl.nasa.gov/cassini/Spacecraft/ ] is now on its way ... to Venus [ http://antwrp.gsfc.nasa.gov/apod/ap971014.html ], the first planetary way point in its 7 year, 2.2 billion mile journey to Saturn. The mission profile calls [ http://www.jpl.nasa.gov/cassini/Mission/traj.html ] for Cassini to swing by Venus during April 1998 and June 1999, Earth in August 1999, and Jupiter in December 2000. During each of these "gravity assist" [ http://www.jpl.nasa.gov/basics/bsf4-1.htm#gravity ] encounters the six ton spacecraft will pick up energy needed to reach Saturn [ http://antwrp.gsfc.nasa.gov/apod/ap970829.html ] in July 2004. Cassini's mission is the most [ http://www.jpl.nasa.gov/cassini/what/whatshot.html ] ambitious voyage of interplanetary exploration ever mounted by humanity and the Huygens Probe's planned descent to the surface of Titan [ http://antwrp.gsfc.nasa.gov/apod/ap951021.html ] will be the most distant landing ever attempted. |
|
Solar System Portrait
| Title |
Solar System Portrait |
| Explanation |
On another Valentine's Day [ http://www.poets.org/poems/poems.cfm?prmID=1166 ] (February 14, 1990), cruising four billion miles from the Sun, the Voyager 1 [ http://antwrp.gsfc.nasa.gov/apod/ap031120.html ] spacecraft looked back to make this first ever family portrait [ http://photojournal.jpl.nasa.gov/cgi-bin/ PIAGenCatalogPage.pl?PIA00451 ] of our Solar System. The complete portrait is a 60 frame mosaic [ http://nssdc.gsfc.nasa.gov/photo_gallery/ photogallery-solarsystem.html ] made from a vantage point 32 degrees above the ecliptic plane [ http://antwrp.gsfc.nasa.gov/apod/ap001014.html ]. Voyager's wide angle camera frames sweep through the inner Solar System (far left) linking up with gas giant Neptune, at the time the Solar System's [ http://www.seds.org/nineplanets/nineplanets/overview.html ] outermost planet (scroll right). Positions [ http://nssdc.gsfc.nasa.gov/image/planetary/solar_system/ family_diagram.jpg ] for Venus, Earth [ http://www.seds.org/billa/psc/pbd.html ], Jupiter, Saturn, Uranus, and Neptune are indicated by the corresponding letters while the Sun is the bright spot near the center of the circle of frames. The inset frames [ http://antwrp.gsfc.nasa.gov/apod/ap980517.html ] for each of the planets are from Voyager's narrow field camera. Unseen in the portrait are Mercury [ http://www.psrd.hawaii.edu/Jan97/Mercury Unveiled.html ], too close to the Sun to be detected, and Mars, unfortunately hidden by sunlight scattered in the camera's optical system. Small, faint Pluto's [ http://antwrp.gsfc.nasa.gov/apod/ap011018.html ] position was not covered. |
|
Lava Flows on Venus
| Title |
Lava Flows on Venus |
| Explanation |
The hot surface of Venus [ http://www.nineplanets.org/venus.html ] shows clear signs of ancient lava flows [ http://antwrp.gsfc.nasa.gov/apod/ap030416.html ]. Evidence of this was bolstered by the robot spacecraft Magellan [ http://nssdc.gsfc.nasa.gov/planetary/magellan.html ], which orbited Venus [ http://antwrp.gsfc.nasa.gov/apod/venus.html ] in the early 1990s. Using imaging radar, Magellan [ http://antwrp.gsfc.nasa.gov/apod/ap040323.html http://www.jpl.nasa.gov/magellan/ ] was able to peer beneath the thick perpetual clouds [ http://antwrp.gsfc.nasa.gov/apod/ap960923.html ] that cover Earth's closest planetary neighbor. Picture above [ http://photojournal.jpl.nasa.gov/catalog/PIA00486 ], lava apparently flowed down from the top of the image and pooled in the light colored areas visible across the image middle and bottom. The lava cut a channel across the darker ridge that runs horizontally across the image center. The picture covers about 500 kilometers across. The lava originates from a caldera [ http://volcano.und.nodak.edu/vwdocs/frequent_questions/grp13/question1006.html ] named Ammavaru [ http://en.wikipedia.org/wiki/Ammavaru ] that lies about 300 kilometers off the image top [ http://www.solarviews.com/cap/venus/ammavaru.htm ]. The hot dense climate makes Venus a more difficult planet on which to land [ http://antwrp.gsfc.nasa.gov/apod/ap031130.html ] spacecraft and rovers [ http://marsrovers.jpl.nasa.gov/home/index.html ]. Venus currently sparkles [ http://skyandtelescope.com/observing/ataglance/article_110_1.asp ] as the brightest object in the western sky after sunset. |
|
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 ]. |
|
Arachnoids on Venus
| Title |
Arachnoids on Venus |
| Explanation |
Arachnoids are large structures of unknown origin that have been found only on the surface of Venus [ http://bang.lanl.gov/solarsys/venus.htm ]. Arachnoids [ http://volcano.und.nodak.edu/vwdocs/planet_volcano/venus/complex_features2.html ] get their name from their resemblance to spider [ http://www.xs4all.nl/~ednieuw/Spiders/spidhome.htm ]-webs. They appear as concentric ovals surrounded by a complex network of fractures, and can span 200 kilometers. Radar [ http://everest.hunter.cuny.edu/terrain/radar1.html ] echoes from the Magellan [ http://www.jpl.nasa.gov/magellan/fact.html ] spacecraft that orbited Venus [ http://www.seds.org/billa/nineplanets/venus.html ] from 1990 to 1994 built up this image. Over 30 arachnoids have been identified on Venus [ http://antwrp.gsfc.nasa.gov/apod/ap960923.html ], so far. The Arachnoid might be a strange relative to the volcano [ http://volcano.und.nodak.edu/ ], but possibly different arachnoids [ http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1996LPI%2E%2E%2E%2E27%2E%2E483H&db_key=AST&nosetcookie=1 ] are formed by different processes. |
|
Cassini To Venus
| Title |
Cassini To Venus |
| Explanation |
Saturn Orbiter Cassini [ http://saturn.jpl.nasa.gov/home/index.cfm ] with Titan Probe Huygens [ http://saturn.jpl.nasa.gov/overview/huygens-probe.cfm ] attached rocketed into [ http://www.ksc.nasa.gov/payload/missions/cassini/movies/ movies.html ] early morning skies on October 15, 1997. The mighty Titan 4B Centaur rocket is seen here [ http://mediaarchive.ksc.nasa.gov/detail.cfm?mediaid=1004 ] across the water, arcing away from Launch Complex 40 at Cape Canaveral [ http://www.astronautix.com/sites/ capveral.htm ] Air Station. Cassini, a sophisticated robot spacecraft [ http://saturn.jpl.nasa.gov/spacecraft/index.cfm ] was actually headed toward inner planet Venus [ http://antwrp.gsfc.nasa.gov/apod/ap020929.html ], the first way point in its 7 year, 2.2 billion mile interplanetary journey to Saturn. In fact, Cassini swung by [ http://saturn.jpl.nasa.gov/mission/ gravity-assists.cfm ] Venus during April 1998 and June 1999, Earth [ http://antwrp.gsfc.nasa.gov/apod/ap990826.html ] in August 1999, and Jupiter [ http://antwrp.gsfc.nasa.gov/apod/ap031114.html ] in December 2000. During each of these "gravity assist" [ http://www.jpl.nasa.gov/basics/ bsf4-1.htm#gravity ] encounters the six ton spacecraft picked up speed, reaching Saturn [ http://www.nasa.gov/mission_pages/cassini/media/ cassini-063004-soi.html ] only three days ago. Cassini is now orbiting the ringed gas giant, with the Huygens Probe scheduled to separate from the spacecraft in December. The probe's descent to the surface [ http://www.space.com/scienceastronomy/ titan_huygens_031014.html ] of Saturn's large moon Titan [ http://www.nineplanets.org/titan.html ] will be the most distant landing [ http://antwrp.gsfc.nasa.gov/apod/ap011013.html ] ever attempted. |
|
Messenger Launch
| Title |
Messenger Launch |
| Explanation |
Streaking [ http://www.jhuapl.edu/newscenter/pressreleases/2004/ 040803.htm ] into the early morning sky on August 3rd, a Delta II rocket [ http://www.boeing.com/defense-space/space/delta/delta2/ delta2.htm ] launches NASA's Messenger spacecraft [ http://messenger.jhuapl.edu/index.html ] on an interplanetary voyage to Mercury [ http://www.nineplanets.org/mercury.html ]. Scheduled to become the first probe to orbit Mercury, Messenger will begin by looping through [ http://messenger.jhuapl.edu/the_mission/ mission_design.html ] the inner Solar System in a series of close flybys of planet Earth and Venus. The flybys are designed as trajectory changing gravity assist [ http://www2.jpl.nasa.gov/basics/grav/primer.html ] encounters to ultimately achieve the goal of orbiting Mercury in 2011. Prior to entering orbit, Messenger will also flyby Mercury in 2008 and 2009 as the first spacecraft to visit the Solar System's innermost planet since Mariner 10 [ http://antwrp.gsfc.nasa.gov/apod/ap011124.html ] in the mid 1970s. This dramatic view [ http://www.geocities.com/ovpathfinder/ MESSENGER.html ] of the Messenger launch was recorded from a pier in Jetty Park at the north end of Cocoa Beach about 2.5 miles from the Cape Canaveral [ http://www.astronautix.com/sites/capveral.htm ] launch site. So what's that erratic blue streak on the right? It's the reflection from a camera blurred in the time exposure. |
|
A Double Conjunction Eclipse
| Title |
A Double Conjunction Eclipse |
| Explanation |
The crescent Moon [ http://www.seds.org/nineplanets/nineplanets/luna.html ], Venus [ http://www.hawastsoc.org/solar/eng/venus.htm ], and Jupiter [ http://pds.jpl.nasa.gov/planets/welcome/jupiter.htm ] all appeared together in the early morning hours of April 23rd. Some locations on Earth [ http://ceps.nasm.edu:2020/RPIF/EARTH/earth.html ] were able to witness [ http://www.staigerland.com/live/astrocam/ ] a rare double conjunction [ http://www.oregano.demon.co.uk/terms.htm#conjunc ] eclipse, where the Moon [ http://antwrp.gsfc.nasa.gov/apod/ap980129.html ] occulted both Jupiter [ http://antwrp.gsfc.nasa.gov/apod/ap980202.html ] and Venus [ http://antwrp.gsfc.nasa.gov/apod/ap970603.html ] at the same time. The next [ http://www.skypub.com/news/news.shtml ] double conjunction eclipse [ http://antwrp.gsfc.nasa.gov/apod/ap970924.html ] will involve Mercury [ http://antwrp.gsfc.nasa.gov/apod/ap971130.html ] and Mars [ http://www.seds.org/nineplanets/nineplanets/mars.html ] and will occur on February 13, 2056. |
|
|
![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)
