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Barsoom
| Title |
Barsoom |
| Explanation |
Yes, I have been to Barsoom again ..." begins John Carter in Edgar Rice Burroughs' 1913 science fiction classic "The Gods of Mars" [ http://www.literature.org/Works/Edgar-Rice-Burroughs/gods-of-mars/ ]. In Burroughs' novels describing Carter's adventures on Mars, "Barsoom" is the local inhabitants' name [ http://humbabe.arc.nasa.gov/mgcm/fun/pop.html ] for the Red Planet. Long after Burroughs' stories were published, Mars continues [ http://history.nasa.gov/SP-4212/on-mars.html ] to inspire Earthdweller [ http://nssdc.gsfc.nasa.gov/planetary/mars/mars_crew.html ]s' interests [ http://antwrp.gsfc.nasa.gov/apod/ap970627.html ] and imagination [ http://antwrp.gsfc.nasa.gov/apod/ap970528.html ]. Soon it will again be invaded by spacecraft from Earth [ http://mars.jpl.nasa.gov ]. This dramatic picture of a crescent Mars was taken by NASA's Viking 2 [ http://nssdc.gsfc.nasa.gov/cgi-bin/ database/www-nmc?75-083A ] spacecraft as it approached [ http://www2.jpl.nasa.gov/files/images/captions/ p17442.txt ] Barsoom in 1976. |
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Diamond Ring in the Sun
| Title |
Diamond Ring in the Sun |
| Explanation |
Today, earthbound skygazers can celebrate a solstice [ http://www-spof.gsfc.nasa.gov/stargaze/Sseason.htm ], a new Moon [ http://aa.usno.navy.mil/faq/docs/moon_phases.html ], the closest approach [ http://mars.jpl.nasa.gov/ ] of planet Mars since 1988 ... oh yes, and a total eclipse of the Sun, the first total solar eclipse [ http://sunearth.gsfc.nasa.gov/eclipse/TSE2001/TSE2001.html ] of the third millennium. Of course for some, today's most spectacular celestial views will be of the eclipsed Sun [ http://science.nasa.gov/headlines/y2001/ast19jun_1.htm ] from along the path of totality as the new Moon's shadow tracks across southern Africa and Madagascar [ http://www.madagascar-eclipse2001.com/eclipse_.htm ]. This picture from the August 1999 total solar eclipse captures the shimmering solar corona just as that eclipse's total phase ended, as seen from eastern Turkey. The first rays of bright sunlight shinning through edge-on [ http://sunearth.gsfc.nasa.gov/eclipse/TSE2001/TSE2001fig/ TSE2001fig08.GIF ] lunar mountains and valleys create the fleeting appearance of glistening diamonds set in a ring around the Moon's silhouette. Do you want to see today's solar eclipse? Eclipse expeditions are offering live webcasts [ http://www.bit-net.com/~pauer/eclipse01/ ]. |
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Tunguska: The Largest Recent
…
| Title |
Tunguska: The Largest Recent Impact Event |
| Explanation |
Yes, but can your meteor do this? The most powerful natural explosion [ http://en.wikipedia.org/wiki/Tunguska_event ] in recent Earth history occurred on 1908 June 30 when a meteor exploded [ http://antwrp.gsfc.nasa.gov/apod/ap011118.html ] above the Tunguska River in Siberia [ http://en.wikipedia.org/wiki/Siberia ], Russia [ http://en.wikipedia.org/wiki/Russian_Federation ]. Detonating with an estimated power [ http://en.wikipedia.org/wiki/Tsar_Bomba ] 1,000 times greater than the atomic bomb dropped [ http://en.wikipedia.org/wiki/Atomic_bombings_of_Hiroshima_and_Nagasaki ] over Hiroshima [ http://antwrp.gsfc.nasa.gov/apod/ap071114.html http://en.wikipedia.org/wiki/Hiroshima ], the Tunguska event [ http://antwrp.gsfc.nasa.gov/apod/ap071114.html http://www.psi.edu/projects/siberia/siberia.html ] leveled trees over 40 kilometers away and shook the ground in a tremendous earthquake. Eyewitness reports are astounding. [ http://en.wikipedia.org/wiki/Tunguska_event#Selected_eyewitness_reports ] The above picture was taken by a Russian expedition [ http://www.unmuseum.org/kulik.htm ] to the Tunguska site almost 20 years after the event, finding trees littering the ground like toothpicks. Estimates of the meteor's size range from 60 meters to over 1000 meters in diameter. Recent evidence [ http://news.nationalgeographic.com/news/2007/11/071107-russia-crater.html ] suggests that nearby Lake Cheko [ http://en.wikipedia.org/wiki/Lake_Cheko ] may even have been created by the impact [ http://antwrp.gsfc.nasa.gov/apod/ap990711.html ]. Although a meteor the size of the Tunguska can level a city [ http://www.youtube.com/watch?v=ls0ME-dX08c ], metropolitan areas take up such a small fraction of the Earth's surface that a direct impact on one is relatively unlikely. More likely is an impact in the water [ http://www.space.com/scienceastronomy/astronomy/asteroid_paine_september.html ] near a city that creates a dangerous tsunami [ http://www.youtube.com/watch?v=AlPqL7IUT6M ]. One focus of modern astronomy is to find Solar System objects [ http://neo.jpl.nasa.gov/neo/report2007.html ] capable of creating such devastation well before they impact the Earth. |
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Water-Ice Imaged in Martian
…
| Title |
Water-Ice Imaged in Martian Polar Cap |
| Explanation |
Does water exist today on Mars? Yes, although the only place on Mars [ http://www.nineplanets.org/mars.html ] known to have water [ http://science.nasa.gov/headlines/y2001/ast05jan_1.htm ] is the North Polar Cap [ http://antwrp.gsfc.nasa.gov/apod/ap981216.html ], and that water [ http://www.nyu.edu/pages/mathmol/modules/water/info_water.html ] is frozen. Views of this potentially life-enabling water-ice are usually obscured [ http://antwrp.gsfc.nasa.gov/apod/ap011017.html ] -- in the winter by darkness and in the summer by clouds [ http://antwrp.gsfc.nasa.gov/apod/ap010417.html ]. Last April, however, the orbiting Mars Global Surveyor spacecraft [ http://nssdc.gsfc.nasa.gov/planetary/marsurv.html ] was able to get a good glimpse of the water-bearing cap [ http://antwrp.gsfc.nasa.gov/apod/ap980924.html ] just before Martian spring. Low, dark layers in the above image [ http://www.msss.com/mars_images/moc/1yearExtend/npolar/index.html ] are thought to contain a large amount of sand [ http://waynesword.palomar.edu/ww0704b.htm ], while high, light layers likely contain higher amounts of water-ice [ http://antwrp.gsfc.nasa.gov/apod/ap010629.html ]. The image spans an area about 5 kilometers across. |
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Ringed Planet Uranus
| Title |
Ringed Planet Uranus |
| Explanation |
Yes it does look like Saturn, but Saturn is only one of four [ http://antwrp.gsfc.nasa.gov/apod/ap020616.html ] giant [ http://antwrp.gsfc.nasa.gov/apod/ap020215.html ] ringed [ http://antwrp.gsfc.nasa.gov/apod/ap981020.html ] planets [ http://ringmaster.arc.nasa.gov/neptune/neptune.html ] in our Solar System. And while Saturn has the brightest rings, this system of rings and moons actually belongs to planet Uranus, imaged here [ http://www.eso.org/outreach/press-rel/pr-2002/ phot-31-02.html ] in near-infrared light by the Antu [ http://antwrp.gsfc.nasa.gov/apod/ap000707.html ] telescope at the ESO Paranal Observatory in Chile. Since gas giant Uranus' [ http://www.seds.org/nineplanets/nineplanets/uranus.html ] methane-laced atmosphere absorbs sunlight at near-infrared wavelengths the planet appears substantially darkened, improving the contrast between the otherwise relatively bright planet and the normally faint rings. In fact, the narrow Uranian rings [ http://ringmaster.arc.nasa.gov/uranus/ uranus.html ] are all but impossible to see in visible light with earthbound telescopes and were discovered [ http://tdc-www.harvard.edu/occultations/ uranus25/ ] only in 1977 as careful astronomers noticed the then unknown rings blocking light from background stars. The rings are thought to be younger than 100 million years and may be formed of debris from the collision of a small moon with a passing comet or asteroid-like object. With moons [ http://antwrp.gsfc.nasa.gov/apod/ap000930.html ] named for characters [ http://antwrp.gsfc.nasa.gov/apod/ap990227.html ] in Shakespeare's plays, the distant ringed world Uranus [ http://vraptor.jpl.nasa.gov/voyager/vgrur_fs.html ] was last visited in 1986 by the Voyager 2 spacecraft. |
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Barsoom
| Title |
Barsoom |
| Explanation |
Yes, I have been to Barsoom again ..." begins John Carter in Edgar Rice Burroughs' 1913 science fiction classic "The Gods of Mars" [ http://www.literature.org/Works/Edgar-Rice-Burroughs/gods-of-mars/ ]. In Burroughs' novels describing Carter's adventures on Mars, "Barsoom" is the local inhabitants' name [ http://humbabe.arc.nasa.gov/mgcm/fun/pop.html ] for the Red Planet. Long after Burroughs' stories were published, Mars continues [ http://mars.jpl.nasa.gov/ ] to inspire Earthdweller [ http://nssdc.gsfc.nasa.gov/planetary/mars/mars_crew.html ]s' interests [ http://antwrp.gsfc.nasa.gov/apod/ap970627.html ] and imagination [ http://antwrp.gsfc.nasa.gov/apod/ap970528.html ]. Soon it will again be invaded by spacecraft from Earth [ http://antwrp.gsfc.nasa.gov/apod/ap990108.html ]. This dramatic picture of a crescent Mars was taken by NASA's Viking 2 [ http://nssdc.gsfc.nasa.gov/cgi-bin/database/www-nmc?75-083A ] spacecraft in 1976. |
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Syrtis Major
PIA03786
Sol (our sun)
Thermal Emission Imaging Sys
…
| Title |
Syrtis Major |
| Original Caption Released with Image |
(Released 1 May 2002) The Science This image is from the region of Syrtis Major, which is dominated by a low-relief shield volcano. This area is believed to be an area of vigorous aeolian activity with strong winds in the east-west direction. The effects of these winds are observed as relatively bright streaks across the image, extending from topographic features such as craters. The brighter surface material probably indicates a smaller relative particle size in these areas, as finer particles have a higher albedo. The bright streaks seen off of craters are believed to have formed during dust storms. A raised crater rim can cause a reduction in the wind velocity directly behind it, which results in finer particles being preferentially deposited in this location. In the top half of the image, there is a large bright streak that crosses the entire image. There is no obvious topographic obstacle, therefore it is unclear whether it was formed in the same manner as described above. This image is located northwest of Nili Patera, a large caldera in Syrtis Major. Different flows from the caldera eruptions can be recognized as raised ridges, representing the edge of a flow lobe. The Story In the 17th century, Holland was in its Golden Age, a time of cultural greatness and immense political and economic influence in the world. In that time, lived a inquisitive person named Christian Huygens. As a boy, he loved to draw and to figure out problems in mathematics. As a man, he used these talents to make the first detailed drawings of the Martian surface - - only 50 years or so after Galileo first turned his telescope on Mars. Mars suddenly became something other than a small red dot in the sky. One of the drawings Huygens made was of a dark marking on the red planet's surface named Syrtis Major. Almost 350 years later, here we are with an orbiter that can show us this place in detail. Exploration lives! It's great we can study this area up close. In earlier periods of history, scientists were fascinated with Syrtis Major because this dark region varied so much through the seasons and years. Some people thought it might be a changing sea, and others thought it might be vegetation. Early spacecraft like Mariner and Viking revealed for the first time that the changes were caused by the wind blowing dust and sand across the surface. What we can see in this image is exactly that: evidence of a lot of wind action. Bright dust patches streak across this image, formed through wind interference from craters and other landforms. These wispy, bright streaks are spread on the surface by a vigorous, east-west wind that kicked up huge dust storms, scattering the fine particles of sand and dust in an almost etherial pattern. The bright streaks in the top part of the image might have formed in a slightly different way, because there is no landform standing in the wind's way. Beneath the bright surface dust are raised ridges that mark the edges of earlier lava flows, from Nili Patera, a Martian "caldera." A caldera is a collapsed, bowl-shaped depression at the top of a volcano cone. Can you imagine how Christian Huygens would feel if he lived today and could see all of this knowledge unfold? Or how it would feel to be the first person to stand in this dark volcanic and cratered region, knowing how many discovers had paved the way to that moment? Yes, exploration lives! |
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Syrtis Major
PIA03786
Sol (our sun)
Thermal Emission Imaging Sys
…
| Title |
Syrtis Major |
| Original Caption Released with Image |
(Released 1 May 2002) The Science This image is from the region of Syrtis Major, which is dominated by a low-relief shield volcano. This area is believed to be an area of vigorous aeolian activity with strong winds in the east-west direction. The effects of these winds are observed as relatively bright streaks across the image, extending from topographic features such as craters. The brighter surface material probably indicates a smaller relative particle size in these areas, as finer particles have a higher albedo. The bright streaks seen off of craters are believed to have formed during dust storms. A raised crater rim can cause a reduction in the wind velocity directly behind it, which results in finer particles being preferentially deposited in this location. In the top half of the image, there is a large bright streak that crosses the entire image. There is no obvious topographic obstacle, therefore it is unclear whether it was formed in the same manner as described above. This image is located northwest of Nili Patera, a large caldera in Syrtis Major. Different flows from the caldera eruptions can be recognized as raised ridges, representing the edge of a flow lobe. The Story In the 17th century, Holland was in its Golden Age, a time of cultural greatness and immense political and economic influence in the world. In that time, lived a inquisitive person named Christian Huygens. As a boy, he loved to draw and to figure out problems in mathematics. As a man, he used these talents to make the first detailed drawings of the Martian surface - - only 50 years or so after Galileo first turned his telescope on Mars. Mars suddenly became something other than a small red dot in the sky. One of the drawings Huygens made was of a dark marking on the red planet's surface named Syrtis Major. Almost 350 years later, here we are with an orbiter that can show us this place in detail. Exploration lives! It's great we can study this area up close. In earlier periods of history, scientists were fascinated with Syrtis Major because this dark region varied so much through the seasons and years. Some people thought it might be a changing sea, and others thought it might be vegetation. Early spacecraft like Mariner and Viking revealed for the first time that the changes were caused by the wind blowing dust and sand across the surface. What we can see in this image is exactly that: evidence of a lot of wind action. Bright dust patches streak across this image, formed through wind interference from craters and other landforms. These wispy, bright streaks are spread on the surface by a vigorous, east-west wind that kicked up huge dust storms, scattering the fine particles of sand and dust in an almost etherial pattern. The bright streaks in the top part of the image might have formed in a slightly different way, because there is no landform standing in the wind's way. Beneath the bright surface dust are raised ridges that mark the edges of earlier lava flows, from Nili Patera, a Martian "caldera." A caldera is a collapsed, bowl-shaped depression at the top of a volcano cone. Can you imagine how Christian Huygens would feel if he lived today and could see all of this knowledge unfold? Or how it would feel to be the first person to stand in this dark volcanic and cratered region, knowing how many discovers had paved the way to that moment? Yes, exploration lives! |
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