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Telescopes (cont). Imaging Spectroscopy Long Term Monitoring. May involve imaging, spectroscopy, or both Over long time durations How do properties change with time? Weather, climate, dust storms, persistence of Jupiter’s red spot, orbits of moons. Discovered Jupiter’s rings
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Telescopes (cont). • Imaging • Spectroscopy • Long Term Monitoring May involve imaging, spectroscopy, or both Over long time durations How do properties change with time? Weather, climate, dust storms, persistence of Jupiter’s red spot, orbits of moons
Discovered Jupiter’s rings • Details of Saturn’s, Uranus’ and Neptune’s rings • Measured magnetic fields as function of distance • Gravitational effect by moons measure moon densities Robotic Spacecraft Some of these measurements are “backlit” from the sun, i.e. in silhouette- cannot be done from Earth at all The “Flyby”, short duration close up study.. Voyager 2 flew by Jupiter July 9, 1997 Saturn Aug 25, 1981 Uranus Jan 24, 1986 Neptune Aug 25, 1989 “Orbiters” can give long term monitoring, but they are much more expensive
Robotic Spacecraft “Landers” on the other hand, stick around and move around on a surface. Close up and Personal! “Probes” on the other hand, go in and don’t come back! Close up and Personal! • Galileo Probe dropped into the atmosphere of Jupiter (1995) • Collected • Temperature • Wind Speeds • Pressure • Composition • Radiation levels • As a function of depth for about an hour before it was destroyed New generations Landers are soft landing rovers…
Robotic Spacecraft to Come This summer! Cassini Orbiter Huygens Probe
Biological Tour of the Solar System (Intro) • Terrestrial Planets and their moons • Mercury (like the moon?) • Venus (like the Earth once?) • Earth’s Moon • Mars (like the Earth once?) • Mars’ Moons • JOVIAN PLANETS--- later date….
Mercury and Earth’s Moon Mercury and Moon are least likely habitats • small, lost internal heat • no outgassing- no atmospheres • scared with craters, surfaces are old • evidence for impacts suggest that some organics and water deposited on these bodies However….
Evidence for Permafrost Water on Lunar Poles? This color-coded map from the Lunar Prospector mission shows evidence for water-ice in craters near the Moon’s North pole. (late 1990). Used neutron detection techniques. Dark blue and purple regions have highest hydrogen concentrations, which may be due to water concentrations on or just below the surface. In these regions, some craters are permanently shielded from the Sun. Similar results were found on the Moon’s south pole. We have no corresponding probe of Mercury…
Magellan Orbiter Radio Maps Venus – Earth’s Sister • 2/3 the distance from Sun as Earth • 80% mass of Earth • Calculations predicted 35C temperature As we know, Venus suffers a runaway greenhouse effect (discuss details of how it got there in Ch 9) Surface is very young, regenerates every so often, last time was 1 billion years ago Earth 1% carbon dioxide Venus 96% carbon dioxide Venus too hot for liquid water, ammonia, methane, or ethane Venera Lander Photo (and then sphttthht!) Early ocean’s on Venus? Discuss implications later…
Small Moons Mars’ two moons are Phobos and Deimos Objects like these most certainly lack liquids Too small to have internal heat that would energize metabolism or allow for liquid Meteorites must have contained liquid water shortly after their formation, and these objects contain organic molecules on them from space (formation). Early life on these bodies would seem very unlikely. These very small moons and asteroids too far from sun to have any ice water melt in the current epoch.