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
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
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
“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!
New generations Landers are soft landing rovers…
Mercury and Moon are least likely habitats
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…
Venus – Earth’s Sister
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…
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.