Jul

16

2017

Prof. David Paige

Ice deposits at the poles of the Moon and Mercury

Location: Geology 3656
Time: 2:30PM

Surficial ice evaporates relatively quickly if exposed to sunlight in the inner solar system. However, some parts of craters near the poles of Mercury and the Earth’s Moon are in permanent shadow. If a water molecule lands in such a spot it is expected to stay there until it evaporates due to heat from a micrometeorite or a photon from a star other than the Sun. New spacecraft data support the interpretation that there is ice in these shadowed regions. Picture: UCLA/JPL/GSFC/NASA

Jun

25

2017

Dr. Frank Kyte

Eltanin, the largest meteorite of which intact fragments are preserved

Location: Geology 3656
Time: 2:30PM

The largest recovered meteorite was discovered at the bottom of the Pacific Ocean about 1500 km west of the southern tip of South America. It has been documented by sediment cores collected during a series of German oceanographic cruises. About 2.5 million years ago a one-kilometer-diameter asteroid impacted the ocean and deposited more than one kilogram of meteorites per square meter over thousands of square kilometers. About 90% of this was melted by the shock of the impact, but 10% is undamaged meteorite fragments.