It is possible, though still not certain, that Mars was once globally warmer and wetter, with liquid water globally stable at the surface during the Noachian. If liquid water was once stable on Mars, most of the following statements are true. One is false. Find the false statement.
The surface temperature was at least 0 degrees Celsius.
Substantially more water was present in the atmosphere than is present today.
Liquid water would also have been stable in the subsurface.
It is likely that a substantial CO2 atmosphere caused a large greenhouse effect.
Rain was likely common, at least in some places.
The giant outflow channels would have brought copious water into a northern ocean at this time.
While it is not surprising the Mars has ice at the poles, there is evidence that subsurface ice on Mars extends even down to the tropics. Which one of the following is the likely explanation for this ice?
A colder equatorial climate during periods of high eccentricity
A colder equatorial climate during periods of high Martian obliquity
Globally cold temperatures during the late Hesperian/early Amazonian as the atmospheric greenhouse diminished
Globally colder temperatures during the Noachian when the sun was fainter
Melting and migration of ground water due to magmatic interaction.
Remnant water from outflow channels which has slowly frozen over time
What is generally thought to be the most likely explanation for most giant outflow channels on Mars?
Massive melting of ground ice by magmatic intrusion
The transition from high obliquity to low obliquity causing substantial melting and runoff
Pre-Noachian impacts causing local regions of liquid water stability and ice melting
Sapping of ground water
Catastrophic flooding from locally intense rainfall
Melting of glacial dams leading to massive outflow of previously confined water
If Mars once had a massive CO2 atmosphere that led to a warmer and wetter Noachian period, all of that CO2 must have gone somewhere. Most of the statements below about atmospheric removal on Mars are true. Which one of the following statements about atmospheric removal is not true?
Mars continues to lose its atmosphere today.
If the Martian atmosphere was removed by hydrodynamic escape, all isotopes of atmospheric molecules would be removed equally well, contrary to what is observed.
If CO2 was removed chemically, large deposits of carbonates should exist somewhere, yet no such large deposits have been found
Giant impacts during the late heavy bombardment could have been responsible for the drying out of the Hesperian, but all isotopes of atmospheric molecules would have been removed equally well, contrary to observations.
If the Martian atmosphere was removed by solar wind scavenging, lighter isotopes of atmospheric molecules would be preferentially removed -- an effect which is seen.
If Mars still possessed a substantial magnetic field, its atmosphere would probably have been protected against loss
Place the following events in the likely order of their occurrence.
1. The presence of the acidic playa environment at Meridiani Planum
2. The formation of the Hellas basin
3. The formation of dendritic channels
4. The formation of the layers visible on the polar caps
Please answer using a single number with no spaces or other punctuation. For example, if you think the correct order is 4, 3, 2, 1 please answer 4321.
Answer for Question 5
We have learned about the interiors of giant planets through many different methods. Once again, most of the statements below are true, but one is not. Which statement below is not true?
Jupiter is more dense than Saturn only because it is more massive and thus more compressed.
Saturn’s interior is currently being heated by helium rain.
Jupiter, Saturn, Uranus, and Neptune likely have metallic hydrogen in them, as evidenced by both the phase