The rules: Collaborative work is encouraged. This homework can be done in consultation with your fellow classmates, the AI, or the professor. However, everyone must submit their own solutions to get credit, and all help should be acknowledged (a single sentence mentioning the others in your study group is sufficient). Show your work.
Recommended Reading: The nineplanets web pages: http://www.seds.org/nineplanets/nineplanets/nineplanets.html
1. Just the facts [14 pts]
(a) [1 pts]
True or False, A planet with a high albedo will have a subsolar temperature lower than a low albedo planet at the same distance from the sun.
(b) [1 pts]
True or False, On Mercury, the solar day is longer than its sidereal year.
(c) [1 pts]
True or False, Scientists claim to have detected water on Mercury.
(d) [2 pts]
List the terrestrial planets (Mercury, Venus, Earth, Mars) and the Earth's Moon
in order of increasing magnetic field strength.
(e) [9 pts]
Using the web, or any other resource, name 3 recent (within the last decade),
or soon to happen,
NASA missions to Mercury, Venus, or Mars. Briefly describe each mission
(date launched and dates of operation, scientific goals, was the mission successful, etc.).
2. Vanished into Thin Air [21 pts]
(a) [6 pts] Earth, Venus, and Mars all have carbon dioxide (CO2) in their atmospheres. Find the ratio of the root mean square speed to the escape speed for each. Comment on the retention of CO2 for these planets.
(b) [5 pts] Compare the scale heights of CO2 in the atmospheres of Mars and Venus.
(c) [5 pts] The inner (terrestrial) planets have relatively small amounts of hydrogen in their atmospheres, yet the outer (Jovian) planets are predominately hydrogen. Taking the Earth and Jupiter as typical examples of each class, calculate the ratio of the root mean square speed to the escape velocity of hydrogen for both the Earth and Jupiter. How do these values affect the relative observed amounts of hydrogen in the atmosphere of each of these planets?
(d) [5 pts] Estimate the lifetime of methane in the atmospheres of Jupiter and Uranus.
3. Tidal Debris [15 pts]
(a) [5 pts] Compare the magnitude of the tidal forces of Jupiter on Io to that of Saturn on Titan. Comment on your conclusion.
(b) [5 pts] Assume Mercury has a satellite whose composition is the same as Mercury's and whose mass is 1% of the mass of Mercury. How closely must it orbit Mercury to remain bound against the tidal force of the Sun?
(c) [5 pts] At what distance from the Sun would Mercury be pulled apart by tidal forces? How does this compare with Mercury's actual distance from the sun?