Dawn enters its low-altitude
mapping orbit around 4 Vesta, as you have considered on
Midterm Exam 1, problem 5. See, in particular, part c of
that problem to find out why it took so long to get there from its
high-altitude orbit. Meanwhile, APOD features some nice
pictures of
nearer-by pieces of Vesta. (12-13-2011)

Kepler 22b, only 2.4 times larger in
diameter than Earth, is confirmed clearly to lie within the
habitable zone around its star, and the Kepler team adds 1094 new
objects to its list of exoplanet candidates. (12-05-2011)

And, just in time for our week-long
discussion of exoplanets, a front-page NY Times article on the hunt
for planets lying in the habitable zones around their stars.
(12-03-2011)

Bon voyage to the Mars Science
Laboratory and its rover, Curiosity. (11-26-2011)

The number of known extrasolar planets
passes 700. (11-23-2011)