Maine earthquake: The 4.0 temblor hit around 7:12 p.m. Tuesday and its epicenter was about 20 miles west of Portland, Maine. The Maine earthquake shook buildings and rattled dishes, but caused no injuries or serious damage.
After the Cassini probe's flyby over Saturn's frozen moon, Dione, scientists saw evidence of ionized oxygen molecules in its atmosphere. This could have interesting implications for astrobiology.
Monitor readers share their favorite book picks.
A new book, 'The Medea Hypothesis,' looks at the opposite of the Gaia hypothesis and suggests that life on Earth is self-destructive.