Earth’s sister planet reaches greatest western elongation and dichotomy as the waxing Moon slides along the ecliptic in the ...

This month's night sky is filled with close-range meteors, swirling nebulas, and prime stargazing conditions. Here’s when you ...

A crescent moon will appear alongside the bright stars Castor and Pollox to form a lopsided grin in the night sky on May 29.

This modern era of high precision stems in part from studies of the oldest light accessible to us—the cosmic microwave background (CMB ... from the entire sky, forming a two-dimensional ...