Up for a challenge? If skies are clear, you may be able to complete a rare feat of visual athletics this coming weekend, and ...

Astronomical twilight is the transition to fully dark skies, when the sun is between 12 and 18 degrees below the horizon. Volcanic activity at Anak Krakatoa ("Child of Krakatoa") in Indonesia.

We move from astronomical winter to spring at the stroke ... The best time to see the twilight planet is 45 minutes to an hour after sunset. An unobstructed view to the west helps!