NASA says 2nd-warmest year on record. NOAA says 3rd-warmest. Their methodologies differ slightly, but - by both standards - the past 4 years are the hottest yet recorded.
The young moon is back, waxing toward a lunar eclipse on January 31. For now, look west after sunset to see the young moon. Judy Lundquist in Lawrenceburg, Kentucky caught last night's young moon with earthshine. She wrote: "After days of overcast and snow, we finally got a clear sun and moonset!" See more photos.
In the 19th century, passenger pigeons were so numerous that hunters competed to shoot as many as possible. But the last passenger pigeon died in the Cincinnati Zoo over 100 years ago. How did it all go so wrong?
Robert Pettengill of Austin, Texas caught the moon on the last evening of fall - December 20, 2017 - from Austin, Texas. The pale glow on the darkened portion of the crescent is called earthshine.