Planets, 'almost-supermoon' brighten this week's sky
Posted January 8
Updated January 10
Raleigh, N.C. — Last year spoiled skywatchers with three supermoons. While 2017 brings only a single supermoon on Dec. 3, we can enjoy an "almost-supermoon" this week.
Look for a big, bright, waxing gibbous moon after sunset Monday into the following morning.
Just after 1 a.m. EST Tuesday, the moon will reach perigee, the closest point in its orbit around the Earth. While it won't be full until Thursday, the surface will be 93 percent illuminated. That is good enough for what I'm going to call an "almost-supermoon." You won't miss that remaining 7 percent.
This week is also a great one to see Mercury. The first planet from the sun is usually not visible to us because its tiny orbit keeps it in front of, behind or so close to the sun that it is too difficult to see. On Wednesday, Mercury will be at its brightest as it nears the point in its orbit which most separates it from the sun. Astronomers refer to this as the point of greatest elongation.
Look to the east just above the treeline just before sunrise. Mercury will be the brightest point of light. If the sky is clear enough, you might also see Saturn, just up and to the right of Mercury.
Venus also continues to shine brightly in the evening sky. It will appear the highest above the horizon on Thursday as the second planet from the sun reaches its point of greatest elongation. This is less rare of an opportunity.