Hey, sky fans! Happy Friday! I hope you’ve had a great week, and are getting ready for the weekend. I raise my nearly empty mug to you. Thanks for all your hard work this week, whatever you did. Thanks, as always for stopping by.
For our Friday photo, here’s something you may not have seen yet. It’s an view of the Moon cutting across the Earth as seen by NASA’s Deep-Space Climate Observatory (DSCOVR) satellite over about four hours earlier this month. DSCOVR orbits the Earth from around a million miles away, keeping an eye on things back home.
In this photo, you can see the Moon’s far side, which no humans saw until Apollo 8 orbited the Moon at Christmastime 1968. The Moon is tidally locked to the Earth so one lunar day takes the same amount of time as one of its orbits around the Earth. This means we always see the same side of the Moon from Earth, the near side.
From the Earth we see the Moon move slowly across the sky from day to day and as the angle changes, the phase changes. If you were on the near side of the Moon, you’d see the Earth sitting beautifully in more or less the same spot of the sky. Quietly, one part after another would come out of the shadows; the Earth phases seen from the Moon are the opposite of the ones we see of the Moon from Earth. The continents would cross in front of you and then disappear around the other side. Meanwhile, if you were on the far side, you’d say “What’s an Earth?”
I love watching things like these. I love being able to see how things work, and see how everything is moving all the time.
Clear skies, everyone!