Be sure to look up Monday night (Jan. 21, 2013) to catch a close encounter of the Moon with Jupiter.
The view should be spectacular anytime that Monday evening, but to view these two objects at their closest, go out around 11:30 p.m. The waxing gibbous Moon and brilliantly shining Jupiter will be less than 1 degree apart. That’s less than the width of your pinky finger when you hold it all the way out, at arm’s length.
Although the Moon and Jupiter might seem very close that night, in reality they are very far away from each other. The Moon’s distance averages about 240,000 miles from Earth, whereas Jupiter lies roughly 500 million miles away.
To put it another way, the Moon is just over 1 light-second away (since light coming from the distance of the Moon takes just over one second to reach our eyes), but Jupiter’s distance is roughly 45 light-minutes.
And those stars that currently appear near Jupiter? The bright orange-ish one, Aldebaran, is 65 light-years away, which means you see the star as it looked when the light left it 65 years ago, shortly after the end of World War II.
Also “near” Jupiter is the Pleiades star cluster (the “Seven Sisters”). But really those stars are more than 400 light-years away.
Getting back closer to home: If seeing the Moon inspires you to want to learn more about it or hear Moon stories from around the world, please join us under the planetarium dome for “Star Families: Moon Myths” on Saturday, Jan. 26, from 3:30-4:15 p.m.
If you miss this conjunction of Jupiter and the Moon, try again March 17, 2013, when they have another fairly close encounter.