Last couple months we’ve seen some nice conjunctions of Jupiter and the Moon. On January  21st, they will come closest seen from the Earth. They would be seen about half a degree apart at the closest. As a comparison, the full Moon is about half a degree in diameter.

Here is a simulated view of the conjunction.


This conjunction is well placed seen from the western hemisphere, because it happens during the early part of night for this side of the Earth. The closest point being around 7:00 pm Pacific time.  If you remember the Moon moves almost 13 degrees in one day,the conjunction may not appear so close from the eastern hemisphere  unless you wait until late in night/early morning. In any case, don’t forget to look up at the Moon on 21st January 2013

This conjunction is also a good time to observe the movement of the Moon in the background of stars on the Ecliptic. Jupiter being farther away does not move much in a few hours. But the Moon is much closer, and also there is a the advantage of a bright Jupiter close by – So if you see the Moon at an hours interval a few times in the night, you will easily be able to see how the Moon has traveled towards East  in the background of stars.

A bonus this time is the conjunction occurs in a very star-studded region of the sky – surrounded by prominent constellations such as Orion, Taurus, Auriga and Perseus. And by the way, the orange-red star close to the Moon & Jupiter is Aldebaran, also known as Alpha Tauri in sky-terminology, and is the 4th nakshatra Rohini, in the Indian lunar Zodiac.