Posts Tagged ‘conjunction’

Venus, Jupiter and the Moon, Cosmic Ballet in February and March 2012.

February 21, 2012

For those who have been paying attention to the sky over the past few months, you will have seen Venus crawl out of the evening twilight, and Jupiter sink towards it.  These two VERY naked eye planets (both outshine even the brightest stars) are now only about 15 degrees apart (about the spread of your fingers held out at arms length), with that value set to shrink to about 3 degrees over the next 3 weeks.  Get the popcorn is ‘cos its gonna be a fantastic show!

The ballet is highlighted in the sequence below.

Venus Jupiter conjunction of 2012 (click to enlarge)

A) t= 0.  Jupiter and Venus hang in the evening sky.  Venus, by far the brighter of the two lies below Jupiter, and the pair are separated by about 15 degrees.  For reference, the Moon and Sun are about half a degree in diameter, and your outstretched fingers at arms length are about 15 degrees in angular size.

B) t= 5days.  The moons orbit takes it out of the solar glare and by the 26th it resides between Venus and Jupiter.  This will be a spectacular sight for those who get to see it, with the 2nd, 3rd and 4th brightest objects so close together in the sky.  The angular distance between the two planets has now closed to about 10 degrees.  Most of this apparent motion of Jupiter is due to the Earth moving around the Sun, while with Venus, about half of the apparent motion comes from this planet orbiting the Sun.

C) t~21 days. The Venus, Jupiter conjunction of 2012.  The two most spectacularly bright planets appear at their closest  (~3 degrees).

D) t~33days.  The Moon has now made a complete orbit since it last visited these planets.  When it last did, Jupiter was the higher, and Venus the lower.  The second time the moon visits these planets the order is reversed!  Venus the beguiling bright is now the higher of the two objects!  The objects are again separated by about 10 degrees.

For those who want to see what this looks like in animation form, take a look!  Download the  free solar system visualization software Celestia (http://www.shatters.net/celestia/)

Advertisements