Mercury now well placed for observation

coylemj · 01-03-2012 12:10am #1

It's at it's greatest eastern elongation (angular separation from the Sun) on March 5th. The Ecliptic describes a steep angle to the horizon at the time of the Vernal Equinox which falls on March 20th in 2012 so Mercury reaching greatest eastern elongation at this time of the year translates into maximum height above the horizon.

I found it low in the western sky this evening, it was 10 degrees high at 18:30. I found it binos at 18:20 before the sky got dark and then with the naked eye in a darker sky at 18:40 before it disappeared below my neighbours' rooftops.

Follow a line down from Jupiter through Venus to the western horizon where the sun has just set. Mercury will rapidly plunge into the sunset after March 5th so get out in the next few days and see if you can find it. With the naked eye you'll need to be out looking at about 18:40, a bit earlier if you have binos.

Useful tool here: http://www.fourmilab.ch/images/3planets/elongation.html