Astroblog: Mercury at Superior Conjuction Today

Sunday, January 07, 2007

Mercury at Superior Conjuction Today

Image Credit NASA/SOHO

Today turns out to be a very busy day astronomically. There is the Transit of Iapetus visible from Australia, and today is also when Mercury is at Superior Conjunction, that is, when Mercury, the Sun and Earth are in a line, with the Sun between Mercury and Earth. Of course, we can't see it ourselves, the Sun being too bright. But this SOHO image shows Mercury as the very bright dot just under the dark occulation disk (the horizontal line is an artefact of the imaging system).

Last November, when Mercury Transited the Sun, it was at inferior conjucntion (ie between the Sun and ourselves). Mercury didn't turn up on the SOHO images until quite long after transit, as in inferior conjunction the mostly dark side of Mercury faces us, while in superior conjunction the bright side faces us.

Just before conjunction, there were a series of CME's from the Sun that went past Mercury, you can see them and a movie of them at SOHO's Pick of the Week.

Image Credit NASA-Stereo

You can also pick up Mercury in the STEREO images. STEREO data isn't released in near real time, so there is some delay in getting images. This is a stack of 3 images from 2 Jan, showing Mercury's movement. The STEREO images are FTS images, so you need something like The Gimp to open and view them.

# posted by Ian Musgrave @ 6:17 pm

Comments:

Hi Ho Ian and Happy New Year.

It cleared off for a bit today, clouded up just in time to miss the comet.

FITS Liberator 2.1 is also out and works great.

# posted by