Mercury heading in!

Mercury heading in!

Mercury heading in!

Bad Astronomy
The entire universe in blog form
Nov. 8 2006 11:01 AM

Mercury heading in!

As I write this, Mercury is a couple of hours from the start of the transit. As I was reading up on the transit, Ian Musgrave's blog reminded me of an idea I had yesterday about posting a short video from the SOHO satellite.

Phil Plait Phil Plait

Phil Plait writes Slate’s Bad Astronomy blog and is an astronomer, public speaker, science evangelizer, and author of Death From the Skies!  

SOHO -- the Solar and Heliospheric Observatory -- has been watching the Sun steadfastly for many years, and the images can be strung together to make way cool videos. It has different cameras, but the C3 camera is my favorite. The Sun itself is blocked by an "occulter", a piece of metal, so that the glare doesn't wash out fainter objects. In the images you can see stars and planets. As the Earth orbits the Sun, the stars appear to move from left to right across the images, but planets move at different rates. You can also see coronal mass ejections -- hiccups, if you will, from the Sun --- and lots of other events.

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Here is a video I put on YouTube of the C3 view from the past couple of days (YouTube reformatted the originally square video, so it looks squished):

The Sun is blocked, but its position is marked by the circle. Venus is the bright object to the upper left (the line through it is a detector artifact), Mars is to the right. In this 4 second clip, you can see Mercury come in from the right side and head straight for the Sun... of course! Because today it'll move directly across the face of the Sun. Think of this as a warmup for today's events.

Also, if you watch closely right at the start of the clip, you might see a fainter object come in under Venus and head for the Sun-- that's a comet! You can often see them in SOHO images.

I have my binoculars and tripod handy, and I plan on taking a peek later when the fun starts. I heard there's a big sunspot today, too, so the view should be nice-- and the clouds here are breaking up! Hooray!