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.

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.

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!

November 8th, 2006 11:01 AM by Phil Plait in Astronomy, Cool stuff, NASA, Science | 10 comments | RSS feed | Trackback >

10 Responses to “Mercury heading in!”

  1. Phobos Says:

    Did you mean Mercury comes in from the left?

  2. Max Fagin Says:

    I thought Mercury crossed the sun East to West? (Left to right)

  3. Grand Lunar Says:

    Well, too cloudy here to observe the transit.
    Having a difficult time trying to find a website that shows the transit itself.
    Has anyone else had better luck?

  4. Rob Says:

    Unfortunately it is wall-to-wall gray clouds down here in Sydney with intermittent showers forecast all morning. Doesn’t look like I’ll get any images or even a view at present. It appears to be better west of Sydney over the mountains though. The CSU Remote Telescope webcast http://black-hole-net.mit.csu.edu.au/telescope/events/tom/live.html is updating images every 30 seconds.
    Hope your clouds clear Phil. Happy viewing on a fine day in the US.

  5. Michelle Rochon Says:

    Sweet, Rob!

    I was looking at it from SOHO..
    http://sohowww.nascom.nasa.gov/soc/transits/mercury/20061108/realtime.html
    But maybe they should notice that their time updates but the image stays the same. There’s no mercury thus far.

  6. Michelle Rochon Says:

    …upon JUST looking back at the soho website… I see Mercury now! but it seems it’s an hour late.

  7. Absolute Zero Says:

    Yech, New Zealand has the same weather as Sydney today, apparently. Good luck to everyone else.

  8. Grand Lunar Says:

    Those links are just what I was looking for, Rob and Michelle.
    Thanks!

  9. The Bad Astronomer Says:

    I can see it! But apparently I cannot photograph it. Grrr. :( I can’t get the exposure right. Oh well, it’s still cool.

  10. Ian Musgrave Says:

    Blast, I missed the comet, and I was backing and forthing the image to deterimine if the dot that dissapeared really was Mercury (it was). I was a bit discombobulated, as previous times Mercury was in the LASCO C3 camera, it was bright. And then I realised that Mercury had its dark side facing us. DUH. Anyway, check out this sun diving comet. Sorry you couldn’t image the transit BA. I managed to do so by shooting several differnt exposures at each time point, then picking out the ones that worked later. It’s wasteful of film, but at least I get something that works (even though I keep a log of my exposure setting from previous runs, on the day combinations of sun elevation and whatever the heck they have done to the film stock in the year between when I by lots seems to throw things up in the air again.

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