Print Story Perihelion Day
By ana (Thu Nov 28, 2013 at 08:43:45 AM EST) (all tags)
 Comet ISON is making its closest approach to the sun today.

I probably don't need to say this for the present audience, but... Don't Look At The Sun with your naked eyes.

 It's really really close; like 2.7 solar radii.

Most sungrazing comets are fragments of an old comet Kreutz that disintegrated years ago, scattering pieces along its old orbit. You'll remember pictures of Comet Shoemaker-Levy 9 hitting Jupiter, with 11 or more fragments lined up along the orbit. Orbital mechanics is a strange and wonderful science.

Oddly enough, this is a "new comet": the orbital dynamics say it's inbound from the Oort Cloud (well beyond Pluto) for the first time ever.

Anyway, it's being observed by multiple solar observatories. Herewith, the linkfarm.

SOHO/LASCO coronagraphs. As of this writing it's already in the field of view of the C3 instrument; it should be passing into the C2 FOV right about now. SOHO lives at the sun/earth L1 point, about a million miles from the earth, continually observing the sun. It's been there since about 1998. Click around that site for movies and late-breaking images.

It's also visible from similar instruments on the two STEREO spacecraft, which share the earth's orbit, pretty nearly, one ahead (STEREO-A) an one behind (STEREO-B). Currently they're like 130 or 140 degrees away from the earth.

And last but not least, this afternoon during the really close approach, the Solar Dynamics Observatory will be observing it in 8 extreme ultraviolet and soft x-ray bands. They should be live about 1pm eastern time.
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You're meant to say by anonimouse (2.00 / 0) #1 Thu Nov 28, 2013 at 01:08:34 PM EST
Don't go into the light

Girls come and go but a mortgage is for 25 years -- JtL
I believe XKCD by riceowlguy (4.00 / 1) #2 Mon Dec 02, 2013 at 05:36:35 PM EST
had the last word on this:

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