How Much of ISON Survived Its Closest Approach To the Sun?

SternisheFan writes "This Ars Technica article examines what may be left of ISON and contains a detailed animated GIF from the NASA STEREO Ahead spacecraft. 'It looks like comet ISON, or most of it, did not survive its encounter with the Sun yesterday, when it made a close approach at just 1.2 million kms from that fiery surface. This distance may seem large, but it is close enough to have subjected the comet to temperatures of around 2,700C. To survive such a close shave with the Sun may sound unlikely, but a few other sungrazing comets have managed the feat during even closer passes. So some people hoped ISON would perform a death-defying stunt and emerge intact. ISON did not leave us without a final serving of mystery though. Soon after reaching its nearest point to the Sun (known as perihelion), there was no sign of it emerging afterwards. Twitter and news agencies were alight, lamenting its loss and assuming it disintegrated—RIP ISON. But then, moments later, new images emerged showing a hint of something appearing on the other side of the Sun. Was this still a diminished comet ISON or a ghostly version of its former self? Well, even comet experts are not sure.'"

Comments

Re:So...

[Anonymous Coward]

The sun is actually only the small white circle in the middle of the shade. And SOHO is only 1.5M kilometers away from Earth so the sun can’t be much larger from SOHO’s position.

The reason for why the comet appears to be so huge is the massive coma around the core as well as the tail originating from the core and scattering like a bowwave from a ship it extends and expands the further away it is from the source. The sudden seemingly increase in size of the tail when ISON re-appears above the sun comes from the sudden change of direction and the new direction how the ejected material is forced away from the core by the solar wind.

Most comets have a nucleus (the center of a comet) that is less than about 6 miles (10 km) wide. The size of a comet changes depending on how close it is to the sun. As a comet gets closer to the sun, the ices on the surface of its nucleus vaporize and form a cloud called a coma around the nucleus that can expand out to 50,000 miles (80,000 km). A tail also forms on a comet as it approaches the sun. Comet tails can be over 600,000 miles (1 million km) long.

An awesome gif indeed. A little closer to home is ....

http://www.dailygalaxy.com/my_weblog/2013/12/image-of-the-day-a-spectacular-meteor-streaking-through-the-aurora-borealis.html

No Hale Bopp "Koolaide" rerun? Rats!

[Tablizer]

So many idiots, so few comets.