Comet-Sun Impact Caught On Video 61
jomegat writes "NASA has released footage captured by the Solar Dynamics Observatory (SDO) showing a comet slamming into the surface of the sun. The impact created a huge splash as seen on the video, but the impact at the surface was blocked by an occluding disk that allows the SDO to image the sun's corona. It's still very impressive though!"
Not quite as advertised (Score:5, Informative)
The "huge splash" is an unrelated coronal mass ejection. There is no actual splash, or "collision" in the sense we would imagine it. Which should be obvious when you stop to think about it, because the Sun is really freaking hot. The comet evaporated when it got too close.
Still, a pretty cool video. It's always cool to see how tiny things look when they get close to the Sun. In the first video, you'll probably have to watch it a few times before you even notice the comet.
Huge splash? (Score:4, Informative)
The closest thing I've seen to a 'splash' was during the June 7th CME, where a significant amount of the eruption didn't escape the sun's gravity:
http://sdo.gsfc.nasa.gov/gallery/potw.php?v=item&id=54 [nasa.gov]
For the comet, though ... no splash. And they haven't finished the final processing of the last bit of the comet's track across the sun, so I haven't seen it 'evaporate' as others have mentioned.
(Disclaimer: I'm not a solar physicist, but I work for the Solar Data Analysis Center, and on the distribution systems for SDO data)
Re:Not quite as advertised (Score:5, Informative)
Go fast enough, and even the extremely rarefied gases in interstellar space might as well be a brick wall.
Re:Surface? (Score:5, Informative)
The term "surface" when used in relation to the Sun is used to mean the place from which the majority of photons we see are emitted; known as the photosphere. That surface is defined to be at optical depth 2/3 (a photon, on average, escapes without scattering off a particle). It is a fuzzy boundary, varying in depth with wavelength of light, but it is a small range in comparison to the size of a star.