EPTComet W3 Lovejoy crashing into the Sun right now! - Page 2
| Forum Index > General Forum |
|
Jukulmolder
Spain254 Posts
| ||
|
Alvin853
Germany149 Posts
On December 16 2011 10:25 intrigue wrote: omg! the gifs are SO COOL. was the comet surviving a very unexpected outcome? how often does this usually occur? can you explain what i'm looking at here? + Show Spoiler + edited image-url to show the one referred to in this post: ![[image loading]](http://sohowww.nascom.nasa.gov//data/REPROCESSING/Completed/2011/c3/20111215/20111215_2230_c3_512.jpg) Since comets are usually big chunks of ice (not just frozen water, but also dry ice, frozen methane and other stuff) it's not uncommon for them to evaporate when they get too close to the sun. Also the gravitational forces are really strong when they get that close to the sun, so they tend to break into smaller pieces (which is how this comet was initially formed), and smaller pieces melt and evaporate even faster. Considering Lovejoy was not that big of a comet most people expected it to "not make it", but apparently it did. As for the picture: it was taken by a camera specifically made to observe the corona of the sun. The sun itself is in the center and indicated by the white circle, but they put a disc in front of the camera to create an artificial eclipse, otherwise the light coming directly from the sun would oversaturate the picture and you couldn't see anything on it. The black stripe on the top right is probably some fixture to hold the disc. The comet can (or rather can't) be seen in the bottom left, leaving a bright tail of dust behind, but also a dim tail of ions just to the left of the bright tail. The ions are affected by solar winds and therefore "blown away" while the dust is just left behind marking the trail of the comet. You can see the comet in this picture taken earlier (the comet is so bright it oversaturates the camera, which leads to horizontal bars, it does not actually have the shape seen in this picture): ![[image loading]](http://sohowww.nascom.nasa.gov//data/REPROCESSING/Completed/2011/c3/20111215/20111215_1630_c3_512.jpg) Also some youtube videos from SDO: + Show Spoiler + Lovejoy entering the sun's atmosphere Lovejoy emerging from behind the sun: | ||
|
opisska
Poland8852 Posts
That it, like, the most exciting thing in astronomy I have ever seen realtime. Noone believed that!! | ||
|
Warri
Germany3208 Posts
| ||
|
opisska
Poland8852 Posts
It happened before, but with much larger comets, they had enough mass that something was left. But most of the people did not expect this one to be big enough, by far. | ||
|
Pleiades
United States472 Posts
| ||
|
KimJongChill
United States6429 Posts
| ||
|
RxDamitol
United States83 Posts
Thanks for sharing! Great pictures! | ||
|
Deleuze
United Kingdom2102 Posts
| ||
|
Antisocialmunky
United States5912 Posts
| ||
|
MisterD
Germany1338 Posts
On December 17 2011 00:09 Antisocialmunky wrote: If Star Trek has taught us anything, it just went back in time. that was stargate btw ;P in star trek you go back in time through arbitrary wormholes. The loop-around-the-sun-wormhole-time travel is stargate.  </scifinerd> | ||
|
Rorix
357 Posts
| ||
|
opisska
Poland8852 Posts
The interesting thing is, how dim the comet was after the solar passage and that it started to brighten only a couple o hours later. From what I heard from the astronomical community, this commet will require some serious work to make it in line with theoretical models. | ||
|
PoisedYeTi
Australia167 Posts
Thanks | ||
|
RoosterSamurai
Japan2108 Posts
| ||
|
Mawi
Sweden4365 Posts
On December 16 2011 20:54 Warri wrote: Wait what, it flew through the sun and survived? Dear god it must be an extraterrestrial spaceship with super sun resistance! Man seriously this is so cool thank you so much never knew about this :D | ||
|
opisska
Poland8852 Posts
On December 17 2011 04:45 RoosterSamurai wrote: What would have happened if this comet hit the earth? First, it is extremely unlikely. There are many other object with far more probablility of hitting the Earth than a Kreutz comet. Their orbit is so much wrong for ever coming really close to Earth. Second, this quesiton is interesting, because it raises another question: how big is the nucleus of the comet? Honestly, nobody knows. The comet is so intruiging that normal estimates do not apply well. To now about the ballpark: largest ever osberved comets have tens of kilometers (almost certainly not the case here), smallest maybe some hundreds of meters. The actual "comet" is many orders of magnitude bigger, as it is just a huge cloud of gas evaporated from the nucleus, but its density is very low, it is comparable to the "vacuum" we create in our labs on Earth. Anyway, if the nucleus is in the range of kilometers, we could be talking about something only a little less dramatic than dinosaur extinction. But to repeat, this is not going to happen. If something from space is gonna kill us, it is something we do not know at the moment, with a very different trajectory than a Kreutz comet. | ||
|
Antisocialmunky
United States5912 Posts
On December 17 2011 02:29 MisterD wrote: that was stargate btw ;P in star trek you go back in time through arbitrary wormholes. The loop-around-the-sun-wormhole-time travel is stargate. </scifinerd> Nope, the save the whales movie. | ||
|
Lunchador
United States776 Posts
| ||
| ||
