Comet survives pass through solar corona

[popeyespappy]

Comet Lovejoy spent nearly an hour in the solar atmosphere experiencing temperatures that reached into the millions of degrees. The comet was discovered by an amateur astronomer just a couple of weeks ago. On Friday it passed within a 120,000 km of the surface of the sun and lived to tell the tale. The encounter was captured by several space based instruments including NASA’s Solar Dynamics Observatory and twin STEREO probes, Europe's Proba2 microsatellite, and the ESA/NASA Solar and Heliospheric Observatory. There is video of the encounter on the link below.

http://science.nasa.gov/science-news/sci...etlovejoy/

There is also a link to a story with some pretty cool video of Comet Encke being hit by a coronal mass ejection in 2007.

http://science.nasa.gov/science-news/sci...oct_encke/

[Welsh cake]

Which is frightening in that, if it could survive such extreme temperatures, were a comet to collide with us, the Earth-Moon system as we know it would cease to be.

[Moros Synackaon]

I wonder why no one considered the possibility of the comet altering it's orbital heading due to the sudden ablation of it's outer layers from intense heating...

[orogenicman]

Australian observers are reporting that it has not only regained it's stripped tail, but that the comet overall is brightening very quickly. It's already viewable with binoculars in the southern Hemisphere, and some expect it could become a naked eye object very soon.

[Chuck]

(19th December 2011 00:22)Welsh cake Wrote:  Which is frightening in that, if it could survive such extreme temperatures, were a comet to collide with us, the Earth-Moon system as we know it would cease to be.

Actually, the millions degree solar Corona in which lovejoy passed is so tenuous that it is practically a vacuum. While each atom in it might zip around with such kinetic energy as to make the thing millions of degrees, there are so few atoms per cubit meter that it could actually impart very little total molecular kinetic energy, ie heat, to any solid objects inside it.

The main source of heating to the comet would have come from the radiation from the sun's surface, not radiative or contact heating from solar corona. So thousands of degrees, not millions.

Also, the core of lovejob is an dirty iceball about 500 meters across. It's a speck next to the 6 mile wide chixalube impactor that killed the donosaurs. As to it's destructive power should it hit the earth moon system, it's enough to ruin the day of anyone living within a few hundred miles, but it won't make any craters visible from the moon.

[theotherone]

Its impressive, its the first time I heard of any comet approaching so close to the sun and surviving the encounter. But I did know that the corona is extremely tenuous, if also very hot. It does seem reasonable that an object above a certain mass would survive. I learned something new today, thanks ^^_

[Blam!]

To think the comet survived through the extreme temperatures of our star, wow.

(19th December 2011 20:50)Moros Synackaon Wrote:  I wonder why no one considered the possibility of the comet altering it's orbital heading due to the sudden ablation of it's outer layers from intense heating...

Perhaps because the scientists don't have enough content [mass, speed and density of the comet] to confirm the possibility orbital alteration of that comet? Scientists should add the content if there is one.

[downbeatplumb]

(20th December 2011 04:39)orogenicman Wrote:  Australian observers are reporting that it has not only regained it's stripped tail, but that the comet overall is brightening very quickly. It's already viewable with binoculars in the southern Hemisphere, and some expect it could become a naked eye object very soon.

Oh I love those comets, wasnt there a couple of those at the turn of the century?

[KichigaiNeko]

A comet to watch no doubt.

[orogenicman]

(21st December 2011 11:20)downbeatplumb Wrote:  

(20th December 2011 04:39)orogenicman Wrote:  Australian observers are reporting that it has not only regained it's stripped tail, but that the comet overall is brightening very quickly. It's already viewable with binoculars in the southern Hemisphere, and some expect it could become a naked eye object very soon.

Oh I love those comets, wasnt there a couple of those at the turn of the century?

There have been a number of rather spectacular comets in the last 15 years. The brightest, and coolest one I saw during that time was Comet Hyakutake. It was spectacular:



It was orders of magnitude more spectacular than Halley's Comet.

But the barn buster of barn busters of recent comets was Comet p1 McNaught in 2007, which was first spotted in the northern hemisphere, and was a bit unremarkable at the time. But when it got into the southern hemisphere (as seen in Australia), it really lit up:



It was the brightest comet of the last 40 years, was visible in the day time, and holds the record for the largest effect on its surrounding space, as can be seen in the above photograph. Talk about a rock with flatulence!