Comet Lovejoy plunges into the sun and survives (w/ video)

Dec 19, 2011 By Dr. Tony Phillips
This coronagraph image from the Solar and Heliospheric Observatory shows Comet Lovejoy receding from the sun after its close encounter. The horizontal lines through the comet's nucleus are digital artifacts caused by saturation of the detector; Lovejoy is that bright!

Last week, an armada of spacecraft witnessed something that many experts thought impossible.  Comet Lovejoy flew through the hot atmosphere of the sun and emerged intact.

"It's absolutely astounding," says Karl Battams of the Naval Research Lab in Washington DC.  "I did not think the comet's icy core was big enough to survive plunging through the several million degree solar corona for close to an hour, but Comet Lovejoy is still with us."

The comet's close encounter was recorded by at least five spacecraft: NASA's Solar Dynamics Observatory and twin STEREO probes, Europe's Proba2 microsatellite, and the ESA/NASA Solar and Heliospheric Observatory.  The most dramatic footage so far comes from SDO, which saw the comet go in and then come back out again.

This video is not supported by your browser at this time.
Entrance movie: NASA's Solar Dynamics Observatory caught Comet Lovejoy emerging from its scorching close encounter with the sun.

In the SDO movies, the comet's tail wriggles wildly as the comet plunges through the sun's hot atmosphere only 120,000 km above the stellar surface. This could be a sign that the comet was buffeted by plasma waves coursing through the corona.  Or perhaps the tail was bouncing back and forth off great magnetic loops known to permeate the sun's atmosphere.  No one knows.

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Exit movie

"This is all new," says Battams.  "SDO is giving us our first look1 at comets travelling through the sun's atmosphere. How the two interact is cutting-edge research." 

“The motions of the comet material in the ’s magnetic  field are just fascinating,” adds SDO project scientist Dean Pesnell of the Goddard Space Flight Center.   “The abrupt changes in direction reminded me of how the solar wind affected the tail of Comet Encke in 2007.”

Comet Lovejoy was discovered on Dec. 2, 2011, by amateur astronomer Terry Lovejoy of Australia.  Researchers quickly realized that the new find was a member of the Kreutz family of sungrazing comets.  Named after the German astronomer Heinrich Kreutz, who first studied them, Kreutz sungrazers are fragments of a single giant comet that broke apart back in the 12th century (probably the Great Comet of 1106).  Kreutz sungrazers are typically small (~10 meters wide) and numerous. The Solar and Heliospheric Observatory sees one falling into the sun every few days.

At the time of discovery, Comet Lovejoy appeared to be at least ten times larger than the usual Kreutz sungrazer, somewhere in the in the 100 to 200 meter range.  In light of today's events, researchers are revising those numbers upward.

"I'd guess the comet's core must have been at least 500 meters in diameter; otherwise it couldn't have survived so much solar heating," says Matthew Knight. "A significant fraction of that mass would have been lost during the encounter. What's left is  probably much smaller than the original comet."

SOHO and NASA's twin STEREO probes are monitoring the comet as it recedes from the sun. It is still very bright and should remain in range of the spacecrafts' cameras for several days to come. Researchers will be watching closely, because there a good chance for more surprises.

"There is still a possibility that Comet Lovejoy will start to fragment," continues Battams. "It’s been through a tremendously traumatic event; structurally, it could be extremely weak. On the other hand, it could hold itself together and disappear back into the recesses of the solar system."

"It's hard to say," agrees Knight.  "There has been so little work on what happens to sungrazing comets after perihelion (closest approach).  This continues to be fascinating.”

Explore further: Earth survived near-miss from 2012 solar storm: NASA

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User comments : 16

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omatumr
Dec 19, 2011
This comment has been removed by a moderator.
omatumr
1 / 5 (8) Dec 19, 2011
Sorry about the broken link

www.omatumr.com/O...eads.htm
yyz
5 / 5 (5) Dec 19, 2011
A video put together by Scott Wiessinger from Goddard Spaceflight Center combines and zooms in on the best views from the Solar Dynamics Observatory (SDO): http://www.youtub...embedded

These images were taken at a wavelength of 171 Angstroms btw.
SteveL
5 / 5 (2) Dec 19, 2011
vvz - thanks for the link.

That kick in the vapor trail as it exits - is that caused by passing through electromagnetic lines?
Pirouette
1.8 / 5 (5) Dec 19, 2011
"There is still a possibility that Comet Lovejoy will start to fragment," continues Battams. "Its been through a tremendously traumatic event; structurally, it could be extremely weak. On the other hand, it could hold itself together and disappear back into the recesses of the solar system."
I really like the pictures and videos

I still think that the comet's core was a very small rock,, covered with layer upon layer of very hard ice that it had accumulated traveling through outer space. A small core would have made it less heavy than if it had a large rocky or metallic core which might not have accumulated much more ice. Much heavier amount of ice on a small core plus the speed at which it was going could have protected the comet core inside from also melting from the heat of the Sun.
Did anyone determine the size of the comet's core below all the ice? Most likely not.
JustAnyone
3 / 5 (6) Dec 19, 2011
FYI: user omatumr has frequently been cited on these forums as a troll.
Pirouette
2.1 / 5 (9) Dec 19, 2011
Lots of trolls in this site. . . .some of them don't like for members to give their opinions, whether scientific or not scientific, and will track them down and verbally assault them with name calling like dimwit, retard, etc.
But I do like the topic here. . . .comets are fun.
aroc91
4 / 5 (4) Dec 19, 2011
FYI: user omatumr has frequently been cited on these forums as a troll.


I like the part where you implied there are people here that haven't known that for months and even years.
MarkyMark
3.7 / 5 (3) Dec 20, 2011
Lots of trolls in this site. . . .some of them don't like for members to give their opinions, whether scientific or not scientific, and will track them down and verbally assault them with name calling like dimwit, retard, etc.
But I do like the topic here. . . .comets are fun.
Sorry have to point out that you too have been known to troll and spam this site. Remember the topic concerning certain markings in Israil that you thought came from metal forging?
Egnite
5 / 5 (3) Dec 20, 2011
FYI: user omatumr has frequently been cited on these forums as a troll.


A prime example of trolling lol. Its funny to watch adults resort to childlike tactics of name calling when they fail to reach an agreement in opinions. Here's a tip for future attempted insults, learn the definition of a word and ensure it fits in with your intended use. Oliver may be a spammer at times but I've never witnessed him trolling, unlike many on here.
yyz
not rated yet Dec 21, 2011
Cool video of Comet Lovejoy rising over Western Australia on the morning of the 21st has been posted: http://vimeo.com/34007626

A close look reveals two tails (one dust, one gas) have reformed since the comet's recent encounter with the sun. The comet resembles a somewhat fainter version of sungrazing Comet Ikeya-Seki back in 1965 and should put on a good show in the morning twilight (from the southern hemisphere, that is).

Comet Ikeya-Seki: http://en.wikiped...eya-Seki
omatumr
1 / 5 (4) Dec 22, 2011
A video combines and zooms in on the best views from the Solar Dynamics Observatory (SDO):

http://www.youtub...embedded

These images were taken at a wavelength of 171 Angstroms.


Thanks for the links! Fe (iron) is abundant in both objects.

The Solar Trace satellite also used a 171 Angstrom filter sensitive to Fe (IX) and Fe (X) emissions in order to see images of rigid, Fe(iron)-rich structures beneath the Sun's fluid photosphere.

This TRACE video of solar eruptions from rigid, iron-rich structures:

http://vestige.lm...0828.avi

Was published in two peer-reviewed papers [Fig. 1, Physics Atomic Nuclei 69, 1847-1856 (2006); Fig 15, AIP Conference Proceedings, volume 822, 206-225 (2006] before disappearing

http://arxiv.org/...9509.pdf

http://xxx.lanl.g...0001.pdf

Fe (iron) is abundant in the Sun and in the comet.
omatumr
1 / 5 (4) Dec 22, 2011
Perhaps the Fe-rich comet observed leaving the Sun is like a secondary electron observed leaving water vapor after colliding with a fast electron.

http://jcp.aip.or...rized=no
barakn
2.8 / 5 (5) Dec 22, 2011
The Solar Trace satellite also used a 171 Angstrom filter sensitive to Fe (IX) and Fe (X) emissions in order to see images of rigid, Fe(iron)-rich structures beneath the Sun's fluid photosphere.
Since Fe IX and X are heavily ionized versions of iron, they indicate regions of million-degree plasma, not solid iron. If you've seen rigid structures at these wavelengths, you've been hallucinating.
omatumr
1 / 5 (4) Dec 23, 2011
rigid, Fe(iron)-rich structures beneath the Sun's fluid photosphere


Rigid is not necessarily solid., as you must know.

The enormous magnetic field of the Sun's pulsar core may hold iron in rigid form above the melting temperature.

You can see the rigid images yourself if you look at the figures.

If you still work for NASA, you might also ask why the TRACE videos were deleted.
barakn
3 / 5 (4) Dec 23, 2011
My point about Fe IX and X was apparently lost on you. They don't mark the location of a magnetized ferrofluid anymore than they do solid iron. This is iron that has lost 8 or 9 electrons, and it not only takes a lot of energy (and therefore an extremely hot environment) to get it to that state, but it can't be in a solid or fluid state as it would rapidly quench by stealing electrons from neighbors.

I never worked for NASA. If I had to guess, I'd say they removed the movies because TRACE has been officially retired. They gave you about a decade to download the movie in question (or order the DVDs). Luckily for you I have found another source: http://soi.stanfo...0828.avi If there is a conspiracy, Stanford is not in on it.
omatumr
1 / 5 (3) Dec 24, 2011
1. My point about Fe IX and X was apparently lost on you.

2. Luckily for you I have found another source: http://soi.stanfo...0828.avi



1. Not at all. Iron (Fe) is iron atoms. Light emitted from ionized Fe IX and X does not indicate if the iron is gas, fluid or rigid.

2. The video from Stanford (thanks!) records an observation. The observation shows rigid, iron-rich structures beneath the Sun's fluid photosphere.

3. Please address the observation.

a.) Does it tell you anything new?

b.) Is it consistent with the Standard Solar Model?

c.) Does it agree with other models?

www.omatumr.com/a...2002.pdf

www.omatumr.com/a...dity.pdf