Did a Comet Hit Cause an Explosion on the Sun?

by Nancy Atkinson on October 3, 2011

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This amazing video from the SOHO mission (Solar and Heliospheric Observatory) shows a sun-diving comet hitting the solar surface on October 1, 2011 and unexpectedly a huge explosion occurs shortly after. Are the two events related? Probably not, but solar scientists don’t know for sure. The region where the CME originated was on the opposite side of the Sun from the comet hit, so that is very great distance. Scientists say there is no known mechanism for comets to trigger a CME.

SpaceWeather.com reports that before 2011 most solar physicists would have discounted these two events as being related, but earlier this year, the Solar Dynamics Observatory (SDO) watched another sungrazer comet disintegrate in the Sun’s atmosphere, and it appeared to interact with plasma and magnetic fields in its surroundings as it fell apart. Could a puny comet cause a magnetic instability that might propagate and blossom into a impressive CME? Most likely this is just a coincidence, but this is definitely an event in which solar scientists are taking a closer look. The comet, named SOHO-2143, was just discovered on Sept. 30 by an amateur astronomer.

See below for SDO’s look at two solar flares which also occurred on October 1, showing how events on the Sun can be related.

The two solar flares erupted within a very short period of time, and originated from two active regions, the super-huge 1302 region, and the newer 1305. From SDO, scientists have learned that certain events are connected with each other – in this case active regions far apart can be linked together by magnetic fields and can erupt one after another. Called “entangled eruptions,” these two active regions far apart but linked by magnetic fields can explode one after another, with disturbances spreading around the stellar surface domino-style. This appears to be the latest example.

The part of the eruption centered on sunspot 1305 hurled a coronal mass ejection toward Earth. The relatively slow-moving (500 km/s) cloud is expected to reach our planet on Oct. 4th or 5th, possibly causing geomagnetic storms when it arrives. High-latitude sky watchers should be alert for auroras

In this second video segment you can also observe the October 1, 2011 eclipse – where Earth is moving in between the SDO spacecraft and the Sun for over 40 minutes.

Hat tip: John Rowlands

Sources: SpaceWeather.com, SOHO, SunGrazing comet Twitter feed.

About 

Nancy Atkinson is Universe Today's Senior Editor. She also works with Astronomy Cast, and is a NASA/JPL Solar System Ambassador.

Anonymous October 3, 2011 at 9:03 PM

Is this simply a fascinating coincidence or an indication that Sol has a hair trigger.. sometimes?

Torbjörn Larsson October 3, 2011 at 11:24 PM

Since we look for correlations we will find some, whether they are coincidences or causal. To test for causality, you would have to look for a parameter variation resulting in some other observational variation.

(For example, say you and your neighbor get your salary about the same dates. But if you go down to half time and gets half pay, you can be certain your work results in your pay and this is not simply a date correlation. =D)

Anonymous October 4, 2011 at 12:01 PM

This news should have the EU/PC crowd “humming”!

Anonymous October 4, 2011 at 5:17 PM

Hmmmmmmmm…

The SDO *.sat has seen some interesting evidence for magnetic connectivity between widely disparate sun spot groups. Injecting a plasma in the form of a vaporized cometary or asteroid mass MAY vibrate that ‘antenna’ and provide a mechanism for ‘pulling the trigger’ on a CME ejection?

Ray Fowler October 3, 2011 at 11:06 PM

You can’t tell whether the comet actually collided with the Sun. It may have simply passed close by and vaporized from the intense heat as it was blocked by the filter.

This would not be a CME, but simply the destroyed remnants of the comet.

Symbol October 3, 2011 at 11:39 PM

That would be be a huge coincidence. But, of coarse possible.

eddie October 4, 2011 at 1:53 AM

Ok…that´s enough proof for me…so now the bright scientist (and all of you nonbelievers) will need to crash anything from an asteroid driven from the belt to an atomic bomb to BELIEVE it takes nothing more than a “small” rock to ignite the sun…

Rob Goebel October 4, 2011 at 2:21 AM

take abullet of ice and shoot it into a plasma of hydrogen and iron at 60 thousand miles an hr and watch the boom. the reveberations from the impact would be like a car hitting water at high speed the shock wave infront of it would be pushed out the other end. but with a much larger effect. just imagine an entire large comet hitting the sun would produce. We need to look again at the schumacher -levy impacts to the effects on the far side of that planet and see if there was a shock wave that emminated from it.

Anonymous October 4, 2011 at 10:47 AM

Well, taking the size of an entire large comet and compare it to the sun….. I wouldn’t expect such an effect.

Btw: The results of the Schumacher-Levy 9 impact on Jupiter were well covered (e.g. with HST), but the signs of the impact vanished very fast. You will not see any residual markings on Jupiter today.

Bilal October 4, 2011 at 3:14 AM

I saw this events many times before on SOHO movies. A comet or piece of it hits the sun from a side and then an expolsion occurs afterward on the other side of the sun. I think its more than coincidence.

Bilal

ozonator October 4, 2011 at 3:53 AM

Unless the comet had Star Trek shielding, it did not hit. Since telescopes have yet to find a gold (Au) residue, comets and meteors did not bring additional gold to the early Earth. I am on record (google search) for correctly predicting CMEs and other solar event from our AGW. For the comet to cause a CME, it must meet some very specific conditions to be beyond random.

Torbjörn Larsson October 4, 2011 at 11:39 AM

Since telescopes have yet to find a gold (Au) residue, comets and meteors did not bring additional gold to the early Earth.

That came out of the left field, it seems to me.

Presumably you are referring to this recent research:

“Chondritic meteorites don’t have much tungsten-182 compared with the Earth’s mantle, so a veneer of primitive meteorites mixed into the mantle over geologic timescales could have diluted the younger rocks. The amount of incoming material needed to explain the tungsten discrepancy — about 0.5 percent of the Earth’s mass — would also bring enough metals like silver and platinum to the planet to account for the quantities observed today, says Willbold.”

The mistake is in believing that spectroscopic evidence is all we have. Pieces of chondrites, ancient and newly impacted, has been collected here, on the Moon and with diverse sampling missions like Stardust. (Sometimes very small pieces, but large enough for analysis.) Their spectrographic behavior and inferred orbital parameters have been compared with asteroids and in many cases been matched AFAIK.

So that is how we know, according to the hypothesis, that these bodies contain the necessary amount to make up for the early siderophile lack. (I’ll have to refer to google or some astronomical textbook for references, that is a lot of work described shortly.)

They likely also provided a hefty amount of volatiles like water, which for isotopic reasons can’t all come from comets but I think is well matched to inner system bodies. In any case it shouldn’t be much surplus if we make a rough and dirty assumption of volatile content in the planetoids that made Earth, and there are earlier zircon samples that tells of a hefty water supply @ ~ 4.4 Ga bp. (This bombardment is believed to have a tail with a peak ~ 4.1 – 3.8 Ga bp, IIRC.)

However, as the article says there are other explanations for the anomalies. One that I think fits is (perhaps rapid) crust formation. That would have drained the later crust reservoir as it collapsed with the Earth-Moon large impactor. That happened @ ~ 4.5 Ga bp traditionally which can only be predicted by rapid crust formation. Or @ ~ 4.36 Ga bp in a new scenario which allows for traditionally slow formation as the constraint becomes the ~ 4.4 Ga water supply.

This side issue doesn’t really impact the mechanism behind what we see here, if it isn’t a coincidence. For example, Fowler’s hypothesis is certainly the next simplest and have to be shelved too before we come to CME mechanisms.

CMEs are caused by magnetic reconnections though, and those can be like mouse trap setups, a small trigger cause a large reaction. The mere presence of ionizable material can change plasma and magnetic field characteristics. So it is certainly useful to hypothesize in this direction if simpler predictions are invalid.

Anonymous October 4, 2011 at 9:40 PM

Nancy, you said “Late addition: this video below also includes a close-up view from SDO of the comet’s path across and into the Sun:” but as the caption in the video says, that is actually the comet recorded in July.

Anonymous October 4, 2011 at 10:14 PM

I didn’t watch that very well, did I? Thanks for setting me straight. I’ve removed the video because the relevant part is the same as the top video.

Anonymous October 5, 2011 at 3:50 PM

Went into the STEREO mission webpage, found the contact and wrote a question asking if the STEREO spacecraft had witnessed this event? When would the data be released? But there was no need for an RSVP after the APOD image for 10.05.11 was posted…. a ‘HOT’ topic indeed! AND a good answer to the question. Yes, it was coincidence!

Anonymous October 14, 2011 at 3:39 AM

Why is part of the video missing? Looks like about 7 hours?

Anonymous October 14, 2011 at 3:39 AM

Why is part of the video missing? Looks like about 7 hours?

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