NASA’s Solar Terrestrial Relations Observatory, or STEREO, is monitoring Comet ISON as it approaches the sun. NASA’s twin Solar Terrestrial Relations Observatory (STEREO) spacecraft are parked in Langrange zones, known as the L4 and L5 Lagrangian points, each centered about 93 million miles away along Earth’s orbit.
The latest movie from the STEREO-A spacecraft’s Heliospheric Imager shows the comet moving in from the left side over a two-day period from Nov. 20 to Nov. 22, 2013.
In addition to Earth and Mercury, Comet Encke can also be seen moving through the middle of the view. The sun sits outside the field of view of this camera, located to the right, off-screen, hinted at by the steady stream of particles, called the solar wind, moving in from the right. Watch.
In addition NASA’s Messenger spacecraft snapped new images of Comet ISON on Nov. 19 as the icy object sped by Mercury at a distance of 22.5 million miles. Meanwhile, the agency’s sun-studying Stereo-A probe captured its own ISON photo on Nov. 21, and a phalanx of other solar space observatories will watch the comet’s close encounter with the sun on Thursday, which will bring it within just 730,000 miles of the solar surface.
Will it be toast? We’ll find out soon enough.
If this comet passes the sun how hot will it be?
Will it give off Photons?
It is in a vacume so should stay”hot” for time.
Comets are made of ice, rocks and dust. The ice melts and vaporizes as it gets close to the Sun, which forms the tail, pushed away from the Sun by the solar wind. Yes it will get hot, perhaps hot enough to glow on its own (“red hot” = 500C-1000C). But all you will see is the reflected light from the Sun. Yes, it’s in a vacuum, but the rocks can cool off by radiating the heat. So it will cool off as it returns to deep space, if it doesn’t get completely ripped to shreds by the Sun.
Impressive video Anthony; totally impressed with the way they can bring these images to us now.
As a side note: Was sitting here last evening, about 8 pm our time – checking out ISON’s progress on WUWT as our first major snow storm of the year started when suddenly the sky lit up like it was day time. A small meteor? I know that sometimes we can have lightening and thunder during winter storms, I’ve seen it before but this was different. We live off the beaten path between Montreal and Ottawa, and have an almost panoramic view so consequently have no window coverings as it’s all natural vistas for us – lit the (n)eastern side of the sky up and it pulsed a couple quick flashes! We didn’t hear a sound as those to the east of us reported; but we did have heavy cloud cover that was messing with the 2 sat feeds that we use. One of these are still down, wondering now if it’s not that latest solar belch. http://www.solen.info/solar/
The identification of Mercury is correct. The source of the confusion is the assertion that the STEREO satellites are at Lagrangian points. They are not. See the information at http://stereo-ssc.nascom.nasa.gov/where.shtml to see how the observed geometry arises.
Are we dealing with obtuse semantics here?
One of your cited sources reference even states the following:
Notice the terminology in bold above: “constant-shape pattern“?
What does that suggest to you?
.
Bill B says:
November 26, 2013 at 5:08 pm
“When I watch the video, it looks like the comet’s tail is waving upand down. Wht would cause that.”
Coronal Mass Ejection, ie solar particle with mass ejected from the sun. Go to http://www.skyandtelescope.com/observing/highlights/193909261.html click on A frame from STEREO-A with comets ISON (lower left) Encke (near center). Click for movie.
Karl Battams / NRL / NASA-CIOC.
@_Jim
> Notice the terminology in bold above: “constant-shape pattern“?
> What does that suggest to you?
It suggests that you should first determine, theoretically, whether the Lagrange points are stable. Turns out the L1,L2,L3 are unstable, but the L4,L5 are stable.
So, _theoretically_, STEREO A and B could have been inserted into stable orbits around L4 and L5.
But, in actuality, when these birds flew by L4 and L5 in 2009, NASA _did not_ insert them into these orbits. The plan was to let them ride on (in near Earth orbits) to take a peek at the other side of the Sun. So that’s where they are now, roughly 120 degrees from Earth. The L4 and L5 are about 60 degrees from Earth.
BTW, you know what the “other side” of the Sun looks like, don’t you? It’s the ‘dark side’ where it’s safe to land at night. /sarc
😐
Suggest you ‘wire’ NASA and perhaps ‘suggest’ a re-wording of their info page on this subject; I am only floating a few questions in light of conflicting info being posted (perhaps on both sides?) You might be confusing me with an ‘expert’ from NASA who has intimate knowledge of orbital mechanics, and I assure you I am not. I am, rather, assuming the role of ‘the trier of facts*’ here.
.
.
*Trier of fact – A trier of fact is a person, or group of persons, who determines facts in a legal proceeding, usually a trial. To determine a fact is to decide, from the evidence, whether something existed or some event occurred.
.
Its little slow getting into SOHO’s webpage, but Phil Plait (who is better at astronomy than he is with global warming) has put up a nice image here. More recent than other images and it shows the true size of the Sun.
http://www.slate.com/content/dam/slate/blogs/bad_astronomy/2013/11/01/soho_ison_nov27_1645UTC.jpg.CROP.original-original.jpg
John Day says:
November 27, 2013 at 9:39 am
BTW, you know what the “other side” of the Sun looks like, don’t you? It’s the ‘dark side’ where it’s safe to land at night.
… and I thought I saw the other side of the sun a couple of weeks ago. 🙂
@_Jim
>Suggest you ‘wire’ NASA and perhaps ‘suggest’ a re-wording of their info page
Why don’t you notify them? I have no problem with their page. It is factually correct. Perhaps some folks failed to note the date at the top of the page, and assumed that the STEREO birds were still approaching the L4, L5 points.
So that’s ancient history (from 2009) to me.
😐
@Billy Liar
>… and I thought I saw the other side of the sun a couple of weeks ago. 🙂
That must have been a fig-newton of your imagination. 😐
Better someone familiar with the history and background on this subject (like yourself) rather than me (only an interested onlooker and ‘trier of facts’; speaking of which, few I have seen from your side of the argument). This should be a slam-dunk for someone a) in possession of the facts and b) with your acumen, unless, of course, there are serious shortcomings of either of those two points.
If you find no issue with their info/webpage, you have only been arguing with yourself …
.
@_Jim
>If you find no issue with their info/webpage,
> you have only been arguing with yourself …
Actually I was arguing with you. So you still have not grasped that it was _your_ interpretation of the facts vs dates that was at fault, not mine or the NASA page.
Using only basic reading comprehension, it is very clear that the STEREO spacecraft never were parked at the Lagrange points. It is rather alrming to me that this has still not been corrected, especially since the title of the post commits the same error. Makes me wonder about the accuracy of other posts around here.
It suggests that neither STEREO A or B are anywhere near L4 or L5 and you are not paying attention. Those Lagrange points are always on the Earth side of the sun and both STEREO orbiters are on the other side of the sun at present. It is because neither craft are anchored to a Lagrange point that they suffer communications blackouts as they travel behind the sun as seen from Earth and out of line-of-site communication. http://stereo-ssc.nascom.nasa.gov/where/behind_sun.shtml
The L4 and L5 points follow the Earth’s orbit ahead and behind at specific distances and angles from Earth relative to the sun – they don’t move independently of Earth. The satellites do, though.
This must be what they mean by rocket science.
@Brian
>Makes me wonder about the accuracy of other posts around here.
I wouldn’t worry, Anthony usually fixes these bloopers in a jiffy. Don’t know why this one is taking so long, but “dp” caught first the error in about an hour after it was posted. So very unlikely that a big glitch like this would persist very long without being caught by us, the readers of this blog.
😐
_Jim, I think, missed this paragraph from the STEREO website in discussing the Lagrange points:
And pass on through they did.
Thank you John Day.
I had just thought that this comet being close to the sun ,
would heat up quite a lot to say 4000k (warm white).
By the way the video of the comet gives wrong information about the Earth/ Moon , orbit.
The moon does not have a retro-grade orbit.