NASA Answers Your Questions About Comet Elenin


Lord knows, we’ve tried. We’ve featured a couple of articles about Comet Elenin to try and answer questions and allay any fears about this comet; how it will just pass by Earth — harmlessly at 35 million km (22 million miles) at its closest approach — and an FAQ showing how much of the “information” being dished out by breathless scaremongers of how the comet will hit Earth, or cause Earthquakes and floods, or block out the Sun, and the dangers are being covered up by the government is just plain rubbish. But the questions and panic keep coming to our inboxes and in the comments sections of our articles. Scientists at NASA have been bombarded with questions as well, so they have now put together a list of the most asked questions they’ve received, with various scientists answering the questions. Bottom line: Comet Elenin poses no threat to Earth.

Before the questions, just a little info about Comet Elenin, also known by its astronomical name C/2010 X1. The comet was first detected on Dec. 10, 2010 by Leonid Elenin, an observer in Lyubertsy, Russia, who made the discovery “remotely” using an observatory in New Mexico. At that time, Elenin was about 401 million miles (647 million kilometers) from Earth. Since its discovery, Comet Elenin has – as all comets do – closed the distance to Earth’s vicinity as it makes its way closer to perihelion, its closest point to the Sun.

Compiled below are the some of the most-asked questions, with answers from Don Yeomans of NASA’s Near-Earth Object Program Office at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., and David Morrison of the NASA Astrobiology Institute at the NASA Ames Research Center in Moffett Field, Calif.

When will Comet Elenin come closest to the Earth and appear the brightest?

Comet Elenin should be at its brightest shortly before the time of its closest approach to Earth on Oct. 16, 2011. At its closest point, it will be 22 million miles (35 million kilometers) from us.

Will Comet Elenin come close to the Earth or between the Earth and the moon?

Comet Elenin will not come closer to Earth than 22 million miles (35 million kilometers). That’s more than 90 times the distance to the moon.

Trajectory of comet Elenin. Image credit: NASA/JPL-Caltech

Can this comet influence us from where it is, or where it will be in the future? Can this celestial object cause shifting of the tides or even tectonic plates here on Earth?

There have been incorrect speculations on the Internet that alignments of comet Elenin with other celestial bodies could cause consequences for Earth and external forces could cause comet Elenin to come closer. “Any approximate alignments of comet Elenin with other celestial bodies are meaningless, and the comet will not encounter any dark bodies that could perturb its orbit, nor will it influence us in any way here on Earth,” said Don Yeomans, a scientist at NASA JPL.

“Comet Elenin will not only be far away, it is also on the small side for comets,” said Yeomans. “And comets are not the most densely-packed objects out there. They usually have the density of something akin to loosely packed icy dirt.

“So you’ve got a modest-sized icy dirtball that is getting no closer than 35 million kilometers [about 22 million miles),” said Yeomans. “It will have an immeasurably miniscule influence on our planet. By comparison, my subcompact automobile exerts a greater influence on the ocean’s tides than comet Elenin ever will.”

I’ve heard about three days of darkness because of Comet Elenin. Will Elenin block out the sun for three days?

“As seen from the Earth, comet Elenin will not cross the sun’s face,” says Yeomans.

But even if it could cross the sun, which it can’t, astrobiologist David Morrison notes that comet Elenin is about 2-3 miles (3-5 kilometers) wide, while the sun is roughly 865,000 miles (1,392,082 kilometers) across. How could such a small object block the sun, which is such a large object?

Let’s think about an eclipse of the sun, which happens when the moon appears between the Earth and the sun. The moon is about 2,500 miles (4,000 kilometers) in diameter, and has the same apparent size as the sun when it is about 250,000 miles (400,000 kilometers) away — roughly 100 times its own diameter. For a comet with a diameter of about 2-3 miles (3-5 kilometers) to cover the sun it would have to be within 250 miles (400 kilometers), roughly the orbital altitude of the International Space Station. However, as stated above, this comet will come no closer to Earth than 22 million miles.

I’ve heard there is a “brown dwarf” theory about Comet Elenin. Would its mass be enough to pull Comet Honda’s trajectory a significant amount? Could this be used to determine the mass of Elenin?

Morrison says that there is no ‘brown dwarf theory’ of this comet. “A comet is nothing like a brown dwarf. You are correct that the way astronomers measure the mass of one object is by its gravitational effect on another, but comets are far too small to have a measureable influence on anything.”

If we had a black or brown dwarf in our outer solar system, I guess no one could see it, right?

“No, that’s not correct,” says Morrison. “If we had a brown dwarf star in the outer solar system, we could see it, detect its infrared energy and measure its perturbing effect on other objects. There is no brown dwarf in the solar system, otherwise we would have detected it. And there is no such thing as a black dwarf.”

Will Comet Elenin be visible to the naked eye when it’s closer to us? I missed Hale-Bopp’s passing, so I want to know if we’ll actually be able to see something in the sky when Elenin passes.

We don’t know yet if Comet Elenin will be visible to the naked eye. Morrison says, “At the rate it is going, seeing the comet at its best in early October will require binoculars and a very dark sky. Unfortunately, Elenin is no substitute for seeing comet Hale-Bopp, which was the brightest comet of the past several decades.”

“This comet may not put on a great show. Just as certainly, it will not cause any disruptions here on Earth. But, there is a cause to marvel,” said Yeomans. “This intrepid little traveler will offer astronomers a chance to study a relatively young comet that came here from well beyond our solar system’s planetary region. After a short while, it will be headed back out again, and we will not see or hear from Elenin for thousands of years. That’s pretty cool.”

This comet has been called ‘wimpy’ by NASA scientists. Why?

“We’re talking about how a comet looks as it safely flies past us,” said Yeomans of NASA’s Near-Earth Object Program Office. “Some cometary visitors arriving from beyond the planetary region – like Hale-Bopp in 1997 — have really lit up the night sky where you can see them easily with the naked eye as they safely transit the inner-solar system. But Elenin is trending toward the other end of the spectrum. You’ll probably need a good pair of binoculars, clear skies and a dark, secluded location to see it even on its brightest night.”

Why aren’t you talking more about Comet Elenin? If these things are small and nothing to worry about, why has there been no public info on Comet Elenin?

Comet Elenin hasn’t received much press precisely because it is small and faint. Several new comets are discovered each year, and you don’t normally hear about them either. The truth is that Elenin has received much more attention than it deserves due to a variety of Internet postings that are untrue. The information NASA has on Elenin is readily available on the Internet. (See If this comet were any danger to anyone, you would certainly know about it. For more information, visit NASA’s AsteroidWatch site at

I’ve heard NASA has observed Elenin many times more than other comets. Is this true, and is NASA playing this comet down?

NASA regularly detects, tracks and characterizes asteroids and comets passing relatively close to Earth using both ground- and space-based telescopes. The Near-Earth Object Observations Program, commonly called “Spaceguard,” discovers these objects, characterizes a subset of them and predicts their paths to determine if any could be potentially hazardous to our planet. For more information, visit the NASA-JPL Near Earth objects site at .

However, neither NASA nor JPL is in the business of actively observing Elenin or any other comet. Most of the posted observations are made by amateur astronomers around the world. Since Elenin has had so much publicity, it naturally has attracted more observers.

I was looking at the orbital diagram of Comet Elenin on the JPL website, and I was wondering why the orbit shows some angles when zooming? If you pick any other comet, you can see that there are no angles or bends.

Many people are trying to plot the orbit of the comet with the routine on the JPL website, without realizing that this is just a simple visualization tool. While the tool has been recently improved to show smoother trajectories near the sun, it is not a scientific program to generate an accurate orbit. Yeomans explains that the orbit plotter on the Near-Earth Object website is not meant to accurately depict the true motion of objects over long time intervals, nor is it accurate during close planetary encounters. For more accurate long-term plotting, Yeomans suggests using the JPL Horizons system instead: .

Editor’s note: If you want to see some recent images taken from Earth of Comet Elenin, see Ian Musgrave’s Astroblog website and Mike Salway’s Ice in Space forum. The comet appears as just a fuzzy blob.

Here’s a video from David Morrison:

Source: JPL

38 Replies to “NASA Answers Your Questions About Comet Elenin”

  1. Well all i can say is i hope NASA and all the other companies around involved with NEO`s ect will start to learn from there mistake with ELENIN c/2010 x1. I know of ppl that have heard about elenin and have gone out panic buying due to all the scaremongery ect on the Net, Nasa should have said something B4 NOW. You have made the situation worse and worse by closing your buzzroom and denying all questions relating to this aspect which made the fear factor higher as alot of ppl took this into the fact there was a problem and the Goverment was stopping information coming out because of the risk factors involved with everything we can find on the internet via chat rooms / webpages and forums. Please learn from your mistakes and then as and when we do get anything that may cause anykind of fret towards earth that we know that you would come out and say like manny people beleive that the Goverment and sorounding bodies involved would have the public denied the truth.
    I would like to say thank you to all involved with placeing this Q /A above and finally putting peoples mind to rest.

    1. You hope NASA will learn from their mistake?

      The only mistake that has been made by anyone is the unsubstatiated confidence that countless gullible people have put into complete and total bollocks spouted by the relentless peddlers of pseudoscientific doomsday crap.

      My hope is not that NASA learns from their non-existent “mistake”, but that the gullible hordes realise they’ve been had and that they’ll treat future claims from unqualified doom-mongers with a little bit more skepticism.

      It’s not NASA’s responsibility to deny each and every individual apocolypse theory, alien “sighting”, and other assorted bollocks that people pick out of thin air.

    2. I don’t think it’s NASA’s fault at all – it’s the fault of fearmongering by idiots who are largely ignorant of basic science.

      I’m by no means a scientist myself, but for crying out loud – before stocking up on groceries or digging out a bomb shelter in their basements, people ought to just think about it calmly for a couple minutes. My hand is pretty good at blocking out the sun (though admittedly I can’t keep it up for three days) – that doesn’t mean we’re all going to die.

      Honestly! NASA shouldn’t have to waste its time by answering really really stupid questions. The fact that it did probably wasn’t even a public service – more of an OMFG kind of reaction so people would quit bugging them so they can get on with their actual work.

      1. U know what u guys are all right it isnt really nasa thats to blame its just all the crap u read and see everywhere and a lot of them say allsorts bout nasa`s responce in the fact they took there posts and buzzroom ect so ya i will stand corrected on that poin and i do apologisze towards nasa for the comment i was just sick and fed up with hearing so much rubbish out there and so many ppl saying nasa this and that bla bla bla.
        I respect nasa in every way and i use there sites quite alot including there tv service they provide.
        I think it was more the fact that there was atlast some real truthfull info being posted out there on the web taking over alll the dethbringers doomsdayers fearmonmgers ect.

        Respect to all of you for standing out and correcting my mistakes on this post.

      2. No offense meant there man – I just get a little incensed when crazy stuff like this pops up. And there is always a market for such craziness… I wish more people would read UT or Wikipedia before thinking the sky is literally falling. 😉

    3. How is this NASA’s fault Mr. Baker? Do you honestly think that NASA should spend their time debunking “internet scientists”? So we should all call NASA and petition them to create a department that scours the internet for Armageddon idiocy and hold press conferences to explain why this isn’t happening? It’s not NASA’s job to deal with idiots, or inform the public of their existence.

    4. NASA should not waste any time on debunking Elenin.
      Especially when any nut-job claim about Elenin is debunked by someone with half a brain.
      The only advice I would give NASA is replace that embarrassing bad java plugin with something more realistic.

    1. In the wake of the last article here on Elenin the doomster-conspiracy wackos showed up. The media in this country has become so riddled with paranoid delusional nonsense that it has framed a lot of commonly acceptable thinking these days. I also think comets tend to bring out some of this stuff as well.


      1. This reminds me of the American political discourse as of late. A quick background check on some of these candidates shows that most of them hold some pretty ideologically extreme views. Some of them, particularly Michele Bachmann, have constructed this pseudo-religious worldview that seems analogous to the EU/doomsday nonsense here.

        I find it difficult to believe that Americans who feel disenfranchised by Washington politics could seriously consider such candidates. This should be raising more alarm bells then it appears to be. Perhaps I am judging things prematurely and should expect the process of the preliminaries to weed out the non-moderates.

      2. UF,

        The facts as you have stated them are correct. The personages you have indicated as having pseudo-religious worldviews do seem to not agree with the consensual reality of me and thee. Their pseudo-religious worldviews do however agree with the larger part of the rigid right evangelicals such as we have been seeing for several decades hoping to achieve political offices and successive succeeding in greater numbers.

        If a public believes what it wishes and a leader captures those with that general set of wishes then that leader will be thrust up as the mass of that public gathers followers, and so on it goes.

        Freethinking is frowned upon by over 68% of the electorate whether right, left, authoritarian, or indeed, any portion of the political compass other than anarchically inclined individuals. Good luck herding those cats. There needs to be three axis to any political compass, Political (left to right) and Social (extreme authoritarian to extreme libertarian) are only two, add personal comfort level as the third, for isn’t it always a personal choice we make?

        If you wish to know more about RWA (Right Wing Authoritarianism) you can consult the best layman’s text currently available for free. Go to Robert Altemeyer’s site called The Authoritarians. There you can read the interpreted results of his decades long studies and some of his more recent thoughts.

        Any search will discover the site name and I choose to require those interested to expend that little effort in finding it. Your reward might be in the effort.


  2. If something DOES happen on one of the proposed dates, NASA will never be trusted again. -Catch 22

  3. Oh it’s bound to happen, I’m certain of it. On the date of Elenin’s closest approach, if there’s so much as a windy day anywhere on Earth, the conspiracy nutjobs will declare vindication.

    And everyone with a modicum of sense will keep pointing out that correlation doesn’t equal causation, but the nutjobs won’t be having any of it.

    1. Of course, when nothing horrible happens as a result of the comet all the nutjobs will just wander away, or point somewhere else, “but look at THAT!!”…abracadabra! Misdirection.

  4. Humm my comments have gone is there a reason for this? please could you inform me why

  5. oh and let me just say i never expect that question to be answered and no mad nutjob but seems strange to me that its not even mentioned

  6. don,t know if it wil be visable?surely if u know its path and size u wud know if its visable or not.

  7. If that is the case then what about the earthquakes and other natural calamities occurring in globe? and why all the countries were planning for D,U.M.B.S.

    1. Sure, because earthquakes and other natural disasters didn’t exist before this comet, right?

      Seriously? You’re not actually that ignorant, are you?

    2. @Bhagya Chandu,

      Deep Underground Military Bases existed before this moment and will continue to be designed, built and stocked well after everyone’s death (your’s and mine own for example).

      If you wish to ‘believe’ in the causality to global catastrophic damages of a tiny, insignificant comet’s chance alignment with other bodies observable in the sky, and to attribute to those alignments some deeply important earthly events then have at it.

      If on the other hand you grow a backbone and learn to think for yourself and make the effort yourself to do the calculations yourself, –do you get the keyword here, if not I will spell it out… below.

      y o u r s e l f

      You could then trust the data of your own eyes, and the facts revealed by your skills.


  8. Let’s all hope this is not going to hit. If anyone is down-playing or with-holding important information about this comet, then that will be their choice. If you are telling the truth then God Bless you for being honest and sincere with us. But if you are lying, that is so wrong! Not saying anyone is lying, just saying it’s extremely hard to trust anyone these days with all the corruption and deciet and demonish ways of this world. The media is intimidated and have to hold their tongues when broadcasting. Every word they say is extremely supervised and analyzed and changed until it is a fraction of the original thought of the story. I can only imagine what the media would say if they actually had their lost freedom to speak freely. Scary to think about is all I am saying. Think about this

    1. To NASA, you are all an incredible team of scientists, very intellegent. The technology you have is incredible, and I’m aware of this. But, I believe there are some things you are not sharing, just a thought, not saying for sure you are but this is crazy times with crazy people and a crazy government running a crazy world. God knows the truth only. I really can’t say whats going to happen but I believe in prophecy and science and they are related alot. Revelations- please just see and read the part about the something from the sky hitting us. You study, live and breath to understand and decipher and interpret the universe and space, you all are experts on it, please read the Bible and just see, so you can find out where this thing that is going to hit us is coming from, when, and where, how long, how big and how devestating to Earth? It is worth finding out about. I care about this Earth and the people, each and every one of them, the children, the babies, the women, the men, everyone, and I care for their safety too, just like you. So if anything at all is risking our safety, Please, I beg you, I plead tell us. Who cares what the BIG Government has to say about it, we need to know these things. Not saying Comet Elenin is going to do anything but is there anything else out there that is dangerous to us? And why aren’t yall going back to space? Why the shutdown all of the sudden? What did you find and see last time you went to space? There is still alot of questions, so that’s why I wonder why ya’ll aren’t going back to find more answers. Curiosity is keen. And I find it hard to believe yall’s curiosity is just gone all the sudden.

  9. yeah why isn,t elenin showing on neo web site?read that its not coming close to warrant a mention but nither was honda but that was tracked.little strange that a comet that is getting alot of press isn,t even getting a hit,explain plz.

  10. even if it was going to be a direct hit then there is no way they r going to tell us anyway,its enjoy the show and peace out .

  11. why elenin and why do ppl only caps ELEnin? does it mean Extinction Level Event ? pretty odd dont you think. . . . .my question is :is the trajectory of this elenin even close enough to worry, is the date still sep 26, 27th….

    1. @Jorge Soto,

      The name is from that person who first reported the discovery, detected on Dec. 10, 2010 by Leonid Elenin. People wishing to scare-monger have capped the first three letters much as you have seen.

      There is not a good reason to expect that fear and scare mongering to change anytime soon as this is a ‘joke’ which keeps giving and giving as your questions indicate.

      As to you question… the article to which you have posted this comment indicated the trajectory of Comet Elenin (aka C/2010 X1) to be a harmless 35 million km (22 million miles) at its closest approach on Oct. 16, 2011.

      The dates you mention of September 26th, 27th, of some unspecified year, refer to some event great fear-mongers would have you think is going to happen; as to what that is on that set of dates I would have no idea. There is no particle or grain of truth in most of what you have been exposed to re Comet Elenin (aka C/2010 X1) on the sites which fear and scare monger.


      1. no scare mongerer but explain then why on the near earth project website it doesn,t even get a mention,i,ve asked this question half a dozen times and no1 has given me an answer.

      2. oh and plz don,t give me its not deemed close enough to warrant that cause theres objects getting tracked that are further away than elenin

  12. why elenin and why do ppl only caps ELEnin? does it mean Extinction Level Event ? pretty odd dont you think. . . . .my question is :is the trajectory of this elenin even close enough to worry, is the date still sep 26, 27th….

  13. A magnetic cloud is incurring as it has done periodically every 5,000 yrs. The reason we have a 10,000 yr ‘history’ is that 10,000 y ago was the last time Earth passed to the back side of the double layer plasma sheath. The 5,000 y ago event was the same as now, compression due to being in front of the cloud; all our weather changes are due to this compression.
    If there is a comet/planet in the cloud, it might be a neutron star (typically less than 15 m in diameter), the source of the gravity/magnetic anomaly in Sol’s system. There may be many other bodies in the cloud hence all the terminology of names.
    Objects identified in the neighborhood of Sol should be associated with the sun, and not assumed to be missed on their way into our system.
    The time of greatest concern will be when the magnetic field drops suddenly which may be the beginning of 2013. Gravity does not bend space, magnetism does.

  14. NASA is train to lie to us they don’t want people panicing and don’t care also its in the BIBLE in REVELATION.Just like Bush lied to us about the twin towers they gonna lie to us.

  15. Nasa is train to lie just lik Bush lied about the twin tower also if you read the BIBLE in REVILATION it also states an fire ball also United States is not mentiond so we prolly wont be here!

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