Screenshot of a video of images from the GRAS telescopes in Mayhill Station, New Mexico on Oct. 21, 2011, showing what might be a diffuse blob of material, all that's left of Comet Elenin. Credit: Ernesto Guido, Giovanni Sostero and Nick Howes.
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A series of images of Comet Elenin taken on October 21, 2011 might show an “extremely faint and diffuse blob of light,” according to Ernesto Guido, Giovanni Sostero and Nick Howes, who used two remote telescopes in New Mexico to image again the field of view where Comet Elenin should be. Their first observing session with a 10” reflector showed no obvious moving object in the telescope’s field of view, while the second session a 0.1 meter refractor showed a hint of something moving in the background when images taken 2 hours apart were “blinked,” but interference from moonlight hasn’t been ruled out.
The trio of astronomers encourage other observers to confirm or refute this view with additional observations/images. “We suggest the use of wide-field, fast focal ratio scopes, possibly under very good sky conditions,” they said.
Image taken with the 2m Faulkes North Telescope of the region of sky where Comet Elenin should have been. . Field of view 10 arcmins Stack of up to 13 Bessel R band filtered images (20s) Limiting Magnitude 20.5 Image (c) Nick Howes, Ernesto Guido, Giovanni Sostero/LCOGT/Faulkes Telescope Project. Used by permission
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If you were waiting for Comet Elenin to wreak havoc on Earth so that you didn’t have to pay off your credit card debt or go into work today, I’m sorry to inform you that doomsday didn’t happen. All that remained of Comet Elenin, — which wasn’t much — made its closest pass by Earth yesterday (Oct. 16, 2011) without causing any earthquakes, tsunamis, or high tides and it didn’t collide with Earth, either. Moreover, there was no brown dwarf or Mothership hidden in the comet’s coma. And in case you didn’t notice, this comet did not cause three days of darkness around September 26, 2011.
“I don’t know why fearmongers chose my comet,” the comet’s discoverer Leonid Elenin told Universe Today. “I received many letters from scared people. But if they believe in conspiracy theories I can’t help them.”
For some reason, conspiracy and doomsday theorists chose this small little comet — one that was to come no closer to Earth than 34 million km (21 million miles) during its closest approach on October 16th – to be the harbinger of doom.
But here we are, just fine.
Well, except for wars, terrorism, global warming and other things that the human race inflicts on itself. There are enough bad things going on here on planet Earth that conspiracy theorists shouldn’t fabricate doomsday predictions just to needlessly scare people for fun and profit.
So why didn’t Comet Elenin cause doomsday?
1. It couldn’t have hit Earth, or affected Earth’s orbit. The comet was predicted to come 34 million km (21 million miles) away at its closest approach. Just in case you can’t figure that out, one object can’t hit another at that distance. Plus, the gravity exerted by a small object won’t affect Earth either. To put this in perspective, this distance is only a little closer than the closest approach of Venus to Earth, and roughly 100 times the distance from the Earth to the Moon. Nothing happens to Earth when Venus is at closest approach, and Venus is 12,000 kilometers in diameter, while Elenin was 3-5 kilometers across. When the comet was intact it had less than a billionth of the tidal force of the Moon.
Where Comet Elenin should have been in the sky on October 16, 2011 shows nothing left of the the distinegrated comet, and all that is visible are star trails. Credit: Ian Musgrave, using the Global Rent-a-Scope.
2. Comet Elenin fell apart. Sometimes, long period comets that originate from the outer parts of our solar system begin to dissipate as they get closer to the Sun. But Elenin was hit by solar flares from the Sun on August 19 and began disintegrating. When it reached its closest point to the Sun on September 10, it basically was toast. Just recently the location of where the comet should be has become visible in the night sky, out of the Sun’s glare. Several images from different amateur astronomers show absolutely nothing. The comet has completely disintegrated and fallen apart.
Earlier today, astronomer Nick Howes and his colleagues using the 2 meter Faulkes telescope took 30 minutes worth of exposures and saw nothing of Comet Elenin in the sky (top image). “We observed objects at magnitude 20.5, but saw no trace at all of Comet Elenin,” Howes told Universe Today. “If it had stayed together, it should have been almost visible with the naked eye now.”
3. What is left of the comet won’t cause problems, either. The average density of a comet’s coma is about the same as the density of the atmosphere on the Moon, and any rocks or debris that might be left over from the comet are small enough that they would burn up in Earth’s atmosphere if Earth does go through the wake of the coma or debris from the comet. And remember, several times a year Earth goes through the debris from comets and all that happens is we get beautiful meteor showers to enjoy.
And after this, don’t worry about Comet Elenin or its leftovers. Earth won’t pass through it again for another 12,000 years.
And if you proudly claim you aren’t a sheeple and are now just waiting and searching for the next doomsday theory to hang your every hope upon, why don’t you try expending your energy on this: Enjoy every day on this beautiful planet and live your life in its fullest. Use real science and learn to think critically. And perhaps you could be a person who could help come up with solutions to some of the real problems on planet Earth.
(And by the way, don’t worry about Oct. 21, 2011 (Harold Camping makes another prediction) or Dec. 21, 2012 (Mayan calendar) either. Same story.)
Comet Elenin, the supposed “doomsday comet” that has inspired so much confusion and controversy since its discovery in December 2010, may have broken apart completely during its recent pass around the Sun.
Discoverer Leonid Elenin posted the image above earlier today on his website, SpaceObs.org. Taken with the International Scientific Optical Network’s 18″ telescope in New Mexico (ISON-NM), it shows what may be the remnants of Elenin, a faint cloud barely visible after its exit from behind the Sun.
“On the left you can see possible position of this ‘cloud’,” Leonid writes. “Brightness of this object does not exceed 18m, which means what now, magnitude of the comet is lower then predicted on 12m. Hopefully in the near future debris of the comet will be observed on a large telescopes, and perhaps we’ll see some details of this ‘cloud’.”
Ground-based viewing of Elenin’s remains may be hampered over the next few days by the full Moon, he adds.
Although many rumors have been spread about the catastrophic danger Elenin poses to humans, in reality the comet was never a threat. Not expected to come any closer than 22 million miles (35 million km) to Earth, it’s been previously speculated that Elenin would most likely disintegrate during its current orbit.
“I don’t know why fearmongers [chose] my comet,” Leonid Elenin told Universe Today. “I received many letters from scared people. But if they believe in conspiracy theories I can’t help them.”
Hopefully this helps put some of the doomsday nonsense to rest!
Comet Elenin on Sept. 14, 2011. Image and annotated chart by Michael Mattiazzo. Used by permission
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As far as Comet Elenin goes, the only chance of impending doom is for the comet itself: it is disintegrating and quickly fading away. Australian amateur astronomer Michael Mattiazzo has been monitoring this comet’s trip toward perihelion (closest point in its orbit to the Sun), which occurred on September 10, 2011, and he says Comet Elenin has likely has not survived. The image above was taken by Mattiazzo on today (Sept. 14) and it is barely visible as a disintegrating smudge.
Elenin’s mass is smaller than average and its trajectory will take it no closer than 34 million km (21 million miles) of Earth as it circles the Sun. It will make its closest approach to Earth on October 16th, but was closest to the Sun on Sept. 10.
“On the night of August 19th, I estimated the brightness of comet Elenin as magnitude 8.1 and it was on target for naked eye observability in September,” Mattiazzo wrote on his website, Southern Comets. “On the following night of the 20th, the comet had faded dramatically by half a magnitude and appeared more diffuse. This was a sign of impending doom for comet Elenin.”
Elenin is at about magnitude 10 now, and fading as it is in the process of disintegrating.
It failed to recover, (you can see a series of images taken between August 19 and September 11 on Mattiazzo’s website), with the comet’s the nucleus taking on an elongated appearance with progressive fading.
Comet Elenin on Sept. 11, 2011. 20x10second exposures taken with a C11 SCT and Starlight Express MX7c CCD imager. Credit: Michael Mattiazzo. Used by permission
“Such acts of disruption are all too common for small comets that have close encounters with the Sun,” Mattiazzo said.
One of the most spectacular examples of a comet breaking apart occurred in July 2000 when comet C/1999 S4 LINEAR disintegrated and several observatories had a good view of the action.
A closeup photo of the breakup of Comet S4 LINEAR taken on August 6, 2000 by the European Very Large Telescope (VLT) in Chile. Credit: ESO
Elenin is now nearly in an inferior solar conjunction, where it will be directly between the Earth and the Sun (so we won’t be able to see it due to the brightness of the Sun). Another amateur astronomer from Australia, Ian Musgrave, says it is doubtful that it will be bright enough to see in the cameras from the Sun-orbiting SOHO spacecraft, and that we will probably have to wait until October when the comet moves away from the Sun for powerful Earth-based telescopes to try and find if any of the comet survives.
Comet Elenin -- the little fuzzy blob in the middle of the image -- as it appeared on May 22, 2011. Credit: Peter Lake
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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 http://www.jpl.nasa.gov/news/news.cfm?release=2011-135) If this comet were any danger to anyone, you would certainly know about it. For more information, visit NASA’s AsteroidWatch site at http://www.jpl.nasa.gov/asteroidwatch/.
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 http://neo.jpl.nasa.gov/ .
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: http://ssd.jpl.nasa.gov/horizons.cgi?find_body=1&body_group=sb&sstr=C/2010%20X1 .
Orbit of Comet C/2010 X1 Elenin (red) visualised with Celestia, showing Elenin at closest approach to Earth. Image courtesy of Ian Musgrave
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Astronomer and blogger Ian Musgrave from South Australia has been active in debunking the misinformation and nonsense that is being disseminated about Comet Elenin. He has written several wonderful posts featuring the actual realities of this long-period lump of dirty ice that has, for some reason, attracted the attention of doomsdayers, 2012ers, and end-of-the-world scaremongers. Earlier this week, Ian’s Elenin posts on his Astroblog were taken down by the web host, as someone filed a claim for alleged violation of the Digital Millennium Copyright Act (DMCA). “Given that there is no copyrighted material on these pages, with either material generated entirely by me or links to and citation of publicly available material, I believe this was just a frivolous attack on people countering Elenin nonsense” Ian said. Astroblog was not the only site that was targeted, and thankfully, Ian’s web host agreed that the claim was without merit, and the posts are back online. In the interim, however, Universe Today offered to publish Ian’s excellent “Comet Elenin, a FAQ for the Worried” post, and even though the original is now available again, Ian and I decided to still post this on UT so that more people with questions about Comet Elenin would have the chance to have their worries allayed. Have your questions answered below.
Will Comet Elenin Hit Earth?: No, its closest approach is 0.23 AU on Oct 16, 2011, where 1 AU is the distance from the Earth to the Sun. To put this in perspective, this is only a little closer than the closest approach of Venus to Earth, and roughly 100 times the distance from the Earth to the Moon. This distance is from the latest MPEC ephemeris which is based on over 100 observations from multiple observatories that have been continuously tracking the comet, so it won’t change appreciably.
Surely if Elenin Was Going to Hit the Earth NASA/the Government Would Hush it Up? Which government? The Australian Government, the UK Government? The Italian Government? The South African Government? Amateur astronomers world wide are following this comet and continually talking to each other. The have the programs to work out where the comet is going. If the comet was coming anywhere near us, the amateur community would be first to know, and there is no keeping them quite. Consider how wide spread the information is about Apophis, which is a real, if extremely marginal, hazard.
Will it Cause Earthquakes, Abnormally High Tides or Other Disasters: No, Elenin is a mere 3-5 kilometres across and has less than a billionth of the tidal force of the Moon at closest approach (as well as a negligible magnetic field). If the Moon can’t cause the poles to tip, cause massive tidal floods or earthquakes, Comet 2010 X1 Elenin won’t. We’ve been closer to other comets before with no ill effect.
But What About Mensur Omerbashich’s Paper that Says Elenin is Causing Earthquakes? It shows nothing of the sort, earthquakes are no more common during comet alignments than at any other time.
But it’s bigger than Jupiter! No, that’s the coma , the thin haze of gas and dust that surrounds the comet nucleus. The nucleus of C/2010 X1 Elenin is roughly 3-4 Km in diameter and Elenin has a coma around 50,000 km wide at the time of writing (which is a third of the diameter of Jupiter). The average density of the coma is about the same as the density of the atmosphere on the Moon. A coma is a feature of all comets that approach the Sun closely, for example comet 81P Wild (nucleus 4 Km diameter) had a coma of 50,000 Km and 103P Hartley had a coma of 150,000 Km. The Great Comet of 1811 had a nucleus of around 30km in diameter and had a coma nearly as big as the Sun. Comet Halley is 6×15 km and had a coma 100,000 km wide when it last approached Earth. We survived them all (and 103P Hartley came nearly twice as close as Elenin will), and we will survive Elenin without incident.
But I Can See a Picture of it in WikiSky, it’s HUGE! That is the carbon star CW Leonis.
But Brown Dwarf Stars are so Cold, you Can’t See Them. No, coldest detected so far is ~370K (about the temperature of a hot cup of tea), the the warmest are around 2200 K, and most range between 500-1000 K. They may not produce much visible light, but they reflect light. Jupiter has a composition similar to those of Brown Dwarf stars. Jupiter’s cloud tops are a chilly 128 K and it reflects light just fine. Any Brown Dwarf in the inner solar system would be painfully obvious.
Will Going Through the Comets Tail Affect Us? No, should the rather small tail of Elenin actually pass over us, it’s doing a pretty good imitation of a vacuum (about 100 atoms per cm3). We have been through bigger and denser comet tails before with no effect whatsoever (especially the Great Comet of 1861).
Why isn’t Comet Elenin in the News? For the same reason that the other 16 comets discovered in 2010 didn’t get in the news, or the 5 comets discovered in 2011. They are all dim. The News is only interested in comets that are spectacular, readily visible to the unaided eye or are being visited by spacecraft. Comet 2009 P1 will be as bright, if not brighter than C/2010 X1 Elenin, but that’s not in the news either. Amateur and professional astronomers are watching comet Elenin and others avidly, but the news channels don’t care about our obsessions with faint fuzzies.
Why Can’t I Find Information of Elenin at the NASA Website? Because NASA is not the arbiter of all things astronomical. You won’t find information on C/2009 P1, C/2011 C1 or any of the faint comets discovered during 2010 and 2011. NASA does have information of comets that its spacecraft have visited, or are interesting in some other way, but it’s not an exhaustive comet site like Cometography or Aerith.
(editor’s note, NASA and JPL’s Near Earth Object Office did publish an article about Comet Elenin in May, 2011, which can be found at this link, confirming it will safely fly past Earth.)
I Saw Comet Elenin Near the Sun in August 2010/Now: In August 2010 only really powerful telescopes could see Elenin. You saw Venus. If you are seeing something bright near the Sun in the morning sky now, it’s Venus.
How Can I Tell What IS in the Sky and Avoid The Venus Confusion? For freeware standalone programs there is Cartes du Ciel and Stellarium (my favourite). For Web based solutions Skyview Cafe, Sky-Map and GoogleEarth (KMZ file here) all work.
Where Can I Find Orbital Elements for Celestia or Stellarium?Here.
Where Can I Find Images of Elenin? Here, and here and a nice image of C/2010 X1 near to NGC 3376 is here.
I have Photographed/ Seen a Photograph of a Double Sun, is this Elenin? It’s lens flare.
