Archive for April, 2011

Comet Elenin is not a danger to the Earth

April 5, 2011 6 comments

Comet C/2010 X1 (Elenin) is a comet discovered by Russian astronomer Leonid Elenin on December 10, 2010. Elenin was using a robotic observatory near Mayhill, New Mexico.

Mr. Elenin is an amateur astronomer from Lubertsy City, Russia, near Moscow. He is a graduate of the Moscow Aviation Institute, works as a researcher at the Keldysh Institute of Applied Mathematics (Russian Academy of Sciences), is married, and is bilingual (Russian and English). He volunteers with the International Astronomical Search Collaboration, and runs a website at He has had a passion for astronomy since childhood, and studies minor Solar System objects and variable stars. He has discovered more than 10 variable stars and numerous asteroids, and now, a comet.

On December 11th, 2010, Leonid Elenin posted news on his site of a “new and interesting object” discovered during a “routine survey of the sky on Dec. 10, 2010”. The discovery was made at the independent Russian remote observatory ISON-NM, which is located near Mayhill, New Mexico. The observatory is operated under the Russian project ISON (International Scientific Optical Network). His observations were confirmed by Aleksei Sergeyev and Artyom Novichonok at Madinak Observatory in the Ukrane.

Initially the comet was thought to be a short period comet, with aphelion near the orbit of Jupiter, and a perihelion inside the orbit of Earth. However, over a week after its discovery, the Minor Planets Center at Harvard published the orbital elements, revealing that the perihelion would be near Mercury! It was still unclear as to whether this was a rogue (a one time event) or a periodic comet. Further observations and calculations show that its period is on the order of 10,000 years, and that this is likely its first pass through the inner solar system. This leads to the prospect of a very bright comet in 2011. Leonid Elenin also estimates that the comet nucleus is 3-4 km in diameter.

According to the JPL Small Body Database C/2010 X1 is a Hyperbolic Comet, meaning that it will not return. However, Leonid Elenin has calculated that due to perturbations to the comet’s orbit from the gas giant planets, that the orbit of his comet will be modified to a long-period elliptical orbit, and that it will return in about 10,000 years.

Comet Elenin is in an orbit that is close to the plane of the ecliptic. It is currently just past opposition and about 3 times farther away from us than we are from the sun. Here is an illustration of the comet’s orbit as of April 5, 2011.

In August 2011, Elenin will become a naked-eye visible object, as it sweeps in closer to the sun than the Earth is.

By September 1st, 2011, Comet Elenin will approach the orbit of Mercury, and it will reach Perhelion on September 5th. In just a little over a month it will have traveled from the orbit of the Earth to the Orbit of Mercury. At this point it will be so close to the sun from our vantage point that it will be completely hidden. However, it will be visible on solar-observing spacecraft such as STEREO and SOHO.

On October 17th, 2011, Comet Elenin will make its closest approach to the earth. However, its distance to the Earth will still be huge, nearly a quarter of the distance between the earth and the sun.

Wild Claims.

Instead of being excited about the possibility of a naked-eye visible comet, some people are making some very strange and wild claims about the comet, or about Leonid Elenin. Some people are apparently questioning whether Leonid Elenin is even a real person, despite the fact that he is acknowledged as a contributor in various scholarly journal articles since 2009.

Elenin will not collide with Earth.

At its closest approach, Comet Elenin will be 34 million kilometers (21 million miles) away from the Earth. It will also be 4 million kilometers (2.4 million miles) above the orbit of the Earth. See this image showing that Elenin will be well above Earth’s orbit, and this image, showing it will be well ahead of the earth in it’s oribt and the videos below created by member obaeyens using the orbital simulator AstroGrav.

The Earth will not pass through Elenin’s tail.

A common misconception of comets is that the tail streams out behind the comet. Even if that were the case, the images and video above show that we would not pass through the tail. However, the tail of a comet does not stream out behind the comet’s path, but rather points away from the Sun. As such, the tail will never be in a position to cross the path of the Earth.

Even if the Earth were to pass through the tail of the comet, the only effect on the Earth would be a nice show of meteors. The Perseid meteor shower occurs every year between August 9 and 13 when the Earth passes through the orbit of Comet Swift-Tuttle. Comet Halley is the source of the Orionid shower in October.

Leonid Elenin is a real person.

Yes, it has been claimed that “Leonid Elenin” does not, in fact, exist, but that instead his name is a ‘coded message’. The poster finishes off a list of what they see as ‘hints’ in the circumstances with the statement:

You know the way TPTB operate. Everything is scripted well in advance and they use Hollywood to drop clues.

Or, it could be that the poster watches too many fictional movies and thinks that they are ‘coded messages’ from “The Powers That Be”.

Does Leonid Elenin even exist?
Comet Elenin a “smokescreen” for Nibiru:

Don Yeomans on C/2010 X1

Don Yeomans has weighed in on the comet, saying:

“So you’ve got a modest-sized icy dirtball that is getting no closer than 35 million kilometers,” 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.”

NASA’s David Morrison on Comet Elenin claims

“The comet never comes close to the Earth, but it is expected to be visible in binoculars during August and October. Part of the Internet chatter concerns its size. Comets are exceedingly small and enveloped in a tenuous cloud of gas and dust, so the only way to be sure of their actual dimensions is to visit with a spacecraft. This means its mass is less than one billionth the mass of the Earth. Needless to say, we will not be aware of the tiny gravitational pull from Elenin.”

This is a quote from a David’s answer to a question on the “Ask an astrobiologist” page. He has received lots of questions about Elenin as well.


1. Elenin, Leonid. “Новый интересный объект нашей обсерватории | SpaceObs.” Сайт обсерватории ISON-NM / ISON-NM Observatory Site. Web. 06 Apr. 2011. <>.

2. Elenin, Leonid. “«Кометы могут представлять серьезную угрозу» – интервью «Газете.ru» | SpaceObs.” Сайт обсерватории ISON-NM / ISON-NM Observatory Site. Web. 06 Apr. 2011. <>.
3. Beatty, Kelly. “Bright Prospects for Comet Elenin? – Observing Blog.” 24 Dec. 2010. 06 Apr. 2011 <>.
4. International Astronomical Search Collaboration. “Employee List.” Home. 06 Apr. 2011 <>.
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