http://astrobob.areavoices.com/2011/04/04/comet-elenin-will-not-destroy-the-earth/Comet Elenin will not destroy the EarthI did a search for Comet Elenin the other day and was surprised at how much gloom-and-doom blather has been written about this modest comet. The misinformation covers the full range of nonsense – everything from the name ‘Elenin’ being a coded message for ‘Extinction Level Event Notable Impact Nemesis’ to the comet being a secret brown dwarf star called Nibiru (which doesn’t exist). Some are even spreading the rumor that Leonid Elenin the person doesn’t actually exist.
Come on people!
Let’s shed a little light. Comet C/2010 X1 (Elenin) was discovered by Russian amateur Leonid Elenin on December 10, 2010. Although he lives in Lyubertsy, Russia, like many amateur astronomers, Elenin takes astrophotos ‘remotely’ using telescopes that can be controlled by a home computer. The night of his discovery he was taking routine photos of the sky at the independent Russian remote observatory ISON-NM (International Scientific Optical Network) near Mayhill, New Mexico.
By the way, Elenin is real guy who lives near Moscow, loves astronomy and studies asteroids and variable stars. He
a researcher at the Keldysh Institute of Applied Mathematics and volunteers at the International Astronomical Search Collaboration. Elenin also hosts a great website, where he frequently posts updates about his comet.
Elenin’s photos showed an extremely faint, tiny, teardrop-shaped fuzzball. After additional observations, astronomers determined that the comet’s orbit would bring it near the Earth later this summer, when it might become bright enough to see with the naked eye.
When I heard the news, I cheered. While naked eye comets aren’t rare, they’re not common either, with one making an appearance every couple years. Each is a joy to follow. Every comet observer hopes a bright one will show interesting activity in its nucleus and develop a pretty tail. People love a nice comet – remember Hale-Bopp back in 1997? A thing of beauty.
Further study of Comet Elenin’s orbit appeared to indicate that it was making its first-ever visit to the inner solar system. This happens routinely with comets, since, like your in-laws, so many come from great distances. Other comets, like Halley’s for instance, travel on closed oval orbits called an ellipses and revisit the Earth’s vicinity periodically. These are called the periodic comets.
Leonid Elenin has studied the orbit of his comet closely and predicts that gravitational tugs from the giant planets Jupiter and Saturn will likely reshape its orbit into a very long, cigar-shaped ellipse. The closed track would return the comet for another visit in about 10,000 years. Further observations will no doubt refine Elenin’s orbit and narrow the possibilities.
Comet Elenin orbits nearly in the same plane as the planets do. It’s currently in the constellation Leo the Lion and still very faint at 16th magnitude, well below the visual limit of most amateur telescopes. As it slowly moves closer to the sun, the comet should become visible in large scopes by early summer. Right now, it’s cruising out beyond Mars in the asteroid belt some 180 million miles from Earth and looks like a small, fuzzy spot in photographs.
On September 5, the comet will be near the orbit of Mercury and closest to the sun. Unfortunately, from our vantage point on Earth, Elenin will appear in the same direction in the sky as the sun and be lost in the solar glare. Things get better later that month, when the comet moves away from the sun’s direction and makes an appearance in the morning sky at dawn in Leo the Lion.
Closest approach to Earth happens on October 17 when the comet will be 21 million miles away from Earth and 2.4 million miles above our orbit. While we might appear close to each other in the diagram above, we’re still millions of miles apart. After that, we each go our separate ways as Elenin plunges back into deep space.
Here are some more facts:
* Comet Elenin doesn’t appear to be any different from numerous other comets. It’s orbiting the sun in a predictable manner.
* Much baloney has been sliced about the comet or its tail striking the Earth and wreaking havoc. The truth is Comet Elenin is so tiny, its gravitational effect on Earth is practically zero. Even at closest approach it’s still 21 million miles away. Every few years we get almost that close to Venus (23.7 million miles), a rocky planet nearly the same size as our own, and don’t suffer any ill effects. Like the comet, its pull on Earth is tiny, tiny, tiny.
What about a meteor shower from the comet’s tail? After all, most meteors we see originate from comet dust lost through their tails. Elenin appears to cross right through Earth’s orbit in the diagram above. Unfortunately my little picture doesn’t show the third dimension, but this one does.
The comet actually passes above our orbit, missing Earth in the vertical direction by some 2.4 million miles. The chance for an impact is zero. Even stray meteors are extremely unlikely. We’re close but not that close. Keep this in mind too – comet tails point away from the sun. When Elenin and Earth are closest, its tail will be directed back and away from us as depicted in the diagram above.
Even if Earth were to pass through the tail, at worst we’d see a meteor shower. That would be awesome!
I’ll settle on getting up before dawn with binoculars in hand, enjoying the subtle beauty of our fuzzy visitor while trying to comprehend the amazing fact that it arrived in Duluth’s sky after a journey of billions of miles.
Comet Elenin photographed on April 2 by German astrophotographer Bernhard Häusler. Because the comet moves in relation to the stars, the stars appear trailed during the exposure. Credit: Bernhard Bernhard HäuslerRussian amateur astronomer Leonid EleninAn animation of Comet Elenin in March compiled from multiple still photographs. Credit: Bernhard HäuslerThis simplified diagram shows Comet Elenin as it swings through the inner solar system, passing by Earth on the dates shown. The two bodies are closest on October 17. Positions shown are approximate. Illustration: Bob King