Nearby asteroid found orbiting sun backwards

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PostMon May 04, 2009 6:04 pm » by Dirtyrabbit

Nearby asteroid found orbiting sun backwards


The discovery of a 2- to 3-kilometre-wide asteroid in an orbit that goes backwards has set astronomers scratching their heads. It comes closer to Earth than any other object in a 'retrograde' orbit, and astronomers think they should have spotted it before.

The object, called 2009 HC82, was discovered by the Catalina Sky Survey in Arizona on the morning of 29 April.

From observations of its position by five different groups, Sonia Keys of the International Astronomical Union's Minor Planet Center calculated it orbits the sun every 3.39 years on a path that ventures within 3.5 million km of the Earth's orbit. Combined with its size, that makes 2009 HC82 a potentially hazardous asteroid.

What's really unusual is that the calculated orbit is inclined 155° to the plane of the Earth's orbit. That means that as it orbits the Sun, it actually travels backwards compared to the planets. It is only the 20th asteroid known in a retrograde orbit, a very rare group. None of the others comes as close to the Earth.

2009 HC82: A Burnt-Out, Eccentric and Backward Near-Earth Asteroid
The Solar System often throws up surprises for astronomers, but the recent discovery of a 2- to 3-km wide asteroid called 2009 HC82 has sent observers in a spin. A retrograde spin to be precise.

This particular near-Earth asteroid (NEO) should have already been spotted as it has such a strange orbit. It is highly inclined, making it orbit the Sun backwards (when compared with the rest of the Solar System’s planetary bodies) every 3.39 years. What’s more, it ventures uncomfortably close (3.5 million km) to the Earth, making this NEO a potentially deadly lump of rock…

2009 HC82 was discovered on April 29th by the highly successful Catalina Sky Survey, and after independent observations by five different groups, it was determined that the asteroid has an orbit of 3.39 years and that its orbit is very inclined. So inclined in fact that the asteroid’s orbit takes it well out of the Solar System ecliptic at an angle of 155°. Inclined orbits aren’t rare in themselves, but if you find an asteroid with an inclination of more than 90°, you are seeing a very rare type of object: a retrograde asteroid.

in other news...............

May 4, 2009

SOUTHERN METEOR SHOWER: Earth is entering a stream of dusty debris from Halley's Comet, the source of the annual eta Aquarid meteor shower. Forecasters expect the shower to peak on Wednesday morning, May 6th, with as many as 85 meteors per hour over the southern hemisphere. Rates in the northern hemisphere will be less, 20 to 30 per hour. The best time to look is during the dark moonless hour before local sunrise. [details and sky maps]

SPACE STATION FLARE: Watching the International Space Station (ISS) is more exciting than it used to be. Why? Because now the station flares. Martin Gembec witnessed one of the luminous outbursts on May 2nd during a star party at Litice castle in the Czech Republic. "We were watching a bright flyby of the space station when the ISS surprised us with a big flare in the Milky Way." (continued below)

"At maximum, the ISS reached magnitude -8," he estimates. That's more than 25 times brighter than Venus or 400 times brighter than Sirius, the brightest star in the sky. "I photographed the flare using my Canon 30D and an all-sky mirror."

The ISS flares when sunlight glints off the station's enormous solar arrays. A telescopic view recorded by French amateur astronomer Nicolas Biver on April 28th shows the process in action. A new pair of arrays installed by shuttle astronauts in March has boosted the station's "glint power" and increased the likelihood of flares.

Check the Simple Satellite Tracker to find out when the ISS might be flaring over your home town.

LUNAR X-MOVIE: On Friday night, May 1st, a luminous X appeared on the Moon. "We saw it easily through our 5-inch telescope," report Enzo De Bernardini and Rodolfo Ferraiuolo of San Rafael, Argentina. Using a digital camera attached to the telescope's eyepiece, they made a movie of the X emerging from the shadows:


Click to view the movie

What is this "Lunar X"? Once a month when the sun rises over Crater Werner in the Moon's southern hemisphere, sunlight floods the region's high terrain and makes a luminous criss-cross shape. "Observing the X has little or no scientific value. It is a trick of the light. But the effect is striking, and it is exciting to rediscover each month," writes David Chapman in "A Fleeting Vision near Crater Werner" (Journal of the Royal Astronomical Society of Canada, Vol. 101, Issue 2, p.51).

The next apparition: May 31, 2009. Mark your calendar with an X.
Last edited by Dirtyrabbit on Mon May 04, 2009 6:09 pm, edited 1 time in total.

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PostMon May 04, 2009 6:08 pm » by Theshee

Great minds think alike :flop: I posted it the other day Interesting though :flop:

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PostMon May 04, 2009 6:10 pm » by Dirtyrabbit

opps im sorry =\

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PostTue May 05, 2009 3:08 pm » by Crazynutsx

wow this is cool

should we be worried about it tho if its near to the sun that means its near EARTH!

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