Last week, a bright asteroid Iris slipped passed the Sombrero Galaxy, and several members captured the event with the SLOOH telescopes. MaynardP. combined two images to create this animation; and EugeneM.’s image was published on the Spaceweather.com website.
While these two objects may appear similarly sized and close to each other, quite the opposite is true. 7/Iris is one of our solar system’s largest and brightest asteroids, a stony object measuring some 225 km wide and reaching 6th magnitude at perihelion. Traveling at an average 20 km/sec, Iris’ distance can be measured in millions of miles as it orbits the Sun every 1,345 days. The Sombrero Galaxy, on the other hand, is an island unto itself – an immense region of gas and dust measuring tens of thousands of light years wide and home to potentially billions of Iris-type objects. It is some fifty-million light years distant and is moving constantly away from us at an average speed of 1,000 km/sec. So, Iris and the Sombrero are really two vastly different worlds simply sharing a tiny region of the sky for just a few nights, but much to our viewing delight.
Did you, too, image this event? Check your Sombrero Galaxy folder and share your findings in the SLOOH Forum. And remember — keep a sharp eye, because you never know what treasures you’ll capture through the SLOOH telescopes.
The International Astronomical Union announced Tuesday that approaching NEO 2001 SN263 is actually a triple asteroid system. Arecibo radar images revealed the unique triple space rock that was previously believed to be a binary system. While the discovery of a triple-system is not unique, this is the first accomplished by radar and the only such discovery within the Near Earth Asteroid population. Astronomers estimate their diameters at 2km, 1km, and 400m.
The radar team, headed by Principal Investigator Mike Nolan of Arecibo, revealed 2001 SN263 as a triple-system with images obtained on February 12. Coincidentally, that’s the same day we captured live images on Slooh to create this asteroid animation - illustrating the NEO’s movement through Auriga and towards our planet.
The LINEAR Project originally discovered the asteroid in September 2001 and a team of seven astronomers from France’s Haute-Provence Observatory identified it as a possible binary-system in January 2007. It is an AMOR object, passing close to Earth every few years, but never actually crossing our orbit. This time around, 2001 SN263 will pass within 25.6 Lunar Distances on February 20. Currently, it’s visible at 13th magnitude in Auriga, where it will remain for the next two days before slipping into Gemini. By the time of its closest pass, this NEO will reach a brighter magnitude of 12.4.
We’ll be following 2001 SN 263’s approach through the Slooh telescopes, as weather allows. If you would like to catch a glimpse yourself, you can check the Member Missions thread of the Slooh Forum for dates and times.
Tonight, lost within the orange glow of the setting sun, a newly discovered asteroid passed within 84,000 miles of our planet, just a third of the distance to the Moon, and barely anyone noticed. A sharp-eyed skywatcher with a good pair of binoculars might have seen the unfamiliar object gliding silently through Aquarius. But did they know what they were seeing was a very unexpected asteroid? Would they have understood just how close it really was?
Near-Earth Object, 2008 CT1, was discovered only two days before tonight’s close pass by the Lincoln Near-Earth Asteroid Research project, an MIT project funded by the USAF and NASA committed to discovering space rocks that orbit near Earth. Using robotic telescopes located at New Mexico’s White Sands Missile Range, the project has contributed nearly 70% of world-wide Near-Earth Asteroid discoveries since beginning operations in 1998.
Tonight’s asteroid, estimated between 8m - 15m wide, sounds small as asteroids go, but recent studies suggest that even smaller rocks can be devastating. The cause of the Tunguska Event of the early 20th Century is now believed to be a 35m rock that never even touched the surface. The new hypothesis suggests it exploded a few miles above the ground, creating a shockwave that wreaked havoc on the ground beneath. Just last September, the Earth-impacting meteorite that created a 13m wide crater in Peru is estimated to have been just 0.2m - 2m wide.
Tonight’s pass was very close on a cosmic scale - and its late discovery makes it an even closer call. Asteroid 2007 TU24 got a lot of media attention last week, but we knew that one was coming and where to look. We even caught a glimpse on Slooh. With all the telescopes pointed to the heavens, watching the skies for that next great impactor, there are still rocks that slip by unnoticed. Observing close encounters with known asteroids is a great opportunity to learn more about our Solar System, and how to spot future Near Earth Objects - even those not on our radar yet.
