A few hours ago, asteroid 2012 KT42 passed by Earth at distance of a mere 14,440 kilometers (8,950 miles), the 6th closest pass on record. This is almost three times closer than geosynchronous satellites. Alex Gibbs from the Catalina Sky Survey, the discoverer of this asteroid, created this video of 2012 KT42 during its closest approach to Earth. Don’t panic, Gibbs says, as the video shows the asteroid moving at 2,000 times the actual speed. However, the asteroid was zooming along at 17km/sec (38,000 mph). Each image is a 3 second exposure, during which the object moved, creating a trail. The images were taken on May 29, 2012 between 4:30 and 6:55 UT, the latter being 6 minutes before closest approach. This asteroid was less than 10 meters across, so was far too small to make it through our atmosphere intact, even if it did intersect directly with Earth’s path. Gibbs said the asteroid was a little brighter than expected, but otherwise lived up to its predicted pass distance and size.
Other astrophotographers also got images of 2012 KT42’s close pass. Peter Lake has this 20-second image, very close to the time of closest approach:
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Lake said he actually took 15 images via a robotic telescope, of which only three had the asteroid in them. “That’s how fast it was going,” he said.
(Video Courtesy Alex R. Gibbs, Catalina Sky Survey, University of Arizona, NASA Near-Earth Object Program.)
Discovery images of asteroid KT42. Credit: Catalina Sky Survey/Mt. Lemmon Observatory
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A newly found space rock will give Earth a close shave on May 29, passing by at a distance of just 14,440 kilometers (8,950 miles). That distance puts the small asteroid, named 2012 KT42, in the top ten list of closest asteroid approaches. In fact, this is the sixth closest approach to date. The close pass will occur at about 07:00 UTC (03:00 EDT, midnight PDT in the US) on May 29. 2012 KT42 is estimated to be between 3-10 meters in size, and while there is no possibility this asteroid will hit Earth, even if it did, it would surely burn up in the atmosphere.
The sequence of images above were sent to us by Alex Gibbs from the Catalina Sky Survey, who made the discovery of 2012 KT42 with the 1.5 meter telescope on Mt. Lemmon, Arizona on May 28. Gibbs also discovered a similar sized asteroid earlier this year, 2012 BX34, and shared with Universe Today the behind the scenes activities in the discovery of a near-Earth asteroid.
This asteroid closely followed another close pass by a different asteroid, 2012 KP24, which passed by Earth on May 28 at a distance of about 51,000 kilometers (32,000 miles). This rock was bigger, about 25 meters (80 feet) across.
Below is an animation of images of 2012 KT42 taken by Ernesto Guido, Nick Howes and Giovanni Sostero from the Remanzacco Observatory.
An animation showing the motion of 2012 KT42. Each frame is a 5-second exposure through a 2.0-m telescope. Credit: Ernesto Guido, Nick Howes and Giovanni Sostero from the Remanzacco Observatory.
The team said that at the time they took the images on May 28, 2012 KT42 was moving at about ~3.63 “/min and its magnitude was ~17.5. The images were take with the Siding Spring-Faulkes Telescope South through a 2.0-m f/10.0 Ritchey-Chretien telescope.
An interesting note pointed out by the Remanzacco team is that on May 29 at about 10:10 UT, 2012 KT42 will transit across the face of the Sun, and this could be seen from Africa, the Middle East, Asia. But it will be hard to see, if the diameter is about 5m, then the object would only appear about 0.006 of a degree against the solar disk.
In our article about Gibbs’ earlier discovery, he noted that when astronomers look through telescopes, asteroids don’t look much different from stars – they are just points of light. But asteroids are points of light which are moving; however they are moving slow enough that to detect the motion, astronomers take a series of images, usually four images spaced 10-12 minutes apart.
Then, the observers run specialized software to examine their images for any star-like objects that are moving from one image to the next. The software removes any candidates that correspond to known objects or main-belt asteroids. Gibbs said the software has a low detection threshold to avoid missing anything, so the observer looks over what the software found and determines which are real. The remaining objects that the software determines could be interesting are then sent in to the Minor Planet Center (MPC) at the Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, for the team or others to follow up.
Thanks to Alex Gibbs and the Remanzacco team for sharing their images.
