Astronomers are always watching the skies for observations of near-Earth asteroids—”space rocks” that have orbits close to Earth’s and, in the case of potentially hazardous asteroids (aka PHAs), those whose orbits could actually cross Earth’s and are larger than 150 meters (500 ft) across. When a new one of these is discovered—no small feat considering that many are very dark, move quickly, and could really be anywhere in the sky—it’s a scramble to determine the object’s orbital parameters and figure out just how close it can get to us and when. Such was the case on Oct. 19, 2016, when the asteroid 2016 WJ1 was identified with the Catalina Sky Survey. This object, estimated to be anywhere from 110 to 340 meters across—easily within the potentially hazardous range—was initially calculated to pose a threat in 2065 with a possible impact risk, albeit a very small one. Eventually though, scientists were able to refine the risk chance with more observations of 2016 WJ1…observations that had actually occurred over 13 years earlier.
Read the full story from ESA here: Asteroid sleuths go back to the future
For a real weekend treat, check out this beautiful time-lapse video taken by a camera mounted on a catwalk on the Canada-France-Hawaii Telescope (CFHT) on Mauna Kea in – you guessed it – Hawaii. 🙂
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(If you don’t see a video above, click here to watch on YouTube.)
Wow…absolutely beautiful! Especially considering no fancy editing has been done…this is just a night in the life of an island observatory! I particularly like the lengthening shadow of the volcano the observatory is located atop, and the rise of the Moon and how it illuminates the ever-shifting clouds.