A double asteroid approached uncomfortably this weekend. That is what astronomers have seen
On Could 25, 2019, an odd double asteroid (1999 KW4) flew over the Earth at a pace and pace that might make many individuals nervous. As all the time, there was no hazard, because the asteroid crossed the Earth at a minimal distance of 5.2 million km, 15 instances larger than the gap between the Earth and the Moon, and its orbit is nicely understood by scientists.
In consequence, the overflight supplied a perfect alternative for the Worldwide Asteroid Warning Community (IAWN) to conduct a cross-organizational remark of the 1999 asteroid KW4 because it flew near Earth. The European European Observatory (ESO) took half on this marketing campaign and managed to seize some pictures of the item with the assistance of the Very Massive Telescope (VLT).
Found in 1999 by the Lincoln Geostationary Asteroid Analysis Challenge (LINÉAR), the 1999 KW4 is classed as a doubtlessly harmful Close to-Earth Object (NEO). Measuring roughly 1.three km (zero.eight mi) huge, this asteroid has a tiny moon – S / 2001 (66391) 1 – with a diameter of roughly 360 m (1180 ft) and revolves round its major all of the 16 hours at a distance of about 2.6 kilometers (1.6 mi).
The distinctive capabilities of the SPHERE instrument on ESO's VLT gave him the clearest pictures of the double asteroid when he flew over the Earth on Could 25th. Credit score: ESO
For its half within the remark marketing campaign of the IAWN community, ESO relied on the high-contrast exoplanet spectro-polarimetric instrument of the VLT (SPHERE). Due to its state-of-the-art Adaptive Optics (AO) system, SPHERE is without doubt one of the few devices on the planet that may seize sharp sufficient pictures to differentiate the 2 elements of the asteroid.
Since SPHERE was designed to look at distant exoplanets, the AO system is important as a result of it corrects the turbulence of the Earth's environment. It permits the Earth-based VLT Observatory to seize pictures as sharp as these taken by house telescopes. Additionally it is geared up with coronographs, a expertise that reduces the glare of vibrant stars to look at the low reflecting environment of exoplanets in orbit.
The information collected by SPHERE on KW4 1999 allowed astronomers to characterize the double asteroid, placing an finish to their efforts to seek for exoplanets. This included acquiring info on the composition of the asteroid and its moon to see in the event that they had been forming from the identical bigger physique or if the smallest object was captured someplace on the course. As ESO astronomer Olivier Hainaut explains in a lat