P/2016 G1 (PanSTARRS) was a main-belt asteroid that was destroyed by an impact event on 6 March 2016. [1] It was discovered by Robert Weryk and Richard Wainscoat of the Pan-STARRS 1 survey at Haleakala Observatory. The object was initially thought to be an Encke-type comet because of its diffuse appearance, [2] [3] so it received the periodic comet designation P/2016 G1. [4] After further analysis, what had initially appeared to be a comet's halo turned out to be rubble from a collision. By November 2019, analysis suggested the collision had occurred on 6 March 2016, and the asteroid was struck by a smaller object that may have massed only 1 kilogram (2.2 lb), and was traveling at 11,000 miles per hour (18,000 km/h). [5] P/2016 G1's diameter was between 200 metres (660 ft) and 400 metres (1,300 ft). [6] The asteroid had completely disintegrated by 2017. [6]
Astronomers were able to use the asteroid's rubble to determine the date of the collision, since the dispersion of dust was inversely proportional to its size. [6]
The position of P/2016 G1 was imaged 12 additional times in the PS1 data prior to discovery, between 2011 Feb. 23 and 2015 Jan. 17 and nothing was visible down to the limiting magnitudes shown in Table .1.
P/2016 G1 (PANSTARRS) (hereafter P/2016 G1 for short) was discovered by R. Weryk and R. J. Wainscoat on CCD images acquired on 2016 April 1 UT with the 1.8-m PanSTARRS1 telescope (Weryk & Wainscoat 2016).
Astronomers first discovered P/2016 G1 with the Pan-Starrs1 telescope in Hawaii in April 2016. Backtracking through archived images, astronomers realized that it had first been visible the previous month as a centralized collection of rocky clumps: the fractured, rubbly remnants of the asteroid, surrounded by a fine dust cloud, most likely the immediate debris jettisoned by the impact.
By 2017, P/2016 G1 was completely gone, most likely blown apart by the collision.