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Fastest Orbiting Asteroid Observed by LCO Telescopes

Aug 23, 2021

The fastest asteroid in the Solar System has been discovered by NOIRLab using the Dark Energy Camera in Chile — the Sun’s new nearest neighbor. Credit: CTIO/NOIRLab/NSF/AURA/J. da Silva

The NSF NoirLab has announced the discovery of the fastest orbiting asteroid:

"Using the powerful 570-megapixel Dark Energy Camera (DECam) in Chile, astronomers just ten days ago discovered an asteroid with the shortest orbital period of any known asteroid in the Solar System. The orbit of the approximately 1-kilometer-diameter asteroid takes it as close as 20 million kilometers (12 million miles or 0.13 au), from the Sun every 113 days. Asteroid 2021 PH27, revealed in images acquired during twilight, also has the smallest mean distance (semi-major axis) of any known asteroid in our Solar System — only Mercury has a shorter period and smaller semi-major axis. The asteroid is so close to the Sun’s massive gravitational field, it experiences the largest general relativistic effects of any known Solar System object."

The LCO network was used to observe the object, from the observatories in Chile and South Africa.

Scott Sheppard of the Carnegie Institution of Science discovered Asteroid 2021 PH27. Following the newly-discovered asteroid caused the postponement of many scheduled telescope observations.

Though telescope time for astronomers is very precious, the international nature and love of the unknown make astronomers very willing to override their own science and observations to follow up new, interesting discoveries like this,” says Sheppard.

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