US astronomers discover “fastest orbiting asteroid” in solar system

The Astronomers at the Carnegie Institution for Science (CIS) announced the discovery of the fastest orbiting asteroid ever spotted in the solar system.

Dubbed as “2021 PH27”, the space rock, which is 1 kilometre in diameter, completes its orbit in just 113 Earth days.

That’s the shortest orbital period of any known solar system object except the Mercury planet, which takes only 88 days to orbit around the sun, the scientists noted.

“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,” research leader Scott Sheppard, an astronomer at the CIS, said in a statement. 

The work was reported to the Minor Planet Centre, an official body for observing and reporting on minor planets under the auspices of the International Astronomical Union.

According to the scientists, the space rock also gets extremely close to the sun, reaching a proximity of about 20 million kilometres. In comparison, Mercury gets as close as 46 million kilometres (apporx).

Such a close proximity means that asteroid’s surface at times burns up to 500 degrees Celsius.

However, the scientists cautioned that the orbit is not stable. They said the asteroid will likely collide with the sun, Mercury or Venus a few million years from now, if it’s not altered from its current path by a gravitational interaction first.

2021 PH27 was first detected on August 13 by the astronomers using the Dark Energy Camera (DEC), a powerful multipurpose instrument which uses the images taken in the near-ultraviolet, visible, and near-infrared to measure the expansion of the universe.

It is mounted on the Víctor M. Blanco 4-meter Telescope at the Cerro Tololo Inter-American Observatory in Chile. 

The team was able to pin down the asteroid’s orbit over the next few days due to the observations by the DEC and the Magellan Telescopes at the Las Campanas Observatory in Chile.