Astronomers discover the fastest orbiting asteroid in the solar system

An astronomer at the Carnegie Institution for Science has just discovered a new asteroid, and it’s the fastest orbiting asteroid in our solar system – but speed is just one of the space rock’s weird attributes.

Uncharted Space: Astronomers are trying to track nearby asteroids to avoid collisions in space and, if possible, one day avoid impacts with Earth.

Most asteroid surveys take place at night because that’s when objects are easiest to see, but some asteroids have orbits that bring them closer to the sun than Earth.

“The interior of space to Earth’s orbit has been relatively unexplored.”

Scott S. Sheppard

This means that they are never on Earth’s side living at night – they are only in our line of sight during the day.

“The interior of space at Earth’s orbit has been relatively unexplored to date,” Carnegie astronomer Scott S. Sheppard told CNN. “It is difficult to observe the region towards the sun because of the extreme glare from the sun.”

At dusk and dawn: To catch these asteroids flying under the radar, astronomers take surveys when they’re easiest to see: just when the sun is setting or rising.

Sheppard spotted this new asteroid in such twilight images, recorded by Brown University researchers using the National Science Foundation’s Dark Energy Camera in Chile.

The asteroid’s surface reaches temperatures that can melt lead.

the fastest orbiting asteroid: Using these initial images and those captured the following two nights, Sheppard and an international team of collaborators determined that the asteroid, dubbed 2021 PH27, orbits the sun in just 113 days.

This makes it the fastest orbiting asteroid in the solar system and the second-fastest orbiting object of any kind (only Mercury orbits the sun faster, at 88 days).

Hot, strong and unstable: Based on their observations, astronomers believe the asteroid is about a little over half a mile across – Sheppard told CNN it was unusual to find a new asteroid of this size in the solar system internal, as most have already been detected.

The asteroid also has an unstable orbit that places it closer to the sun than Mercury in some places and farther than Venus in others.

An illustration of the unbalanced orbit of asteroid 2021 PH27. Credit: Katherine Cain / Scott Sheppard / Carnegie Institution for Science

“2021 PH27 is getting so close to the Sun that its surface can reach temperatures of 900 degrees Fahrenheit (482 degrees Celsius), hot enough to melt lead,” Sheppard said.

“Because of these temperature extremes,” he continued, “2021 PH27 is unlikely to be composed of volatile material, and it is most likely composed of rock with perhaps a metal like iron. ”

The future and the past: Astronomers plan to keep an eye out for the fastest orbiting asteroid in the solar system early next year, after it circles the sun and comes into view again.

These observations should help refine estimates of the asteroid’s orbit and perhaps clear up some of the mystery surrounding its origin and the roughly 20 other asteroids we’ve discovered between Earth and the sun.

“Where do these inner asteroids come from? ” He asked. “Some are asteroids recently dislodged from the main belt, others[s] could be extinct comets, but there could be another source population, such as the Vulcanoids” – a hypothetical asteroid belt between the Sun and Mercury.

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Arline J. Mercier