Blazing Fast Asteroid Orbits The Sun In 113 Days

Astronomers have discovered what they say is the fastest orbiting asteroid in the solar system. The asteroid orbits the sun in 113 days, giving it the shortest known orbital period for an asteroid and the second shortest orbital period for any object in the solar system. The only object in the solar system with a faster orbital period than the new asteroid, called 2021 PH27, is the planet Mercury.

2021 PH27 was only recently discovered in twilight images taken by astronomers from Brown University. The asteroid measures about one kilometer in diameter and has an unstable orbit. Its orbit crosses the orbits of both Mercury and Venus. Since it has an unstable orbit crossing two planets in the solar system, it is likely to collide with one of the planets or the sun in the future. It could also be ejected from its current orbit.

Scientists put significant effort into studying asteroids to determine where they originate and learn more about the solar system. The current theory is that 2021 PH27 originated in the main asteroid belt orbiting between Jupiter and Mars. Astronomers believe gravity generated by planets in the inner solar system shaped its orbit into what is seen currently.

Another interesting possibility possible due to the 32 degree inclination of 2021 PH27 is that it may be the remnant of an extinct comet that originated in the outer solar system. 2021 PH27 orbits so close to the massive gravity generated by the sun that astronomers believe it experiences the most significant General Relativistic effects of any object in the solar system.

The asteroid passes close enough to the sun that its surface temperature heats to around 900 degrees Fahrenheit during its closest approach. That is hot enough to melt lead on the surface of the asteroid. Currently, the method astronomers used to discover asteroids orbiting around the sun closer than the Earth is to take images using equipment as the sun sets or rises. 2021 PH27 was discovered using that method.