Through a new telescope in Chile, scientists discovered that the fastest asteroid 2021 PH27 so far has a slightly longer orbital period than Mercury, but has the smallest average semi-major axis (the longest diameter inside an elliptical orbit) of asteroids currently known. ), and experience the largest general relativity effect of all solar system celestial bodies.
The asteroid 2021 PH27 is only 1 km wide in diameter and orbits the sun every 113 days. It has the shortest orbital period of any known asteroid in the solar system. For comparison, the orbital period of the nearest planet Mercury to the sun is 88 days.
On August 13 this year, astronomers used the Blanco telescope to discover the asteroid 2021 PH27 for the first time. The team from the University of Hawaii immediately measured and predicted the observation position of the asteroid the next night, followed by the Blanco telescope and the Magellan telescope. Observe it again; the next day, the Las Cumbria Observatory observed it again.
Although the observation time of telescopes around the world is quite precious, astronomers will postpone the original scheduled observation itinerary and follow up enthusiastically as soon as new and interesting celestial bodies appear.
New research led by astronomer Scott Sheppard of the Carnegie Institute of Science shows that the asteroid 2021 PH27 may originate in the main asteroid belt between Mars and Jupiter, and is disturbed by the gravitational force of the inner planets to move closer to the sun; however, the asteroid 2021 PH27 The orbital inclination is as high as 32 degrees, indicating that it may also be a comet from the outer solar system, but it was pulled by gravity to a short-period orbit closer to the sun when it passed the inner planet.
▲ Schematic diagram of asteroid 2021 PH27 orbit (orange line).
In the future, the orbit of the asteroid 2021 PH27 may also be unstable, and it may collide with Mercury, Venus or the Sun in a few million years, or be kicked into the solar system by the gravity of the inner planet.
Scott Sheppard said that compared with distant asteroids, the asteroids inside the Earth and Venus can help us better understand the strength and composition of these objects. If the asteroids with similar orbits to 2021 PH 27 finally seem to disintegrate, then these close asteroids Earth asteroids may be loosely bound piles of rubble instead of hard rock bodies.
Since the orbit of the next asteroid 2021 PH 27 will enter the back of the sun in our eyes, it is expected to be seen again in early 2022, and new observations will be able to determine the trajectory in more detail at that time, which will help this asteroid get an official name.
(Image source: NOIRLab)
