Thanks to astronomers and their constant search for new bodies moving in our solar system, we know a lot of asteroids. Many of them have long elliptical orbits around our Sun, swaying in our system – sometimes making passes close to Earth en route – around the Sun, then backing up.
Now, researchers have spotted an asteroid that never really goes far from the Sun, even at its ultimate point. The object, known as 2019 LF6, completes an orbit of our star every 151 days and is much closer to the Sun than even Mercury.
The LF6 travels in an elliptical orbit that takes it into the orbit of Mercury, around the Sun, then returns beyond the orbit of Venus. He never approaches the Earth and no one knew that it existed until now. The width of the asteroid is estimated at about one kilometer, which is all the more remarkable because it has remained hidden for so long.
"Thirty years ago, people began to organize methodical research on asteroids, starting by looking for larger objects. Now that most of them have been found, the biggest ones are rare birds, "says Tom Price of Caltech. "The LF6 is very unusual both in orbit and size, and its unique orbit explains why such a large asteroid escaped decades of careful research."
Asteroids that gravitate around the Sun and never cross the Earth in the depths of the solar system are often difficult to spot for astronomers. They must devote their observation resources to very close windows of time just before and after sunset, in the hope of locating the objects before sunlight submerges the imaging instruments.
The LF6 has the shortest "year" of all known asteroids and, while not of particular interest to scientists as an object close to the Earth, it is a particular discovery.