News Item: Astronomers invented a new powerful method of tracking asteroids
(Category: Новости)
Posted by Slava
Friday 14 September 2018 - 17:16:04

Radio telescopes are created for observing distant galaxies, quasars, neutron stars and so on. For anything but not for asteroids. But researchers have done the impossible, one quick measurement by reducing the error in the knowledge of the orbit of a celestial body ten times.

Radio telescopes are created for observing distant galaxies, quasars, neutron stars and so on. For anything but not for asteroids. But researchers have done the impossible, one quick measurement by reducing the error in the knowledge of the orbit of a celestial body ten times.

The achievement is described in a scientific paper published in Astronomical Journal a group led by Jorma Harju (Jorma Harju) at the University of Helsinki.

The asteroid Palma is one of the largest bodies in the main asteroid belt between Mars and Jupiter. He is known to mankind since the late nineteenth century, and every 5.6 years makes a complete revolution around the Sun. However, the "heavenly stones" – objects on an astronomical scale is small and dim. Therefore, the shape and orbit of a heavenly body is still known with quite high accuracy.

The scientists used the six antennas of the VLBA system, located in different parts of the United States. With their help, they watched as 15 may 2017, he eclipsed the radio galaxy 0141+268. The radio shadow ran across the surface of the Earth at a speed of 52 kilometers per second.

Encountering the edge of the asteroid, radio waves were around him. This process in physics called diffraction. Astronomers recorded the diffracted waves and compared them with "normal".

"Analyzing samples of diffracted radio waves during this event, we were able to learn a lot about the asteroid, including its size and exact position, and also to get some valuable information about its shape," says Harju.

According to the researchers, the effective diameter of the asteroid was equal 192,1 ± 4.8 kilometers. This is consistent with the data of optical observations. Explain that the effective diameter is the ideal diameter of a ball having the same volume as the real celestial body.

And the asteroid is not round. By calculations of authors of the work, its shape deviates from spherical at 26 ± 13%. In particular, one edge of outer blocks chipped. If palm had a more exotic form, or could boast of satellite, astronomers would have discovered it.

The most spectacular result of researchers in terms of the trajectory of the asteroid. Over the past 120 years its location was determined more than 1,600 times. However, one single measurement using the VLBA immediately reduced the accuracy with which its orbit is known, ten times!

Of course, it is not a palm tree per se, but a new technique, which allows us to study and his numerous brethren. Such studies make it possible to learn a lot about the past of the Solar system. And someday they might save the planet from big trouble.

"These methods will undoubtedly be used in future investigations of asteroids," sums up Kimmo Lehtinen (Lehtinen Kimmo) from the Finnish geospatial research Institute.

We will remind that earlier "News.Science" (nauka.vesti.ru) wrote about the methods of changing the orbits of asteroids and about why some astronomers suggest to send them directly into the Ground.




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