After several months of inactivity in connection with the elimination of the consequences of Hurricane Maria, the main radio telescope of the Arecibo Observatory and one of the most powerful radio telescopes in the world returned to its usual work schedule and has already managed to get the best images of the near-Earth asteroid 3200 Phaeton, which is supposedly the source of one of the most powerful meteor showers - Geminids.
The resulting images show that the asteroid has a spheroidal shape, and on its surface there is a large concavity measuring at least several hundred meters, presumably a crater formed as a result of the collision of the asteroid with some more compact celestial body. Observations of the asteroid were carried out on December 17, 2017 with a resolution of 75 meters per pixel.
“New observations show a similarity of Phaeton in shape with the asteroid Bennu, which is the target of the OSIRIS-Rex spacecraft, owned by the NASA aerospace agency. But at the same time, the asteroid is about 10 times larger than the latter,”says Patrick Taylor, head of the planetary research group at Arecibo Observatory.
"The darkening on the asteroid's surface could be an impact crater or some other form of topographic depression, but it is not yet possible to find out for sure, since this area does not reflect the signal from our telescope."
New images from the Arecibo Observatory also suggest that Phaethon is about 6 kilometers in diameter, which is about 1 kilometer larger than earlier calculations. The asteroid is the second largest near-Earth object classified as “potentially hazardous”. The level of this danger is determined not only by the size, but also by the trajectory of the orbits of such celestial bodies in relation to the Earth.
The asteroid Phaethon was first discovered on October 11, 1983 by the IRAS infrared orbiting observatory. The last observation of the object was carried out by the Arecibo Observatory from December 15 to 19, 2017. At the moment of its closest position to the Earth, the asteroid was at a distance of 10 million kilometers, which is approximately 26.8 times the distance from the Earth to the Moon. The closest approach of the asteroid to the Earth is not expected until 2093.
Promotional video:
Arecibo Observatory has one of the most powerful astronomical radar systems in the world. The Category 4 hurricane, the worst on the island since 1928, sustained minor structural damage to the radio telescope. A few days after the last cyclone, he resumed radio astronomy observations, however, planetary radar observations, requiring increased power and the use of diesel generators, were restored by the observatory staff only in early December.
“Due to its unique capabilities, Arecibo is a very important scientific tool for the entire astronomical society, as well as a critical part of the planetary safety system,” said Joan Schmelz, director of the Arecibo Observatory.
“We have worked hard to get the radio telescope back on track after the devastating Hurricane Maria over Puerto Rico.”
The Arecibo Observatory Telescope is used to observe hundreds of different asteroids. When these small natural objects left over from the formation of our solar system pass relatively close to the Earth, the deep space radar system is best suited for studying their sizes, shapes, surfaces, density, as well as for calculating their orbital trajectories more accurately.
Nikolay Khizhnyak