Threat near-earth asteroid 2017 YE5, opened last December, was a unique “dual” object, each of the halves of which has a different origin and composition.
Learned of NASA scientists received the first pictures of him, reports RIA Novosti.
This celestial body was discovered at the end of December last year Moroccan Oukaimeden Observatory, and at that time it was considered dangerous, but quite ordinary near-earth asteroid.
It is included in the catalogue of the PHA (Potentially hazardous asteroids) — the list of objects that are potentially dangerous for life on Earth. To get into this list, heavenly body has to approach to our planet at a distance of not less than eight million kilometers, to be large enough not to disintegrate in the atmosphere and cause a catastrophe no less than a regional scale.
In June of this year 2017 YE5 again closer to Earth, approaching our planet at a distance of six million kilometers. The next time such a close rendezvous of this heavenly body and our planet will happen only after 170 years, which has given scientists a unique chance to study its structure and form.
To do this, astronomers used NASA’s powerful radar at the Goldstone and the 305-m dish radio telescope, “Arecibo”, Puerto Rico. They “fired” 2017 YE5 beams of radio waves that allowed them to see the exact shape of the asteroid, and uncover some of the details of his device.
These observations, as noted by the representatives of NASA, brought a lot of surprises. First, it became clear that 2017 YE5 much more than expected by scientists, and thus it consists of two halves of approximately equal size. Their diameter is about 900 meters, and they make one turn around each other in approximately 20-24 hours.
Similar properties YE5 2017, according to NASA, translate it into one of the most rare and unique minor planet in the Solar system, “equilibrium” double asteroids whose halves are approximately equal to each other. In total, scientists have discovered only four such object in the entire history of human existence.
The uniqueness of 2017 YE5 enhanced by the fact that its halves, judging by the nature of the reflection of radio waves from their surfaces, consist of different breeds. This radically distinguishes it from all other double asteroids, which arose generally as the result of “promotion” of their grandparent’s warmth and rays of sunlight and its disintegration under the action of centrifugal forces.
How was formed this celestial body, planetary scientists do not yet know. Further observation 2017 YE5 can reveal that if astronomers can measure its density, to know the chemical composition and other important properties.