The ‘Halloween asteroid’ passed by our planet on October 31, 2015 just 480,000 kilometers from us, which gave our scientists the opportunity to capture high-resolution images of the ‘creepy’ asteroid e. The 4-meter-per-pixel snapshots were achieved when a NASA team used giant ground-based radio telescopes to bounce radar signals off the asteroid at the National Radio Astronomy Observatory ‘s 100-meter telescope in Green Bank, Virginia. (USA).
Images of the spherical rock about 600 meters in diameter revealed certain bright spots, many cavities, and some physical features that look like ridges. They also identified that its thermal inertia is consistent with that of similarly sized asteroids. Its albedo is around 5%, or maybe 6%, which shows that it reflects approximately 5-6% of sunlight. That’s why it’s so dark.
The object was discovered on October 10, 2015 from Hawaii using the Pan-STARRS telescope, however the fact that it came ‘so close’ to our planet helped it to be known as the Halloween asteroid.
Subsequently, the Halloween asteroid flew over the Earth in 2018 (and has done so on other occasions, but at an even greater distance), but in the month of September, although it did so at a distance of about 38 million kilometers, a quarter of distance between the Earth and the Sun, approximately, nothing to do with the proximity that it offered us in 2015 to be able to study it in some detail.
Why call it a Halloween asteroid?
For many reasons. The initial one was that it happened around Halloween night in 2015, and another one is that this dark object whose rotation period is about three hours, resembles a human skull (under certain lighting conditions at particular times). of its rotation), hence its nickname.
When will an asteroid pass so close again?
The data obtained suggest that the next close approach to Earth should be expected in 2088, when an asteroid will fly towards us at just under 20 lunar distances (still ‘not too close’). And in 2027, it will be possible to observe a close approach to 137108 (1999 AN10) that will pass 388,960 km from Earth. It is an asteroid that is part of the Apollo asteroids discovered on January 13, 1999 by the Lincoln Near-Earth Asteroid Research team from the Lincoln Laboratory, Socorro, New Mexico and has a radius of 550 meters .
Scientists believe that the Halloween asteroid could be an extinct comet that lost its volatile compounds after circling the Sun several times and not a typical asteroid, although the line that distinguishes them is quite blurred . What is known is that both formed in the early stages of our solar system, which came into existence about 4.6 billion years ago.
Reference: TG Müller, A Marciniak, M Butkiewicz-Bąk, R Duffard, D Oszkiewicz, HU Käufl, R Szakáts, T Santana-Ros, C Kiss and P Santos-Sanz. “Large Halloween Asteroid at Lunar Distance”. Astronomy&Astrophysics 598- A63, 2017.