Astronomers were able to see an asteroid before it collided with Earth for only the sixth time in recorded history.
Nearly four hours prior to impact, on November 19, 2022, the
Catalina Sky Survey found an asteroid with the designation 2022 WJ1 travelling
inward. When the asteroid was about to strike the earth, precise calculations
were made using a network of observatories and scientists.
This is fantastic news. The asteroid 2022 WJ1 was too tiny to
cause much harm, but its discovery demonstrates that asteroid monitoring
methods are becoming more effective globally, giving us a greater chance of
defending ourselves against larger space rocks that may potentially cause harm.
Even if most of space is not actually space, there is still a
lot of it. Asteroids that circle the Sun in a way that puts them near to
Earth's orbit make up the majority of the not-space in the area around the
Earth. Near-Earth asteroids are what we call them, and as of this writing,
30,656 of them have been identified.
The majority of these asteroids are really rather tiny, and
researchers are sure that we have located almost all of those that are large
enough to pose a substantial risk, researched them, and decided that none of
them will approach Earth close enough within the next century to constitute a
concern.
However, it's vital to keep track of what's going on in the
area around us and develop our ability to spot cunning rocks planning to make a
grand entry.
On November 19, 2022, at 04:53 UTC, the Mount Lemmon
Observatory, a component of the Catalina network, made the discovery of 2022
WJ1. It kept tracking the object and captured four photographs that helped
astronomers confirm the discovery. At 05:38 UTC, it reported the discovery to
the IAU Minor Planet Center.
Four photos were sufficient to determine the asteroid's
course across the sky, and numerous impact monitoring algorithms determined
that the rock had a 20% probability of crashing somewhere on the continent of
North America.
Scientists were able to improve their data by making
additional observations that provided a time and place. On schedule, 2022 WJ1
was spotted speeding across the sky as a bright green fireball at 08:27 UTC
above the Golden Horseshoe area in Southern Ontario, Canada.
The rock was not dangerous, despite being the first
anticipated meteor to ever pass over a heavily populated region at the time of
the discovery. The tiniest asteroid ever seen before atmospheric impact, it was
roughly one metre (3.3 feet) wide when it entered Earth's atmosphere.
It then disintegrated into smaller bits that largely landed
in Lake Ontario's water as it dropped to Earth as a fiery bolide. The smallest
fragments of the meteorite should be the most easily found; scientists are
expecting to recover some of these to advance their understanding of the
asteroid.
2008 TC3, which was about 4 metres across, 2014 AA, which was
about 3 metres across, 2018 LA, which was also about three metres across, 2019
MO, which was about 6 metres across, and 2022 EB5, which was about 2 metres
wide, were the last five asteroids identified before impact.
The discovery of 2022 WJ1 and the international cooperation
that followed it are a magnificent demonstration of how sensitive technology
has become and the marvel of human collaboration to comprehend renegade space
pebbles.
Of course, such observations offer a unique chance to learn
more about what happens to asteroids when they approach Earth's atmosphere.
"This fireball is especially noteworthy since the parent
meteoroid was seen up close before it entered the atmosphere. This is a unique
chance to correlate an asteroid's telescopic data with its atmospheric
breakdown behaviour to learn more about its interior structure "says
University of Western Ontario physicist and astronomer Peter Brown.
This extraordinary occurrence will provide information about
the composition and strength that, when paired with telescopic observations,
will further our grasp of how tiny asteroids fragment in the atmosphere, a
crucial piece of information for planetary defence.
The debris from 2022 WJ1 should have a grayer stony interior,
a thin and new fusion layer, and a black appearance. Any fragments that are
questionable should be submitted to the Royal Ontario Museum, according to
scientists.
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