A "potentially hazardous" asteroid the size of a blue whale is set to zip
past Earth on Friday (Aug. 12), according to NASA.
The asteroid, named 2015 FF, has an estimated diameter between 42 and 92
feet (13 and 28 meters), or about the body length of an adult blue whale
(Balaenoptera musculus), and it will zoom past the Earth at 20,512 mph
(33,012 km/h).
At its closest approach, the asteroid — traveling at around than 27 times
the speed of sound — will come within about 2.67 million miles (4.3 million
kilometers) of Earth, a little more than eight times the average distance
between Earth and the moon. By cosmic standards, this is a tiny margin.
NASA flags any space object that comes within 120 million miles (193 million
km) of Earth as a "near-Earth object" and any fast-moving object within 4.65
million miles (7.5 million km) is categorized as "potentially hazardous."
Once the objects are flagged, astronomers closely monitor them, looking for
any deviation from their predicted trajectories — such as an unexpected
bounce off another asteroid — that could put them on a devastating collision
course with Earth.
NASA knows the location and orbit of roughly 28,000 asteroids, which it maps
with the Asteroid Terrestrial-impact Last Alert System (ATLAS) — an array of
four telescopes capable of performing a complete scan of the entire night
sky once every 24 hours. Since ATLAS came online in 2017, it has detected
more than 700 near-Earth asteroids and 66 comets. Two of the asteroids
detected by ATLAS, 2019 MO and 2018 LA, actually hit Earth, the former
exploding off the southern coast of Puerto Rico and the latter landing near
the border of Botswana and South Africa. Fortunately, those asteroids were
small and didn’t cause any damage.
NASA has estimated the trajectories of all the near-Earth objects beyond the
end of the century, and the good news is that Earth faces no known danger
from an apocalyptic asteroid collision for at least the next 100 years,
according to NASA.
But this doesn’t mean that space watchers think they should stop looking.
Though the majority of near-Earth objects may not be civilization-ending,
like the cataclysmic comet that appears in the 2021 satirical disaster movie
"Don't Look Up," there are still plenty of devastating asteroid impacts in
recent history to justify the continued vigilance.
In March 2021, a bowling ball-sized meteor exploded over Vermont with the
force of 440 pounds (200 kilograms) of TNT, Live Science previously
reported. Those fireworks, however, have nothing on the most explosive
recent meteor event, which occurred near the central Russian city of
Chelyabinsk in 2013. As the Chelyabinsk meteor struck the atmosphere, it
generated a blast roughly equal to around 400 to 500 kilotons of TNT, or 26
to 33 times the energy released by the Hiroshima bomb. Fireballs rained down
over the city and its environs, damaging buildings, smashing windows and
injuring approximately 1,200 people.
If astronomers were to ever spy an asteroid careening straight toward our
planet, space agencies around the world are already working on possible ways
to deflect the object. On Nov. 24, 2021, NASA launched a spacecraft as a
part of its Double Asteroid Redirection Test (DART) mission, which plans to
redirect the non-hazardous asteroid Dimorphos by ramming it off course in
autumn 2022, Live Science previously reported. China is also in the early
planning stages of an asteroid-redirect mission. By slamming 23 Long March 5
rockets into the asteroid Bennu, the country hopes to divert the space rock
from a potentially catastrophic impact with Earth.
Originally published on
Live Science.
Tags:
Space & Astrophysics