NASA is constantly discovering dangerous asteroids that are classified as “potentially dangerous”.
Fortunately, they pose no real threat to us on Earth.
The term is used as a warning about large rocks that could wreak havoc if they hit us.
Right now, experts don’t expect anyone to even come close for hundreds of years, so don’t panic.
But we should be prepared for the future, which Nasa has been working on with its recent DART mission, which deflected an asteroid by hurling a spacecraft at it.
In fact, there are more than 30,000 near-Earth asteroids in the solar system.
Some even hide in the glare of the sun.
Here are some of the biggest we know exist.
Although the dimensions are of course always approximate.
It’s quite difficult to determine the true size of an asteroid since measurements are based on things like brightness and reflections.
3122 Florence (1981 ET3)
3122 Florence (1981 ET3) was discovered long ago in Marsh 1981.
It is estimated to be about three miles across.
In 2017, the rock approached Earth, reaching about eighteen times the Moon’s average distance.
3200 Phaeton (1983TB)
3200 Phaethon (1983 TB) was first seen in October 1983.
The asteroid’s diameter is approximately 3.8 miles.
It made a close encounter in 2017, but there won’t be another similar one until 2093.
53319 (1999 JM8)
53319 (1999 JM8) is the largest potentially dangerous asteroid known to exist at 4.3 miles.
It was found much later than other large rocks, in 1999.
Fortunately, the next close approach is not expected until 2075.
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https://www.thesun.ie/tech/9698120/biggest-potentially-hazardous-asteroids-ever/ Three largest ‘potentially dangerous’ planet-killing asteroids discovered by Nasa – and one is four miles wide