A "City Killer" steroid hissed on Earth Thursday that terrified astronomers who captured the trajectory of the rock only days before it passed through the planet
The asteroid, whose diameter is 187 feet to 427 Foot was estimated this week by two people discovered astronomy teams in Brazil and the US – confirmed by the Jet Propulsion Lab of NASA.
It's the biggest stone that passes this year on Earth – and maybe even this decade.
"This is one of the closest approaches to Earth from an asteroid we know. And it's pretty big, "said Michael Brown, associate professor at the Department of Physics and Astronomy at Monash University.
" It's impressively close. I think it's not quite finished yet. It's a pretty big deal.
Astronomers generally continue to track asteroids in advance, but these were difficult to detect as they migrated from the direction of the sun.
The size of the rock may seem small ̵
"It's a city killer asteroid. But because it's so small, it's incredibly hard to tell until the very last minute. "