Just for a moment, imagine how much havoc would be caused by a a 650-metre space rock smashing into the Earth.
It would make the horrific Boxing Day 2004 tsunami look like a mild disaster by comparison.
Fortunately, that won't be on the agenda on April 19 when a large asteroid, 2014 JO25, passes by our planet.
According to NASA, it's going to miss Earth by 1.8 million kilometres. That's five times as far away as the moon.
"Small asteroids pass within this distance of Earth several times each week, but this upcoming close approach is the closest by any known asteroid of this size, or larger, since asteroid Toutatis, a 3.1-mile (five-kilometer) asteroid, which approached within about four lunar distances in September 2004," NASA said in a statement.
JO25's pending arrival will have astronomers around the world peering through telescopes. Anyone who takes a photo is welcome to email it to us at email@example.com.
"The encounter on April 19 is the closest this asteroid has come to Earth for at least the last 400 years and will be its closest approach for at least the next 500 years," NASA said.