Asteroid 4179 Toutatis will zip past Earth this week. At its closest approach Tuesday night and into Wednesday morning, it will come within 18 lunar distances of the planet.
That's 18 times the distance from the Earth to the moon.
That may not sound too close, but the asteroid's erratic orbit occasionally has it zipping by a little too close for comfort. That's why the asteroid has been designated "potentially hazardous." In 2004 for example, the asteroid's orbit took it even closer to the Earth -- just about four lunar distances.
Toutatis passes by Earth every four years. Sky and Telescope describes it as "an irregular double lump measuring just 2.8 × 1.5 × 1.2 miles (4.5 × 2.4 × 1.9 km) in size -- a largish mountain."
It was first seen in 1934, and then lost for decades. It was rediscovered by Christian Pollas in 1989. He gave it the name Toutatis, after the Gaulish god. The name was well known thanks to a French animated series called "Les aventures d'Asterix" that tells the stories of two heroes living in 50 B.C. who fear nothing but the sky falling on their heads.