The European Southern Observatory labeled yesterday the ‘Day of Toutatis,’ when the 4.6 kilometer-long asteroid passed Earth at no more than four times the Earth-Moon distance. Discovered in 1989, Toutatis swings close to Earth every four years, but not since 1353 has it come as close as yesterday. Closest approach occurred at roughly 1340 hours GMT (0940 ET). ESO’s coverage can be found here.

The asteroid ToutatisNear-Earth asteroids like Toutatis are a reminder of the space debris that has showered Earth throughout its history. Our future in space is not optional: we’ll need the technology to detect and deflect any asteroids that seem likely to make impact (Toutatis does not), and that means building up a space-based infrastructure into the outer Solar System. It is exactly that kind of system-wide presence that will one day allow us to build and send our first interstellar probes.

You can read more about Toutatis at NASA’s Near Earth Object Program site.

Image: Asteroid 4179 Toutatis, November 26, 1996. Credit: Steve Ostro, JPL.