An asteroid the size of a house is whizzing by the Earth today—apparently the fifth closest fly-by of all time. Because it’s not going to crash into us, it’s been given the terribly boring name of Asteroid 2011 MD, as opposed to something fun like Death Harbinger or Violent Destruction from Outer Space. But that doesn’t mean it won’t be fun to follow, and you can do so with the SkySafari 3 app from Southern Stars, available at half price in honor of the event.

Vito Technology is celebrating the second birthday of their app by way of an update that brings augmented reality to your iPod Touch. For iPhone 4 users, the new version of Star Walk brings in real-time satellite tracking, a calibration tool, TelRad, and other new contents. If you have not installed Star Walk before and have no idea what this app can do, it basically turns your iOS device into a personal planetarium which answers some of the things you want to know about the sky.

If you’re at all interested in astronomy, Star Walk is a fantastic resource for an evening of star gazing. If you’re not into astronomy, you just may be after playing around with this. Yes, it’s educational, but more importantly, it’s very cool. It’s also easy to use, so you can spend more time looking at the sky and less time pushing buttons. Get this app, you won’t be disappointed.