Planetary systems form out of the remnant gas and dust of a primordial star. The material collapses into a protoplanetary disk around the young star, and the clumps that form within the disk eventually become planets, asteroids, or other bodies. Although we understand the big picture of planetary formation, we've yet to fully understand the details. That's because the details are complicated.

Take, for example, the mystery of asteroids and collisions. You would think that planets and asteroids formed gradually: small clumps colliding with others to make bigger clumps. As an object gets bigger, it would be more likely to attract other bodies, and thus be more likely to experience collisions. But as a recent study shows, that isn't always the case with asteroids.

Many asteroids can be grouped into families, groups that are similar in their chemical composition.

Researchers at the Australian National University (ANU) have harnessed a technique that helps telescopes see objects in the night sky more clearly to fight against dangerous and costly space debris.

The researchers' work on adaptive optics—which removes the haziness caused by turbulence in the atmosphere—has been applied to a new 'guide star' laser for better identifying, tracking and safely moving space debris.

Space debris is a major threat to the $US700 billion of space infrastructure delivering vital services around the globe each day. With laser guide star adaptive optics, this infrastructure now has a new line of defense.

The optics that focus and direct the guide star laser have been developed by the ANU researchers with colleagues from Electro Optic Systems (EOS), RMIT University, Japan and the U.S. as part of the Space Environment Research Centre (SERC).

EOS will now commercialize the new guide star laser technology, which could also be incorporated in tool kits to enable high-bandwidth ground to space satellite communications.

The laser beams used for tracking space junk use infrared light and aren't visible.

There are a lot of things that pose a threat to our planet—climate change, natural disasters, and solar flares, for example. But one threat in particular often captures public imagination, finding itself popularised in books and films and regularly generating alarming headlines: asteroids.

In our solar system there are millions of space rocks known as asteroids. Ranging in size from a few metres to hundreds of kilometres, these objects are mostly left over from the formation of our planets 4.6 billion years ago. They are building blocks that didn't quite make it into fully fledged worlds.

Asteroids and other objects that make a closest approach to our sun of less than 1.3 astronomical units (1 astronomical unit, AU, is the Earth-Sun distance) are known as