The Valentine's Day front page of many newspapers in Alberta, a western province of Canada, announced a near miss by a piece of space junk as big as a pickup truck had been heading for a crash landing. If it had not changed course, this piece of junk might have landed in Calgary, a city of over one million. There could have been considerable loss of life. The space junk changed course and landed in the Atlantic.

The junk was spotted by NORAD in Colorado, which notified Public Safety Canada, who in turn notified the emergency operations of the Government of Alberta. The emergency response for this type of thing is uncertain. A media alert was minutes away from being issued. But had they issued the alert, what would people have done? There is no recommended procedure for dodging space junk.

The business of tracking all objects in space is known as space situational awareness. US agencies like NORAD and DARPA take on this responsibility. A bit of research on space situational awareness shows that it is a relatively tedious and low tech process. There is a lot of stuff on space, most of which congregates in the preferred orbits, much like ocean traffic using preferred shipping lanes. Radar is not effective so much of the tracking is done manually. Computer programs predict the position of objects and these positions are verified by someone finding the object with a telescope. There are many limitations to this process, such as the time it takes to move and refocus the telescope.

DARPA is exploring new ways to accomplish space situational awareness, such as, clusters of smaller telescopes or ramping up radar technology to make it suitable for tracking space objects. This could be enhanced by a space based tracking system. These systems need to be developed to provide greater protection for critical communication satellites that may be vulnerable to attack.

NASA estimates that there are about 18,000 human made things floating around in space. Both US and Russian agencies monitor their movements and determine when orbits are about to degrade. Most dilapidated satellites and other debris burn when they hit the earth's atmosphere.  But if they survive re-entry, predicting their path can be tricky business. The Centre for Orbital and Reentry Studies (really - there is such a place) points to increasing evidence of the reentry of space debris.  The risk to life on earth is negligible, but the risk to space missions is increasing.

Should we be concerned about space situational analysis? The short answer is yes. The incident over Alberta demonstrates that the present system is working, at least when it comes to identification of large objects. But if the random path of a piece of unused space junk had not been changed, damage to earth or to satellites could have been considerable. Likely a need in the near future will be the capability not only for space situational awareness but also action that can stop loose objects and destroy them before they hit earth.

In the meantime, you could be sitting in your living room, watching American Idol, when the screen goes red with a space junk falling alert. What do you do? Perhaps look up at the sky, maybe get your video camera, get ready to run if you see it coming, I'm not sure. The communication systems appear to be working, but the response is something that needs some thought. Or maybe we are better off not knowing what could happen.