Davis Strait - 19 Oct 2011 - space debris

Not much to report today on oceanography. Have not seen land for days.  We are south of Davis Strait in the northern Labrador Sea. As I said yesterday (I think) it is a balmy 3-4C and no longer feels like the Arctic.  We finished a line yesterday morning and we have been steaming toward Baffin Island for about 18 hours. In about 1 hour we will reach the beginning of our final line.  Then we will sample our way back to the east to Nuuk Greenland which is our final destination. We expect to arrive Thursday night / Friday morning.

Today's topic is space debris. A conversation with Elizabeth about the aurora borealis led to a brief discussion on space junk when I realized that she had no idea that we were polluting outer space.

When we put satellites in orbit we generate space debris. The big stuff is spent fuel rockets, old satellites, picees from collisions.  However most of the debris is small particles such as dust from rocket motors, paint flakes, and coolant. These are typically less than 1 cm in size.   The space debris site on wikipedia has lots of details.

The NASA Obrital Debrid Program Office actually tracks all this stuff using telescopes.  They seem to have at 5 or 10 telescopes dedicated to this. They care because collisions with small particles can damage satellites.  Here is an image from NASA showing a hole in the Hubble space telescope caused by a small particle hitting it.

The interesting part of this story (for the apocaltypic minded among us) is as follows.  This is taken directly  from the wikipedia entry on space debris .
As the chance of collision is a function of the number of objects in space, there is a critical density where the creation of new debris occurs faster than the various natural forces that remove these objects from orbit. Beyond this point a runaway chain reaction can occur that reduces all objects in orbit to debris in a period of years or months. This possibility is known as the "Kessler Syndrome".

So space debris could eventually wipe out satellite communication. Whoops.

The image below is a NASA image from the wikipedia site. It shows all the particles being tracked. You can see that the majority of the debris is in low earth orbit and in the ring of geosynchronous satellite orbits. That is the particles are where the satellites are. The dots are not to scale relative to the earth.