Happy Retirement to the Best Satellite Mission Ever!

If you have even a passing interest in science or astronomy, you have probably seen this image:

Image Credit: NASA/JPL

Point a radio telescope in any direction, and you will detect microwaves which are not associated with any celestial object. They are just there.

First discovered in 1964, it was a huge mystery what this radiation was. In fact, the astronomers who first detected the background radiation cleaned the bird poop out of the telescope before they investigated further, in case it was messing up their instruments, because they had no idea what else it could be (true story!).

But fortunately, it was not fecal matter, but an amazing discovery!

This is the Cosmic Microwave Background Radiation (CMBR). It is radiation leftover from the creation of the universe, roughly 13.75 billion years ago.

When the universe was first created, it was a hot, opaque cloud. But as the universe cooled, it became transparent, and photons were able to travel freely without being absorbed. These photons have been travelling lo these last 13-14 billion years, and are what comprises the CMBR. Only in the last few decades, however, have we truly been able to study it in detail.

Image Credit: WMAP Science Team

So in 2001, a satellite called the Wilkinson Microwave Anisotropy Probe (WMAP) was launched to study the CMBR. Their results are the picture you see above. See how it’s not quite uniform? There are flecks of yellow and red and green. That is because matter did not spread out uniformly after it was created. It clumped together a bit here and there, and that’s how eventually atoms were able to eventually clump together and form gas clouds, stars, and planets.

Portrait of WMAP satellite. Image Credit: NASA/JPL

And now, after 9 years of study, WMAP is shutting down. It is now sitting in a nice retirement village in orbit around the sun.

For a satellite only designed to last 2 years, WMAP went well beyond its original lifespan, and is a big success for NASA. It has increased our understanding of the universe and how we were created more, I would argue, than any other mission NASA has launched before it.