Yesterday, after 15 years and at a cost of US$3.75 billion, the long-delayed, and much maligned, Stratospheric Observatory for Infrared Astronomy (SOFIA) published its first photos of the sky.

The 2.5-metre, mid-infrared telescope is mounted in the back of an aged Boeing 747. The airplane carries it into the stratosphere — above much of the atmospheric water vapour that absorbs infrared light. SOFIA took its first images of the Orion star-formation complex using a mid-infrared camera. The image is a bit fuzzy, but it shows a lot more than what you’d see observing at optical wavelengths.

It’s a triumph for SOFIA, though for many astronomers it comes late. The airborne telescope has been in the works since 1996, and many hoped it would fly much earlier than it has. The problem is that it’s pretty difficult to mount a telescope inside a 747, and even more difficult to get approval for a giant retractable door on the side of the plane.

Now the instrument must make up for lost time. It’s already had many of its capabilities scooped by the European Herschel space telescope, which launched in 2009. Still, SOFIA’s superior ability to measure the spectrum of dust clouds will make it good at studying how planets form, among other things.

My colleague Eric Hand wrote a great feature about the trials and tribulations of SOFIA, which is well worth a read.

Image: SOFIA