SOFIA will unravel the mystery of how new stars form out of clouds of gas
A new and powerful telescope is being used by NASA astronomers for studying the atmospheres of planets and the formation of stars.
However, unlike most of the space agency's telescopes, the Stratospheric Observatory for Infrared Astronomy (SOFIA) is not in space — rather it flies around mounted on a Boeing 747 jet with a large door cut on the side for it to see out.
One reason why scientists have chosen to put the telescope on a plane is that the plane lands every day, says Alycia Weinberg, astronomer at the Carnegie Institution for Science, who is in charge of planning observations on SOFIA. The daily landings let researchers fix things or upgrade instruments. Plus, with no more space shuttle missions, fixing telescopes in space ranges is no more viable.
Another reason a flying telescope makes sense is that at 45,000 feet you're above most of the moisture in atmosphere. For, water vapour makes viewing the sky at infrared wavelengths impossible. Like sounds that are too low or too high for human ears to hear, infrared wavelengths are light and the human eye cannot see them.
But, Dr. Weinberg says, lots of things glow at infrared wavelengths like “the cocoons of dust that old stars give off as they go through their final stages of life.”
Those cocoons of dust are where new stars come from.
One of the things astronomers especially like to do with light from distant objects is put it through a spectrometer that can reveal the kinds of atoms and molecules that are in the light from whatever the telescope is pointed at.
David Neufeld, Professor of Physics and Astronomy at Johns Hopkins University, has big plans for one of SOFIA's spectrometers.
“I'm looking for a small molecule composed of one sulfur atom and one hydrogen atom. It's called mercapto, and it's never been seen before in the interstellar gas.”
Professor Neufeld will be observing a cloud of gas in the interstellar space between the Earth and a patch of space with the memorable name, W49N.
Mercapto radicals form at certain temperatures. “So if we see it, what it will tell us is that the clouds of interstellar gas that we are looking at, which are thought to be very, very cold, may have parts of them where it's been heated up to much higher temperatures,” he says.