Viewing the galaxy from the Earthly edge of outer space
It's a trip UCLA astronomer Mark Morris would love to take – being lofted 40,000 to 45,000 feet into the Earth's stratosphere in a specially modified Boeing 747 carrying the world's most versatile airborne astronomical observatory – the largest of its kind ever built.
Hundreds of thousands of stars and stellar dust swirl in the center of our galaxy in this image taken by NASA's Spitzer Space Telescope.
Called SOFIA, short for Stratospheric Observatory for Infrared Astronomy, it will carry instruments that will give the astronomer his clearest view ever of the clouds of dust and gas at the center of the Milky Way some 25,000 light years away, a region of the universe he has been probing for decades. It's a view that is impossible to see using the largest Earth-based telescopes because of atmospheric interference.
"The plane will be flying as high as you can ask a 747 to fly, but yet not go into space" said Morris, one of three astronomers recently selected to participate in the first scientific observations to be conducted by SOFIA, scheduled to begin in May 2009. "We'll be able to observe things that you absolutely cannot observe on the ground. And that's what's exciting about this."
NASA is developing SOFIA as the only airborne observatory of its kind in the world to complement the Hubble, Spitzer and other space telescopes as well as major Earth-based telescopes. In its cavernous fuselage, the plane will carry two instruments during the first phase of observations, in which Morris will participate. One will be an infrared camera designed and operated by a team from Cornell University, with whom Morris will work. The other is a spectrometer nicknamed GREAT (German Receiver for Astronomy at THz Frequencies) from the Max Planck Institute for Radioastronomy in Bonn, Germany. SOFIA is a joint program between NASA and the German Space Agency, Deutsches Zentrum für Luft- und Raumfahrt.
A rendering of SOFIA, or Stratospheric Observatory for Infrared Astronomy, NASA's flying observatory.
Morris's UCLA colleague, Eric Becklin, professor emeritus in astronomy and the chief scientific advisor for SOFIA, said enthusiasm for the project was reflected in the large number of applications from astronomers eager to get in on the first round of observations. "The proposals we received set a high standard for future observation projects onboard SOFIA," Becklin said.
Whether Morris will actually ride in the 747 as an on-site observer hasn't yet been decided. To give the instruments their unparalleled view of the universe, the 747, when airborne, will slide its door up, over and around the fuselage, leaving "a huge cavity open to the elements," the astronomer said. Onboard observers will sit comfortably in a pressurized cabin separated from the telescope by a bulkhead able to withstand a million pounds of differential force.
"I would love to go," Morris said, but since most of the critical decisions will be made well in advance, joining the flight isn't vital to his observations of this special place. "The center of the galaxy is extremely interesting because everything is concentrated there – stars, magnetic fields, dust, gas. It's a place where nature reaches many extremes. The central supermassive black hole is one of those extremes, but the other is all this gas and dust. The gas can form new stars, and it can also feed the black hole over time."
UCLA astronomer Mark Morris.
What is critical is that he will be able to see the long infrared wavelengths emitted from the clouds of gases and dust at the center of our galaxy. "At UCLA, we've been studying the very unusual star formation that's going on at the center of the galaxy for awhile. We need to know what that fuel – the clouds of gas and dust – is doing. So with SOFIA flying into the stratosphere, we avoid the problems caused by Earth's atmosphere, which prevents infrared light from cosmic sources from reaching our telescopes."
From the W.M. Keck Observatory on the summit of Hawaii's dormant Mauna Kea volcano, Morris uses the advanced infrared cameras built in UCLA’s Infrared Lab to see shortwave infrared light at wavelengths near the optical range "where we can see the night sky with our eyes. But as you go further into the infrared, the wavelengths get longer and longer. That's where the atmosphere blocks the view. But that's where we need to go to see the dust. … The cool dust – almost all of the dust in the universe is very cold – emits long infrared wavelengths that require SOFIA to observe."
To be named one of the first scientists to use SOFIA during the observatory's "first light" – when the observatory is officially "turned on" -- is thrilling, Morris said.
Of course, he adds, "I would be thrilled if I could drive to NASA's Dryden Flight Research Center (next to Edwards Air Force Base) and hop on that plane."
To find out more about SOFIA, go here