On March 31, a team from UC Davis and NASA Ames installed the EXES Science Instrument aboard SOFIA, the Stratospheric Observatory for Infrared Astronomy. EXES (Echelon-Cross-Echelle Spectrograph) is designed to observe light in the mid-infrared at high resolution. It operates from 4.5 to 28.3 microns, a region of the spectrum with many molecular transitions, according to UC Davis researcher Matt Richter, lead investigator on the EXES project.
Richter and colleagues hope to use to observe molecules such as water, methane and hydrogen both in our solar system and in nearby galaxies. Proposed projects include observing water and methane around forming stars, and mapping hydrogen, methane and water in the atmospheres of Jupiter and Mars.
Water in the Earth’s atmosphere blocks much of the infrared light from the sky. SOFIA, a joint project involving NASA and the German Space Agency, is a Boeing 747SP aircraft modified to take a 2.5 meter telescope to the stratosphere and above 99 percent of the Earth’s atmospheric water vapor for 8-9 hour observing sessions. At that altitude, large portions of the infrared spectrum, blocked at even the best ground-based sites, become available for astronomical observations.
The combination of EXES’s high spectral resolution and SOFIA’s access to new wavelengths will provide data that cannot be duplicated by any facility: past, current, or in development; ground-based or space. Of particular interest will be studies of water, methane and molecular hydrogen, basic molecules that are difficult to study from the ground.
EXES is the sixth instrument of the seven initial instruments for SOFIA and will have its first two flights April 7 and April 9.