- Spitzer space telescope making Milky Way map
- Focusing on our galaxy’s outer reaches
NASA’s Spitzer space telescope—which is similar to the Hubble Space Telescope but is optimised to pick up infrared radiation (heat)—is partway through producing a huge map of the outskirts of our Milky Way galaxy.
Our galaxy is made up of a central bulge surrounded by octopus-like spiral arms. The overall shape is that of a disc…round, with a thicker middle and thinner edges.
Our Solar System is located on one of the spiral arms, about two-thirds of the way out from the central bulge.
The Galactic Legacy Infrared Mid-Plane Survey Extraordinaire 360, or GLIMPSE360, is a follow-up to the GLIMPSE and GLIMPSE3D surveys, which focused on the inner parts of our galaxy.
GLIMPSE360 will look outwards to where the Milky Way’s star fields begin to fade out and intergalactic space begins.
“GLIMPSE360 will see to the edge of the Milky Way galaxy better than any telescope has before,” says Barbara Whitney, principal investigator for the survey, Senior Scientist at the University of Wisconsin and a Senior Research Scientist at the Space Science Institute in Boulder, Colorado.
Astronomers don’t know much about the outer limits of the Milky Way, and a number of puzzles remain to be solved.
One of them is how and why stars are born in regions where there is little star-making material—interstellar clouds of gas and dust.
“It’s like looking into the wilderness of our galaxy,” says Whitney. “While mapping the stars and dust out there, we hope to answer some major questions about an environment that is very different from the inner Milky Way.”
Studies of other galaxies have shown that there can be a surprising amount of star formation going on in the outer reaches.
Being an infrared telescope, Spitzer was launched with a cooling system to keep it’s own equipment very cold in order to prevent stray heat from interfering with its observations. But the coolant fluid ran out in early 2009, and the telescope has been operating in “warm mode” ever since. It can’t do quite the same observations as before, but it is still an incredibly capable facility that is in very good technical health.
“We look forward to what GLIMPSE360 will show us,” Whitney says. “The adventure is just getting started.”
Story by Jonathan Nally, Editor, SpaceInfo.com.au
Images courtesy NASA / JPL-Caltech / 2MASS / B. Whitney (SSI/University of Wisconsin).
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