Touring the Milky Way now is as
easy as clicking a button with NASA's new zoomable, 360-degree mosaic presented
Thursday at the TEDActive 2014 Conference in Vancouver, Canada.
The star-studded panorama of our galaxy is constructed from more than 2
million infrared snapshots taken over the past 10 years by NASA's Spitzer Space
Telescope.
"If we actually printed this out, we'd need a billboard as big as the Rose
Bowl Stadium to display it," said Robert Hurt, an imaging specialist at NASA's
Spitzer Space Science Center in Pasadena, Calif. "Instead we’ve created a
digital viewer that anyone, even astronomers, can use."
The 20-gigapixel mosaic uses Microsoft’s WorldWide Telescope visualization
platform. It captures about three percent of our sky, but because it focuses on
a band around Earth where the plane of the Milky Way lies, it shows more than
half of all the galaxy's stars.
The image, derived primarily from the Galactic Legacy Mid-Plane Survey
Extraordinaire project, or GLIMPSE360, is online at:
Spitzer, launched into space in 2003, has spent more than 10 years studying
everything from asteroids in our solar system to the most remote galaxies at the
edge of the observable universe. In this time, it has spent a total of 4,142
hours (172 days) taking pictures of the disk, or plane, of our Milky Way galaxy
in infrared light. This is the first time those images have been stitched
together into a single expansive view.
Our galaxy is a flat spiral disk; our solar system sits in the outer
one-third of the Milky Way, in one of its spiral arms. When we look toward the
center of our galaxy, we see a crowded, dusty region jam-packed with stars.
Visible-light telescopes cannot look as far into this region because the amount
of dust increases with distance, blocking visible starlight. Infrared light,
however, travels through the dust and allows Spitzer to view past the galaxy's
center.
"Spitzer is helping us determine where the edge of the galaxy lies," said Ed
Churchwell, co-leader of the GLIMPSE team at the University of
Wisconsin-Madison. "We are mapping the placement of the spiral arms and tracing
the shape of the galaxy."
Using GLIMPSE data, astronomers have created the most accurate map of the
large central bar of stars that marks the center of the galaxy, revealing the
bar to be slightly larger than previously thought. GLIMPSE images have also
shown a galaxy riddled with bubbles. These bubble structures are cavities around
massive stars, which blast wind and radiation into their surroundings.
All together, the data allow scientists to build a more global model of
stars, and star formation in the galaxy -- what some call the "pulse" of the
Milky Way. Spitzer can see faint stars in the "backcountry" of our galaxy -- the
outer, darker regions that went largely unexplored before.
"There are a whole lot more lower-mass stars seen now with Spitzer on a large
scale, allowing for a grand study," said Barbara Whitney of the University of
Wisconsin, Madison, co-leader of the GLIMPSE team. "Spitzer is sensitive enough
to pick these up and light up the entire 'countryside' with star formation."
The Spitzer team previously released an image compilation showing 130 degrees
of our galaxy, focused on its hub. The new 360-degree view will guide NASA's
upcoming James Webb Space Telescope to the most interesting sites of
star-formation, where it will make even more detailed infrared observations.
Some sections of the GLIMPSE mosaic include longer-wavelength data from
NASA's Wide-field Infrared Survey Explorer, or WISE, which scanned the whole sky
in infrared light.
The GLIMPSE data are also part of a citizen science project, where users can
help catalog bubbles and other objects in our Milky Way galaxy. To participate,
visit:
More information about Spitzer is online at:
NASA
Guillermo Gonzalo Sánchez Achutegui
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