NASA’s Spitzer Space Telescope, which captured beautiful images of the sky for sixteen years, has produced one final image from data collected before it was retired earlier this year. It shows the California Nebula, located 1,000 light-years away from Earth.
Spitzer imaged in the infrared wavelength, meaning it could see through clouds of dust that would be opaque in visible light wavelengths. As structures like nebulae have large amounts of warm dust in them, being able to see through this gave a whole new view of what was going on inside.
This final image is a mosaic, showing images captured at different wavelengths. On the left, in the cyan section, the infrared light was captured at the 3.6-micrometer wavelength. On the right, in the red section, the light was captured in the 4.5-micrometer wavelength. In the middle, in the grey section, both wavelengths are combined to create an image that has more detail that could be achieved by imaging in any one single wavelength.
The images were captured on January 25 this year, just a few days before the telescope was officially decommissioned on January 30. The scientists managing the Spitzer project wanted to make the best use of the last days of the telescope, so they chose this nebula to image because it had not been imaged before and it has interesting features that were viewable in infrared.
Although the telescope will no longer be capturing any more images, it does leave behind a trove of publicly-accessible data which astronomers will be able to comb through to continue making new discoveries.
“Sometime in the future, some scientist will be able to use that data to do a really interesting analysis,” Sean Carey, manager of the Spitzer Science Center at Caltech, and one of the team members who chose this location to be imaged, said in a statement. “The entire Spitzer data archive is available to the scientific community to use. This is another piece of the sky that we’re putting out there for everyone to study.”