NASA's Spitzer space telescope signed off on Thursday and went silent. But even during its final week of operation, the spacecraft was making one-of-a-kind observations.
The telescope, the size of a family sedan, follows Earth in its orbit around the sun, but trails 158 million miles behind. Lately, it has gazed out with its infrared eyes, taking sensitive measurements of fine cosmic dust that pervades the space between planets in the solar system. The resulting imagery will enable researchers to better understand our local celestial neighborhood, the New York Times reported.
Since it launched on Aug. 25, 2003, Spitzer has provided unique contributions to science. It gave us new views of distant galaxies, newborn stars and nearby exoplanets, as well as of asteroids, comets and other objects in our solar system. Its infrared cameras have observed the universe in a light imperceptible to human sense, providing otherwise unattainable visions of the sky.
The end of a spacecraft's mission always provides a moment for reflection. But Spitzer's conclusion is particularly challenging for infrared astronomers, and many wish it wasn't yet time to say goodbye.
"There is no field of investigation that has not been touched by Spitzer," said Daniela Calzetti, an astronomer at the University of Massachusetts.
For his part, George Helou, an astronomer who was part of a NASA review into whether the telescope should continue to operate, said: "From a purely technical point of view, we could continue to operate it. The decision was taken at a time when it seemed the rational thing to do was to terminate the mission now.”
Spitzer costs the agency NASA less than $14 million each year, and its overall lifetime expenditure has been calculated to be around $1.3 billion. Information from the infrared telescope has been used in more than 8,700 research papers.
"It's really the end of an era, particularly for me. Spitzer has been around for as long as I've been doing science," said Heather Knutson, an astrophysicist at the California Institute of Technology.
