The Spitzer Space Telescope scans the universe with infrared eyes. It has done this job for 16 years. But now NASA is pulling the plug. Goodnight, Spitzer. You’re going to sleep for good.

For years, Spitzer peered through dusty clouds. It did a lot of good work. Spitzer sawuntold stars and galaxies. It uncovered a huge, nearly invisible ring around Saturn. Spitzer even helped discover seven Earth-size planets around a nearby star. Altogether, Spitzer observed 800,000 space objects. It took more than 36 million pictures. 

Spitzer stands about 13 feet tall. It weighs 1,906 pounds. Its detectors and telescope have to be very cold—negative 450 degrees Fahrenheit. This cold temperature makes it possible for Spitzer to observe super cold space objects. That way, its own heat doesn’t interfere with measurements. 

Spitzer circles the Sun just like Earth does. The telescope gets more difficult to operate as it drifts farther behind Earth. Right now, it trails Earth by 165 million miles. 

Spitzer was designed to last no more than five years. NASA launched Spitzer in 2003. Its infrared instruments can sense heat coming off space objects. The instruments act like night vision goggles. They show objects invisible to regular telescopes. That includes stellar nurseries. (Awww . . . look! Baby stars!) It also includes failed stars. (Nice try, huge star-like objects. You didn’t have quite enough mass to burn like stars do.)

It would be great if people could keep using Spitzer forever. But that’s not possible. Spitzer will continue to fall even farther behind Earth. It will get harder and harder to use. And Spitzer costs big money to operate—about $12 million each year.