These images are some of the first to be taken during Spitzer's warm mission -- a new phase that began after the telescope, which operated for more than five-and-a-half years, ran out of liquid coolant. The pictures were snapped with the two infrared channels that still work at Spitzer's still-quite-chilly temperature of 30 Kelvin (about minus 406 degrees Fahrenheit). The two infrared channels are part of Spitzer's infrared array camera: 3.6-micron light is blue and 4.5-micron light is orange.
The main picture shows a cloud, known as DR22, bursting with new stars in the Cygnus region of the sky. Spitzer's infrared eyes can see dust, and see through dust, giving it a unique view into star-forming nests. The blue areas are dusty clouds, and the orange is mainly hot gas.
The picture at upper right shows a relatively calm galaxy called NGC 4145. This galaxy has already made most of its stars and has little star-forming activity. It is located 68 million light-years away in the constellation Canes Venatici. Blue shows starlight and dust.
The final picture at lower right shows a dying star called NGC 4361. This star was once a lot like our sun, before it evolved and puffed out its outer layers. The object, called a planetary nebula, is unusual in that it has four lobes, or jets, of ejected material instead of the standard two. Astronomers suspect that there might be two dying stars inside the nebula, each producing a bipolar jet. Orange primarily shows heated gas.