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.
Ancient Mars featured flowing rivers and sizable lakes — but that doesn't mean the Red Planet definitely could have supported life, one prominent researcher stresses.
The presence of liquid water is just one of many factors that researchers need to take into account when investigating the past or present habitability of Mars or any other cosmic body, astrobiologist and mineralogist Pamela Conrad wrote in a "Perspectives" piece published online on Dec. 11 in the journal Science.
"The things that make a place livable are numerous, and sometimes, there's a showstopper you didn't think of," Conrad, deputy principal investigator for the Sample Analysis at Mars instrument aboard NASA's Curiosity rover, told SPACE.com. "So it's important to take a poll of the diversity of attributes that could contribute to making an environment livable or not."