Differences in these, e.g., w1-w2 and w2-w3 are useful
in identifying obscured active galactic nuclei (AGNs).
When the intended mission was completed, the spacecraft was put in
hibernation even though it was still operational. It was revived in 2013
for a new mission, NEOWISE (for Near Earth Object WISE),
specifically to search for near-Earth objects (NEOs), remaining active until
July/August 2024, after which it entered Earth atmosphere
in November 2024.
Infrared has an advantage over ground visible-light
observations in estimating the size of observed NEOs: thermal emission
is a greater contributor to such an object's infrared
magnitude, which has more relationship to the object's size
and less to its albedo than do visible-light magnitudes.
"WISE" is used as a designator for WISE discoveries, but so
are numerous variants (such as "WISEA") for various discoveries and
astronomical catalogs, some of which are listed here.