posted on Mar, 20 2014 @ 10:26 PM
reply to post by Nightspore
What WISE looks for is heat. It looks in the extreme infrared for faint heat signatures.
Gas giants and Brown Dwarfs do not emit visible light, but they do emit heat. Brown Dwarfs are more massive than Jupiter (at least 15 times more
mass), but their size is actually not too much bigger (their diameter) than Jupiter.
If there were something bigger in size, it would have a lot more surface area to emit heat, which means it would have been easier to detect.