The two frigid, distant planets may contain the key to understanding why Earth is so habitable and comparable worlds outside our solar system.
Kathleen Mandt, a planetary scientist at Johns Hopkins' Applied Physics Lab, said, "The more we discover, the less we know about these two remarkable worlds."
Uranus and Neptune haven't been visited by dedicated missions, leaving big gaps in our understanding of the solar system.
Planetary scientists have urged NASA and other funding organizations to prioritize these worlds for future expeditions, and now they may be investigated soon.
The scientists found that Uranus has a thicker layer of methane haze in the middle of its atmosphere than Neptune does. This gives Uranus its unique greenish color.
It's still not clear where Uranus and Neptune formed in the disk of gas and dust surrounding the Sun during the early moments of the solar system.