While Curiosity continues to comb Mars for life, scientists are actively sketching out plans to explore other potentially habitable regions. And on the list, much closer than that so-called Earth-like planet that's 44 light years away, is the moon Europa, which researchers for years have considered a leading candidate for life after it was discovered the surface is composed of water and ice.

The moon, which is the sixth closest to the planet Jupiter, is the "most promising in terms of habitability," according to Robert Pappalardo, a planetary scientist at JPL. It's not exactly a new sentiment, but with such emphasis lately on discovering the potential for alien life, Pappalardo sees Europa as an intriguing spot to explore.

According to io9, reddish oxidants on the moon's icy surface—you can see the satellite takes on a peculiar color palette—is often a sign of organic materials. The reason researchers have so anxiously turned their gaze to Europa is because that life could currently be thriving on Jupiter's moon—that's the important part. So while Mars could have inhabited organisms, Europa might have some undiscovered ongoing ecosystem.

An exploration project known as "Clipper" has been developed— it could be launched by 2021—but funds are drought tight. If it does launch, however, the spacecraft is intended to orbit Europa and perform close flybys, and possibly even deploy a lander for closer inspection.

Until then, we'll have to be content with our own little planet, and the dangers that come with it.