Our solar system is a rough, wild place filled with endless silences, unimaginable darkness, and strange glimpses of lights from the Milky Way. But smelly? Not so much. However, recent evidence shows that the solar system can reek of rotten eggs — especially if you’re traveling around the surface of Jupiter’s moon, Io. Space.com reports on an interesting new report about this tiny moon that holds some of the strangest, rankest landscapes in the solar system.

Jupiter’s Io is the fourth-largest moon in the solar system. Named after a lover of Zeus, the moon was first discovered by Galileo in 1610. It is characterized by extreme volcanic activity, mostly caused by the gravitational pull of Jupiter and three other moons, Europa, Ganymede and Callisto. This super volcanic activity has shaped the surface of lo into giant mountains, some of which are larger than Mount Everest.

It is Io’s volcanic activity that has impressed scientists. Io holds onto volcanic gases in its atmosphere, which is surprising for a moon. Arielle Moullet is a researcher at the Harvard Smithsonian Center for Astrophysics who studied lo using giant telescopes. As she told Space.com, "What is special about Io is, it's pretty small so it's surprising it can retain an atmosphere. It's as big as our moon, so that's why people are looking for what is the main source of this gas."

Io may have this atmosphere because of its close proximity to Jupiter. Io is only 260,000 miles from the largest planet in our solar system. The intense gravitational pull of the large planet causes the layers below Io’s surface to heat up and explode into volcanic eruptions. The lava spews out into the atmosphere, freezes, and then eventually transitions into gas. Lo and behold, the moon gets an atmosphere.

And apparently, this atmosphere stinks. Since it is filled with sulfur gases from the volcanic eruptions, the moon generally smells like a mass of rotten eggs. Still, it remains a hot destination possibility for future NASA missions. As Moullet concludes, "It's an exciting place … It’s the most volcanic place in the solar system and as far as we know in the universe. It is unique."

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