NASA Finds a Crucial Life-Building Chemical on Jupiter’s Moon

Jupiter's icy moon Europa hides a deep saltwater ocean under its frozen crust, with twice as much water as Earth's oceans. This ocean, rich in chemicals, makes Europa a prime target in the search for life beyond Earth. In a new analysis of data from NASA's Galileo mission, scientists discovered ammonia-bearing compounds on Europa's surface — the very first such finding there. Ammonia is nitrogen-bearing, a key element for life.

Galileo Data Reveal Ammonia on Europa

According to NASA, researchers found weak spectral indications of ammonia-bearing material on the surface of Europa in data from the 1997 Europa flyby of the Galileo spacecraft. The NASA composite image highlights the red pixels, which represent the regions where the researchers found ammonia signals on the icy surface of Europa. The icy crust of Europa has a network of dark cracks and ridges that covers the entire surface. The ammonia deposits are aligned with these cracks. The researchers think that ammonia-filled water recently appeared in the cracks via cryovolcanic eruptions.

Implications for Europa's Ocean and Life

Ammonia causes a large decrease in the freezing point of water and can be readily decomposed by radiation. This implies that any ammonia present on the surface must have been transported recently from the ocean on Europa. The presence of ammonia is important because it contains nitrogen, which is a vital ingredient for life. The Europa Clipper spacecraft, which will arrive at Europa in 2030, is a NASA mission that will investigate Europa's surface and ocean for the presence of such compounds.