Of all the celestial bodies in our solar system, many scientists think that one of the most likely candidates to find extraterrestrial life on is one of Jupiter’s moons called Europa. Evidence was so strong for water, an essential ingredient for life as we know it, on Europa that it was deemed a high-priority target for investigation by NASA. Europa has been passed by several spacecraft as part of scientific studies over the years. Images from the spacecraft is seen in the composite image below.
The Europa image on the far left was snapped in 1979 by the Voyager 1 spacecraft, the middle image was taken by Voyager 2 in 1979, and the image on the right was snapped by the Galileo spacecraft in the late 1990s. Scientists have had evidence that liquid water is present under the icy and cracked surface of the moon. For the first time, scientists have detected water vapor above Europa’s surface.
Scientists measured the vapor by looking at Europa using a telescope in Hawaii. The confirmation of water vapor above Europa helps scientists to understand the inner workings of the moon better. One critical item is that the presence of the water vapor supports the idea, of which scientists are now confident that there is a liquid water ocean under the frozen surface of the moon.
The team says that the water ocean on Europa is possibly twice as big as Earth’s oceans under the miles thick shell of ice. The team notes that two of the three elements required for life are common in the universe, but liquid water is rare. While liquid water hasn’t been confirmed directly, finding water vapor is said to be the next best thing.
The team observing the moon said that in 17 nights of continuous observations, they detected the distinct signal of water vapor once. Scientists hope to confirm liquid water when Europa Clipper arrives in the mid-2020s.