NASA has found what appear to be water vapor jets shooting from Europa’s southern pole. Jupiter’s ice-covered moon is believed to contain underground oceans, say NASA scientists on Thursday. The observation of vapor plumes was made from the orbiting Hubble Space Telescope.
Planetary scientist, Kurt Retherford, from the Southwest Research Institute in San Antonio, Texas, said this could possibly affect future scientific assessments. If the water vapor is verified, scientists may need to reassess whether the moon contains the right conditions to support life. Retherford spoke to reporters in a conference at San Francisco’s American Geophysical Union.
Retherford stated that the discovery has only been observed in one position, and it’s too early to guess whether it has a global effect or just an isolated occurrence.
Researchers observed these water jets shooting a distance of 125 miles off of the surface of Jupiter’s moon. The Hubble Space Telescope was aimed at Europa’s south polar region this time last year, when it captured the anomaly. The telescope was also aimed at Europa in October 1999 and November of 2012, but did not find any plumes at those times. In the late 1990’s there were also no vapour plumes detected when NASA’s Galileo spacecraft made nine passes by Europa.
Scientists believe that the water vapor may be caused by Jupiter’s massive gravitational forces when the moon is at its farthest distance from Jupiter. The varying gravitational forces create stress cracks in the moon’s polar ice through which water vapor is escaping.
A planetary scientist from Santa Cruz’s University of California, Francis Nimmo, thinks that when Europa is closer to Jupiter the massive gravity forces the cracks together and the water plumes have no way of escaping. Now that the moon is at its farthest distance from Jupiter, the gravity is at its minimum force opening the cracks in the ice allowing the water vapor to escape.
Another theory is that the plumes are the product and outcome of frictional heat being created from ice blocks rubbing together. Yet another theory is that Hubble actually timed the capture of the images to a recent comet strike on Europa.
This is actually not the only time such an observations been made. Saturn’s moon Enceladus has been observed shooting similar plumes much farther. This is not surprising as there is 12 times less gravity on Enceladus than there is on Europa. What is surprising is that both moons appear to being ejecting out close to the same amount of water. Scientists estimate the vapor jets are spewing approximately seven tons of water per second.
The observations on Encleladus are being made by NASA’s Cassini spacecraft which is orbiting around Saturn and its moons. Saturn has 60 moons which is a very recent discovery. Eight of the moons have yet to be named. However, it’s Jupiter with the most moons in the Solar System with a count of 63. Cassini entered the position around Saturn in 2004 after its NASA launch in 1997.
Since the discovery of the water vapor jets, scientists have planned for future observations of Europa. They will also look at archives of the Galileo data when Europa was at a similar distance from Jupiter. The Galileo space craft is now defunct since September 2003.
NASA planetary scientist, Jim Green, says that now they know where the plumes of Jupiter’s moon Europa occur, it will narrow down their search of comparable data. Either finding the water jets are great results or Green thinks they may have uncovered another controversy.
By Brent Matsalla