Webb took this image of Europa using his own near-infrared camera. It may look a little strange to our eyes, but this camera sees things that we normally can’t detect! The large white area in the middle and to the right is the Taro Reggio region, where carbon was discovered. Credits: NASA, ESA, CSA, G. Villanueva (NASA/GSFC), S. Trumbo (Cornell University), A. Pagan (STScI).
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September 26, 2023
Earth is a paradise for life, but could other worlds in our solar system host simple living organisms? We’ve long known that Jupiter’s moon Europa has a saltwater ocean and a rocky sea floor. However, this strange ocean is hidden beneath a thick ice crust, so whether it contains any of the ingredients necessary for life has remained a mystery… until now!
Astronomers using the James Webb Space Telescope to study Europa have made a startling discovery: signs of carbon dioxide on the moon’s surface! This is very exciting because carbon is thought to be essential for life. Finding it does not mean that life has been discovered, but it is a sign that life may exist.
This image of Europa (taken by NASA’s Galileo probe) shows the moon’s icy surface as it naturally appears to our eyes, rather than the infrared view provided by Webb. The dark lines are cracks. Could carbon from the ocean rise through cracks and settle on the surface? Image source: NASA/JPL-Caltech/SETI Institute.
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Carbon dioxide doesn’t last long on the moon’s surface, so it must have gotten there recently, but how? The carbon was discovered in an area called Taro Reggio, where the surface ice appears relatively fresh. This is an indication that water from the secret ocean was able to pass through the lunar crust, perhaps through cracks, and reach the surface. Therefore, the carbon is likely to come from the ocean. Other observations of Taro Regio made with the Hubble Space Telescope, showing ocean salt on the surface, confirm this claim.
This is particularly exciting, because drilling through the ice crust to explore the ocean would be extremely difficult. If ocean samples break out of the ice and reach Taro Reggio, as they appear to be doing, they will be easier to study.
Scientists hope we can follow up these discoveries with observations from ESA’s Jupiter Icy Moons Explorer (JUICE), which will launch in April 2023. JUICE will make detailed observations of Europa, as well as two other icy moons: Ganymede and Callisto. A closer look at Europe will help us determine its suitability for life.
Do you think there could be extraterrestrial life in Europa’s secret ocean? If so, what would it look like?
Strange fact: Webb is the largest and most powerful telescope ever launched into space. It is operated jointly by NASA, the European Space Agency and the Canadian Space Agency (CSA).
James Webb Space Telescope, drawn by an artist. Source: ESA/ATG medialab.
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