Jupiters moon, Europa. Credit: NASA/JPL-Caltech/SETI Institute
Planetary astronomers are extremely interested in exploring the moon Europa in search of life. Slightly smaller sized than Earths moon, Europa orbits monstrous Jupiter.
Below the strong ice crust there might be a worldwide ocean with more water than found on Earth. And, where there is water, there could be life. Like a dripping garden hose pipe, the ocean vents water vapor into area from geysers poking through fractures in the surface area, as first photographed by the Hubble Space Telescope in 2013.
The latest twist comes from archival Hubble observations, spanning 1999 to 2015, which discover that water vapor is continuously being renewed throughout one hemisphere of the moon. Thats a bit strange. The atmosphere is only one-billionth the surface area pressure of Earths atmosphere.
Unlike the geysers, this water vapor is not coming from Europas interior, but rather sunshine is causing the surface area ice to sublimate. A similar water vapor environment was just recently discovered on the Jovian moon Ganymede.
Europa is so amazing as a potential house of life it is a target of NASAs Europa Clipper and the Jupiter Icy Moons Explorer (JUICE) of the European Space Agency– prepared for launch within a decade.
Hubble Space Telescope observations of Europa have exposed the presence of persistent water vapor in its extremely rare atmosphere. Previous observations of water vapor on Europa have been associated with plumes erupting through the ice, as photographed by Hubble in 2013. The new results, nevertheless, reveal similar quantities of water vapor spread over a larger location of Europa in Hubble observations covering from 1999 to 2015. Even at the lower temperature, the brand-new observations recommend water ice is sublimating– that is, transforming directly from strong to vapor without a liquid stage– off Europas surface, simply like on Ganymede.
The ultraviolet STIS observations allowed Roth to identify the abundance of oxygen– one of the constituents of water– in Europas environment, and by translating the strength of emission at various wavelengths he was able to infer the presence of water vapor.
This photograph of the Jovian moon Europa was taken in June 1997 at a variety of 776,700 miles by NASAs Galileo spacecraft. A little smaller sized than Earths moon, Europa has a really smooth surface and the solid ice crust has the look of a cracked eggshell. The interior has an international ocean with more water than discovered on Earth. It could potentially harbor life as we understand it. Hubble Space Telescope observations of Europa have revealed the presence of consistent water vapor in its really tenuous environment. Hubble observations, covering 1999 to 2015, find that water vapor is constantly being replenished throughout one hemisphere of the moon. This is a various finding from Hubbles 2013 observations that discovered localized water vapor from geysers venting from its subsurface ocean. This water vapor originates from a various procedure totally. Sunlight triggers the surface ice to sublimate, transitioning directly into gas. This color composite Galileo view integrates violet, green, and infrared images. The view of the moon is revealed in natural color (left) and in boosted color designed to highlight subtle color differences in the surface (right). The brilliant white and bluish part of Europas surface is composed primarily of water ice, with very few non-ice materials. Long, dark lines are fractures in the crust, some of which are more than 1,850 miles long. The Galileo mission ended on Sept. 21, 2003, when the spacecraft was purposefully commanded to dive into Jupiters atmosphere, where it was ruined. Nevertheless, to this day scientists continue to study the information it collected. The Jet Propulsion Laboratory (JPL) in Pasadena, California handled the Galileo mission for NASAs Office of Space Science, Washington, DC. JPL is a running division of California Institute of Technology (Caltech). This image and other images and information gotten from Galileo are published on the Galileo objective house page. Background information and academic context are also readily available for the images. Credit: NASA, NASA-JPL, University of Arizona
NASAs Hubble Space Telescope observations of Jupiters icy moon Europa have exposed the presence of relentless water vapor– however, inexplicably, just in one hemisphere.
Europa harbors a huge ocean beneath its icy surface area, which might offer conditions hospitable for life. This result advances astronomers understanding of the climatic structure of icy moons, and assists prepare for prepared science objectives to the Jovian system to, in part, explore whether an environment half-a-billion miles from the Sun could support life.
Previous observations of water vapor on Europa have actually been related to plumes appearing through the ice, as photographed by Hubble in 2013. They are comparable to geysers in the world, but extend more than 60 miles high. They produce short-term blobs of water vapor in the moons atmosphere, which is just one-billionth the surface pressure of Earths environment.
The brand-new results, nevertheless, show similar amounts of water vapor spread over a bigger area of Europa in Hubble observations covering from 1999 to 2015. This suggests a long-term presence of a water vapor environment just in Europas tracking hemisphere– that part of the moon that is always opposite its instructions of movement along its orbit. The cause of this asymmetry in between the trailing and leading hemisphere is not fully comprehended.
This discovery is gleaned from a new analysis of Hubble archival images and spectra, using a strategy that recently led to the discovery of water vapor in the atmosphere of Jupiters moon Ganymede, by Lorenz Roth of the KTH Royal Institute of Technology, Space and Plasma Physics, Sweden.
” The observation of water vapor on Ganymede, and on the tracking side of Europa, advances our understanding of the environments of icy moons,” said Roth. “However, the detection of a stable water abundance on Europa is a bit more surprising than on Ganymede due to the fact that Europas surface area temperature levels are lower than Ganymedes.”.
Europa shows more sunshine than Ganymede, keeping the surface 60 degrees Fahrenheit cooler than Ganymede. The daytime high up on Europa is a freezing minus 260 degrees Fahrenheit. Even at the lower temperature level, the brand-new observations suggest water ice is sublimating– that is, changing directly from strong to vapor without a liquid stage– off Europas surface area, simply like on Ganymede.
To make this discovery, Roth explored archival Hubble datasets, selecting ultraviolet observations of Europa from 1999, 2012, 2014 and 2015 while the moon was at numerous orbital positions. These observations were all taken with Hubbles Space Telescope Imaging Spectrograph (STIS). The ultraviolet STIS observations allowed Roth to figure out the abundance of oxygen– one of the constituents of water– in Europas atmosphere, and by translating the strength of emission at different wavelengths he was able to presume the presence of water vapor.
This detection leads the way for extensive studies of Europa by future probes consisting of NASAs Europa Clipper and the Jupiter Icy Moons Explorer (JUICE) mission from the European Space Agency (ESA). Understanding the formation and advancement of Jupiter and its moons also helps astronomers gain insights into Jupiter-like planets around other stars.
These outcomes have been released in the journal Geophysical Research Letters.
Recommendation: “A Stable H2O Atmosphere on Europas Trailing Hemisphere From HST Images” by Lorenz Roth, 13 September 2021, Geophysical Research Letters.DOI: 10.1029/ 2021GL094289.
The Hubble Space Telescope is a project of worldwide cooperation in between NASA and ESA (European Space Agency). NASAs Goddard Space Flight Center in Greenbelt, Maryland, handles the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, carries out Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C.