A new instrument aboard NASA’s Europa Clipper may be sensitive enough to detect any life emanating from the plumes of far-off icy moons like Saturn's Enceladus and Jupiter's Europa. Over the years, scientists have found evidence of water underneath both moon’s frozen surfaces.
The instrument dubbed the SUrface Dust Analyzer (SUDA) on the Europa Clipper, can detect even the slightest biological signatures in one out of hundreds of thousands of grains of ice from plumes on Europa and Enceladus. "Our results give us more confidence that using upcoming instruments, we will be able to detect lifeforms similar to those on Earth, which we increasingly believe could be present on ocean-bearing moons," said Fabian Klenner, an astrobiologist and study lead author at the University of Washington, in a press release. Details on the study were published in Science Advances.
Unlocking the Secrets of Icy Moons
The team simulated how SUDA would detect any biological signatures in space by feeding a stream of water through a vacuum so it would disintegrate into water droplets or vapor. Then, they used a laser beam and a mass spectrometer to mimic the instruments. The team used a bacterium called Sphingopyxisalaskensis to test the instrument's capability to detect tiny organisms.
"They are extremely small, so they are, in theory, capable of fitting into ice grains that are emitted from an ocean world like Enceladus or Europa," Klenner said in the press release. Using these tools, the team found that SUDA could detect the bacteria or pieces of it in a tiny fragment of ice. Its ability to analyze single grains of ice might be more successful than probing a large sample with billions because biological material might be concentrated in a smaller sample. This breakthrough with SUDA not only showcases its promising capabilities but also introduces a new chapter in our space exploration timeline. Here's a look at the journey that brought us to this point.
Read More: European Spacecraft JUICE Travels to Jupiter's Icy Moons
1972: Voyager 2 Identifies Frozen Water on Europa
Enceladus and Europa are places of scientific interest because of their observed water features. In 1972, researchers first noticed that Europa's surface was covered in frozen water using spectroscopic observations. When NASA's Voyager 2 spacecraft passed close enough to Europa in 1979, it took images of the moon and showed its unusually smooth surface.
The images gave some clues to ice opening cracks along its featureless surface. Further observations with the Galileo spacecraft in the 90s led researchers to suspect that underneath Europa's frozen shell of ice is a large salty ocean. The ocean is about 40 to 100 miles deep and is one of the places experts suspectmight harbor life outside of Earth.
Read More: With Icy Volcanoes, the Moon Europa Is Obscure, Along With These 3 Other Moons
2019: Hubble Space Telescope Finds Water Plumes on Europa
The plumes from Europa were only more recently observed with the Hubble Space Telescope and some reanalysis of data from the Galileo spacecraft. In 2019, researchers directly observed the first evidence of water plumes in Europa. The water, whether a spacecraft probes it as the now-defunct Cassini mission did with Enceladus, could reveal if Europa's Ocean is hosting some form of life.
Because Europa’s Ocean is shrouded in a thick layer of ice, it’s difficult to study what is underneath. Researchers can get around this by studying its plumes. Analyzing the plumes might be the answer to whetherthere is life in its subsurface ocean.
Read More: Astronomers Catch Water Erupting from Plumes on Jupiter’s Icy Moon Europa
2023: James Webb Telescope Snaps Plumes on Enceladus
As for Enceladus, just last year, the James Webb Space Telescope (JWST) captured signs of large plumes rushing from the Saturnian moon. The vapor jets were about 6,000 miles long, roughly the distance between Boston, Massachusetts, and Santa Monica, California, and back.
Before JWST, the Cassini probe found cracks near Enceladus' south pole that seemed to emanate plumes of gas and ice fragments. Other evidence collected from Earth's telescopes and other space probes suggests that Europa vents its water vapor similarly to Saturn's Enceladus. But scientists need more observations to know for sure.
Read More: NASA's Europa Clipper Will Find Out if Europa is Habitable
The Europa Clipper Mission: The Quest for Life Continues
NASA's Europa Clipper mission, set to launch in October 2024, will explore Europa to see if an ocean of water exists underneath its surface.If an ocean is underneath Europa's surface, tides will warp it. So, the spacecraft will measure any flexing on the moon's surface and take scans of the entire moon during its 50flybys. The red bands or red scarring found on the surface are thought to be made of salts and sulfurs that mixed with the moon's water ice and werebaked by radiation.
The team suspects that if bacteria are present in the oceans of these icy moons, they might rest towards the ocean's surface, similar to the types found on Earth's oceans. When the plumes shoot out into space, the cellular material would be in the ice grains within the plume, which the Europa Clipper could then pick up on."We here describe a plausible scenario for how bacterial cells can, in theory, be incorporated into icy material that is formed from liquid water on Enceladus or Europa and then gets emitted into space," Klenner said in a statement.
From the discovery of water beneath the frozen surfaces of Enceladus and Europa to the cutting-edge SUDA instrument on NASA's Europa Clipper, we edge closer to answering the age-old question: are we alone in the universe?
Article Sources:
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review them for accuracy and trustworthiness. Review the sources used below for this article:
Bulletin of the American Astronomical Society. A comparative look at Europa and Enceladus, two active ocean worlds
Eureka Alert. Signs of life detectable in single ice grain emitted from extraterrestrial moons
Sciences Advances. How to identify cell material in a single ice grain emitted from Enceladus or Europa
Nasa.gov. Europa: Facts
Nasa.gov. Cassini at Enceladus
Webbtelescope.org. Webb Maps Surprisingly Large Plume Jetting From Saturn’s Moon Enceladus
Nasa.gov. Why Europa
