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17 exoplanets discovered by NASA have oceans and possibly extraterrestrial life

An exciting new study by NASA has significantly expanded the horizons of our search for extraterrestrial life. This study reveals that 17 exoplanets, worlds located outside our solar system, could potentially harbor oceans of liquid water beneath their icy surfaces. This discovery holds profound implications for our understanding of life’s possibilities beyond Earth.

The research team, pioneering in their approach, has calculated the geyser activity on these exoplanets. This is a first-of-its-kind estimate, offering a novel method to observe signs of life in distant worlds. Intriguingly, two of these exoplanets are sufficiently close to enable telescopic observation of these potential eruptions.

Exoplanets, oceans, and the “habitable zone”

Traditionally, the search for extraterrestrial life focuses on exoplanets residing in the “habitable zone” of their stars. This zone is defined by the range of distances where liquid water can exist on a planet’s surface.

However, this study suggests that life could also exist on planets outside this zone if they possess oceans under ice crusts, heated internally. This theory is supported by examples within our own solar system, such as Jupiter’s moon Europa and Saturn’s moon Enceladus.

Dr. Lynnae Quick of NASA’s Goddard Space Flight Center, the lead author of the study, explains, “Our analyses predict that these 17 worlds may have ice-covered surfaces but receive enough internal heating from the decay of radioactive elements and tidal forces from their host stars to maintain internal oceans.”

This internal heating could also result in cryovolcanic eruptions, akin to geysers. Dr. Quick continued, “Thanks to the amount of internal heating they experience, all planets in our study could also exhibit cryovolcanic eruptions in the form of geyser-like plumes.” 

Estimating conditions on exoplanets

The team recalculated the surface temperature estimates of each exoplanet, using the known surface brightness and other properties of Europa and Enceladus as models. They calculated the total internal heating of these exoplanets by analyzing the shape of their orbits to determine the tidal heat generation and added the expected heat from radioactive activity.

These calculations of surface temperature and total heating determined the thickness of the ice layers on each exoplanet, as the oceans beneath them cool and freeze at the surface while receiving heat from within. The team then compared these data with Europa’s characteristics, using Europa’s geyser activity as a conservative baseline to estimate the geyser activity on the exoplanets.

Geyser activity: A marker for detecting life

The team’s predictions indicate that the surface temperatures of these exoplanets are up to 60 degrees Fahrenheit (16 degrees Celsius) colder than previously estimated. The estimated thickness of the ice shells varies significantly, ranging from approximately 190 feet (58 meters) for Proxima Centauri b and one mile (1.6 kilometers) for LHS 1140 b, to 24 miles (38.6 kilometers) for MOA 2007 BLG 192Lb.

This compares to an estimated average of 18 miles (almost 29 kilometers) for Europa’s ice shell.

The predicted geyser activity also shows a wide range, starting from a mere 17.6 pounds per second (about 8 kilograms/second) for Kepler 441b, escalating to 639,640 pounds/second (290,000 kilograms/second) for LHS 1140b, and reaching a staggering 13.2 million pounds/second (six million kilograms/second) for Proxima Centauri b.

These figures stand in contrast to Europa’s geyser activity, which is estimated at 4,400 pounds/second (2,000 kilograms/second).

Alien life in exoplanet ocean geysers

Dr. Quick, presenting her research at the American Geophysical Union meeting, emphasized the potential for detecting geological activity on these exoplanets through their geyser activity.

As exoplanets like Proxima Centauri b and LHS 1140 b pass in front of their stars, telescopes may observe water vapor dimming or blocking starlight. This sporadic detection of water vapor could indicate cryovolcanic eruptions, offering clues to the planets’ habitability.

For planets not crossing their stars from our viewpoint, advanced telescopes could detect geyser activity through light reflected from the exoplanet. Such observations could reveal the composition of the geysers, further assessing the potential for these distant worlds to support life.

In summary, this NASA study not only opens new avenues in the search for extraterrestrial life but also challenges our understanding of where life can exist in the universe. With continued research and technological advancements, we edge closer to answering the age-old question: Are we alone in the universe?

The full study was published in The Astrophysical Journal.


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