extraplanetary life and exoplanets

8/10/2019 Extraplanetary Life and Exoplanets

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Extremophiles, Exoplanets,and the Possibility of Life on

Europa

Presented to you by Claire, Colby, Ellen, and Sam


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Extremophiles

Extremophiles are any life form, microbial or otherwise, that arable to live and thrive in physically or geochemically dangerousconditions that would be impossible for other creatures to existin.

Recently, as documented in Astronomy magazine, extremophile

life in the form of microbes has been documented to live half amile below the icy surface layers of Antarctica.


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What They Found

Researchers have found what could be described as the first hinof a massive microbial ecosystem buried beneath the ice in arange as large as 5 million square miles.

Samples collected from Lake Whillans, which resides beneath aglacier, and found that the organisms there are not just survivin

but thriving. These life forms pull their energy from rocks, and take carbon

from CO2.


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What This Means for Life in the Universe

Both Jupiters moon Europa and Saturns moon sharea similar environment with that in which therecently discovered Antarctic life thrives.

This suggests that the same microbial life theyfound deep under the ice could survive (if notthrive) in the oceans of other planets or moons.

The tidal effects of Jupiter especially support thepossibility of life on its moon Europa, because itcauses a heating effect of around 250 degreeskelvin.


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The Environment on Europa

The surface of Europa is frozen, with temperatures between 50and 100 kelvin (or between -369 and -279 degrees Fahrenheit. Tenvironment is not conducive to life, and is too cold for most lifas we know it to develop.

However, in 2013, it was discovered that plumes of liquid water

erupt from the ice at various locations throughout this icecovering, suggesting a liquid ocean underneath the icy surface.

This ocean is under constant pressure due to the gravitationaleffects of Jupiter.


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Origins and Maintenance of these Oceans

Europa has an iron center with an internal temperaturemaintained by the radioactivity of the rock at its core.This outputs an equivalent of 100 nuclear plants worth ofenergy into the ocean, keeping it heated at 250 degreeskelvin (or -9 degrees Fahrenheit)

Because of its elliptical orbit, this water does not freeze,thanks to the additional heat generated by the tidaleffects of Jupiter, which adds an additional terawatt ofenergy into the mix, raising the net internal temperatureto the levels needed for liquid water.


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Oxygen in the Ocean

At first glance, it would seem that only the simplest of organismcould survive in such an environment due to the lack of oxygen,however, the intense radiation from trapped charged particles iJupiters atmosphere that bombards Europa generates a plethorof oxidants.

These oxidants, mixed into the Europas oceans, create anenvironment very conducive to a more diverse biosphere.


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Terrestrial Life on Europa

There are species on Earth that could likely survive theconditions on Europa, including:

Desulforuds Audaxviator (bold traveler) survives morethan a mile beneath the Earths surface in completeisolation, without sunlight, oxygen, or organiccompounds. They survive by feeding off of chemical foodsources in the surrounding rocks, much like the recentlydiscovered life under Antarctica.

Tube Worms can live around underwater vents, living offthe microbial life that feeds off of these vents output.


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Exploring the Dark Oceans

In 2022, the European Space Agency hopes to launch a probereferred to as JUICE (JUpiter ICy moon Explorer) that would seras a flyby mission through the Jovian moons.

NASA has a concept for the Europa Clipper, which is currentlyslated for a 2025 launch that would sample the southern waterplume of Europa and flyby the moon, gathering data and snappipictures.

Actually entering one of the dark oceans is currently only a hopfor the future, as we test technology with the necessarycapabilities in similar environments here on Earth.


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Dark Oceans Throughout the Cosmos

If dark oceans exist in our solar system, they could easily existthroughout the galaxy, in all manner of moons or planets outsideour solar system.

Our galaxy, as we have discovered, has all manner of strangesystems and planets throughout it, and Dark Oceans would be n

stranger than any other.


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Exoplanet Systems

The first planet in another solar system wasdiscovered twenty years ago circling the Pulsar PSR1719-14. The orbit of this planet is the shortestknown, at only 2.2 hours per revolution.

Three years later, another planet was discoveredorbiting the sun-like star Kepler-90. Since then, wehave discovered seven total planets orbiting this star.

All in all, we have found upwards of 1800 exoplanetsin our part of the Milky Way, and we have foundseveral stars that harbor five or more stars.


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Diverse and Numerous Worlds

Worlds have been discovered that have an orbital period of twohours, and worlds have been discovered with an orbital period otwo thousand years.

We have even discovered Earth-sized worlds that lie in their stahabitable zones, where temperatures are just right for liquid

surface water. In addition to the 1800 planets we have confirmed discovered, w

have another 4000 that have been observed and are awaitingconfirmation.


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Habitable Planets

With the number of planets in the galaxy, it is absurd to thinkEarth is the only habitable world. After all, we havent evenobserved but a tiny fraction of nearby worlds, and theres a whouniverse out there to pick and choose from.

One of the planets around Gliese 876, Gliese 876b, spends its

entire orbit inside the habitable zone around a red dwarf, andcould very easily support life.

Gliese 667C has three planets inside its habitable zone, two ofwhich are Super Earths. Any of these could be conducive to life.


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The Possibilities of Life Beyond Earth

are endless. Intelligent life is not something we have observedanywhere off of earth, but that does not mean it does not exist. Aeven more common are microbial life forms, which can exist inalmost any environment, and sentient, but not sapient life.

Our capabilities to find and study this life may be limited by thescope of our technology for now, but as we continue to advance,there is nothing suggesting that we wont find life on worlds outsour own solar system, or even beyond our own galaxy. Perhapseven beyond our own universe?


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extraplanetary life and exoplanets

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