NASA: Life on Another Planet?



Caption: Imagine standing on the surface of the exoplanet TRAPPIST-1f. This artist’s concept is one interpretation of what it could look like.
Credit: NASA/JPL-Caltech. AP Images.

About 40 trillion light years outside our solar system, in the constellation Aquarius, a system of planets exists that orbit a cool dwarf star. According to NASA, “this exoplanet system is called TRAPPIST-1, named for The Transiting Planets and Planetesimals Small Telescope (TRAPPIST) in Chile.” Calculations by scientists suggest that conditions on these exoplanets might be right for liquid water to exist on their surface. Follow-up observations are needed to find out whether they can support some form of life, and what kind. Astrobiologists will likely work overtime to create simulations on computers in attempt to recreate likely conditions on these rocky planets.

Whether life on these planets can be sustained is a topic of uncertainty and debate among scientists. A red dwarf star very active in its early years, often shooting off light flares and spurts of radiation. Although red dwarfs emit much lower energy than our own sun, which is a yellow dwarf star, they live much longer – perhaps by trillions of years.

Science suggests after a billion years or so, a red dwarf may calm down enough to allow planets nearby to be habitable. The planets are orbiting the red dwarf orbit so closely that they complete a full orbit in anywhere from 1.5 days to 20 days and therefore are tidally locked. This means that one half of each planet is always facing the red dwarf while the other half stays frozen.

A recent NASA study:

that relied on computer simulations of red dwarf planets, found that the flaring tempers of young red dwarfs, with their bursts of high-energy X-rays and ultraviolet emissions, could actually strip oxygen from the atmospheres of nearby planets. However, bursts of radiation also break molecules into atoms and through ionization some electrons are knocked free of their atoms, sending them to free float into space. These electrons are negatively charged and by consequence attract positive charge. Hydrogen, being the lightest element, and having positively charged electrons therefore escapes the atmosphere, presumably leaving the atmosphere heavier in elements such as oxygen and nitrogen. Oxygen and nitrogen, the building blocks of life, as we know it, could possibly allow life to develop and be sustained.

When scientists accounted for superflares and the release of radiation, it was found that oxygen and nitrogen would indeed escape the atmosphere along with the hydrogen molecules. The loss of oxygen and hydrogen would dry up the planet’s water supply before life could develop.

Some scientists maintain that life would adapt to the superflares and radiation. Tom Barclay, a senior research scientist at the NASA Ames Research Center in Moffett Field, Calif. says, “You have regular events, but life is used to this, it just deals with it. We certainly see life on Earth capable of hibernating for very extended periods of time. We see that life goes into a state where it shuts down, sometimes for years or decades. So I think we shouldn’t rule it out, but we should put a lot of effort into studying whether this is a place where we think life could thrive.”

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