NASA scientists made an important discovery 40 light years away
NASA has discovered an Earth-like planet 40 light years away that could be a promising candidate for human habitation. The exoplanet, dubbed Gliese 12 b, is slightly smaller than our planet and has an estimated surface temperature of 107 degrees Fahrenheit – assuming it has no atmosphere.
Gliese 12 b is located just inside the habitable zone – the distance from the star , on which liquid water can exist on the surface of rotating planets, writes the Daily Mail.
Astronomers now plan to analyze Gliese 12 b to determine whether it has an atmosphere similar to Earth's, which could reveal whether the exoplanet can maintain the right temperature to form water on its surface, an important compound for supporting life.
As the Daily Mail notes, Gliese 12 b has been called “the closest Earth-sized transiting temperate planet to date” and is a candidate for future exploration with the $9.5 billion James Webb Space Telescope.
An international team of astronomers used NASA's TESS (Transiting Exoplanet Survey Satellite) to determine the location of Gliese 12 b.
These discoveries are usually made using the “transit method” – when a planet passes in front of its star, causing its brightness to drop. .
During an exoplanet's transit, light from the star passes through its atmosphere, absorbing some wavelengths that release gas molecules that telescopes such as the James Webb can detect.
The team found that Gliese 12 b has a much narrower orbit than Earth, meaning it crosses its cool red dwarf host, called Gliese 12, more often, orbiting once every 12.8 days.
“Gliese 12 b represents one of the best targets for studying whether Earth-sized planets orbiting cool stars can retain their atmospheres, an important step in improving our understanding of the habitability of planets throughout our galaxy,” says Shishir Dholakia. , doctoral student at the Center for Astrophysics, University of Southern Queensland (Australia).
The exoplanet's distance from its dwarf star is only seven percent of the distance between Earth and the Sun, providing it with 1.6 times more energy.
However, conditions suitable for life on Gliese 12 b depends on whether it has the same type of atmosphere as Earth, which brings its temperature closer to our planet's average 59 degrees Fahrenheit.
“The atmosphere holds heat and, depending on the type, can significantly change the actual surface temperature,” explains Dholakia. “We give the “equilibrium temperature” of the planet, which would be what it would be if the planet had no atmosphere.”
< p>The team compared Gliese 12 b to Venus, reporting that it is about the same size and receives slightly less energy from its star – about 85 percent.
But because Venus does not have an atmosphere to block the sun's harmful rays , a greenhouse effect arose on it, the temperature reached 752 degrees Fahrenheit.
“Earth is habitable, but Venus is uninhabitable due to complete loss of water,” says Larissa Pailthorpe, a doctoral student at the University of Edinburgh and University College London.
“Because Gliese 12 b is between Earth and Venus in temperature, “its atmosphere can tell us a lot about how planets evolve to become habitable,” she added.
An important factor in understanding whether an exoplanet might be habitable is the level of storms emitted by its star.
Typically, red dwarfs are magnetically active, resulting in frequent X-ray flares that can destroy the atmosphere.
However, the team is very hopeful that this is not the case, since Gliese 12 Star showed no signs of extreme storms or behavior.
Astronomers have already discovered about 5,000 such planets, but it is estimated that there are more than a trillion exoplanets in the Milky Way alone – so far only a few are thought to have the environment necessary to support life.< /p>
“We know of only a few temperate planets similar to Earth that are close enough to us and meet the other criteria needed for this kind of research,” said Michael McElwain, a research astrophysicist at the Center for Space Research. NASA Goddard Flight and co-author of the Gliese 12b study.
“To better understand the diversity of atmospheres and the evolutionary outcomes of these planets, we need more examples like Gliese 12b,” he added.
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