The discovery could dramatically narrow the search for space creatures

The discovery could dramatically narrow the search for space creatures

The discovery could dramatically narrow the search for space creatures

Image of a red dwarf star orbited by a hypothetical exoplanet. Red dwarfs explode with intense flares that can over time strip nearby planets of their atmospheres, or render the surface inhospitable to life as we know it. Credit: NASA/ESA/STScI/G. bacon

An Earth-like planet orbiting an M dwarf—the most common type of star in the Universe—appears to have no atmosphere. This discovery could lead to a major change in the search for life on other planets.

Because M-dwarfs are so ubiquitous, this discovery means that the large number of planets orbiting these stars may also lack atmospheres and are therefore unlikely to harbor life.

The work that led to revelations about-the atmosphere GJ 1252b has a detailed description of the planet Astrophysical Journal Letters.

This planet orbits its star twice a day on Earth. It is slightly larger than Earth, and is much closer to its star than Earth is to the Sun, making GJ 1252b intensely hot as well as inhospitable.

“The pressure from the star’s radiation is enormous, enough to blow off a planet’s atmosphere,” said UC Riverside astrophysicist and study co-author Michelle Hill.

Earth also loses some of its atmosphere over time to the Sun, but volcanic emissions and other carbon cycling processes help replenish what is lost, making the loss barely noticeable. However, at greater proximity to a star, a planet cannot make up for the lost amount.

In our solar system, this is Mercury’s fate. It has an atmosphere, but one that is extremely thin, made up of atoms blasted from its surface by the Sun. These atoms escape into space due to extreme heating of the planet.

Illustration of the atmosphere being blown off a planet by a nearby star. Credit: NASA

To determine whether GJ 1252b lacks an atmosphere, astronomers made measurements Infrared radiation During a minor eclipse its light from the planet was obscured. This type of eclipse occurs when a planet moves behind a star and the planet’s light, as well as light reflected from its star, is blocked.

The radiation revealed the burning of the planet daytime temperature, estimated to reach 2,242 degrees Fahrenheit—so hot that gold, silver, and copper would melt on all planets. The heat, combined with the assumed low surface pressure, led researchers to believe there was no atmosphere.

Even with large amounts of carbon dioxide, which traps heat, the researchers concluded that GJ 1252b would still not be able to retain an atmosphere. “The planet could have 700 times more carbon than Earth, and still not have an atmosphere. It would form initially, but then decay and decay,” said Stephen Kane, UCR astrophysicist and co-author of the study.

M dwarf stars are more prone to flares and activity than the Sun, which further reduces the likelihood that the planets around them can retain their atmospheres.

“It’s possible that the condition of this planet could be a bad omen for planets further away from such stars,” Hill said. “This is something we will learn from the James Webb Space Telescope, which will look for such planets.”

Hill’s work on this project was supported by a grant from the NASA Earth and Space Science and Technology Program’s Future Investigators.

Earth’s solar neighborhood contains 5,000 stars, most of which are M dwarfs. Even if planets orbiting them were completely ruled out, there are still about 1,000 Sun-like stars that could be habitable.

“If a planet is far enough away from an M dwarf, it could potentially retain an atmosphere. We can’t yet conclude that all are rocky. the planet Mercury’s fortunes decline around this star,” Hill said. “I’m optimistic.”

Earth-like atmospheres are quickly destroyed by young stars

More information:
Ian JM Crosfield et al, GJ 1252b: A warm terrestrial super-Earth without an atmosphere, Astrophysical Journal Letters (2022). DOI: 10.3847/2041-8213/ac886b

quote: Discovery could dramatically narrow search for space creatures (2022, October 21) Retrieved 21 October 2022 from

This document is subject to copyright. No part may be reproduced without written permission, except in any fair dealing for personal study or research purposes. The content is provided for informational purposes only.

#discovery #dramatically #narrow #search #space #creatures

Related Articles

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button