Astronomers have discovered a nearby exoplanet that may prove to be the first such world covered in water.
Jon Kelvey
https://uk.yahoo.com/news/astronomers-nearby-planet-entirely-covered-221640595.html
TOI-1452 b is an exoplanet slightly larger and more massive than Earth about 100 light years away from our planet in the Draco constellation. In a paper published Wednesday in The Astronomical Journal, researchers from the University of Montreal determine that the mass of the planet suggests it is largely made up of something less dense than rock, but denser than gas — a potential sign of a global ocean.
“TOI-1452 b is one of the best candidates for an ocean planet that we have found to date,” University of Montreal astrophysics PhD student Charles Cadieux said in a statement. “Its radius and mass suggest a much lower density than what one would expect for a planet that is basically made up of metal and rock, like Earth.”
TOI-1452 b first came to astronomers’ attention through Nasa’s Transiting Exoplanet Survey Satellite, or Tess spacecraft, which studies distant stars for telltale dips in their light that signify an exoplanet passing in front of, that is transiting, the star. Tess data suggested the existence of an exoplanet, but the observation was not definitive.
The star TOI-1452 b orbits is part of a binary star system, and Tess does not possess the power to resolve the individual stars in that system. The University’s Observatoire du Mont-Mégantic (OMM) observatory, however, along with new analytic methods, was able to confirm that TOI-1452 b exists.
“The OMM played a crucial role in confirming the nature of this signal and estimating the planet’s radius,” Mr Cadieux said. “This was no routine check. We had to make sure the signal detected by TESS was really caused by an exoplanet circling TOI-1452, the largest of the two stars in that binary system.”
An instrument installed on the Canada-France-Hawaii Telescope in Hawai’i then measured the planet’s mass.
Unlike Earth, which is a mostly rocky and metallic planet with water covering around 70% of its surface, TOI-1452 b appears to be made largely, but not entirely, of water, with about 30% of its mass coming from the liquid. That’s a sort of deep global ocean more akin to the deep waters believed to lurk beneath the icy crust of Saturn’s moon Enceladus than the oceans of Earth; water makes up less than 1% of our planet’s mass.
Exoplanets are located outside of our solar system.
It’s still not certain that TOI-1452 b is an ocean world, and just what that might mean for the chances of discovering alien life in its waters, but the researchers note that the James Webb Space Telescope should soon be able to help penetrate the mystery of this strange new watery world.
https://uk.yahoo.com/news/james-webb-telescope-finds-evidence-154427737.html
NASA’s new space telescope has been providing us with awe-inspiring images of the cosmos since it went into operation this summer.
The James Webb Space Telescope has already unveiled parts of the universe that had previously never been observed, as well as showcasing stunning images of the biggest planet in our solar system, Jupiter.
But the telescope’s capabilities don’t end there.
Scientists have found the first clear evidence of carbon dioxide in the atmosphere of an exoplanet, a breakthrough discovery that could open the door to similar observations on planets more hospitable to life.
That’s a planet that is outside of our solar system - in this case, a gas giant orbiting a star similar to our Sun, some 700 lightyears away.
"As soon as the data appeared on my screen, the whopping carbon dioxide feature grabbed me," said Zafar Rustamkulov, a graduate student at Johns Hopkins University and member of the JWST Transiting Exoplanet Community Early Release Science team, which undertook this investigation.
"It was a special moment, crossing an important threshold in exoplanet sciences".
James Webb's abilities
The findings, accepted for publication in the journal Nature, show that the telescope may therefore be able to detect and measure CO2 in the atmospheres of smaller rocky planets.
The planet, WASP-39 b, is a gas giant a little larger than Jupiter. It was first discovered in 2011, from ground-based observations of dimming of light from its host star as the planet passed in front of it.
Previous studies have revealed the presence of water vapour, sodium, and potassium in the planet’s atmosphere, but only James Webb’s superior infrared sensitivity was able to confirm beyond a doubt the presence of carbon dioxide.
"Detecting such a clear signal of carbon dioxide on WASP-39 b bodes well for the detection of atmospheres on smaller, terrestrial-sized planets," said Natalie Batalha of the University of California at Santa Cruz, who leads the team.
NASA says the results show the telescope’s ability to gather insights into the composition, formation, and evolution of planets across the galaxy.
"Carbon dioxide molecules are sensitive tracers of the story of planet formation," said Mike Line of Arizona State University, another member of this research team.
"By measuring this carbon dioxide feature, we can determine how much solid versus how much gaseous material was used to form this gas giant planet. In the coming decade, JWST will make this measurement for a variety of planets, providing insight into the details of how planets form and the uniqueness of our own solar system".
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