A rocky planet discovered in the constellation Virgo could change the way we look for life in the universe
A newly discovered planet could be our best chance to study the atmospheres of planets outside the solar system, according to new international research led by UNSW in Sydney.
The planet, known as Gliese 486b (pronounced Glee-seh), is a super-Earth: that is, a rocky planet, larger than Earth but smaller than ice giants like Neptune-Rahab and Uranus-Uron. It orbits a red dwarf star about 26 light-years away, making it a close neighbor, galactically speaking.
With a surface temperature of 430 degrees Celsius, Gliese 486b is too hot to support human life. But studying its atmosphere could help us understand whether a similar planet might indeed be habitable for humans—or whether they might support other forms of life.
The findings were published this weekend in Science.
Possibility to examine the composition of the atmosphere of a planet outside the solar system
"This is the kind of planet we've been dreaming about for decades," says Dr Ben Mont, astronomer and lecturer at UNSW Science and co-author of the study.
"We've known for a long time that Earth-sized rocky planets must exist around nearby stars, but we didn't have the technology to look for them until recently. This finding has the potential to change our understanding of planetary atmospheres."
Like Earth, Galiza 486b is a rocky planet - but that's where the imagination ends. Our new neighbor is about 30 percent larger and almost three times heavier than Earth. Its surface may be hot enough to melt lead, and may be filled with glowing rivers of lava.
A planet slightly larger than Earth is not a rare phenomenon, but Gliza 486b is special for two main reasons: first, its heat 'inflates' the atmosphere and helps astronomers make atmospheric measurements; And secondly, it is a planet that was discovered by the transit method, which means that it crosses its star from our point of view on Earth - which allows scientists to perform an in-depth analysis of its atmosphere.
"Exploring (super-Earths) is a challenging thing because we don't have samples in our own backyard," says Dr. Montet. "Gliese 486b will be the planet we study for the next 20 years."
Lessons from the atmosphere
A planet's atmosphere can reveal a lot of information about its ability to support life. For example, a lack of an atmosphere might indicate that that planet's sun is volatile and prone to high interstellar activity - making the chance of life developing impossible. On the other hand a healthy and long-lived atmosphere could indicate that conditions are stable enough to support life. Both possibilities help astronomers solve part of the puzzle of planet formation.
"We think that Galiza 486b could have retained some of its original atmosphere, despite being so close to its red dwarf," says Dr. Montet. "Everything we learn about the atmosphere will help us better understand how rocky planets form."
As a former planet, Gliese 486b gives scientists two unique opportunities to study its atmosphere: first when the planet passes in front of its star and a fraction of the star's light shines through its atmospheric layer (a technique called 'transmission spectroscopy'); Then when starlight illuminates the surface of a star as it orbits around and behind the star (called 'emission spectroscopy').
In both cases, scientists use a spectrograph - a tool that splits light according to its wavelengths - to decipher the chemical composition of the atmosphere. "This is the best planet for emission spectroscopy studies of all the rocky planets we know," says Dr. Montet. "It's also the second best planet for studying transmission spectroscopy."
Life on a Glide 486b
Galiza 486b is a great place for astronomers - but you wouldn't want to live there, says Dr Montet. "With a surface temperature of 430 degrees Celsius, you won't be able to get out without a spacecraft," he says.
"Gravity is also 70 percent stronger than on Earth, which makes walking and jumping difficult. Someone who weighs 50 kilograms on Earth will feel like he weighs 85 kilograms on Glyza 486b.”
“On the plus side, the planet's rapid transit around its star means that interstellar visitors will have a birthday every 36 hours. They just have to hope the party isn't disrupted. The planet is really close to its star, which means you'll really have to watch out for star storms," says Dr. Montet.
"The effects can be as harmless as beautiful aurora events covering the sky, or ones that completely wipe out electromagnetic systems."
But despite these dangers of life on Gliese 486b, Dr. Montet recommends visiting it: "If humans can travel to other star systems in the future, this is one of the planets that will be on our list," he says. "It's so close and so different from the planets in our solar system."
Narrowing down the search for habitable planets
The research was part of the CARMENES project, a consortium of eleven Spanish and German research institutions looking for signs of low-mass planets around red dwarf stars.
Red dwarfs are the most common type of star, accounting for about 70 percent of all stars in the universe. They are likely to have more rocky planets than around Sun-like stars.
Based on these numbers, the best chance of finding life in the universe may be to look for it around red dwarfs, says Dr. Montet. "Red dwarfs are known to have a lot of stellar activity, such as coronal flares and eruptions," says Dr. Montet. "This type of activity threatens to destroy the planet's atmosphere.
"Measuring the atmosphere of Galiza 486b will advance us on whether to consider looking for signs of life around red dwarfs."
The findings were made possible by data from NASA's all-sky survey, called the "Transiting Exoplanet Survey Satellite" (TESS) mission and telescopes in Spain, the USA, Chile and Hawaii.
Almost 70 researchers from all over the world participated in the study. "This is an interesting period in astronomy," says Dr. Montet. “TESS produces all this data, but it is more information than any one person or group can analyze.
"Citizen scientists who enjoy astronomy have an opportunity to help check astronomical data, whether it's confirming the existence of a planet or searching for planets using the transit method. "This type of collaboration between professional astronomers and amateurs really helps advance the scientific field."
"The easiest way to get involved is to create an account and start looking at TESS data," he says. "You don't even need a telescope for that."
"Who knows - maybe you'll even find the next planet the size of Earth?"
More of the topic in Hayadan:
3 תגובות
To Judah
I had a dream that Bibi was my friend and that he was afraid of going to prison, so I shouted to everyone who heard "Forgive him, forgive him, he didn't really mean it"
"The planet, known as Gliese 486b (pronounced Glee-seh)"
Why not write in Hebrew: pronounced glise
Since it has been proven that on the "Super Earth" there is no room for installation towards elections in the near future, it is unlikely that human life exists on it in the trouble we know from Israel. At most, only collect vaccine vials that have not been kept in deep refrigeration.