“Super Earth” beyond our own solar system A new study suggests that life forms may exist for a longer period of time than Earth.
Researchers say rocky exoplanets with atmospheres dominated by hydrogen and helium have surfaces warm enough to accommodate liquid water.
The presence of liquid water is “favorable for life”, so these planets could provide conditions for life and exotic habitats, perhaps even for 8 billion years.
By comparison, the Earth is estimated to be 4.5 billion years old, with at least 1.5 billion years left to sustain life.
Some planets in the universe may even be more habitable than our home planet because they host a wider range of organisms.
Rocky exoplanets — planets outside our solar system — with primordial atmospheres dominated by hydrogen and helium, have surfaces warm enough to hold liquid water, the researchers say.
The new study was carried out by scientists at the University of Zurich in Switzerland and published today in the journal. Astronomy of nature.
The authors say these super-Earths are likely “very little like our home planet” and could host organisms at very high pressures.
“Life on the planets described in this work will exist in conditions significantly different from most living things on Earth,” the authors say.
“Surface pressure in our results is on the order of 100-1000 bar, the pressure range of the ocean floor and troughs.
“There is no theoretical pressure limit for life, and some of the most extreme examples in the Earth’s biosphere thrive at around 500 bar.”
Billions of years ago, the early universe contained only hydrogen and helium, gases that were readily available in the materials that form planets around young stars like our sun.
Therefore, all the planets created an atmosphere dominated by these two elements, including the Earth.
“When the planet first formed from cosmic gas and dust, it collected an atmosphere composed mainly of hydrogen and helium — the so-called primordial atmosphere,” said study author Ravit Helled of the University of Zurich.
However, over the course of their development, the rocky planets, including Earth, lost this primordial atmosphere in favor of heavier elements such as oxygen and nitrogen.
When our planet first formed from cosmic gas and dust, it gathered an atmosphere consisting mainly of hydrogen and helium – the so-called primordial atmosphere.
However, other, more massive planets can collect much larger primordial atmospheres, which in some cases they can retain indefinitely.
“Such massive primordial atmospheres can also cause a greenhouse effect – just like Earth’s atmosphere today,” Helled said.
“So we wanted to find out if these atmospheres could help create the necessary conditions for liquid water.”
For the study, the team modeled nearly 5,000 exoplanets, some locked to their star and some free-floating, and modeled their development over billions of years.
The researchers took into account not only the properties of the atmospheres of the planets, but also the intensity of the radiation of the corresponding stars, as well as the internal heat of the planets radiated outward.
While on Earth this geothermal heat plays only a minor role in surface conditions, it may contribute more significantly on planets with massive primary atmospheres.
An exoplanet is any planet outside of our solar system. Most of them orbit other stars, but free-floating exoplanets called rogue planets orbit the galactic center and are not tied to any star (file photo)
The findings suggest that, depending on the mass of the planet and how far away it is from its star, these planets can maintain a temperate surface environment for 8 billion years, provided the atmosphere is thick enough—100 to 1,000 times thicker. than Earth.
“We found that in many cases, the primary atmosphere was lost due to intense radiation from stars, especially on planets that are close to their star,” said Marit Mol Lus, graduate student and lead author.
“But in cases where the atmosphere is preserved, suitable conditions for liquid water can arise.”
“In cases where sufficient geothermal heat reaches the surface, the radiation of a star like the Sun is not even required, so that the conditions on the surface that allow the existence of liquid water prevail.”
“Perhaps most importantly, our results show that these conditions can persist for very long periods of time—up to tens of billions of years.”
The researchers say instruments such as the James Webb Space Telescope, which is currently in space, and the Extremely Large Telescope, which is currently under development, should reveal more biomarkers in exoplanet atmospheres.
NASA CONFIRMS THAT THERE ARE OVER 5,000 PLANETS OUTSIDE OUR SOLAR SYSTEM
NASA confirmed that there are more than 5,000 known planets outside our planet. solar systemknown as exoplanets.
US space agency adds 65 more exoplanets online NASA Exoplanet Archivebringing the total as of April 1, 2022 to 5,009.
On March 22, that number was 5005, showing that four planets had been added to the total in just 10 days.
As of June 8, there are 5,044 exoplanets, according to the database.
Exoplanets discovered so far include small rocky worlds like Earth, gas giants many times the size of Earth. Jupiterand “hot Jupiters” in very close orbits around their stars.
The more than 5,000 exoplanets confirmed in our galaxy include many types, including a mysterious variety known as “super-Earths” because they are larger than our world and possibly rocky.
However, NASA emphasizes that only a “tiny fraction” of all planets has been discovered in the Milky Way galaxy alone.
Most exoplanets are gaseous, like Jupiter or Neptune, not terrestrial. NASA online database.
Most exoplanets are detected by measuring the obscuration of the star the planet passes in front of, which is called the transit method.
Another way to detect exoplanets, called the Doppler method, measures the “wobble” of stars due to the gravitational pull of orbiting planets.
