Since the discovery of the first exoplanets in the 1990s, many have wondered if we could find another one Terra, A place called Planet B.
Natalie Batalha, professor of astronomy and astrophysics at the University of California, Santa Cruz, watched, Science Of the exoplanets growing and changing since the first discoveries. Battle was a research associate and scientist on the Kepler mission, the first that can survey Earth-sized planets around other stars. The mission changed the science of the outer planets.
Compare: “In the first decade of the exoplanet, it was as if we were collecting postage stamps, discovering one planet at a time.” “But after launching the Kepler mission, we made a path in terms of sensitivity. We were able to discover hundreds of planets at once. (James Webb Telescope) will give us a new lens in studying the diversity of exoplanets. We are entering the third era of exoplanet atmosphere characterization.”
So far, the study of exoplanets has not revealed another Earth, which is unlikely, even with the launch of the James Webb Space Telescope in December. It will examine the atmospheres of exoplanets orbiting stars much smaller than our sun.
said Klaus Pontopedan, a Web project scientist at the Space Telescope Science Institute in Baltimore.
But the planets that will be studied by the telescope may be linked to an interesting idea: what if life occurred differently outside Earth? It’s a topic that the successors of the Webb Telescope will be able to investigate for decades to come.
“There really isn’t a B planet for us,” said Gil Tarter, an astronomer and former director of the SETI Research Center, who is currently president emeritus of SETI Research (an acronym meaning “life beyond Earth”). “Unless we figure out a way to solve all the global problems we face here and how to mitigate those challenges, wherever we go we will create the same problems we created here on this planet. There is no emergency exit.”
What is Planet B?
If there is a Planet B somewhere in space, is it more like Earth, or will it surprise us and be something completely unexpected?
“When we find Planet B, it should be a true twin planet of Earth, a planet orbiting a sun-like star, in an Earth-like orbit, with a thin atmosphere, oceans and continents,” explains Sarah Seeger, astrophysicist, planetary scientist and professor at the Institute Massachusetts Technology (MIT).
As astronomers were keen to point out, each telescope brought many unexpected discoveries beyond what was expected to be observed. Planet B might be similar.
“I want us to find life in something that doesn’t look much like Earth,” said Nicole Lewis, an astrophysicist and professor of astronomy at Cornell University.
“It’s safe to say that if it looks and smells like Earth, it’s probably Earth and therefore has life in it. But I don’t think that’s an adventure enough, so I’d like to start looking at atmospheric chemistry and planetary temperature which is probably a little bigger than Earth “.
The search for Planet B is not easy: it is too complicated to balance what we understand about life on Earth with what we don’t.
On Earth, even in the most extreme environments, life depends on carbon, liquid water plays its role as a biochemical solvent and DNA encodes genetic information, Batalha explained. It stands to reason that life elsewhere is likely carbon-based and water-dependent. Hydrogen, oxygen, and carbon are very abundant elements in the universe.
“Planet B, from our point of view, is a planet with liquid water on its surface,” Batalha said. “In addition to searching for biometrics, I think the best thing the Webb Telescope can do is look for signs of a habitable environment.”
It’s also possible that if conditions aren’t right elsewhere, life will find a way “to be in niches and perhaps even find other biochemical pathways when pressed.”
Perhaps life on another planet could use methanol instead of water for biochemistry. Or in the future, we will develop different scales and signatures to detect life and habitable planets.
The main thing the astronomers we spoke with agreed on was to be open-minded in the search for life – and to respect what is always there.
“If there is a Planet B, it is not our planet by definition,” Patalha said. “We talked about the idea of searching for habitable worlds as if they were our own. And if a planet is exactly like Earth with conditions for life, it is by definition a living world, not ours.”
sign of life
The Webb telescope is unlikely to be the main tool in identifying signs of life on another planet. The mission is for future telescopes, as shown by the recently launched Astro2020 survey (a survey conducted every ten years), which will monitor 25 potentially habitable exoplanets.
“We know how to find this planet, but the search has been delayed until 2045 or later,” Seeger said.
According to the astronomer, life as we understand it needs proper energy, fluids and temperature, what happens when a possible sign of life is discovered? Finding the signal is great — but figuring out the next step is crucial, Seeger said.
Lewis of Cornell University says that if it is determined that there is no other way to create a possible sign of life, it will take team work to advance the discovery. Engaging with chemists, biologists, and people from various disciplines outside of astronomy and planetary sciences can point the way forward.
“I hope we’ll be careful and engage with all the experts involved to try to understand if this is actually a signature that could just mean there is life on this hypothetical planet and then announce something to the public,” Lewis said.
It probably won’t be a unique moment that will happen overnight.
“It will be a long process to study the biochemistry of the world because, in any bio-signature we can find, it is necessary to prove that no other abiotic form (physical, not biological) produces this signal. This will take a long time,” Patalha explained.
The search for life is a journey that involves taking new paths, asking new questions, and developing new hypotheses. Experiments will be designed to answer these questions.
Patalha hopes that future telescopes will help scientists complete a planetary count, including how often Earth-like planets occur in the galaxy. “I think the most important thing is that we keep moving forward and moving forward,” he said.
Understanding the significance of what scientific observations and findings mean in the search for life is a priority for NASA, as written in a recent report. Led by Jim Green, chief scientist at NASA, and document It encourages the creation of a new scale to assess evidence that answers the question of whether we are truly alone.
“Having a scale like this will help us understand where we are in terms of searching for life at specific sites, the capabilities of the tasks, and the technologies that help us in the search,” Green wrote in a statement.
The seven levels of this scale reflect the rungs of the ladder in the way of declaring the encounter with extraterrestrial life.
“So far, we’ve left everyone thinking there are only two options: Either it’s life or it’s not life,” Marie Vojtek, head of NASA’s astrobiology program, recalls in a statement. “We need a better way to share the excitement of our discoveries and show how each discovery paves the way for the next, so we’ll engage the public and other scientists along the way.”
Tarter of the SETI Research Center believes that the answer to finding life may rely on technical fingerprints rather than biometrics, because the evidence for past or current technology is “potentially less ambiguous.”
Biometrics can be gases or particles that show signs of life. Technological signatures are tags that can be generated by intelligent life.
It’s “something we can look at to indicate that not only does life exist on a distant planet, but that it logically qualified and created or created something that we can observe with our ever-increasing abilities to look at the universe,” she said.
Since the 1960s, scientists have been listening for radio signals or looking for wavelengths of optical light that indicate someone is sending something.
Tarter said that if an intelligent civilization “modifies its environment, such as building solar collectors to collect a lot of energy and use it on the planet’s surface, it is possible that we can discover the consequences of using this technology.”
Tarter is encouraged by investing in missions that investigate the search for past and present life in our solar system, as are many of the missions. Exploring Mars, the dragonfly that will explore Saturn’s moon Titan and Europa Clipper, which will fly through vapors of oceanic material on Jupiter’s moon.
She believes that future missions will dig deeper into the planets than the persistent rover, which collects rock samples on Mars. Drilling more than 10 meters deep can show evidence of ancient technology.
“I think in just a century we will have done a good job of exploring life, but I really like to keep an open mind,” Tarter said.
If the samples collected by Perseverance, which will be brought back to Earth on future missions in the 2030s, show evidence of ancient biological life on Mars, that raises another question.
“Are we Mars? At the beginning of the solar system, there was a lot of material exchange, collisions were plentiful, and bits of rock that ripped off Mars ended up landing on Earth,” says Tarter. “Life probably began somewhere other than Earth.”
An even more exciting possibility is the example of a second genesis if the biology of Mars is not relevant to us, and brings us the hypothesis of an independent origin of life. For Tarter, “It means that life happened twice and that it is everywhere. It would be amazing. I wish I could live to see it.”
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