Then use the spectrograph to try to find important molecules such as oxygen and methane. What they look for next, such as carbon dioxide or ozone, depends on how much of each they find. (Photosynthesis, which can also occur in other worlds, produces oxygen. Organisms that use oxygen usually produce carbon dioxide and water, while certain microorganisms such as bacteria produce methane. increase.)
best to estimate all If possible, more than just one of these potential biosignatures. However, depending on the wavelength range to which the telescope’s spectrograph is sensitive, it can measure molecular weights better than other molecules. Charting all these paths in Young’s decision tree tells astronomers whether they are seeing a world similar to present Earth, a past version of Earth, or something else entirely. I know there are.
You might wonder why the search for extraterrestrial life is focused on Earth rather than gas giants like Jupiter or ocean worlds like Saturn’s largest moon Titan and its sibling Enceladus. Hmm. “Strategically, it makes sense to look for life as we know it. Despite tantalizing hints here and there, we only have one example of a habitable planet,” says Seattle. Ken, an astrobiologist at the Blue Marble Space Science Institute, said Williford.
He works with NASA’s Perseverance rover. The rover is looking for signs of past life on Mars and will head to what scientists believe was the coast of a former body of water. If Mars was anything like ancient Earth, rovers might be able to excavate fossilized ‘microbial mats’ — layered communities of microbes — from the remnants of shallow-water marine environments.
But inevitably, those who follow Young’s flowchart will find some planets that return ambiguous results — some promising signs and uncertainties. Maggie Thompson, who also presented her findings at a recent astronomy conference, said that false positives should be avoided when apparently life-friendly signs are in fact from non-biological sources such as methane-producing volcanoes. said it was important.
Titan’s atmosphere, for example, is blanketed in methane, but with its frigid temperatures and lack of water, it’s probably devoid of life. (But this is just “probably”. Perhaps Titan hosts some of the most bizarre, never-before-seen microbes that can survive in methane lakes, eat acetylene, and breathe hydrogen instead of oxygen. It’s possible, but we won’t know the details until NASA sends a Dragonfly rotorcraft to investigate.)
Nonetheless, methane may be an important biosignature for more hospitable exoplanets, especially warm exoplanets with water. It can be something very simple,” says Thompson. His Webb telescope, which has just discovered the first exoplanet, will prove useful in this endeavor thanks to its near-infrared spectrometer. “Methane is one of the few gases that the JWST can actually detect, but she probably won’t be able to find planets with definitive biosignatures with the JWST alone,” she says.
Young has high hopes for Webb’s successor, the Habitable World Observatory. The Habitable World Observatory is tasked with searching for signs of life on Earth-sized planets around Sun-like stars. (So far, it’s been easier for astronomers to spot gas giant planets orbiting red dwarfs with more dangerous activity.) NASA chief in December Bill Nelson announced We plan to develop an observatory in the 2030s. Depending on the exact sensitivity of the new telescope, Young’s modeling shows that it could probe dozens of Earth-like worlds.
She is also as open to life as we are. please do not I know that. The decision tree contains planetary branches that do not look like any stage of Earth’s history. “We want to be prepared for surprises, such as strange cases that cannot be categorized,” she says. “Let’s put them in the ‘obscure planet’ category and flag them as interesting targets. ”
