Can James Webb Space Telescope Hunt For Alien Life?

In doing so, we might find extraterrestrial life, as it is believed that one or more of these planets might feature a chemical signature required to sustain life. Solar systems that have liquid water can potentially have alien life. However looking for life in these places isn’t easy, as it would require sending a probe to bring back physical samples. Several scientists believe that life is possible on planets orbiting other stars out there.

Hunting For Biosignatures In Space

As per theoretical calculations, there are around 300 million potentially habitable planets in the Milky Way galaxy alone and many Earth-sized planets that are only 30 light-years away, a nominal figure in astronomical terms. Researchers have managed to discover more than 5,000 exoplanets, where around 100 are capable of harnessing life. But these measurements only provide the size and mass of an exoplanet.

To discover alien life, scientists need to study starlight that interacts with a planet’s atmosphere. If the surface of the planet was transformed by life, the light could carry some sort of sign of life known as “biosignature.” When light passes through a gas, some wavelengths of light get trapped in the gas, which results in why we see objects in different colors.

Presence Of Gases Hint At Potential Alien Life

By measuring the specific color of light coming from a planet, astronomers can understand the presence of atmospheric gases that can give a clue about life on the planet. These gases could be oxygen or methane as they leave specific signatures in light. 

Scientists can make use of a highly-sensitive infrared camera to detect the colors produced by these pigments. If they are able to see this color bouncing off the surface of a faraway planet, it could mean that the atmosphere of the planet has chlorophyll. To detect these minute changes in light coming from distant exoplanets, researchers need incredibly powerful telescopes. 

Can James Webb Actually Find Life Beyond Earth?

The only telescope capable of studying light coming from exoplanets right now is the James Webb Space Telescope. Currently, the telescope has its eyes locked on exoplanet WASP-96b. While the research showed the presence of clouds and water, the hot nature of the exoplanet doesn’t make it an ideal candidate for hosting life.

However, this data is a testament that James Webb can efficiently detect subtle chemical signatures in light reflecting from exoplanets. JWST is soon expected to shift focus on TRAPPIST-1e, which is an Earth-sized planet believed to be habitable. It is also just 39 light years away from our planet, making it easier for the telescope to study.

James Webb can look for biosignatures of planets when they pass in front of their stars. But the telescope was not created to hunt for life, so it can only study potentially habitable planets. While combinations of gases might hint at life, the telescope cannot detect unbonded oxygen, the biggest signal for life on a planet. We might have such telescopes in the future, but until then scientists will have to rely on JWST’s data.