How astronomers plan to detect signs of alien life

Over 6K exoplanets are there. A promising method is to analyse gases present in atmospheres of these planets

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We live in a very exciting time: answers to some of the oldest questions humanity has conceived are within our grasp. One of these is whether Earth is the only place that harbours life.

In the last 30 years, the question of whether the Sun is unique in hosting a planetary system has been resoundingly answered: we now know of thousands of exoplanets orbiting other stars.

But can we use telescopes to detect whether any of these distant worlds also harbour life? A promising method is to analyse the gases present in the atmospheres of these planets.

We now know of more than 6,000 exoplanets. With so many now catalogued, there are a number of ways to narrow down which worlds are the most promising for biology. Using the planet's distance from its host star, for example, astronomers can work out its likely temperature.