It may be that life is lurking out there on other planets. But stuck here on Earth, how can we ever know for sure? A good place to start is by looking for the compounds on other worlds that are known to be the key ingredients of life as we know it.
Twenty-four years ago, Swiss astronomers Michel Mayor and Didier Queloz discovered the first planet orbiting a sun-like star outside our solar system – a milestone recognised by this year’s Nobel prize in physics. Today we know of thousands more ‘exoplanets’, and researchers are now trying to understand when and how they form.
Rocky planets larger than our own, so-called super-Earths, are surprisingly abundant in our Galaxy, and stand as the most likely planets to be habitable. Getting a better idea of their interior structures will help predict whether different planets are able to generate magnetic fields – thought to be conducive for life to survive.
From the first discoveries of planets beyond our solar system in the 1990s, we now know of thousands of alien worlds, some of which could even be habitable to life as we know it. Now we need to detect more of these exoplanets and study them in detail, says astronomer Dr Michaël Gillon from the University of Liège in Belgium, who was involved in one of the most important exoplanet discoveries to date.
Little more than a decade ago, two astronomers discovered mysterious bursts of radio waves that seem to take place all over the sky, often outshining all the stars in a galaxy. Since then, the study of these fast radio bursts, or FRBs, has taken off, and while we still don’t know what exactly they are or what causes them, scientists are now edging closer to some answers.
Scientists have revealed the first ever image of a black hole, a major milestone in astrophysics which not only backs up Einstein’s theory of general relativity but also opens up a new era of black hole observations.
The first-ever image of an event horizon – the gravitational boundary of a black hole beyond which light cannot escape – was revealed on 10 April and is the best evidence yet that these phenomena really do exist. It was the result of a global collaboration of hundreds of scientists, using multiple telescopes around the world to pick up the high-frequency radio waves emitted by matter pulled into the event horizon.
Gravitational waves – the invisible ripples in the fabric of space predicted by Albert Einstein – are opening up a new era of astronomy that is allowing scientists to see parts of the universe once thought to be invisible, such as black holes, dark matter and theoretical subatomic particles called axions.
Space missions have long benefited from some autonomous operations being carried out aboard spacecraft, but with a sharp increase expected in the number of satellites being launched in the next few years, researchers are using automation and artificial intelligence to make them smarter and more effective.
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Dr Michaël Gillon on what's next for exoplanet science.