Sara Seager - Finding a planet like Earth

When I think of an Earth-like exoplanet, I think of a planet with oceans, continents and a friendly atmosphere. In short, a planet like Earth orbiting a star like our own sun.

About Sara Seager 

"I’m an astrophysicist and professor at the Massachusetts Institute of Technology and Kavli Prize in Astrophysics, 2024.

My research focuses on exoplanets, planets which orbit stars other than our sun. My quest is to find another Earth, a true ‘Earth twin’, and to search for signs of life on any kind of exoplanet by studying their atmospheres. I’ve played a leadership role on space missions, and I’m also working for new, more sophisticated ways to find planets."

Searching for a second home

When I think of an Earth-like exoplanet, I think of a planet with oceans, continents and a friendly atmosphere. In short, a planet like Earth orbiting a star like our own sun. Currently, finding the so-called Earth twin seems unlikely to occur soon.

After all, most of our attention in astronomy is focused on small stars rather than more prominent sun-like stars. This is because finding a planet suitable for life orbiting these smaller stars is much easier. We think of these potential planets more like an Earth cousin than like an Earth twin.

Regardless, finding a planet like Earth could actually happen at any time. We have maybe a dozen candidates we're just waiting to observe with the James Webb Space Telescope or JWST. The next generation of large, ground-based telescopes will also help find and characterise more planets and determine if they are anything like Earth.

Key Points

• Nearby planets like Proxima Centauri b and Kepler-186f may receive enough energy and have other conditions suitable for life.
• Observing Earth-like planets is challenging. It requires sophisticated telescopes to be sent into space beyond the atmosphere's blurring effect.
• The brightness of host stars also makes planets challenging to observe. Starshade, a specially designed screen, may help identify Earth-like planets by blocking light.