An Update on the Potential Habitability of TRAPPIST-1. No Aliens yet, but We’ve Learned a lot.

An Update on the Potential Habitability of TRAPPIST-1.  No Aliens yet, but We’ve Learned a lot.
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One year ago, I wrote an article about the remarkable discovery of the TRAPPIST-1 planetary system, a system of seven temperate terrestrial planets orbiting an ultra-cool red dwarf star. This was an enormous astronomical discovery because these low-mass stars are the most numerous ones in our galaxy, and the discovery of potentially habitable planets around one of them led many people to speculate about the existence of life there and elsewhere in our galaxy around similar stars.

This announcement also inspired a lot of additional studies by astronomers worldwide, who have used additional instruments and run complex models to better understand this planetary system and its potential for hosting life.

One year later, it seems to me that the time is right to give you an update on what we’ve learned about this planetary system, which is located only 41 light-years from Earth.

Proxima Centauri b: Have we just found Earth’s cousin right on our doorstep?

What began as a tantalizing rumor has just become an astonishing fact. Today a group of thirty-one scientists, led by Guillem Anglada-Escude at the Queen Mary University of London, UK, announced the discovery of a terrestrial exoplanet orbiting Proxima Centauri. The discovery of this planet, Proxima Centauri b, is a huge breakthrough not just for astronomers but for all of us. Here’s why.

This artist’s impression shows a view of the surface of the planet Proxima b orbiting the red dwarf star Proxima Centauri, the closest star to the Solar System. The double star Alpha Centauri AB also appears in the image to the upper-right of Proxima itself. Proxima b is a little more massive than the Earth and orbits in the habitable zone around Proxima Centauri, where the temperature is suitable for liquid water to exist on its surface. Credit: ESO/M. Kornmesser
This artist’s impression shows a view of the surface of the planet Proxima b orbiting the red dwarf star Proxima Centauri, the closest star to the Solar System. The double star Alpha Centauri AB also appears in the image to the upper-right of Proxima itself. Proxima b is a little more massive than the Earth and orbits in the habitable zone around Proxima Centauri, where the temperature is suitable for liquid water to exist on its surface.
Credit: ESO/M. Kornmesser

The Next Step in Exoplanetary Science: Imaging New Worlds

In 2003, I was lucky enough to be part of a small group of astronomers that met at the University of California at Berkeley to brainstorm on an innovative idea: the design of an instrument to image and characterize planets around other stars, called exoplanets, using a telescope in the 8 – 10 meter class. A decade later, such an instrument became reality with the arrival of the Gemini Planet Imager (called also GPI, or “Gee-pie”) instrument at the Gemini South telescope in Chile.

Five known planetary systems imaged with current adaptive optics systems. Fomalhaut shown on the top-right is the only system detected with the Hubble Space Telescope. HR8799 discovery was announced in a Science article in 2008 by a team led by C. Marois including members of the GPI team (credit: C. Marois).
Five known planetary systems imaged with current adaptive optics systems. Fomalhaut shown on the top-right is the only system detected with the Hubble Space Telescope. HR8799 discovery was announced in a Science article in 2008 by a team led by C. Marois including members of the GPI team (credit: C. Marois).