Sight of seven new planets stirs the imagination


The discovery of seven Earth-size planets orbiting a dwarf star 40 light-years away — a mere 235 trillion miles from Earth as the crow flies — has excited the world’s scientists in ways the discovery of other exoplanets hasn’t.

That’s because the seven planetary siblings circling Trappist-1 are part of an older star system that happens to be close enough to Earth to be observed from a network of observatories on the ground and the Hubble Telescope in space.

All seven planets are as close to Trappist-1 as Mercury is to our own sun, but the dwarf star has only the fraction of our sun’s heat and light. Consequently, water can exist on the surface of those worlds without being scorched away. Temperatures may even be relatively mild on some worlds.

Along with Hubble and the observatories, a powerful infrared telescope to be launched next year will aid scientists in determining the atmospheric composition of these new worlds. We’ll soon know if water exists on these exoplanets and whether the chemical compounds that make life as we know it possible can be detected.

If there is advanced or primitive life in that planetary system, there will be telltale signs of it in the atmosphere. Humanity is tantalizingly close to discovering whether life exists beyond the confines of this planet. Who knows? It may even usher in an era of humility and wonder.

— Pittsburgh Post-Gazette