The Harmony That Keeps Trappist-1s 7 Earth-size Worlds From Colliding

[brooklynite]

New York Times:

In February, astronomers announced the discovery of a nearby star with seven Earth-size planets, and at least some of the planets seemed to be in a zone that could provide cozy conditions for life.

The finding of these planets circling the star Trappist-1 40 light-years away came with a bit of mystery. The orbits of the planets are packed tightly, and computer calculations by the discoverers suggested that the gravitational jostling would send the planets colliding with each other or flying apart, some to deep space, others spiraling into the star and destruction.

Now new research provides an explanation for the dynamics of how this planetary system could have formed and remained in stable harmony over billions of years.

“It’s actually a very special system,” said Daniel Tamayo, a postdoctoral researcher at the University of Toronto Scarborough and the lead author of a paper appearing in The Astrophysical Journal Letters.