Orbit of Earth-Size Exoplanet TRAPPIST-1h in Alien Solar System Nailed Down

The orbits of all seven Earth-size planets in the TRAPPIST-1 system are now known.

Astronomers have nailed down the path of TRAPPIST-1h, the outermost planet in the system, finding that this world takes just under 19 Earth days to complete one lap around its small, faint host star. 

The new result suggests that TRAPPIST-1h is too cold to host life as we know it, and it confirms that all seven TRAPPIST-1 worlds circle their star in a sort of gravitational lockstep with one another, study team members said. [Exoplanet Tour: Meet the 7 Earth-Size Planets of TRAPPIST-1]

"It's incredibly exciting that we're learning more about this planetary system elsewhere, especially about planet h, which we barely had information on until now," Thomas Zurbuchen, associate administrator of NASA's Science Mission Directorate at the agency's headquarters in Washington, D.C., said in a statement. -read more