How Much Does a Planet Really Weigh?

Astronomers have figured out a new way to weigh planets using radio signals.

ScienceDaily (Oct. 23, 2010) — An international CSIRO-led team of astronomers has developed a new way to weigh the planets in our Solar System -- using radio signals from the small spinning stars called pulsars.

"This is first time anyone has weighed entire planetary systems -- planets with their moons and rings," said team leader Dr David Champion from Germany's Max-Planck-Institut für Radioastronomie.

"And we've provided an independent check on previous results, which is great for planetary science."

Measurements of planet masses made this new way could feed into data needed for future space missions.

Potentially Habitable Planet Found Near Earth

It's only 20 light years away!

AFP reported:

WASHINGTON (AFP) – US astronomers said Wednesday they have discovered an Earth-sized planet that they think might be habitable, orbiting a nearby star, and believe there could be many more planets like it in space.

The planet, found by astronomers at the University of California, Santa Cruz, and the Carnegie Institution of Washington, is orbiting in the middle of the "habitable zone" of the red dwarf star Gliese 581, which means it could have water on its surface. Read more here.

A Planet Eating Star Found

Artist's concept of the exoplanet WASP-12b. (Credit: NASA/ESA/G. Bacon)

A planet eating star has been found by Hubble.

Hubble Finds a Star Eating a Planet