A larger sixth planet, closer in mass to Saturn, also appears significantly in the data at a greater distance from HD 10180, but the study's authors note that the signal could be caused by a long - term magnetic cycle on the star rather than the tug of an orbiting planet. (scientificamerican.com)
It's been orbiting the sixth planet from the sun ever since, sending back data of immense scientific value and images of magnificent beauty. (businessinsider.com)
The fifth and sixth planets, both in the habitable zone, are more than half water — a volume so large that the water pressure alone could force much of it into a form of ice, Unterborn says. (sciencenews.org)