A new rocky planet dubbed a "mega-Earth" has been discovered in a distant star system.
The heavyweight world is up to 17 times more massive than the Earth, scientists announced.
According to scientists, the planet should have evolved over time into a gaseous "mini-Neptune."
Instead, Kepler-10c has managed to remain solid despite being more than twice as old as the Earth.
"We were very surprised when we realised what we had found," said astronomer Dr Xavier Dumusque, from the Harvard-Smithsonian Center for Astrophysics, who has led the research.
The discovery suggests that potentially life-bearing rocky planets may be far more abundant than was thought, and some could be immensely ancient.