Scientists discover ‘mega-Earth’ 17 times bigger than our planet

A new kind of 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 and, according to theory, should have evolved over time into a gaseous mini-Neptune.

Instead the planet, known as Kepler-10c, has managed to remain solid despite being more than twice as old as the Earth.