In a galaxy far, far away…

Kepler-10b orbits close to its host star – a star similar to the Sun – at a distance that is five per cent the orbit of Mercury. This results in an orbit that takes less than a single Earth day and a surface temperature hotter than 1,300 degrees Celsius (2,372 degrees Fahrenheit).

Because Kepler-10b – discovered in 2011 by the Kepler telescope – is tidally locked to its star, it also creates molten droplets of iron and silicates. The planet’s surface is likely covered with lava much hotter than that found on Earth. Because the harsh radiation from its host star has stripped away its atmosphere, these droplets on Kepler-10b won’t fall on the nightside of the planet, and are instead blown clear of its surface by stellar winds, giving it a fiery tail.

Kepler-10b isn’t the only lava world discovered by Kepler. In 2013 the space telescope also found the exoplanet Kepler-78b – 40 times closer to its host star than Mercury – that completes a full orbit in a matter of hours. The result is an Earth-like world dominated by lava, which has been described by astronomer Dimitar Sasselov as “an abomination”.

Given their molten lava surfaces, it’s little wonder that these exoplanets have been compared to Mustafar, the planet in the Star Wars franchise that hosts a lightsaber duel between Obi-Wan Kenobi and Anakin Skywalker. The lava of that fictional world results in hideous injuries to the young Jedi, which force him to wear the iconic black armour and breathing apparatus of Darth Vader. Perhaps when considering a world to hold a duel to the death, somewhere that offers a cooler climate may be advisable.