Discovered in 2015, K2-18b is about 2.6 times larger and 8.6 times more massive than Earth. Its temperature is very similar to Earth's, but the planet orbits so quickly that a year on K2-18b lasts just 33 day
Dmitry Medvedev, Deputy Chairman of the Russian Security Council, added to the rising tension by suggesting that Moscow may consider preemptive strikes on the West