The Kardashev scale, named after the Soviet scientist Nikolai Kardashev, who devised it in 1964, assesses alien civilizations based on their ability to harness energy. It is a purely energy-based scale for measuring a civilization’s technological prowess. The more energy a civilization has ...

Billions of years ago, another planet smashed into Earth. An event of this epicness could have created our Moon. It also could have brought alien life to our planet. What evidence of this planet still exists on Earth today? Could there be life deep inside the Earth’s surface? And could that ...