Effects of a 150,000 kilogram object launched at Earth, just below the speed of light: 99.99999999999999 percent 'c' speed. The object weighing 150,000 kilograms gets a relativistic mass increase of 183,648,173,214,437,391 kilograms, therefore getting a relativistic energy of 16,505,474,674,203,172,344,215,046,082,011,484 joules (3,944,903,124,809,553,619 megatons.) This energy is far larger than the necessary energy needed to completely destroy a planet like the Earth, which is about over 53 quadrillion megatons worth of TNT (mean-estimate.) At nearly 4 quintillion megatons, this object has enough energy to create a literal planet-killing explosion upon impact, doing a lot more than just sterilizing the surface of the Earth of all life. Kinetic energy in this object increases in a relativistic way to 16,505,474,674,189,691,016,533,993,817,411,484 joules (3,944,903,124,806,331,505 megatons.) And that means the relative kinetic energy is pretty much equal to the overall relative energy inside the object now. The material slams into the Earth's surface in an inconceivably short amount of time and, since it's moving so fast, the particles in the atmosphere are practically frozen in time. All of the particles nitrogen, oxygen, water vapor, carbon dioxide, and whatever else in the air is hit with so much force in such a short time scale, that nuclear fusion occurs. The explosive energy release from the object is about 4 quintillion megatons, which is about 7,400 - 7,500 percent the power needed to cause total planetary devastation. Whatever continent the object strikes at its velocity is immediately annihilated as an explosion the likes of which the world has never seen erupts and completely destroys the Earth. Whether or not the Earth would become a new asteroid belt orbiting around the Sun, I do not yet know. Were the calculations accurate? Please correct me if I'm wrong on some parts! Thanks!