Objects closer to Earth than the L1 point are controlled by Earth's gravity. Objects beyond the L1 point are controlled by the Sun. When J002E3 came close to the L1 point in April 2002, the object passed throuhgh L1--like a portal--from a Sun-orbit to an Earth-orbit.
In the top 20km of the Earth's crust, the conditions are right to produce a nearly inexhaustible supply of hydrogen, said Prof Freund. Studies by the team of common rock types such as granite and olivine have revealed extraordinarily high levels of trapped hydrogen.
Earth's two cores. There are two cores inside the Earth. The average density of the Earth is 5,515 kilograms per cubic meter. The Earth's crust density is 3,000 kilograms per cubic meter. Therefore scientists decided the core must contain iron and other heavy metals that sank to the center as the Earth was forming.