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.
The earth is not made mostly of hydrogen because the earth is small (less gravity) and hydrogen is light, so the hydrogen that was here, has mostly escaped the gravitational pull of Earth. On Earth, hydrogen can be found in many places. Hydrogen combines with oxygen to form water, which is essential for life on earth. Water makes up three quarters of the earth s surface (See Fig. 4). Three quarters of our bodies are made of water. Fossil fuels are made of hydrocarbons, a combination of hydrogen and carbon.