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.
Composed of a single proton and a single electron, hydrogen is the simplest and most abundant element in the universe. It is estimated that 90% of the visible universe is composed of hydrogen. Hydrogen is the raw fuel that most stars 'burn' to produce energy. The same process, known as fusion, is being studied as a possible power source for use on earth. The sun's supply of hydrogen is expected to last another 5 billion years. Hydrogen is a commercially important element.