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 ultimate energy source, for most Earth life, is nuclear fusion reactions taking place in âourâ star â the sun, fusing hydrogen to helium â which release copious amounts of highly energetic photons, a very small portion of which eventually reaches Earth, thus providing the energy needed to sustain most Earth life (excepting some very deep sea ecosystems, which are sustained by energy provided by undersea volcanic hydrothermal vents (a.k.a. âblack smokersâ)).