At the center of the nebula lies the Crab Pulsar, a neutron star 28–30 kilometres (17–19 mi) across with a spin rate of 30. 2 times per second, which emits pulses of radiation from gamma rays to radio waves. At X-ray and gamma ray energies above 30 keV, the Crab Nebula is generally the brightest persistent source in the sky, with measured flux extending to above 10 TeV. The nebula’s radiation allows detailed study of celestial bodies that occult it. In the 1950s and 1960s, the Sun’s corona was mapped from observations of the Crab Nebula’s radio waves passing through it, and in 2003, the thickness of the atmosphere of Saturn’s moon Titan was measured as it blocked out X-rays from the nebula.
An Icy Nest Of Space Eggs. Methone is actually only one member of an icy nest of Space eggs, which also includes the very strange and smooth moons of Saturn, Pallene and Aegaeon. Aegaeon is a very, very small moonlet that also twirls around between Mimas and Enceladus. Like Methone, Aegaeon displays a mysteriously unblemished surface. The Solar System forms a tiny part of the Milky Way Galaxy, a vast conglomeration of stars and planets. What makes astronomy so thrilling is that despite its size, the Milky Way is not the only galaxy in the universe. There are hundreds of billions of galaxies out there, probably more. The closest galaxy to our own Milky Way is Andromeda. Now, brace yourself for the distance: it is 2.3 million light years away. One of the most exciting phenomena for astronomers is the black hole. It is an area of the universe where the concentration of mass is so massive (no pun intended) that the gravitational pull it generates sucks in everything around it. Everything includes light. Remember that the escape velocity for any object in the universe is the speed required to escape the objects gravitational pull. The escape velocity for the Earth is slightly over 11 kilometers per hour while for the Moon is 2.5 kilometers per second. Well for a black hole, the escape velocity exceeds the speed of light. That is how strong the pull is. Second, there is the issue of sharing wealth. The Third World wants to redistribute wealth in its favor, and it pursues this end by a combination of moral persuasion and threats of terrorism using weapons of mass destruction. A frontier could make such threats less persuasive. The Third World reaction to a space frontier initiative is unpredictable and possibly violent. This makes pioneering a taboo for Western governments. And that's why they would keep it secret.