Outer space, or simply space, is the expanse that exists beyond the Earth and between celestial bodies. Outer space is not completely empty—it is a hard vacuum containing a low density of particles, predominantly a plasma of hydrogen and helium, as well as electromagnetic radiation, magnetic fields, neutrinos, dust, and cosmic rays. The baseline temperature of outer space, as set by the background radiation from the Big Bang, is 2. 7 kelvins (−270. 45 °C; −454. 81 °F). The plasma between galaxies accounts for about half of the baryonic (ordinary) matter in the universe; it has a number density of less than one hydrogen atom per cubic metre and a temperature of millions of kelvins. Local concentrations of matter have condensed into stars and galaxies. Studies indicate that 90% of the mass in most galaxies is in an unknown form, called dark matter, which interacts with other matter through gravitational but not electromagnetic forces. Observations suggest that the majority of the mass-energy in the observable universe is dark energy, a type of vacuum energy that is poorly understood. Intergalactic space takes up most of the volume of the universe, but even galaxies and star systems consist almost entirely of empty space.
Only once since I began a twenty year fascination with Einstein's time/light theory have I heard from anyone connected to NASA who dared to address this fact to a sublimely ignorant public. He was hushed up in the slow lane with indifference and a public that couldn't tell you how the world can make it through the next decade without imploding. With a list of almost infinite problems how can we think of getting people out that far, much less plan for the return of our astronauts after 4000 generations of time. So this is your time! Use it wisely my friend! Give yourself that chance of honest communication and the intimacy and deepening connection which can come out of it. Moons, Myths, Etc. Our bewitching, and sometimes bewildering Moon, has long been the inspiration for magical myths, weird legends, bedtime stories, and beautiful poetry. Earth's Moon is a very ancient symbol of femininity, as well as for wild bouts of strange madness and romantic love. Some ancient, traditional legends and childhood stories tell of a man's face etched out on its shining surface, while others tell strange tales of a "Moon Rabbit." Lovely, ancient myths, tales, and bedtime stories aside, Earth's Moon is a very real object. It has been a companion-world to our Earth almost from that very ancient era, when our Solar System was first forming, about 4.5 billion years ago.