Outer space comprises the relatively empty regions of the universe outside the atmospheres of celestial bodies. Outer space is used to distinguish it from airspace and terrestrial locations.

Contrary to popular understanding, outer space is not completely empty (i.e. a perfect vacuum), but contains a low density of particles, predominantly hydrogen plasma, as well as electromagnetic radiation and neutrinos. Hypothetically, it also contains dark matter and dark energy.

Outer space is the closest approximation of a perfect vacuum. It has effectively no friction, allowing stars, planets and moons to move freely along ideal gravitational trajectories. However, no vacuum is truly perfect, not even in intergalactic space where there are still a few hydrogen atoms per cubic centimeter.
(For comparison, the air we breathe contains about 1019 molecules per cubic centimeter.) The deep vacuum of space could make it an attractive environment for certain industrial processes, for instance those that require ultra clean surfaces.

All of the observable universe is filled with large numbers of photons, created during the Big Bang, the so-called cosmic background radiation, and quite likely a correspondingly large number of neutrinos called the cosmic neutrino background. The current temperature of the photon radiation is about 3 K (−270.15 °C; −454.27 °F).

Many people ask that if we put a thermometer in Space with no other light or heat source around and absolutely no background radiation there, what it would read. Would the temperature be really cold or what?

Yes, it would be really cold. Temperature measures the energy per “degree of freedom” (i.e. way something can move) of whatever molecules happen to be around. So, it becomes so cold that the molecules stop all together, and then this is the “absolute zero” temperature. On the Celsius Temperature Scale (i.e. water freezes at 0, and boils at 100), this takes place at -273 degrees C.

We usually use the Kelvin temperature scale, where Zero Kelvin is this “absolute zero” temperature -- or -273 degrees C. Water freezes at +273 Kelvin and water boils at +373 Kelvin.

If we put a thermometer in darkest space, with absolutely nothing around, it would first have to cool off. This might take a very long time. Once it cooled off, it would read 2.7 Kelvin. This is because of the “3 degree microwave background radiation”. No matter where you go, you cannot escape it -- it is always there.

Twentieth century archaeology uncovered a literary gold mine from the past when they excavated the massive library of clay tablets stored in the area that was once known as Sumeria in our current Middle East. Thousands of records written in cuneiform, possibly the first written human language, divulged a great storehouse of information, including much that on first look conflicted greatly with our understanding of our planet's past and our rise to dominance of the planet.

These records describe to gravitational capture of a rogue planet that had been traveling the depths of interstellar space for unknown eons. This planet, called Nibiru, turned out to be much more than a mere wayward rock. According to the Sumerian texts, this planet was inhabited by a race of virtually immortal beings that the Sumerians considered to be their gods. This intrusion was so far back in our solar system's history that planet Earth was said to be formed from the collision of two planetary bodies being knocked together by the gravitational disruption Nibiru caused by passing within the inner part of the system.

Whether due to the long voyage between the stars or because of damage to Nibiru during it's gravitational capture, its inhabitants needed the raw materials to fix the damage and maintain the internal heat of this "radiant" planet. As time passed they colonized the earth and began mining operations. While they took many materials, it was gold they most fervently sought for its electrical properties to heal the wounds in Nibiru's atmosphere.

Using the astronomical data about Nibiru that was presented in the Sumerian texts, astronomers used the "Infrared Astronomical Satellite" to scan the far reaches of our system to see if they could locate what was causing the wobble in the orbits of the outer planets. In the 1983-84 observations from this satellite’s data was discovered a planetary body immersed in to Oort cloud of debris on the edges of our star system. This planetary body fit the descriptions of a retrograde orbit that did not lie along the plane of the elliptic and was roughly where projected orbital calculations would put Nibiru at this time in history. While this discovery made news at first, it quickly became a buried subject that no one seemed to want to discuss.

Had they realized they had discovered the home planet of the ancient aliens that walked our Earth long before we even existed?