What is "outer space"

Space \Space\ (sp[=a]s), n. [OE. space, F. espace, from L. spatium space; cf. Gr. spa^n to draw, to tear; perh. akin to E. span. Cf. Expatiate.]

1. Extension, considered independently of anything which it may contain; that which makes extended objects conceivable and possible.

   Pure space is capable neither of resistance nor motion.
   --Locke.

2. Place, having more or less extension; room.

   They gave him chase, and hunted him as hare; Long had he no space to dwell [in].
   --R. of Brunne.

   While I have time and space.
   --Chaucer.

3. A quantity or portion of extension; distance from one thing to another; an interval between any two or more objects; as, the space between two stars or two hills; the sound was heard for the space of a mile.

   Put a space betwixt drove and drove.
   --Gen. xxxii. 16.

4. Quantity of time; an interval between two points of time; duration; time. ``Grace God gave him here, this land to keep long space.''
   --R. of brunne.

   Nine times the space that measures day and night.
   --Milton.

   God may defer his judgments for a time, and give a people a longer space of repentance.
   --Tillotson.

5. A short time; a while. [R.] ``To stay your deadly strife a space.''
   --Spenser.

6. Walk; track; path; course. [Obs.]

   This ilke [same] monk let old things pace, And held after the new world the space.
   --Chaucer.

7. (Print.)

   1. A small piece of metal cast lower than a face type, so as not to receive the ink in printing, -- used to separate words or letters.

   2. The distance or interval between words or letters in the lines, or between lines, as in books, on a computer screen, etc.

      Note: Spaces are of different thicknesses to enable the compositor to arrange the words at equal distances from each other in the same line.

8. (Mus.) One of the intervals, or open places, between the lines of the staff.

9. that portion of the universe outside the earth or its atmosphere; -- called also outer space.

   Absolute space, Euclidian space, etc. See under Absolute, Euclidian, etc.

   deep space, the part of outer space which is beyond the limits of the solar system.

   Space line (Print.), a thin piece of metal used by printers to open the lines of type to a regular distance from each other, and for other purposes; a lead.
   --Hansard.

   Space rule (Print.), a fine, thin, short metal rule of the same height as the type, used in printing short lines in tabular matter.

n. 1 Region outside explored space. 2 Any region of space beyond limits determined with reference to boundaries of a celestial system or body, especially the region of space immediately beyond Earth's atmosphere 3 A bluish shade of black

n. any location outside the Earth's atmosphere; "the astronauts walked in outer space without a tether"

Outer space comprises the relatively empty regions of the universe outside the atmospheres of celestial bodies.

Outer space may also refer to:

• Outer Space (video game), a 1978 video game
• OuterSpace, a hip hop duo
• Outer Space (EP), an EP by S-Endz
• " Out of Space", a song by The Prodigy
• "Cosmos (Outer Space)", a song by t.A.T.u. from Dangerous and Moving
• Outer space (group theory), a cell complex operated on by the outer automorphism group of the free group

Outer Space is an EP album by the British-Asian music producer and vocalist S-Endz, who is well known as a member of the band Swami. The song Outer Space itself also features vocals from Kazz Kumar and Rukas.

Outer space, or just space, is the void that exists between celestial bodies, including the Earth. It is not completely empty, but consists of 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, as set by the background radiation from the Big Bang, is 2.7 kelvins (K) (−270.45 °C; −454.81 °F). Plasma with a number density of less than one hydrogen atom per cubic metre and a temperature of millions of kelvins in the space between galaxies accounts for most of the baryonic (ordinary) matter in outer space; local concentrations have condensed into stars and galaxies. In most galaxies, observations provide evidence that 90% of the mass is in an unknown form, called dark matter, which interacts with other matter through gravitational but not electromagnetic forces. Data indicates that the majority of the mass-energy in the observable universe is a poorly understood vacuum energy of space which astronomers label dark energy. Intergalactic space takes up most of the volume of the Universe, but even galaxies and star systems consist almost entirely of empty space.

There is no firm boundary where outer space begins. However the Kármán line, at an altitude of above sea level, is conventionally used as the start of outer space in space treaties and for aerospace records keeping. The framework for international space law was established by the Outer Space Treaty, which was passed by the United Nations in 1967. This treaty precludes any claims of national sovereignty and permits all states to freely explore outer space. Despite the drafting of UN resolutions for the peaceful uses of outer space, anti-satellite weapons have been tested in Earth orbit.

Humans began the physical exploration of space during the 20th century with the advent of high-altitude balloon flights, followed by manned rocket launches. Earth orbit was first achieved by Yuri Gagarin of the Soviet Union in 1961 and unmanned spacecraft have since reached all of the known planets in the Solar System. Due to the high cost of getting into space, manned spaceflight has been limited to low Earth orbit and the Moon.

Outer space represents a challenging environment for human exploration because of the dual hazards of vacuum and radiation. Microgravity also has a negative effect on human physiology that causes both muscle atrophy and bone loss. In addition to these health and environmental issues, the economic cost of putting objects, including humans, into space is high; in 1969, the Apollo program cost approximately $24,000,000,000 ($395,000,000,000 as of 2015).