what is space?

 

what is space?

 

• Space is a term that can refer to a variety of phenomena in science, mathematics, and computing, and generally includes the concept of an area or region. It is often used as shorthand for outer space.
• What is outer space?

       

• Outer space is the region beyond the atmosphere of a planet. For Earth, it begins about 100 kilometers (62 mi) above sea level. The line separating the atmosphere and outer space is called the Karman line. The terms outer space and universe are broadly similar, except that outer space refers only to the region between the planets, while the universe includes the planets as well.
• There is very little matter in outer space. It is a rigid vacuum, in which there is no air. This also makes it extremely cold. However, there are some stray particles and radiation. Ironically, even though space itself is cold, due to the lack of particles to interact with, it is difficult to get rid of waste heat from spacecraft, requiring specialized infrared radiators.
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• The universe is organized into larger and larger structures. The planets in the solar system revolve around the stars. The stars are arranged in galaxies. Galaxies form clusters. Clusters of galaxies form superclusters.
• The universe is approximately 13.8 billion years old. It came into existence during the Big Bang. Because of the speed of light, telescopes can only see as far as 13.8 billion light-years away. The universe is still expanding. There is a debate among scientists whether the universe is infinite or finite in size. It is unknown what lies beyond the edge of the visible universe.
• Man-made satellites orbit the Earth at various orbit heights. Low Earth orbit is closest to Earth. This is where many Earth observation satellites, some communications satellites and the International Space Station orbit.
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• In geosynchronous orbit, the satellite remains above the same area of the Earth's surface. Getting a satellite into geosynchronous orbit is more expensive, so it is mainly used for satellites that are dedicated to certain regions of Earth.