Definition of space Space is defined as the space between celestial bodies, and it is called the term outer space to distinguish it from the air space that resides around the globe, and space can also be defined from a physical perspective as a three-dimensional, unlimited space, in which objects take a relative position and direction. 1[2]

Outer space Outer space is about 100 km or more from Earth, and it lacks air that helps all living things breathe, and light is also not scattered in it, and black prevails over blue, due to the lack of oxygen in outer space, which makes the sky blue. [3] It is worth noting that it is not possible to accurately determine the area of ​​outer space, due to the difficulty faced by specialized detectors, as long distances in space are measured in light years, which means the distance that light travels in one year, and is estimated at about 9.3 trillion km, and it has been able to Astronomers, using telescopes and conducting studies, have redrawn galaxies since the universe began 13.7 billion years ago, that is, before the Big Bang phenomenon occurred in the universe.

3] Components of Space Outer space contains a lot of gases, and small dust plankton, in addition to some particles and radiation, and magnetic and electric fields,[4] Space is not empty as many people think, as it contains a lot of materials, the space surrounding the stars is affected With the components of stellar winds, magnetic fields, and what remains of the elements from the death of stars.[5] The empty regions surrounding stars are described as cold and fragile, as the number of molecules present varies from one medium to another, in some regions every 1 cm2 contains only one molecule, while regions contain Other elements contain many molecules, and hydrogen and helium molecules are widely spread in stellar media, as they make up 98% of the molecules, and some other elements are available, but with a lower density than hydrogen and helium, which are as follows: [5] Oxygen.

Nitrogen. Calcium. carbon. some other metals. Why is there no gravity in space? After many trips to space, it became clear why there is no gravity in it, because it is relatively empty, and there are no signs of movement in it, and the movement in space is very slow, and here are some aspects of the difference between Earth and space regarding gravity: