We often refer to our expanding universe with one simple word: space. But where does space begin, and more importantly, what is it? Satta king

With almost no material and very little pressure, the vacuum location is nearly perfect. In space, sound does not travel because there are not enough molecules between them to transmit sound. Not empty enough, bits of gas, dust and other material float around in the "empty" regions of the universe, and the most populated regions can host planets, stars, and galaxies.

From land, it is often assumed that outer space begins at the so-called Kerman Line, which is approximately 62 miles (100 kilometers) above sea level. It is an imaginary limit at altitude where there is no significant air to breathe or light to scatter. As soon as you cross this height, the blue starts giving a black color because there are not enough oxygen molecules to turn the sky blue. Playbazaar

No one knows how big the place is. It's hard to tell what our detectives see. We measure long distances in space in "light years," which means how long it takes light to travel in one year (about 5.8 trillion miles (9.3 trillion kilometers)).

With reflected light in our telescopes, we have mapped galaxies that date back to the Big Bang, which is thought to have started our universe some 13.8 billion years ago. This means that we can "see" a "total space" of about 13.8 billion light-years. But the universe continues to expand, making "measuring space" even more challenging.

Most of the space is relatively empty, with only loose particles of dust and gas floating around. This means that when humans send an explorer to a distant planet or asteroid, the craft does not "pull" in the same way that an airplane does when traveling through space.

In fact, the vacuum environment in space and the Moon is one reason why Apollo's lunar lander was designed to look almost like a spider, as described by the Apollo 9 crew. Since the spacecraft was designed to operate in the atmospheric region, it did not require smooth edges or a streamlined shape.