Space has many features, some of which are beneficial to man, like the celestial bodies, most importantly the sun and the moon, which illuminate the earth, leading to discovery of various sources of energy, and the process by which humans use to measure time and other things, the planets that make up the solar systems, which of only 9 have been discovered so far and are at far distance from each other, and are constantly rotating around the fixed sun, the stars that beautify the sky at night, experienced from Earth, and the wonderful and beautiful Nebulas. Another fascinating property of space is the fact that sound cannot travel out there, and there's no gravity, hence, floatation of any mass in it, the slightest push or pull could send a mass floating to far far distances without stop, unless interrupted by another mass. Due to no gravity, it makes space travel much more difficult, and because of its behavior that's similar to the extremely large water bodies (cold, dark and unsuitable for human survival), similar terminologies are used in describing scenarios and objects in such environment, like movement in both space and ocean is termed ‘sailing’ and others.