If we assume that we are alone in cosmos and we become aware of it at some point, it a manner it would be really terrifying discovery because it would cause in us a feeling of endless loneliness, perhaps even fear, and the universe itself, from our, human standpoint, would lose it meaning. Because m what it the point, all that empty space, if there is no one to live in it. Still there are those who feel that we are alone in all that infinity.

One of basic goals of science is to acquire appropriate explanations for occurrences and regularities in studied reality. The explanation of certain occurrence is based on finding regularity, which in essence is the interest of the science and it enables its development and progress.

Space always represented a great challenge for a man and unsolvable puzzle. People throughout history tried to answer many questions, but only in the middle of last century man managed to answer just some of them. Cold war what raged nearly half a century between the “East” and “West”, lead not only to arms race, but to race in space conquering. Great forces competed in space exploration in order to be one step ahead of their rival.

National Air Force and Space Administration (NASA) was founded in 1958 and is responsible for civil part of space program of SAD. Agency is also responsible to long term civil and military researches and the field of Air Force. When founding, it was comprised by four laboratories with about 8.000 employees.

Time is one of basic terms in religion, philosophy and science. Time is often described as irreversible sequence that stretches to past and future. Depending on theoretical frame, this sequence is seen as infinite or as finite. In physics, time is one of basic physical attributes, which is determined with the motion of celestial bodies.

Hardness is a property of the material which opposes the penetration of foreign body in its structure (or surface). Information about material hardness are necessary when it comes to manual or machine processing. Tools always need to be harder than the material that is being processed. We cannot cut metal objects with wooden saw.

They are among us, aliens are our reality!-This sentence was said by an American coronel James Bo Grotz during the meeting with president of SAD Ronald Regan in a secret base Fort Carson in Colorado! This fantastic claim could be read in science fiction literature.

Although many people get headaches from mathematics and mathematical equations, precisely thanks to them we enjoy numerous inventions and achievements they brought. Equations are often used to point out equality of two expressions that contain one or more variables.

Substance is the form of existence of matter. It consists out of tiny particles-atoms. Today, around 17 million different substances are known. Of those substances, around 100 thousand have practical use. Some substances are located in nature, while other are produced in artificial way, by chemists and other laboratory experts.

The moon is the only Earth’s natural satellite and at the same time the closes celestial body, located at an average distance of 384.400 km, so that light from the Moon reaches Earth in 1.25 seconds. The moon is moving around Earth in elliptical path with average speed of 1.02 km/s, and crosses daily arch of 13 degrees and 10 minutes. It is considered that the Moon was created before some 4,5 billion years, after the comet impact.