Look up in the sky at night and you will be fascinated with the glittering lights brought by the world of astronomy. Determining the distance of the planets by simply looking up is not possible. Determining the relative space distances is a little more tricky than comparing solar system planet sizes. First, it is important to understand what a solar system is and its composition.
According to researchers, our solar system was formed more than 4.56 billion years ago. It is composed of one major star - the Sun. Around that star gravitates eight known planets: Mars, Venus, Earth, Mercury, Jupiter, Saturn, Uranus, Neptune. There are also dwarf planets (including Pluto and Eris), natural satellites, minor planets, comments and other objects. Most of us had considered Pluto as a planet, but it is now classified as a dwarf planet belonging to a different class of objects. These objects are pulled by the gravitational pull of the Sun. The composition of our solar system is, directly and indirectly, orbiting around the Sun. The entire Solar System is so vast that, explaining its relative distance, one must use a model where its size is reduced by a factor of a billion, according to NASA.
With this model in mind, the planet Earth is now the size of a grapefruit which has about 1.3 in diameter. One foot away from the Earth is the Moon orbiting around it. The Sun, which has a diameter of 4 feet, about a 7-year-old child's height, is located at 150 meters away or 492 feet. Around 4 times the deepest indoor pool size, which is at 34.5 meters or 113 feet. The planet Jupiter is about 400 meters away from the Sun, equivalent to at least 5 blocks. Saturn's distance is doubled, which is at least within 10 blocks from the Sun. Uranus and Neptune are further away, which is at 20 and 30 blocks away, respectively. Using this visual model provided by NASA, human beings will be of the same size as an Atom.
Many might be wondering how close the planet Earth is to the Sun and the rest of the other planets without this kind of visualization aid. In determining our solar system's distance, it is measured in Astronomical Units (AU), which is equivalent to 149, 6000, 000 km. As described by the National Aeronautics and Space Administration (NASA), the Astronomical Unit is determined by the average distance between the Earth and the Sun. If we are to consider the speed of light at 186,000 mi/sec, the travel time of light from Sun to Earth would be 8 minutes. Neptune, now considered the farthest planet, has an orbit distance of 4,500,000,000 km from the Sun or 30 AU.
Knowing the relative distance of the planets from the Sun enables us to determine how much sunlight a certain planet is receiving. According to NASA, the planet Mars is 1.6 AU away from the Sun. This would mean that the sunlight in Mars is 2.5 less than the sunlight planet Earth is getting. This would further explain the temperature on planet Mars. Research showed that the planet Mars is too cold that water does not exist in its liquid form. On the other hand, Venus is a planet that is at 0.7 AU away from the Sun. Venus has an opposite story with that of Mars. The amount of sunlight in Venus is twice greater than what planet Earth is getting. The hot temperature makes it impossible for humans to survive in Venus. In NASA's report, Saturn's distance from the Earth was determined through a Spacecraft called Cassini. Traveling at a speed of 5.2 kilometers per second, Cassini took 6.7 years to reach the planet Saturn. If it was to continue its journey from Saturn to Pluto, it would take 27 years to reach this dwarf planet.
Apart from the planets orbiting the Sun, other objects within the Solar System are farther than the planets. Farther from the planet Neptune's orbit is the Kuiper Belt. Its relative distance from the Sun is estimated to be between 4,400,000,000 to 14,900,000,000 km or between 30 to 100 AU. This is where the planet Pluto is now considered a member. NASA considered the Kuiper Belt as the source of comets that takes 200 years or less to orbit the Sun.
Eris, also considered as another dwarf planet similar to Pluto has a current distance from the Sun of 97AU. This dwarf planet is much further from the planet Pluto. Eris is considered to be 3 times farther from Pluto's distance to the Sun.
Farther away is the hypothetical Oort cloud. It is believed that this is a source of comets with a relative distance of 5,000 to 50,000+ AU away from the Sun. NASA differentiates the Kuiper belt to be shaped like a disc or a doughnut. The Oort cloud would be more like a thick bubble that covers the entire solar system. Orrt cloud remains to be a theory where long-period comets are coming from. Given its distance, there is no means of proving the authenticity of such a theory. According to Johannes Kepler, a German Astronomer, the farther the planets are to the Sun, the slower it moves. Conversely, the closer these planets to the Sun, the faster it moves. He was the first person to explain the motion of the planets, which are revolving in an elliptical manner rather than spherical.
There is a continuous exploration of the object in space. It is so vast that research and explorations take years to get more information on what lies above us. Technology has been a great aid for these explorations as we explore deeper into space. Understanding our planet and the neighboring planets around us helps us better understand our habitat and consider the possibility of life outside Earth.