Eight Planets

Our solar systemMan has marveled at the mysteries of space since the beginning of time. Before telescopes, people could only speculate as to what the lights were in the sky at night, andhad no real idea of how big space really was. Since the invention of the telescope, scientists and astronomers have been able to study the planets more closely, and are still learning more every day.

Until recently, we were taught that there are nine planets. In 2006, the IAU (International Astronomical Union) made the decision that Pluto was in fact not a real planet, but was renamed a dwarf planet. What remains is Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

Mercury is the closest planet to the sun, and is the second smallest planet in our solar system. Mercury is unique in that because of its location, it does not experience any seasons whatsoever. Instead, temperatures can range from extreme hot during the day to extreme cold at night. There is almost no atmosphere on Mercury, so the surface is a lot like the surface of our moon, with many craters that are there due to comets and meteoroids constantly crashing into the planet.

Venus is the second planet from the sun, and is hotter than any other planet. With a toxic atmosphere, there is no way that life could be sustained. Before discovering what was underneath the dense clouds, many believed the surface of the planet was tropical, but then found out that it is simply a dry, dense, unbearable surface. Venus is unique in that it spins slowly and in the opposite direction of other planets, and like Mercury does not experience seasons. Because of the slow rotation, a typical day on Venus would equal to 243 of our Earth days. Venus is also very close to Earth in size and density, but has no detectable magnetic field. Since it does not have moving plates, the surface moves up and down instead of sideways.

solar systemEarth, the third planet from the sun and the one we call home, is the only one that is known to harbor life because of the oxygen and nitrogen atmosphere. Astronauts first called Earth “The Blue Planet” because 70% of it is covered with water. Researchers have found that Earth is about 4.5 billion years old, and despite what people think, is not a perfect sphere. While it is not flat, like what was first believed, the mass is distributed unevenly, and the greater the mass, the stronger the gravitational pull. This is also due to the formations of mountains and valleys that disappear and reappear from plate tectonics.

Mars is the fourth planet from the sun, and is also called “The Red Planet” because of a dusty iron oxide. Mars is a lot like Earth. Discoveries have uncovered that weather is similar to ours, with storms and tornados, and even snow. It is believed that, at one point, it may have been warm on Mars, but today is very cold. The atmosphere is now too thin to for water to remain on the surface, but scientists believe that life may have existed at one point.

Jupiter, the fifth planet from the sun, is the biggest planet in our solar system. Jupiter is made up mostly of gases, namely hydrogen and helium. The biggest feature of Jupiter is the giant red spot, which is believed to be a giant storm that has been going on for years, although researchers do say that it seems to be shrinking. The magnetic field is fourteen times as strong as Earth’s, and ionized particles become trapped by the magnetic field and accelerate them to nearly the speed of light, which can make it dangerous for a space shuttle to attempt to land there. The fastest spinning planet in our solar system, taking only 10 hours to completely turn in comparison with the Earth’s 24 hours.

Saturn is the sixth planet from the sun, and is best known for its rings. While we do know that the rings are made of ice and rock, we still do not know exactly how they formed. Saturn also has 60 moons, and is made up mostly of hydrogen and helium. Since the planet does not have a solid surface, it was initially very hard to figure out how long a day was on Saturn, but scientists have determined that it is around 10 hours and 45 minutes.

Uranus, the seventh planet from the sun, is odd in that it orbits on its side, which is believed to be caused by a crash with another planet long ago. The tilt has caused there to be a pole that is always pointed toward the sun, which means that a day on Uranus at the north pole would be equal to 84 years on Earth! The bluish tint that you see is caused by the Methane in the atmosphere.

Neptune is the eighth planets from the sun, and is best known for its strong winds, which are sometimes faster than the speed of sound. While a person could not actually stand on the surface of Neptune without sinking in, the gravity is very similar to Earth’s, only 17% stronger. Being furthest from the sun, it is also the coldest planet in our solar system. Neptune has 13 moons, Triton, its biggest moon, is said to be even colder than the surface of Neptune, but still has activity such as volcanoes and geysers that erupt liquid nitrogen.