Tag Archives: Solar System

The Eight Planets of Our Solar System

Solar System

Yes. That is correct. Eight planets. Not nine, since Pluto was decommissioned as a planet in 2006. It is now a dwarf planet that is part of the Kuiper Belt. An area at the edge of the solar system that is filled with icy bodies that orbit the sun.

A dwarf planet is an object that revolves around the sun but is not considered a planet because it doesn’t meet the criteria set forth by the International Astronomical Union (IAU), an international organization that helps to set the standard for outer space quantifications.

Want to learn more about the dwarf planet, Pluto, check it out here.

Mercury

The planet Mercury is mainly composed of the element iron. It is one of the few planets that have no moons and there is a reason. Being so close to the Sun, the gravitational pull would grab those moons like a magnet to iron, and they would be incinerated.

Planet Mecury
The planet Mercury is seen in silhouette, the lower third of the image, as it transits across the face of the sun Monday, May 9, 2016, as viewed from Boyertown, Pennsylvania. Mercury passes between Earth and the sun only about 13 times a century, with the previous transit taking place in 2006. Photo Credit: (NASA/Bill Ingalls)

Designated as the smallest planet in our solar system, Mercury is the closest planet to the sun. Only 36 million miles or 0.39 AU.  Mercury orbits the sun every 88 Earth days. (The closer the planet is to the Sun, the faster it revolves around it).

It has a thin atmosphere. We could not survive in this atmosphere without protective equipment, but it is unlikely you would want to go there when the average temperature is 354 degrees F. In 1974, two spacecraft visited Mercury: Mariner 10 and Messenger. Learn More.

Venus

The second planet from the sun and slightly smaller than Earth, it revolves around the sun every 225 Earth days. Over 40 spacecraft have explored Venus. Notably, Magellan mapped over 98% of the planet’s surface. Venus’ temperatures can go up to 480 degrees. The planet is unusual as it spins backward, resulting in the sun rising in the west and setting in the east.

Earth

NASA Photo of the Earth
Photo by Pexels

Where would we be without it? Our planet is considered to be in the Goldilocks Zone. The name was coined from the Three Bears children’s story. We are located in the area of the solar system where it is not too hot, not too cold, but just right for life as we know it to exist and strive.

With that said, scientists are currently looking at exoplanets in other solar systems that also are in the Goldilocks Zone. 15% of all stars in our galaxy have planets orbiting around them and if you add them together, it would total over 500 habitable planets that have been discovered so far, so who knows? We may not be alone after all!

Getting back to Earth’s facts, we are the third planet from the sun and 93 million miles away or one AU.

Mars
Mars is the fourth planet from the sun at a distance of 142 million miles or 1.52 AU. Mars makes a complete orbit around the sun in 687 Earth days. There are two moons orbiting Mars. Phobos and Deimos. It is believed that Mars once sustained life many years ago and we are still searching the planet with the Mars Voyager program to determine just that. If confirmed, scientists can determine that Earth is not the only planet that can sustain life.

There are plans by NASA to send men or possibly women as well to Mars.  But we better hurry up as China is also planning on manned missions to Mars as well.

Jupiter
The largest of the eight planets. If Jupiter was a soccer ball, Earth would be a pea in comparison. Jupiter is about 484 million miles, 5.2 AU from the sun.

Jupiter makes a complete orbit around the sun every 12 Earth years. Known as the ‘gas-giant’, it has no solid surface. Imagine landing on Jupiter with no solid surface!

There are 53 moons revolving around this planet. Jupiter is known for its Great Red Spot. A gigantic storm of immense proportions that has been happening since we first discovered Jupiter hundreds of years ago.

Saturn
Saturn is the sixth planet from the sun (886 million miles, 9.5 AU.) Saturn makes a complete orbit around the sun every 29 Earth years. As with Jupiter, Saturn is also a gas-giant with no solid surface. There are Saturn has 82 moons. Fifty-three of these moons have been calculated by scientists and another 29 have been located but are awaiting confirmation.

Some of Saturn’s moons are larger than the planet Mercury like the moon Titan and some are smaller than a football stadium. Saturn is probably the most popular plant with its outer rings circling it. The rings, seven in all are gaseous objects that stay intact due to the planet’s gravitational pull.

Uranus
Uranus orbits our sun at a distance of about 1.8 billion miles or 19.19 AU. Uranus makes a complete orbit around the sun in about 84 Earth years. Because of the distance from the sun, Uranus is a cold, icy planet. The planet contains 27 moons revolving around it.

Neptune
This blue planet is 2.8 billion miles, 30.07 AU from the sun. Like Uranus, Neptune is also a cold (actually colder) planet than Uranus. Neptune has 13 moons. It takes Neptune 165 Earth years to revolve around the sun. And just recently, it was discovered that the temperature of Neptune unexpectedly went down. Scientists are baffled as to why. Guess we’ll just have to go there to find out!