About 342,012,346 miles past Mars lies the largest planet in our solar system, Jupiter. Jupiter is much different than the past four planets that we’ve talked about because you cannot actually stand on it’s surface. It is called a “gas giant” meaning it’s made of entirely gas. It is composted of about 75% hydrogen and about 25% helium. Viewed from Earth, it can be one of the brightest objects in the sky due to the high amount of sunlight that reflects off the clouds on the surface.

Jupiter, being the fourth planet from the sun also has the fourth largest/longest orbital period. It takes almost 12 Earth years for one year on Jupiter to pass. It’s mass is about 317 times the mass of Earth’s. Much like our planet, Jupiter has a magnetic field that protects it from the Sun’s harmful radiation. Some believe that it might have a solid iron core in it’s center to cause that, but it is not yet proven. The magnetic field allows for beautiful auroras to appear on it’s south and north poles much like Earth. Another similarity to our planet is that there are hurricanes! The “Great Red Spot” on Jupiter’s surface is believed to be a hurricane that has existed since 1831. Images have shown that it has been decreasing in size in the past few years but it is still a giant storm(Much larger than hurricane Matthew).

In addition to various Earth originating satellites that are currently orbiting Jupiter, there are 61 natural moons around the planet. One of these moons, named Europa, is currently the prime candidate for body that could have life in our solar system. Of course, it’s too cold for life to be on it’s surface, but under the surface, there is something interesting. Europa has a multiple mile thick sheet of ice on it’s surface, but we have evidence that there is a liquid ocean under it’s surface that could be warm enough to support life.

Jupiter is a planet that literally helps define our solar system. Without it, asteroids would be randomly scattered throughout, orbits would not be the same, and Earth might have not even formed. It’s amazing how one planet can have such a big influence.

A second Earth? Not exactly. Mars, the fourth planet from the sun, has been the prime candidate for human colonization. Climate wise, it wouldn’t be too bad, but when you look at the bigger picture, it isn’t as friendly.

Mars is the second smallest planet in the solar system. It is oftentimes referred to as the “red planet” due to it’s reddish appearance cause by iron oxide on its surface. Mars is believed to have had a thick atmosphere at one time, but due to the lack of a magnetic field, the Sun’s solar blasts have slowly degraded it over time. The surface itself has been proven to have traces of liquid water. There are mountains, canyons, valleys, volcanoes, and ice caps. These ice caps are believed to be comprised of enough frozen water that if they melted, they’d cover the entire planet with a depth of 11 meters. Mars has two moons that are believed to be asteroids caught in its gravitational pull due to their very irregular shape.

Years on mars last about 667 Earth days due to it being 143,000,000 miles away from the sun.  The days on mars are only slightly longer than our’s, being 24 hours 39 minutes. Despite Mars being a lot smaller than Earth, it actually has the same landmass. How is this you ask? Well Earth, as you know, is covered with nearly 70% water.

There have been ongoing investigations of the Martian surface searching for evidence of past life. In addition, there have been various missions to test to see if humans could ever visit. Out of the 40 attempted missions to the planet, only 18 have been successful. Radio signals from Earth can vary between four and 24 minutes to reach Mars depending on its current position in orbit. This makes it very difficult to do any coordinated landing procedures. Astronomers just have to watch, wait, and hope for the best.

Mars is undoubtedly the number one candidate for human exploration. There have been various films about this. The most popular, and most recent, “The Martian” has sparked a lot of public interest in the planet. The company SpaceX has plans to put humans on the planet within the next ten years! The only problems are the toxic, carbon dioxide, filled atmosphere, and an interesting climate that we are still studying. Hopefully humans can do it though if we never give up!

Now for the place that is what all of us call home, the Earth. It’s a nearly perfect planet when you think about it. It’s the third planet from the sun so it is in what scientists call “the habitable zone”. This is an area where the sun isn’t too close(too hot) or too far(too cold) to the planet so life is able to flourish. Earth is the only known planet to have life. It is believed that it formed 4.5 Billion years ago, and it is one of the four rocky planets in the solar system.

Earth is the third planet from the Sun, about 93,000,000 million miles away, and it makes it’s rotation at approximately 19 miles per second. Therefore it has the third largest orbit, taking about 365 days for one revolution. In addition, it takes Earth around 24 hours to spin on it’s own axis(1 day). In addition, as we know, it has a moon(Or as scientists call a satellite). This moon causes the oceans of Earth to have tide shifts as the moon rotates around. Earth is the only planet in the solar system to have a large amount of liquid water on it’s surface.

Since the Earth has been around for so long, it’s been through a lot of changes. For example, Earth didn’t always have an oxygen rich atmosphere like it has today. Microorganisms are to thank for the breathable air we enjoy. Also, not a lot is known about exactly how such an abundant amount of liquid water got here. Some scientists speculate that many comets, containing large amounts of ice crashed into the planet early in our history and supplied the water.

Earth is made up of a crust, mantle, and core. The crust is divided into sections called tectonic plates and these cause Earthquakes and Volcano eruptions to occur. The core of the planet is made up of mostly iron. This is how we get our magnetic field that protects us from the Sun’s very dangerous electromagnetic radiation and how we can see the beautiful northern and southern lights if conditions are right!

About 7 Billion people inhabit Earth thanks to it’s near perfect climate, chemical composition, and resources. It is the only planet we know of to have such characteristics. Something so novel is also very delicate so it is all of our duties to take care of the place that is all most of us have ever known, the planet Earth!

Stop number two on the journey through the solar system is Venus. Venus is oftentimes overlooked due to it being the hottest planet in the solar system, but it is actually a planet that scientists have wanted to put humans on. It is very similar to Earth’s size, composition, and distance from the sun. The only problem is it’s atmosphere is the densest in the solar system and the surface pressure is 92 times that on Earth. It’s contains more than 96% carbon dioxide so that creates a run away greenhouse effect that traps all the heat which is why it’s so hot.

Venus can be seen in the sky fairly easily due to being blanketed by a friendly, reflective cloud of sulfuric acid! In addition, this cloud covering the entire planet makes it impossible to view the surface of the planet itself without special cameras. Venus orbits opposite to the other planets in the solar system and it’s years last approximately 225 Earth days. The best time to view it is in the evening. It was actually one of the first planets to have it’s movements mapped by humans because it seemed to move fairly quickly in the sky.

Despite being toxic for humans, the surface of Venus acts much like Earth’s. There are volcanoes, earthquakes(Venusquakes), mountains, and valleys. As we will discuss in a later post, just because conditions are toxic for humans, doesn’t mean there couldn’t be life on a a planet. There has been speculations that some microorganisms could be thriving on more temperate regions of Venus closer to the poles. This is very unlikely though due to the vast amounts of carbon dioxide in the atmosphere.

There has been some disputes about whether to try to colonize Venus instead of Mars. What do you think? There’s pros and cons to both. There was an interesting video done by PBS on this topic. Click Here to Watch it!

Next up in our journey through the solar system is the planet Mercury. Mercury is the smallest planet(Excluding Pluto) in the solar system and it is also the innermost. It is about 36 million miles from the sun so you’d think it’d be pretty hot all the time, right? Well sort of. Mercury’s temperature varies more than any other planet in the solar system mostly because it has barely any atmosphere to act as a blanket to keep heat in. The temperature can range from -280 degrees Fahrenheit during the night to about 800 degrees during the day. That fact really makes you appreciate how perfect Earth is, but that’s for another post!

A year on Mercury is only about a third of an Earth year, about 88 days. It also has one of the oddest orbits of all the planets. Instead of being on a horizontal plane like us, it’s elliptical orbit tilts about seven degrees upward. In addition, Mercury itself has a very interesting orbit. Earth rotates independently from the sun on it’s own axis once every 24 hours(One day). Days on Mercury, on the other hand, last two years.

Mercury probably wouldn’t be the best place to live, but if you were considering to move there, you would enjoy an earthquake free life! Unlike Earth, it has a very thick crust with no tectonic plates. There are craters of meteor strikes that are thought to be billions of years old that are still perfectly preserved. Also, you would be much lighter on the surface of mercury due to the lesser gravitational pull of the planet. If you weighed 200 pounds on earth, you would come in at just over 80 pounds on Mercury.

All in all, Mercury is a pretty neat planet. I wouldn’t consider moving there any time soon because of the toxic atmosphere, freezing temperatures, boiling temperatures, and solar wind storms, but it’s a pretty cool place. Learning about other planets makes us admire how perfect our world is and how we need to appreciate it.

Video with some cool facts about Mercury