We know quite a bit about our own home, the Earth, as well as the universe around us, but what do we know about our surrounding planets? Let’s look at each of our celestial neighbors in a bit of detail.
But first, the basics. We have 7 surrounding planets in our solar system (and no, Pluto doesn’t count). But what is a planet? Or rather, what defines a planet? This seems like a simple question, but the answer isn’t simple. To be considered as a planet, the celestial body must be able to do three things:
- It should be big enough so that it has enough gravity to remain in a spherical shape.
- The planet should be massive enough to clear away other objects from its orbit.
- The planet must orbit around a star (the Sun is the star in our solar system).
While Earth, Mars, and Jupiter have been scientifically confirmed as planets, Ceres and Pluto have been denied. There has been a lot of scientific debate around how to define these two, and the general consensus is that these planets are considered dwarf planets.
What Do We Know About Our Surrounding Planets? A Look At Each Of Our Celestial Neighbors
For now, we will look at the surrounding planets in our solar system that are confirmed by NASA to have the status of “Planet.”
The planet Mercury is first on our list, and so, when answering the question, “what do we know about our surrounding planets?” we have to start with Mercury. Mercury is the smallest planet in the solar system, as well as the closest to the Sun. Named after the god of travelers, Mercury has a diameter of 4,879 kilometers, which is a small fraction compared to the 12,742 kilometers of Earth. It doesn’t have any moons or rings, and it rotates slowly, so a day on the planet is actually 58 Earth days long.
However, because it’s so close to the Sun, Mercury actually completes one year pretty quickly. It takes around 88 Earth days for Mercury to complete one orbit of the Sun, which means that a year on Mercury is 88 Earth days.
Venus is the second planet in the solar system in terms of its distance to from our Sun. It’s also the closest planet to the Earth, and because of this, it is the third brightest object in the sky after the Sun and moon. Since the mass and size of the planet is so similar to Earth, it is sometimes referred to as Earth’s sister planet. Venus has no rings or moons and is named after the Roman goddess of beauty and love. Venus’s surface is hidden under a thick, opaque cloud layer made from sulfuric acid.
Venus rotates slowly on its axis, which is why a day on the planet can last longer than a year. It takes 243 Earth days to complete a day on Venus, and 225 Earth days to complete a year. Hence, a day on Venus is much shorter than a year on the planet.
The climate of the planet could have been similar to that of Earth billions of years ago. Scientists believe that once upon a time, the planet possessed large amounts of oceans and water. However, the water boiled off due to the planet’s close proximity to the Sun, as well as the build-up of huge amounts of greenhouse gases. Venus’s surface is now too hostile and hot to sustain life.
Mars is the fourth planet in the solar system. It is named after the Roman god of war and is also referred to as the Red Planet due to the brownish-red color of its surface. It is the second smallest planet after Mercury.
Earth and Mars have similar landmasses since 70% of the Earth is covered by water. However, the gravity of Mars is only 37% of the gravity of Earth, which means you could jump three times as high as you could on Earth. 39 missions have been sent to Mars, out of which only 16 have been successful. The first mission to Mars was Marsnik 1, sent by the Soviet USSR in the 1960s.
The second tallest mountain in our solar system is present on Mars. Olympus Mons has a 600 km diameter and is 21 km high. It formed billions of years ago but still has trace amounts of lava, which can mean that it’s still active; however, this is unlikely.
Mars also experiences the largest dust storms in the solar system. The elliptical shape of the orbit path of Mars causes fierce dust storms that can last for many months.
Currently, the plan is to send humans to Mars before 2050, which means that we might learn a whole lot more about the red planet.
Jupiter is the fifth planet. It was first recorded by the ancient Babylonians around the 7-8th century BC. It is named after the god Jupiter, the king of all the gods. Jupiter is also known as Zeus in Greek mythology.
Jupiter has the shortest day – a day on the gas giant only lasts 9 hours and 55 minutes. The quick rotation has given the planet a slightly flat, oblate shape. A year on Jupiter lasts for 11.8 Earth years. The upper atmosphere of the planet has cloud zones and belts made of sulfur, ammonia crystals, and different mixtures of the two.
The Great Red Spot on is a huge storm called on Jupiter that has been raging for almost 350 years. The spot is so large that it can easily fit three Earths inside of it. The interior of the planet is made up of hydrogen, metal, and rock. Scientists have also theorized that Jupiter might have layers of liquid metallic hydrogen, hydrogen gas, and a core of metals, rock, and ice.
Jupiter has a lot of moons and a ring system too. The largest moon orbiting the planet is Ganymede, which has a diameter of 5,268 km. This makes Ganymede even bigger than Mercury. The thin ring system mainly consists of dust particles that come from asteroids and comets.
Around 8 space crafts, including Voyager 1 and 2, Pioneer 10 and 11, Cassini, Galileo, New Horizons, and Ulysses, have visited the planet.
Saturn is the furthest planet that we can see using the naked eye. It was first recorded by the Far East Observers and the Babylonians. It is named after the Roman god called Saturnus. Saturn has a low density and really fast rotation, making the polar dimension 90% of the equatorial diameter. It has the second shortest day of 10 hours and 34 minutes.
Saturn takes 29.4 Earth years to complete one orbit around the Sun. The planet has bands of cloud layers in the upper atmosphere. The topmost layer is made of ammonia ice, followed by a layer of water ice, then sulfur ice, and a cold hydrogen-mixed layer.
Saturn has an extensive ring system made up of mostly dust, ice, and rocks. These rings stretch as far out as Saturn’s entire diameter! However, they are only 20 meters thick individually. Saturn also has the most moons in the solar system; it has 150 moons and small moonlets. The largest moon of Saturn is Titan, which is known for its nitrogen-rich, dense atmosphere.
Uranus is the seventh planet in the solar system and is not visible to the naked eye. The odd thing about this planet is that it is tipped at its axis at 98 degrees, which is looks like it’s on its side while it orbits the Sun.
It was discovered in 1781 by Sir William Herschel through a telescope. A day on Uranus is 17 hours and 14 minutes long, and a year is equitant to 84 Earth years. It is often referred to as the ice giant planet and has an upper layer of hydrogen. The methane ice crystals, ammonia, and water give it a pale blue color. The planet regularly hits temperatures of -224°C.
Finally, on our quest to answer the question, “what do we know about our surrounding planets,” we arrive at Netpune. Neptune is the eighth planet from the Sun and is the third-largest in terms of mass. It is named after the Roman god of Sea due to its blue color. It was discovered by Le Verrier and was originally named after him.
Neptune takes around 164.8 Earth years to complete one orbit around the Sun. Since it was discovered in 1846, it has just completed its first full orbit in 2011. It has the second largest gravity among all the planets in the solar system. The largest moon of the planet is Triton and was discovered 17 days after the planet itself was discovered.
Neptune also has a storm that is similar to the Great Red Spot. It is called the Great Dark Spot and is the size of Earth. It also has another storm called the Small Dark Spot. This raging monstrosity of a storm is almost as big as our moon.
There you have it, a trip through the various planets of our solar system. We have managed to find a lot about our surrounding planets due to the tireless efforts of astronomers throughout history, as well as the hundreds of probes that we have sent out to explore the solar system. So, what do we know about our surrounding planets? Quite a lot, actually.