The Solar System is our home. We marvel at the way it’s so precisely located in the galaxy, with such a precise amount of mass, a precise number of planets, and a precise amount of light from the Sun, to create such beauty and magnificence is a marvel in itself. Yet the more we learn about it, the more we are awed by its numerous wonders and immense possibilities. Whether we would be able to completely understand it in our lifetime or not, we certainly can admire the things we do know about it. So, here are some facts about our Solar System that you might find interesting.
1. The Sun accounts for about 99.86 percent of the total mass in the Solar System.
The Sun is the most important source of energy for life on Earth and also the biggest body in the Solar System. Its mass is over 330,000 times that of Earth and is about 99.86 percent of the Solar System’s total mass. About three-quarters of its mass is hydrogen, and the rest is helium with trace amounts of oxygen, carbon, neon, and iron. Born over 4.6 billion years ago, the Sun is considered a fairly middle-aged star with five more billion years left. After that, it will become a red giant consuming the orbits of Mercury and Venus, making Earth unfit for life.(source)
2. It takes 243 Earth days for Venus to spin on its own axis and 224.65 Earth days to go around the Sun. This means that on Venus, a day is longer than a year.
Venus has a retrograde rotation, which means that while the direction of its rotation on its axis is clockwise when seen from the north pole, its orbit is anti-clockwise around the Sun. That means, for Venus, the Sun rises in the west and sets in the east. A day on it is a very long time compared to Earth. A sidereal day, the time it takes for a planet to complete one axial rotation is 243.025 Earth days which is to 23 hours 56 minutes and 4.1 seconds. On the other hand, a solar day, the time it takes for the Sun to reach the same point in the sky, is 116.75 Earth days while it is exactly 24 hours on Earth. The time it takes for Venus to orbit around the sun is 224.7 Earth days.(source)
3. Saturn’s average density is so low that it can float on water.
Just like Jupiter, Saturn is a gas giant and together they hold 92 percent of the planetary mass in the Solar System. Saturn is mostly composed of hydrogen, about 96 percent, and helium, around three percent. Being a massive planet, the pressure, temperature, and density steadily increase toward the core. So, the hydrogen transitions from gas to liquid and to metal as you go deeper. Though Saturn has 95 times the mass of Earth and its core is considerably denser than water, its average density is only 0.69 grams per cubic centimeter. It is the only planet in our Solar System that is less dense than water.(source)
4. Around four billion years ago, Mars had an oxygen-rich atmosphere.
When the scientists from the Department of Earth Sciences at the University of Oxford analyzed the meteorites from Mars and the surface rocks on Mars, they found a discrepancy. They found that the surface rocks had five times more nickel than the meteorites. This meant that, though they both have similar origins in the depths of Mars, the surface rocks have signs that they’ve come from an oxygen-rich environment. The scientists believe that because of a process called “subduction” in which one tectonic plate moves under another tectonic plate. The oxygen-rich material was drawn into the interior and was spewed back during volcanic eruptions. This means that about four billion years ago, Mars had an oxygen-rich atmosphere, and was wet and warm.(source)
5. The Sun is so loud that if space was filled with air it would be 125 decibels on Earth even though it is 92 million miles away.
With so much nuclear activity, the Sun is incredibly noisy, almost equal to 10 million keys strikes of a piano. It emits 383 “yottawatts” per second (“yotta” is 1024). That means it gives out 290 decibels of sound. But, since distance dissipates sound energy, by the time it travels all the way to Earth, we hear 125 decibels of sound. It’s five decibels less than the sound of a train horn about one meter away, and five decibels more would literally hurt our ears.(source)
6. The base of Mars’ Olympus Mons, the tallest known mountain in the Solar System, is so large that if you stood on its peak you wouldn’t know you were standing on a mountain as the slope would be obscured by the planet’s curvature.
Olympus Mons is a “shield volcano.” That means is it was made entirely from fluid lava flowing out of it and hence has a very gentle slope. The mountain is about the size of Italy and covers an area of 300,000 square kilometers (120,000 square miles). It stands approximately 21 kilometers (13 miles) high. Because of its shallow slopes, you cannot view it completely even from a great distance or from its peak. The curvature of the planet and the volcano itself would obscure a complete view. If you stand on top, you would be unaware that you are on top of a mountain because its slope extends beyond the horizon.(source)
7. Jupiter is the Solar System’s “cosmic vacuum cleaner.” Its gravity attracts so many comets and asteroids that the rate of their collisions is about 2,000 to 8,000 times that of the Earth.
The impact a major collision can have on life on Earth was demonstrated during the Cretaceous-Paleogene impact event which wiped out all dinosaurs and created the Chicxulub Crater. This has led astronauts to speculate that without Jupiter to take the brunt of collisions, there would have been more extinction events on Earth. Though Jupiter doesn’t exactly clean up all the comets and asteroids, it does have a strong gravitational influence which attracts many of them to collide with its surface giving it the nicknames “cosmic vacuum cleaner” or “cosmic liver.”(source)
8. Neptune has the strongest winds in the Solar System. They blow at a speed of 2,100 kilometers per hour (1,305 miles per hour).
Neptune’s weather is extremely stormy with winds reaching supersonic speeds. Strangely, the winds generally flow in a direction opposite to that of the planet’s rotation, at high latitudes, but flow in the same direction of the planet’s rotation at lower latitudes. The difference is due to what is called the “skin effect,” the tendency of currents to flow only on the outer layers. Also, not being completely solid, Neptune undergoes differential rotation, that is its rotation at the equator takes 18 hours while its magnetic field takes 16 hours and its poles take 12 hours. It has the most pronounced differential rotation in the Solar System which also results in strong latitudinal wind shears.(source)
9. It snows metal on Venus, while it rains diamonds on Saturn and Jupiter.
Being the second planet from the Sun and having an atmosphere with 96.5 percent carbon dioxide, a greenhouse gas, Venus has a very hot climate. Its surface temperatures reach an average of 462 degrees Celsius. That is hot enough to evaporate reflective pyrite minerals over the basalt volcanic rocks in the lowlands into a metallic mist. The mist, after reaching higher altitudes, condenses into shiny metallic frost which snows back down over the planet’s surface.
The scale heights of the atmosphere on Jupiter and Saturn are 27 and 59.5 kilometers respectively compared to 8.5 kilometers on Earth. This means that the atmospheric pressure on the two giant planets is considerably higher, not to mention their force of gravity and the heights from which the rain has to fall. Scientists believe that the methane in their atmospheres breaks down into elemental carbon and hydrogen due to lightning during storms.
As the carbon falls through the length of their atmospheres, it could bond together into graphite. As the graphite falls further into the much denser layers of gaseous and liquid hydrogen getting exposed to even higher pressures and temperatures of about 8,000 degrees Celsius, it could condense even more into solid diamond. Another theory is that, rather than the pressure and temperature, further lightning is what causes the graphite to turn into diamond, and quite possibly rain diamonds.(1, 2)
10. Scientists believe there is a ninth planet in our Solar System that’s around 10 times larger than Earth. They haven’t been able to locate it yet, but know it exists because of its gravitational effects on other objects.
The existence of “Planet Nine” was proposed in 2014 by astronomers Chad Trujillo and Scott S. Sheppard to explain the improbable orbital configuration of a group of trans-Neptunian objects that orbit beyond the Kuiper belt. In 2016, two researchers from Caltech explained how a massive outer planet could be the explanation for the orbits of these six objects. They proposed parameters which indicate that the hypothetical ninth planet is ten times the mass and two to four times the diameter of Earth. It orbits at a distance 20 times that of Neptune from the Sun in a highly elliptical orbit which takes 15,000 years for it to complete. The planet hasn’t yet been named, though the researchers call it “Phattie” among themselves.(source)
And here’s some thermonuclear art of the Sun made by scientists at NASA.