8 Solar System Facts: Beautiful and Strange at the Same Time
You might expect this post to be about a solar system you can put on your roof. Well, let me surprise you: This is about the solar system way, way above your roof. The original, real thing: THE solar system.
Our solar system is – as the name suggests – dominated by a central star, the sun. Then, there are bodies moving in orbit around it. There are eight planets: Mercury, Venus, Earth (hello!), Mars, Jupiter, Saturn, Uranus and Neptune. Besides those , the solar system has 61 natural satellites, thousands of asteroids, comets, meteorites and interplanetary dust. It is a little like the Delhi airspace.
The sun, much larger than anything else in the solar system, is a vast source of electromagnetic energy (including the light, we see). When you look into a clear starry night (reminder: get out of your congested city and take a hike in the mountains!), you will notice thousands of visible starts and sometimes you see a ring of higher density of stars. This is our galaxy, the Milky Way. The nearest large galaxy is the Andromeda. If you think of our solar system as our cosmic village, the Milky Way is our cosmic country. Our village is on the remote fringes of it. So yes, you could say that we live in the cosmic back-of-beyond.
The stars that we see in the sky and that apparently seem to have the same size and distance from Earth, are much farther than our Sun. As you know, the universe is very large. And it is ver empty: The galaxies occupy only one hundred-thousandth of the known universe, and the space between them is increasing. The total size of the universe is not unknown. We can try and triangulate it by hypothesising about a possible starting point (the big bang) and the speed at which it expands – but we are learning new things all the time and our ideas are far from proven. (What we can exclude with some certainty, however, is that the universe was created in Biblical times some thousands of years ago. The Vedic guess of millions of years might be closer to the truth.)
While most us know these basics of the solar system, here are some interesting, lesser-known facts: 8 wonderful and strange secrets of the solar system.
Discover 8 solar system facts
Pluto and the dwarfs
You might have followed the controversy around Pluto, the farthest planet from the Earth. Actually it is no longer considered a planet at all. It was demoted to the status of, well, “dwarf planet”. On the plus side, however, other dwarf planets in the solar system are called “plutoids”. A dwarf planet is a large planetary body that has no defined orbit – a criterion for the classification as a planet. At the same time, this type of cosmic object does not orbit around another planets and hence cannot be considered to be a moon. Today there are five dwarf planets in our system – all of them beyond Neptune: Pluto, Ceres, Eris, Haumea and Makemake.
Funny names, you might say. This is what they mean: “Pluto” is the mythological god of the ancient Roman underworld. “Ceres”, lying between Mars and Jupiter, is named after the ancient Roman goddess of agriculture. The “Dawn” spacecraft is scheduled to reach it on the 6th of March 2015. “Eris”, the largest dwarf planet (and really far away), was named as late as 2006 after the ancient greek goddess of discord. Another name in the race was “Lila”, a concept in Hindu mythology that describes the cosmos as the outcome of a game played by Brahma. “Haumea” is named after the matron Goddess of the island of Hawaii, where the observatory is located where the dwarf planet was discovered in 2004. “Makemake” is the god who created mankind in the mythology of the Rapa Nui people of the Easter Islands. It was chosen because the the dwarf planet was discovered around easter time in 2005.
The Pluto controversy
Pluto’s status as a planet was questioned for more than 30 years. The controversy has spread throughout the world of astronomy and beyond: many people still refuse to accept that Pluto is no longer a planet, contradicting everything they had learned in school. However, there was always doubt amongst astronomers, even if it did not become part of the mainstream public discourse until recently. The announcement caught the world by surprise.
Don’t believe the asteroids you see in the movies
You know the scene (glued to your seat, stuffing popcorn into your mouth): The hero of a science fiction movie has to drive his spaceship through a field of asteroids. Feels a bit like Bombay traffic. In a collision, the ship is destroyed and the story ends in tragedy. Don’t buy it: It’s just fiction (at least in our solar system). Yes, our solar system has an asteroid belt between Jupiter and Mars. However, the asteroids in orbit are not close to each other. There is an enormous expanse of space separating the asteroids. You’d more likely fall asleep than hit one by accident.
Which is the hottest planet?
Most people think the hottest planet in the Solar system is Mercury, only because it is the closest to the sun. Temperatures on Mercury vary hugely from a freezing -170 to a boiling +450 degrees celsius. Venus, the second closest to the sun, on the other hand, consistently reaches temperatures of +450 degrees celsius. Do you know why? It has something that Mercury (almost) lacks: an atmosphere to retain heat. The atmosphere of Venus is quite thick and thus able to absorb the heat generated by the sun.
Jupiter, the Earth’s guardian
Jupiter is the largest planet in the solar system. Scientists consider it to be the protector of planet Earth. Due to its large size (over 1,ooo times the volume of the earth) it has a strong gravitational pull. This acts as a protective barrier shielding Earth from space debris. Pulling towards itself dangerous objects, Jupiter is diverting these same residues from the Earth’s orbit. In the past, comets directed to the Earth were drawn to the gravitational field of Jupiter thus avoiding collision.
One day with more than 1390 hours?
One day corresponds to one complete rotation of a planet around its own axis. The Earth’s rotation, for example, takes 24 hours to be completed. But this does not happen in all the other planets of the Solar system. One day on Venus, for example, has 243 days: Very, very long nights, and very, very long days. You can visualise the effect of it by thinking about the Arctic or Antarctica, where the sun stays below the horizon for the whole of winter so it’s night for many months. And here is next crazy thing: A “Venus day” is longer than a “Venus year” (i.e. the time it takes Venus to orbit around the sun). Interestingly, the shortest day, of just about 10 hours, is on Jupiter, which also has the largest surface area. You’d get dizzy at the speed of rotation…
A season with twenty years
Uranus has an orbital tilt of eighty-two degrees. What does this mean? It’s very easy to understand: Uranus is practically on its side as seen against the sun. As a result, a season on Uranus lasts about 20 years and causes all sorts of odd weather. For instance, in recent years Uranus went through a terrible and harsh winter. Until approximately 2025, the planet will enjoy a long spring and temperatures below zero. Of course, the Game of Thrones fans among you will immediately think “winter is coming”.
How many times would our Earth fit into the Sun?
The Sun is much, much larger than any of the planets surrounding it. It represents 99% of the mass of the entire solar system. Other planets, like Jupiter, make up the majority of the remaining 1%. In the scheme of things, our planet Earth is almost too small to notice. It would take 960,000 planets Earth to fill up the Sun.
Did you like to learn these solar system facts? Read more in our Sun Science section on the blog ABC of Solar.