Interesting Facts About the Solar System.

Interesting Facts About the Solar System.




1. The Solar System only has 8 planets.





That’s right, only 8 planets. Not the 9 planets you grew up with. That’s because the International Astronomical Union reclassified Pluto as a dwarf planet in 2006. Why is Pluto not a planet? To qualify as a planet, an object needs to orbit the Sun, have enough mass to pull itself into a spherical shape, and have cleared out its orbit of other material. It’s this third requirement that Pluto hasn’t fulfilled; it’s just a fraction of the mass in its orbit, while the other planets are millions of times more massive than everything else in their orbits.



2. But the Solar System has 4 dwarf planets





Pluto has been downgraded, but there are now 4 dwarf planets in the Solar System: Ceres, Pluto, Eris and Makemake. Dwarf planets are objects that orbit the Sun and have enough mass to form a sphere, but they share their orbit with other objects. And as telescopes improve, more dwarf planets will be discovered. There might eventually be more dwarf planets than planets.



3. The influence of the Solar System extends out for almost 2 light-years


The theoretical size of the Solar System goes out as far as the the Sun’s gravity overpowers anything else in the region; and this is almost 2 light-years away, nearly halfway to the nearest star. It’s thought that the Oort Cloud – a region where the long-period comets come from – extends out to 100,000 astronomical units from the Sun (1 astronomical unit, or AU, is the average distance from the Earth to the Sun).



4. Most of the mass of the Solar System is the Sun





In fact, the Sun contains 99.86% of the mass in the Solar System. And the Sun is 73% hydrogen, so most of the matter in the Solar System is hydrogen, with the remaining amount being mostly helium, oxygen and carbon. Everything else, like the metals and rocks is just a tiny fraction of a fraction of the mass in the Solar System.



5. The Solar System is 4.6 billion years old





Since the Earth is constantly resurfacing itself, we can’t find out how old it is, but there’s another way to find out. Meteorites, which date back to the formation of the Solar System, have been raining down on Earth for millions of years. Scientists have sampled meteorites and learned that they’re all 4.6 billion years old. That means that everything in the Solar System formed around the same time – give or take a few million years.



6. Everything orbits in the same direction





All the objects in the Solar System orbit the Sun in a counter-clockwise direction. This matches the theory that the Solar System formed all at once from a cool cloud of hydrogen. As the gas came together, it began to spin, so that the Sun collected in the middle, surrounded by an accretion disk of gas and dust. All the planets and other material in the Solar System formed within this rotating disk. There are a few exceptions, however, like Halley’s Comet.



7. The Sun is just one star in 200 billion in the Milky Way





Doesn’t that give you perspective? Our whole world is just one planet orbiting one star in a galaxy of 200 billion stars.



8. But they’re really far apart





There are only a few stars within 10 light-years of the Sun. The closest system is the Alpha Centauri system, 4.4 light-years away. Barnard’s Star is 5.9 light-years away, and then Wolf 359 (7.8 light-years), Lalande 21185 (8.3 light-years), Sirius (8.6 light-years), Luyten 726-8 (8.7 light-years), and finally Ross 154 at 9.7 light-years away. Interstellar travel will be difficult when you’re dealing with these distances.



9. Astronomers used to think the Earth was the center





You take it for granted that the Sun is the center of the Solar System, but astronomers used to think that the Earth was the center of the entire Universe. It wasn’t until the 17th century, when Nicolaus Copernicus first presented the concept, and showed how it accurately predicts the positions of the planets.



10. Humans have sent spacecraft almost everywhere





Spacecraft from Earth have visited or orbited every planet in the Solar System, and more are on their way to visit some of the dwarf planets. We’ve explored the Sun, the Moon, and many asteroids. And now some of the oldest spacecraft still active – NASA’s Voyager spacecraft – have almost reached the Sun’s heliosphere; the point where the solar wind slows down as it bumps against the interstellar wind.


Thank you for reading.

reply to post by Alpal


Nice little pieces of information and well put together..

s&f

Nice thread!

I found the informations interesting out there. How can't it be anyway, it's where we are in the universe right? It brang to me a question tough. What exactly is the blue sun in the picture of the two suns? It's not the first time I see this and I was wondering what exactly it was.


Thruthseek3r

Beautifully presented post, thank you OP!

Although I was already familiar with most of these the pictures were an added bonus.
Who knows what strange things are out there in our solar system alone, we still have so much left to learn.

Thanks for the post, take care everyone.

I thought I was going to learn something new & strange

nevertheless, some good info for the school kids here to learn from