13 stellar things to know about the sun

While eclipse mania is reaching a fever pitch, here’s what to know about the star of the show.

The sun is such a fundamental part of life that it’s easy to take it for granted. But seriously, it’s a giant flaming nuclear reactor in the sky that makes us don protective eyewear and coat our skin with shielding lotions! And maybe the most profound part of all is that our sun is just one of more than 100 billion stars in the Milky Way. It also just so happens to fuel life on this planet, for which we are forever grateful.

As we are entering peak eclipse-a-palooza, we thought it high time to shine some light on the heart of our solar system and the star of the show. From how long it would take to drive there to the fact that its surface could boil diamonds, consider the following:

1. It's very big!
Our beautiful yellow dwarf star is huge. With a radius of 432,168.6 miles (695,508 kilometers), it isn't quite as big as many other stars, but compared to Earth, it's enormous. It holds 99.8 percent of the solar system's mass; and equals the mass of 332,946 Earths. Think of it this way, in terms of volume we could fit 1.3 million Earths inside of it. Or consider it in surface area, of which it has 2,347,017,636,988 square miles.

2. It's not called a solar system for nothing
Despite what everyone believed before Copernicus came around and set the record straight in the 16th century, things revolve around the sun, not our home planet. The sun's massive gravity holds the system together, making sure that everything from the biggest planets to the ittiest bits remain in its orbit.

solar systemAdam and Charles Black's chart of the Solar System and the Theory of the Seasons, 1873 /CC BY 2.0 3. It's far away
The sun is 93 million miles (~150,000,000 kilometers) from Earth. Going 60 mph, non-stop, it would take 177 years to drive there. Don't have that kind of time? Flying there in a commercial jet at 550 mph (885 kph) would shave off 158 years for a 19-year long flight.

4. But in space terms, it's really close
Space is big. So big, that 93 million miles is actually really close! The next closest star to Earth, after the sun, is one of three stars in the Alpha Centauri system. Proxima Centauri is about 4.22 light years from Earth – to refresh your high-school memory, a light year is 5,878,499,810,000 miles (9,460,528,400,000 kilometers).

5. It's in a nice neighborhood
The sun resides in a spiral arm of the Milky Way Galaxy, called the Orion Spur ... the Orion Spur branches out from the Sagittarius arm. From its position, it orbits the center of the Milky Way Galaxy, bringing along all of its followers – planets, asteroids, comets and the rest – along with it.

6. It flies
The sun and her band of tagalongs orbit at an average speed of 450,000 mph (720,000 kph). But even at this impressive velocity, it still takes us about 230 million years to make one complete trip around the Milky Way. Who's got the time for that?

7. It's has extreme shine
Obviously the sun is bright, but just how bright is it? Easily the brightest object we can see, with an apparent magnitude of −26.74. This is about 13 billion times brighter than the next brightest star, Sirius, which has an apparent magnitude of −1.46.

8. It's an illusionist
Crepuscular rays are the sunbeams that burst out from behind clouds; they've clearly inspired every childhood drawing of a sun with rays extending to all corners of the page. Created when clouds block bits of light and make shadows, they appear to radiate out from the sun and increase in size as they do. But it's an illusion! The rays are actually parallel to each other and simply look like they get closer together as they recede in the distance, the same optical illusion presented by train tracks.

crepuscular raysPiccoloNamek/CC BY 2.0 9. It's hot as Hades
Of course the sun is hot, but just how hot? NASA explains that at its core, the sun reaches temperature of 27 million degrees F (15 million degrees C); enough to sustain thermonuclear fusion. The surface reaches a mere 10,000 degrees F (5,500 degrees C) – which is hot enough to make diamonds boil.

10. It's rather gassy
Like many a star, the sun is made up mostly of hydrogen, followed by helium. The rest is oxygen, carbon, neon, nitrogen, magnesium, iron and silicon. For every 1 million atoms of hydrogen in the sun, there are 98,000 of helium, 850 of oxygen, 360 of carbon, 120 of neon, 110 of nitrogen, 40 of magnesium, 35 of iron and 35 of silicon.

11. It's middle-aged
At about 4.6 billion years of age, the sun is entering middle age – though it is young compared to its peers. As part of a generation of stars known as Population I, it's from a relatively new group of stars. Scientists believe that the sun is a bit less than halfway through its life, which should last for another 6.5 billion years.

12. It's a hungry hungry star
Once the sun burns up its massive store of hydrogen, it will start on its reserve tank and begin burning helium, which will last 130 million years or so. During this time, it will get so big that it will engulf its neighbors ... meaning an end to Mercury, Venus, and even our little rock, Earth. When it reaches this point, it will be known as a red giant star.

13. And then it will demure
Once it's done burning helium and devouring planets, it will collapse – because after a run like that, who wouldn't? – retaining its mass but with a size similar to that of Earth. When that happens, it will be known as a white dwarf, and will remain so for the billions of years it takes to cool down ... twinkling in the night sky, hopefully for beings on the other side of the galaxy to admire and make a nightly wish upon.

Tags: Nature | Nature Blows My Mind | Solar Energy | Space

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