Exploring the sun: You could put an eye out
Most people go to an observatory to see stars at night. Being contrarians, we went to see the sun. During the day.
It seemed kind of silly. I mean, you can look up and see the sun right?
So as we drove up to the McDonald Observatory, near Fort Davis, Texas, we didn’t have high expectations. It was a beautiful ascent, with stunning views over the West Texas mountains, and we figured the drive made the trip worth it.
Then we sat down in the auditorium, and Judy Meyer blew our minds.
First, Meyer, a public affairs specialist with the Observatory, flashed up a live picture of the sun. It was black and white, and you could see black spots, sunspots, and texture, solar granules.
Then she switched to a telescope that showed only one wavelength of light, hydrogen, which is what the sun is, mostly. We could see jets of hydrogen, called solar filaments, flying off the edges of the sun, and dark spots that were clouds of hydrogen floating above the surface of the sun, making cooler spots.
She showed us photos of the different telescopes they use to look at the sun, one with a red window that only allows the red spectrum, hydrogen. One that used a Herschel wedge, an optical prism that refracts most of the light, so you don’t burn your eyeball out looking into the sun.
Then she got heavy. Really heavy. Telling us the mass of the sun is 2 X 10 to the 33rd degree, or 2,000,000,000,000,000,000,000,000,000,000,000 kilograms, which are about 2.2 pounds each. It’s made up of 73.4 percent hydrogen, 24.8 percent helium and 1.8 percent other, meaning every other chemical element found on earth. It’s 805,000 miles in diameter, 109 times the size of earth, and is 4.5 billion years old, with an estimated life of 106 billion years. It’s light travels 186,000 miles per second, and reaches the earth in eight and a half minutes.
There was more, like while the sun is 10,000 degrees, some stars are 80,000 degrees, and while it seems pretty big to us, it’s near the bottom of all stars in size. She talked about how its gravity is pulling the sun together, how nuclear fusion is happening in its core and how the matter then moves up to the surface as bubbling gases.
Then it got kind of wild.
She showed us photos from a telescope that uses chromosphere, and we could actually see the bubbles, which were about 1,000 miles across, or the size of Texas. And we could see the corona, an aura of plasma and gases that surround the sun.
Turns out it’s about attraction, magnetic attraction and resistance. See, the sun has magnetic north and south poles, like the earth, but as it rotates, it rotates faster at its equator than at its poles, so the magnetic lines start to get all warped, then they get really twisted up, like a rubber band, and then they pop, like when you release the twisted rubber band, and spit matter out into space, a solar flare.
Turns out these magnetic flares are so huge, they can disrupt magnetic fields on earth, disrupting communications and create auroras, like the Aurora Borealis, the Northern Lights, or the Aurora Australis, the Southern Lights.
We needed a break, so we went to see the Hobby-Eberly Telescope, on next-door Mount Fowlkes. It has a 433-inch mirror made up of 91 hexagonal pieces all perfectly aligned. It is one of the world’s largest optical telescopes, housed in a three-story building, and benefits from some of the darkest night skies in the country. It’s designed specifically for spectroscopy, the decoding of light from stars and galaxies to study their properties, and ideal in searching for planets around other stars, studying distant galaxies, exploding stars, black holes, according to the website.
We may have to come back for a nighttime star party.