WeatherBill's Weather 101


Bill's Weather 101: The Sun

Posted at 6:05 PM, Mar 26, 2020
and last updated 2020-04-09 17:55:10-04

The Sun is our star. It’s a ridiculously hot ball of gas and plasma about 93 million miles away from us. It’s just the right distance to keep temperatures pleasant for almost all life as we know it. It’s also the driving force behind every bit of weather.

Our weather occurs and changes because of the way the Sun heats the Earth. In general, our atmosphere does not like things that are out of balance, and it’s always shifting and moving things around to correct those imbalances, both on small micro levels as well as gigantic planetary wide scales.

As we talk about in Bill’s Weather 101, the Sun heats things differently. It heats the North Pole, where it’s cold, much differently than the equator, where it’s hot. The atmosphere tries to balance this by taking warm air from the equator and moving it toward the Pole. Simultaneously, cold air from the Pole moves south toward the equator trying to cool it. The mechanisms used by Nature to accomplish this are the cold fronts, warm fronts, highs and lows you see on a weather map.

If the Sun were able to heat the Earth equally, all the way around, our weather would never change, and your friendly neighborhood weatherguy’s job would get really dull. Luckily for us, the Sun is always heating things differently, the air is constantly moving and that is our changing weather.

Now more about the Sun…It’s gigantic. The diameter is about 865,000 miles. You could put over 100 Earths in front of it. If you wanted to fill the Sun, it would take over 1 million Earths to do it (1.3 million if you’re really interested). Considering it’s all gas, the sun is remarkably heavy…it’s a number with about 30 zeros after it in kilograms. It’s 330 thousand times more massive than the Earth. It’s losing over a million tons of stuff every second to the solar wind…and it’s just a blip. It also contains over 99 percent of the mass of the rest of the solar system, COMBINED. It’s that mass that gives it the gravity to keep all of the planets in line.

Even with all that, our Sun is considered a G-type yellow dwarf star. It sits about in the middle of most star classifications, so we’re pretty average. However, if you

view the Sun from space, it’s actually white. Our atmosphere gives it the yellow look.

The Sun is basically made up of 2 things at this point in its life, hydrogen and helium. At the Sun’s 27 million degree core hydrogen atoms are going through nuclear fusion creating helium. The Sun is not going to need a fill up of hydrogen anytime soon as it’s only in middle age (and no it won’t be buying a convertible). It is about 5 billion years old and has about another 5 billion to go…so don’t sweat it becoming a red giant like the star Betelgeuse and swallowing up the Earth…and everything out to Jupiter for that matter. The giant phase at the end of the star’s life comes when it’s fuel changes from hydrogen becoming helium to helium becoming carbon and other things.

For all the wonderful things the Sun does for us, if we didn’t have our protective layer of the atmosphere around us, we wouldn’t be having this lesson. The Sun does send out a constant stream of different radiations. Things like ultraviolet light are part of the normal spectrum. There are also charged particles that are in the solar wind that is always hitting us that can react with the Earth’s magnetic field and create the Aurora displays. The solar wind goes out for about 11 billion miles and that is the end of our Sun’s influence.

Only 2 man-made object have left the heliosphere (the area of our sun’s influence) the Voyager 1 and 2 spacecrafts are now in interstellar space.

So as we continue through spring just sit back and enjoy the warmth our Sun provides. Then stop and wonder about just how big and wonderful our star is, and at the risk of sounding like Carl Sagan (youtube it kids), is just one of billions and billions of similar objects in our galaxy and universe.