What the Sun Does For Us | Universe Today

Written by Fraser Cain

I hate the Sun, and try to cower in the shadows as often as I can. I laughingly joke with my friends that I'd destroy the Sun if I could. That would be a very bad idea, though, since we need the Sun. In fact, without the Sun, there wouldn't be any life on Earth, we'd just have a cold ball of rock floating through space forever. Here's what the Sun does for us.

The Sun keeps us in place. Even though the Earth is located approximately 140 million kilometers away from the Sun, the Sun's gravity can reach out and hang onto us. Without this pull of gravity, we'd just fly off into space, away from the warmth and light of the Sun, and out into the cold black of space. This is a very important job that the Sun does for us, and makes everything else possible.

The Sun helps with the tides. Most of the daily ocean tides happen because of the Moon. But we experience our highest and lowest tides when the Sun, Earth and Moon are lined up in a row.

The Sun keeps us warm. Every spot on Earth is receiving an average of 342 watts of energy from the Sun. This is an average across every part of the Earth, and includes both night and day. This number is much higher for locations near the equator. Most of this energy bounces off the Earth and goes back into space, but our atmosphere acts like a blanket, trapping some of this heat from the Sun. Thanks to the Sun, we enjoy a nice average temperature of 15 °C.

The Sun causes the weather. As you know, the Sun is constantly heating up the planet. But it's not always heating the same parts of the planet at the same time. It's these differences that create the weather. When one part is warm, like over the land, and another part is cold, like over the oceans, air moves from one region to the other creating winds. When the Sun heats water, it evaporates, becoming clouds and eventually falling again as rain. We wouldn't have weather without the Sun.

The Sun gives us energy. In addition to the heat we receive from the Sun, plants absorb energy from the Sun, mix this with carbon dioxide in the atmosphere, and grow. All of the fossil fuels we use to run our modern economy come from energy from the Sun, stored over millions of years.

That's what the Sun does for us.

Here's an article about how much energy comes from the Sun. And here's an article that discusses what plants might look like on another planet.

Here's an article from NASA that explains why the Earth isn't as hot as an oven, and here's an article about how the Sun's energy might be out of balance.

We have recorded an episode of Astronomy Cast just about the Sun called The Sun, Spots and All.

Filed under: Astronomy