Do you know your star?

Many people worshiped it in the past; some still do. Most of us, however, rarely give it much thought these days. Yes, we feel its power upon our skin but how often, if ever, do we reflect on the fact that without the Sun our planet would be dead, dark and frozen. Considering all that it does for us, it is probably the most unappreciated and underrated thing in our lives. We would not even have lives if not for the reliable work of the Sun. But how many of us really know this star? Even basic questions about it stump most people. How old is the Sun? How big is it? How does it work? How much longer will it continue to produce the heat and light we need to exist? Read on and by the end of this column you will know your star a little better.

One of the most common misconceptions about the Sun is that it’s no big deal, just a mediocre star. Not true! Our star is gigantic! It’s not the biggest by any means—some stars are more than 100 times more massive—but our star is bigger than 80 percent of the stars in our galaxy. So don’t pay attention to that “mediocre star” nonsense.

The Sun is 93 million miles away but so powerful that it can still start forest fires and burn skin here on Earth. If we could drive to the Sun in a car it would take almost 200 years—with no rest stops. By the way, the Sun accounts for more than 99 percent of all the mass in our Solar System. Think about it; it’s like we and all the other planets are just a few specks of dust by comparison. It’s a shame the Sun is so hot. If we could somehow protect ourselves from the heat and visit it safely, just imagine what it would be like to walk around in that immense raging forest of fire. Of course heat or not, we wouldn’t be able to walk around because its gravity would crush us. Footing would be a problem as well because the sun is ball of gasses with no solid surface.

The Sun is about 4.6 billion years old, not much older than the Earth. It’s difficult to comprehend how large the Sun is. The best way is probably this: a million Earths could fit inside the Sun.

Our star generates its heat and light thanks to a continuous controlled nuclear reaction. The astounding heat generated—try 10,000 degrees on the surface and 27 million degrees in the centre—is difficult if not impossible to imagine. It’s not really like a bomb because bombs blow up and that’s that. The Sun is so massive, however, that its gravity restrains it so it just keeps on burning. But it won’t last forever.

The Sun poses interesting thoughts for those who dare to think about our ultimate fate. Yes, our end will come one day, really. Once the exclusive domain crackpots, fools and conmen, doomsday is now also a matter of scientific certainty. Our star will only maintain its current warmth-giving services in the manner we are accustomed for another couple of billion years, and then things will begin to get very nasty on planet Earth. I hate to disappoint you but our star will not go supernova, as some believe. So the Earth will not be vaporized in one gigantic and dramatic explosion. Astronomers today think that our star will become a red giant. But don’t worry, that will be exciting too.

As the Sun throbs toward its death in a few billion years or so it will expand and contract. During this time, it will incinerate life, boil away our oceans and even melt the Earth’s crust! The good news is that we will probably have become extinct long before this happens so I wouldn’t worry too much about your descendants. If we somehow manage to survive asteroids, supervolcanoes, nuclear wars, evolving viruses, ecosystem collapses, and overpopulation, we likely will have evolved into a super-intelligent spacefaring species that is capable of moving to a better neighbourhood well before the Sun starts acting up.

It is sobering to pause and accept the reality of our star’s eventual death. Assuming our descendants will not be able to move the entire planet to safety or somehow control the natural life cycle of stars, there can be no eternal cities on Earth. Our libraries, museums, statues, paintings and so on will all vanish from existence. Even if these things managed to survive the next two or three billion years against all odds, they cannot endure.

Today, when you feel the life-giving warmth of the Sun, try to remember that nothing lasts forever and appreciate the moment.