Excerpt
Chapter 1: Meet the Sun
The Sun is the biggest, brightest, and most powerful thing in our sky. It’s the reason we have daylight, warmth, and life on Earth. Without it, our planet would be a cold, dark, and lifeless rock floating in space. Every plant, animal, and person depends on the Sun in ways that might not be obvious at first. It’s not just a giant ball of light—it’s a star, and not just any star, but the one that holds our entire solar system together.
A lot of people think of the Sun as a giant fireball, but that’s not exactly right. Fire needs oxygen to burn, and there’s no oxygen in space. Instead, the Sun is a massive sphere of super-hot gases, mostly hydrogen and helium. Deep inside, something incredible is happening—hydrogen atoms are smashing together and turning into helium. This process, called nuclear fusion, releases an enormous amount of energy. That energy travels outward, reaching Earth as light and heat. It’s what makes the Sun shine and what keeps our planet from turning into a frozen wasteland.
If the Sun is just one of billions of stars, what makes it special? For one thing, it’s the only star close enough to light up our world. If you’ve ever looked up at the night sky and seen tiny specks of light, those are stars too, but they’re so far away that they look small and dim. The Sun is close enough—about 93 million miles (150 million kilometers) from Earth—that it dominates our sky. That might sound really far, but compared to other stars, it’s practically next door.
The Sun is huge. If it were hollow, more than one million Earths could fit inside! Its surface alone is about 109 times wider than Earth, which means if you lined up 109 Earths side by side, they would stretch across the Sun’s width. And yet, compared to some of the biggest stars in the universe, the Sun is just an average-sized star. Scientists call it a yellow dwarf, which doesn’t mean it’s actually yellow—it just describes the kind of star it is. It burns bright, but compared to larger stars, it’s not the hottest or the biggest.
The Sun may look like a perfect, glowing circle in the sky, but if you could get a closer look, you’d see that it’s constantly changing. Its surface is boiling and bubbling, with powerful bursts of energy shooting out. These bursts, called solar flares, send waves of charged particles into space. Sometimes, these particles reach Earth and create beautiful glowing lights in the sky, called the auroras (also known as the northern and southern lights). Other times, they can mess with satellites, radios, and even power grids.
Even though the Sun seems to rise and set every day, it’s not really moving—we are. Earth is spinning, and as it turns, different parts of the planet face the Sun at different times. That’s what creates day and night. The Sun itself is also in motion, traveling through space at around 514,000 miles per hour (828,000 kilometers per hour) as it orbits around the center of our galaxy, the Milky Way.
The Sun’s gravity is what keeps everything in the solar system in place. Planets, moons, asteroids, and comets are all held in orbit because of the Sun’s pull. If the Sun suddenly disappeared, everything would drift off into space. Luckily, that’s not going to happen anytime soon. The Sun is about 4.6 billion years old and has enough fuel to keep burning for another 5 billion years or so before it starts to change.
The Sun is the biggest, brightest, and most powerful thing in our sky. It’s the reason we have daylight, warmth, and life on Earth. Without it, our planet would be a cold, dark, and lifeless rock floating in space. Every plant, animal, and person depends on the Sun in ways that might not be obvious at first. It’s not just a giant ball of light—it’s a star, and not just any star, but the one that holds our entire solar system together.
A lot of people think of the Sun as a giant fireball, but that’s not exactly right. Fire needs oxygen to burn, and there’s no oxygen in space. Instead, the Sun is a massive sphere of super-hot gases, mostly hydrogen and helium. Deep inside, something incredible is happening—hydrogen atoms are smashing together and turning into helium. This process, called nuclear fusion, releases an enormous amount of energy. That energy travels outward, reaching Earth as light and heat. It’s what makes the Sun shine and what keeps our planet from turning into a frozen wasteland.
If the Sun is just one of billions of stars, what makes it special? For one thing, it’s the only star close enough to light up our world. If you’ve ever looked up at the night sky and seen tiny specks of light, those are stars too, but they’re so far away that they look small and dim. The Sun is close enough—about 93 million miles (150 million kilometers) from Earth—that it dominates our sky. That might sound really far, but compared to other stars, it’s practically next door.
The Sun is huge. If it were hollow, more than one million Earths could fit inside! Its surface alone is about 109 times wider than Earth, which means if you lined up 109 Earths side by side, they would stretch across the Sun’s width. And yet, compared to some of the biggest stars in the universe, the Sun is just an average-sized star. Scientists call it a yellow dwarf, which doesn’t mean it’s actually yellow—it just describes the kind of star it is. It burns bright, but compared to larger stars, it’s not the hottest or the biggest.
The Sun may look like a perfect, glowing circle in the sky, but if you could get a closer look, you’d see that it’s constantly changing. Its surface is boiling and bubbling, with powerful bursts of energy shooting out. These bursts, called solar flares, send waves of charged particles into space. Sometimes, these particles reach Earth and create beautiful glowing lights in the sky, called the auroras (also known as the northern and southern lights). Other times, they can mess with satellites, radios, and even power grids.
Even though the Sun seems to rise and set every day, it’s not really moving—we are. Earth is spinning, and as it turns, different parts of the planet face the Sun at different times. That’s what creates day and night. The Sun itself is also in motion, traveling through space at around 514,000 miles per hour (828,000 kilometers per hour) as it orbits around the center of our galaxy, the Milky Way.
The Sun’s gravity is what keeps everything in the solar system in place. Planets, moons, asteroids, and comets are all held in orbit because of the Sun’s pull. If the Sun suddenly disappeared, everything would drift off into space. Luckily, that’s not going to happen anytime soon. The Sun is about 4.6 billion years old and has enough fuel to keep burning for another 5 billion years or so before it starts to change.