Bài tập that the formation of the sun năm 2024
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In a wide expanse of space, gravity drew dust and gas together to create the young solar system. The sun formed first from the vast material, with the planets close behind. But how did a sea of swirling particles become the brightest star in our sky? "The sun is terrifying and gorgeous, and it's also the best physics laboratory in our solar system," Sabrina Savage, project scientist for NASA's Hinode at NASA's Marshall Space Flight Center in Huntsville, Alabama, said in a statement. Although it may look empty, space is filled with gas and dust. Most of the material was hydrogen and helium, but some of it was made up of leftover remnants from the violent deaths of stars. About 4.5 billion years ago, waves of energy traveling through space pressed clouds of such particles closer together, and gravity caused them to collapse in on themselves and then start to spin, the first steps of how the solar system formed. The spin caused the cloud to flatten into a disk like a pancake. In the center, the material clumped together to form a protostar that would eventually become the sun. "There is a rotationally supported disk around this protostar," astronomer John Tobin told Space.com about a similar early sun, adding it's a "key element" in building planets. "It lets the material hang out long enough for the planet formation process." The young protostar was a ball of hydrogen and helium not yet powered by fusion. Over tens of millions of years, the temperature and pressure of the material inside increased, jumpstarting the fusion of hydrogen that drives the sun today. "A star the size of our sun requires about 50 million years to mature from the beginning of the collapse to adulthood," according to NASA. "Our sun will stay in this mature phase … for approximately 10 billion years." The formation of the sun didn't take up all of the cloud it was born from. What was left continued to orbit the star, while planets formed from the leftover material. The sun is an average-size star, not too big and not too small. Its size makes it an excellent star to orbit, as it is neither large and fast-burning nor small and dim. Several billion years from now, the hydrogen inside of the sun will run out, and the star will swell up into a red giant with a radius extending to Earth's orbit. The helium at its core will also be consumed. The star will never be hot enough to burn the oxygen and carbon that are left behind, so the sun will fizzle out and become a white dwarf. Of course, when the sun was born billions of years ago, no human scientists were around to study it. Astronomers learn about the life of the sun by studying the myriad of stars in the Milky Way. Combined with models, these observations can help tell us about the youth of our closest star. Related:
Follow Nola Taylor Redd at @NolaTRedd, Facebook, or Google+. Follow us at @Spacedotcom, Facebook or Google+. Join our Space Forums to keep talking space on the latest missions, night sky and more! And if you have a news tip, correction or comment, let us know at: [email protected]. Breaking space news, the latest updates on rocket launches, skywatching events and more! Nola Taylor Tillman is a contributing writer for Space.com. She loves all things space and astronomy-related, and enjoys the opportunity to learn more. She has a Bachelor’s degree in English and Astrophysics from Agnes Scott college and served as an intern at Sky & Telescope magazine. In her free time, she homeschools her four children. Follow her on Twitter at @NolaTRedd Stars are born in clouds like the one in the picture. Gravity pulls material together. When it is extremely dense, it begins nuclear fusion. That is, it becomes a star. We can see places where stars are being born right now. Of course, it takes light a long time to travel to us. So what we see right now may have happened many millions or even billions of years ago. Formation of the Solar SystemOur solar system began about 5 billion years ago. The Sun, planets, and other solar system objects all formed at about the same time. The leading hypothesis for how they formed is called the nebular hypothesis. The Solar Nebula The Sun and planets formed from a giant cloud of gas and dust. This was the solar nebula. The cloud contracted and began to spin. As it contracted, its temperature and pressure increased. The cloud spun faster and formed into a disk. Scientists think the solar system at that time looked like these disk-shaped objects in the Orion Nebula. New stars are forming in the Orion Nebula today. Solar System Bodies Form Gravity pulled a lot of material to the center of the cloud. Temperatures and pressures at the center of the cloud were extreme. It was so hot that nuclear fusion reactions began. A star was born—the Sun. In these reactions, hydrogen fuses to make helium. Extreme amounts of energy are released. An artist’s painting of a protoplanetary disk. Meanwhile, the outer parts of the disk were cooling off. Matter condensed from the cloud. Small pieces of dust started clumping together. These clumps collided and combined with other clumps. Gravity brought more clumps together to make larger bodies. Gravity at the center of the disk attracted rock and metal. Lighter material remained farther out in the disk. Eventually, these small bodies grew to become the planets and moons that we find in our solar system today. The Planets Since gravity pulled the more dense material inward, the inner planets—Mercury, Venus, Earth, and Mars—are made of rock and metal. The outer planets—Jupiter, Saturn, Uranus, and Neptune—condensed farther from the Sun (Figure below). They are made from lighter materials, such as hydrogen, helium, water, ammonia, and methane. Out by Jupiter and beyond, where it’s very cold, these materials form solid particles. Dwarf plants, comets, and asteroids formed too. The Sun and planets (note that this image is old enough to include Pluto, which is no longer considered one of the planets). |
