The Sun, our star Lesson 1 of the space course of Mova's primary school: 16 sentences, each with its syntax tree and pragmatics. The lessons are written for Mova, and their agreed trees are part of Mova corpus 0.4 (CC BY-SA 4.0). How Mova does on its tests: the lesson at school .
0 The Sun is a star, the same kind of thing as the tiny dots you see at night, only so close that it fills our day with light. 1 It is a gigantic ball of hot gas: if the Sun were a football, the Earth would be a peppercorn about 25 metres away. 2 The Sun does not burn like a bonfire, there is no oxygen fire at all; deep in its core hydrogen is squeezed into helium, and that nuclear fusion gives out the light and heat. 3 Light is fast but the Sun is far, so when you watch a sunset you see the Sun as it was about 8 minutes earlier. 4 The Sun is not calm: it has dark sunspots, flares and a wind of particles that, when it hits the Earth's magnetic field, lights up the northern lights. 6 The Sun is a star, an ordinary yellow dwarf, and it holds about 99.8 percent of all the mass in the Solar System. 7 About 109 Earths would fit side by side across the Sun, and about 1.3 million Earths would fit inside it. 8 The Earth is about 150 million kilometres from the Sun, and sunlight takes about 8 minutes 20 seconds to reach us. 9 In the Sun's core, hydrogen nuclei are squeezed together to make helium, and this nuclear fusion releases the energy that makes the Sun shine. 10 The Sun is not a fire: nothing burns with oxygen there. 11 The Sun's visible surface, the photosphere, is about 5,500 degrees Celsius, but its thin outer atmosphere, the corona, is over a million degrees; exactly why the corona is so hot is still being studied. 12 Sunspots are darker, cooler patches where strong magnetic fields stop hot gas rising; they look black only because the rest of the Sun is brighter, and many are bigger than the Earth. 14 The Sun constantly blows out charged particles called the solar wind, which flows past all the planets at hundreds of kilometres per second. 15 The Earth's magnetic field shields us from most of the solar wind, and particles leaking in near the poles make the aurora, the northern and southern lights; near solar maximum, as in 2024, aurorae were seen much further from the poles than usual, even in England. 17 The Sun is about 4.6 billion years old, roughly halfway through its life; in about 5 billion years it will swell into a red giant and end as a white dwarf. 18 The Sun is a ball of gas, so different parts spin at different speeds: about 25 days at its equator and about 35 days near its poles; astronomers first noticed the Sun spins by watching sunspots move across its face. next → How the Solar System was born↑ back to Space This page in Markdown → https://md.mova.elamur.ai/free/en/corpora/school/space/1-the-sun-our-star/