--- title: Asteroids and the asteroid belt — a lesson of Mova's school · trees and pragmatics description: «Asteroids and the asteroid belt», a lesson of the space course of Mova's primary school, sentence by sentence with dependency trees and pragmatics. It begins: Asteroids are the leftover building blocks from when the planets formed, lumps of rock and metal from pebble size up to hundreds of kilometr --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/space/9-asteroids-and-the-asteroid-belt/) [home](https://md.mova.elamur.ai/free/en/) / [corpora](https://md.mova.elamur.ai/free/en/corpora/) / [school](https://md.mova.elamur.ai/free/en/corpora/school/) / [Space](https://md.mova.elamur.ai/free/en/corpora/school/space/) / Asteroids and the asteroid belt # Asteroids and the asteroid belt Lesson 9 of the space course of Mova's primary school: 17 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](https://md.mova.elamur.ai/free/en/school-run/space/9-asteroids-and-the-asteroid-belt/). - [0](https://md.mova.elamur.ai/free/en/corpora/school/space/9-asteroids-and-the-asteroid-belt/0/) — Asteroids are the leftover building blocks from when the planets formed, lumps of rock and metal from pebble size up to hundreds of kilometres across. - [1](https://md.mova.elamur.ai/free/en/corpora/school/space/9-asteroids-and-the-asteroid-belt/1/) — Most of them circle the Sun in the asteroid belt between Mars and Jupiter, but it is not like the crowded rock fields of films: the belt is so empty that spacecraft fly through without dodging anything. - [2](https://md.mova.elamur.ai/free/en/corpora/school/space/9-asteroids-and-the-asteroid-belt/2/) — All the belt's asteroids together weigh only about 3 percent of our Moon; Jupiter's strong pull stopped them ever joining into a planet. - [3](https://md.mova.elamur.ai/free/en/corpora/school/space/9-asteroids-and-the-asteroid-belt/3/) — A few asteroids cross the Earth's path, so astronomers track them, and in 2022 NASA's DART spacecraft even knocked a small one onto a new path as a test of defending the Earth. - [4](https://md.mova.elamur.ai/free/en/corpora/school/space/9-asteroids-and-the-asteroid-belt/4/) — 66 million years ago a 10-kilometre asteroid hit what is now Mexico and helped wipe out the dinosaurs, except the birds, whose relatives still sing outside your window. - [5](https://md.mova.elamur.ai/free/en/corpora/school/space/9-asteroids-and-the-asteroid-belt/5/) — Asteroids are rocky or metallic leftovers from the birth of the Solar System, ranging from pebbles to hundreds of kilometres across. - [6](https://md.mova.elamur.ai/free/en/corpora/school/space/9-asteroids-and-the-asteroid-belt/6/) — Most known asteroids orbit in the asteroid belt between Mars and Jupiter, and more than a million have been catalogued. - [7](https://md.mova.elamur.ai/free/en/corpora/school/space/9-asteroids-and-the-asteroid-belt/7/) — The belt is mostly empty space, with asteroids usually hundreds of thousands of kilometres apart. - [8](https://md.mova.elamur.ai/free/en/corpora/school/space/9-asteroids-and-the-asteroid-belt/8/) — All the asteroids in the belt put together have only about 3 percent of the mass of our Moon. - [9](https://md.mova.elamur.ai/free/en/corpora/school/space/9-asteroids-and-the-asteroid-belt/9/) — Ceres is the largest object in the asteroid belt, about 940 kilometres across, big enough for its gravity to pull it round, so it is classed as a dwarf planet. - [10](https://md.mova.elamur.ai/free/en/corpora/school/space/9-asteroids-and-the-asteroid-belt/10/) — Vesta is the second most massive asteroid, and a giant impact on it blasted off rock that still falls to Earth as meteorites. - [11](https://md.mova.elamur.ai/free/en/corpora/school/space/9-asteroids-and-the-asteroid-belt/11/) — Some asteroids are dark and rich in carbon, some are stony, and a few are mostly metal, like the asteroid Psyche. - [12](https://md.mova.elamur.ai/free/en/corpora/school/space/9-asteroids-and-the-asteroid-belt/12/) — Japanese probes brought back dust from the asteroids Itokawa and Ryugu, and NASA's OSIRIS-REx returned samples from Bennu in 2023. - [13](https://md.mova.elamur.ai/free/en/corpora/school/space/9-asteroids-and-the-asteroid-belt/13/) — Some asteroids cross the Earth's orbit, and astronomers track tens of thousands of these near-Earth objects to check whether any could hit us. - [14](https://md.mova.elamur.ai/free/en/corpora/school/space/9-asteroids-and-the-asteroid-belt/14/) — In 2022 NASA's DART (Double Asteroid Redirection Test) spacecraft crashed into the small asteroid Dimorphos and changed its orbit, the first test of defending the Earth. - [15](https://md.mova.elamur.ai/free/en/corpora/school/space/9-asteroids-and-the-asteroid-belt/15/) — About 66 million years ago an asteroid about 10 kilometres wide hit what is now Mexico and helped wipe out the dinosaurs, except birds. - [16](https://md.mova.elamur.ai/free/en/corpora/school/space/9-asteroids-and-the-asteroid-belt/16/) — A meteoroid is a small space rock, a meteor is its streak of light in the sky as it burns up in our air, and a meteorite is a piece that reaches the ground. - ← previous: [Mars](https://md.mova.elamur.ai/free/en/corpora/school/space/8-mars/) - next →: [Jupiter](https://md.mova.elamur.ai/free/en/corpora/school/space/10-jupiter/) - ↑ back to [Space](https://md.mova.elamur.ai/free/en/corpora/school/space/)