Comets, Meteors and Asteroids | Grade 8 Science DepEd MELC Quarter 2 Module 5

[Music] recent advances in space technology have allowed scientists coming from different backgrounds such as physics chemistry biology and geology to collaborate on studying near-earth objects such as comets and asteroids with more powerful telescopes and spacecrafts the study of comets and asteroids provide more clues about the origins of our solar system in this video we will take you on a flyby tour outside the earth providing you a closer look at the asteroids comets and natures in space so let's get started people have been aware of comets since ancient times try to ask your grandfather or grandmother about comets and they might tell you that a comet brings bad luck why some people believe that comets were bad spirits who took on the appearance of a head of a woman with its long hair streaming behind to old folks this was a traditional sign of mourning sometimes to other people a comet appeared as sword which is a sign of war death and famine a comet is a fuzzy luminous big snowball composed of rock dust wrap around a big ball of ice they are icy objects this beautiful sight in the sky moves very slowly and may remain in our sight for weeks before fading out of view a comet enters a huge elliptical orbit each time the comet passes close to the sun it loses some of its material when it returns to the distant part of the solar system it gradually appears smaller and dimmer over time it disappears completely in some cases the comet may have a solid rocky core that is then left to continue traveling around its orbit as a dark barren asteroid as it gets closer to the sun it becomes visible because the heat of the sun melts the ice of the comet and turns it to gas this gas becomes the comma which wraps and hides the nucleus from our view the nucleus is the center of the comet made of frozen water the nucleus and the comet together are called the head of the comet they become bigger and bigger as more gas and dust are released from the comma the solar wind blows more and more gas from the comma causing it to form a tail which in some comets can reach up to 150 million kilometers in length most comets are thought to originate from a huge cloud called the word cloud which is too far away for astronomers to see there is no evidence that a comet has ever crashed into earth however it is one possible explanation for the extinction of dinosaurs the hypothesis is that a large comet or asteroid crashed into our planet and triggered a chain of disastrous events like earthquakes and tidal waves causing radical changes in the climate and eventually wiped out the dinosaurs now that we're done discussing about comets let's talk about meteors a meteor is also called the falling star or shooting star a meteor is observed when a meteoroid passes through earth's atmosphere and burns up in the process when meteors hurtle through the layer of air surrounding earth friction caused by the molecules of gas that make up our planet's atmosphere heats them up and the meteor surface begins to warm up and glow eventually the heat and high speed combine to vaporize the meteor usually high above the earth's surface the visible light produced by a major may take on various hues depending on the chemical composition of the meteoroid and the speed of its movement through the atmosphere the color of meteors depend on the relative influence of the metallic content of the meteoroid versus the superheated air plasma which is brought about by its passage orange yellow for sodium yellow for iron blue green for magnesium violet for calcium and red for atmospheric nitrogen and oxygen [Music] so what's the difference between a meteoroid meteorite and a fireball they're all related to the flashes of light called shooting stars sometimes seen streaking across the sky but we call the same object by different names depending on where it is meteoroids are objects in space that range in size from dust grains to small asteroids think of them as space rocks when meteoroids enter earth's atmosphere or that of another planet at high speed and burn up the fireballs or shooting stars are called meteors when a meteorite survives a trip through the atmosphere and hits the ground it's called a meteorite [Music] here are some interesting facts about meteors did you know that there are millions of meters in the earth's atmosphere every day meteors can become visible as high as 120 kilometers above earth if a meteor produces a sound called a sonic boom it is typically heard seconds after the meteor becomes visible meteors are usually the size of pebbles and no larger than a baseball although meteors have existed since ancient times they were not believed to be from our solar system until 1833 asteroids are simply rocky or metallic objects that orbit the sun in the same way that planets orbit asteroids are hard to see because they reflect little light and they are always on the move asteroids come in all sizes and shapes some are as tiny as pebbles and some are as big as mountains since they are smaller than planets they are often called minor planets or planetoids cerus which was once considered the largest asteroid is now classified as a dwarf planet it is about 940 kilometers in diameter can you imagine how huge that is nearly all asteroids are irregular in shape and heavily pockmarked by impact craters only a handful of the largest members possess enough gravity to pull them into spherical shapes [Music] many asteroids orbit the sun in a region between mars and jupiter this area is called asteroid belt they follow a slightly elliptical path as they orbit the sun in the same direction as the planets a larger object such as a planet may pull an asteroid out of orbit if it were not for the giant planet jupiter pulling the asteroids outward large asteroids would constantly bombard mercury venus mars and earth now let's wrap things up comets asteroids and majors are considered as celestial objects that orbit around the sun they come in different sizes and shapes asteroids are small rocky objects that orbit the sun they are smaller than a planet but they are larger than the pebble-sized objects we call meteorites comets orbit the sun like asteroids but comets are made of ice and dust not rock a comet has three parts the nucleus head and a tail a meteor is what happens when a meteoroid a small piece of an asteroid or comet burns up upon entering earth's atmosphere creating a streak of lightened sky that's all for now see you on our next video and don't forget to keep your minds busy if you like this video please subscribe to our channel and hit the notification icon for more videos like this

Channel: The Learning Bees

Views: 118,704

Keywords: The Learning Bees, Department of Education, DepEd, MELC-Based, Most Essential Learning Competencies, Science, MELC, Grade 9, What’s the difference between asteroid comet meteor meteoroid meteorite and fireball, Asteroid, Comet, Meteor, Meteroid, Meteorite, Fireball, Space technology, Telescope, Oort cloud, Asteroid belt, Why asteroid won’t crash on Earth, How Jupiter saves Earth, Ancient beliefs and practices about comets meteors and asteroids, Different colors of meteors, Space fun facts

Id: zemP1zQ2Vko

Length: 9min 40sec (580 seconds)

Published: Mon Jan 11 2021