Stars And Galaxies

A meteoroid is a small rocky or metallic object traveling through space. Most meteoroids range in size from small grains to 1 meter and are fragments from comets or asteroids. When meteoroids enter the Earth's atmosphere, friction and compression cause them to heat up and glow - appearing as "shooting stars" or meteors. If they survive atmospheric entry and reach the ground, they are called meteorites.

A meteorite hitting Earth could have major environmental consequences depending on where it lands. If it hits land, it could cause earthquakes, lower global temperatures by blocking the sun with dust for months, and disrupt power systems. If a meteorite hits the ocean it could trigger tsunamis across the ocean as well as hurricanes, again block the sun for months, cause earthquakes, and disrupt power. On average, 38,000 meteorites have hit Earth, with impacts concentrated at the poles. The meteorite that formed the Grand Canyon was around 30 meters wide and weighed 100,000 tons, entering the atmosphere at 20 km per second.

1. Stars form from nebulae, which are dusty clouds in space. They begin as protostars and then become main sequence stars like our sun or massive stars. 2. After billions of years, main sequence stars become red giants as they run out of hydrogen fuel. Massive stars become red supergiants. 3. When stars die, red giants form planetary nebulae and red supergiants explode as supernovae. The remains of stars form neutron stars, black holes, white dwarfs or black dwarfs.

Comets and asteroids are remnants from the formation of the solar system. Comets originate from the Kuiper Belt and Oort Cloud and are icy bodies, while asteroids originate from the Main Asteroid Belt and are rocky fragments. Both have irregular shapes and sizes ranging from 1-100 km. Comets have highly elliptical orbits with periods of 75 years to millions of years, while asteroids have more rounded orbits with periods of 1-100 years. When a meteoroid from space enters the atmosphere, it becomes a meteor or "shooting star"; any fragments that reach the ground are called meteorites.

This lesson plan aims to teach students about meteoroids, meteors, and meteorites. It will begin with a motivation activity to familiarize students with related terms. Students will then learn about the differences between meteoroids, meteors, and meteorites - specifically what happens when a meteoroid enters Earth's atmosphere. The lesson emphasizes the importance of perseverance in achieving goals by relating shooting stars to making wishes come true through hard work. To evaluate learning, students will define and differentiate key terms and concepts in exercises.

This document discusses comets, meteors, asteroids, and the moon. It provides details on their composition, sizes, orbits, and the potential effects of large impacts. A large comet impact would likely only injure humans, while the largest meteor ever could endanger humanity. The largest known asteroid impact 65 million years ago caused the extinction of dinosaurs. A second moon would result in bigger tides and more frequent solar eclipses.