STUDY GUIDE
Unit 3 – Lesson 4
The terrestrial planetsare the warm, rocky, dense, inner planets that are closest to the sun.
Mercury is the smallest planet. It has a heavily cratered surface, and no moons. Mercury rotates slowly, which causes the largest difference between its high and low temperatures than any of the other planets.
Venus is the same size as Earth, and it has no moons. It has a surface full of volcanoes, and a very dense, very hot, and toxic atmosphere. It also has a retrograde rotation, and a day on Venus is longer than its year!
Earth is the most special of all the planets. We have an abundance of water, oxygen, and life. It is also the only planet that has tectonic plates, and an atmosphere that is just the right thickness for keeping us the perfect temperature.
Mars is called the “red planet” because of its orange-red soil. It is very cold due to its thin atmosphere and distance from the sun. It also has the largest mountain and deepest canyon in the entire solar system. Mars has 2 moons.
Unit 3 – Lesson 5
The gas giant planets are cold and have deep, massive atmospheres of hydrogen and helium. They have the greatest gravitational forces allowing them to attract more objects such as moons. The gas giants are further away from the sun than the terrestrial planets.
Jupiter is the largest planet in the solar system with the highest surface gravity. It also has the most moons of all the planets. The fast rotation of Jupiter causes high winds and cloud bands.
Saturnhas a large ring system, which consist of small icy bodies. It is the second largest gas giant and is considered to be a near twin to Jupiter.
Uranusis tilted on its side as it orbits the sun. The ring system and moons of Uranus orbit over the top and along the bottom of this planet.
Neptuneis known as the blue ice giant. It has the strongest winds. Neptune is about the same size as Uranus.
Unit 3 – Lesson 6
A comet is a small body composed of ice, rock, and dust that follows a highly elliptical path. The body of a comet is called the nucleus and coma, which are composed of snow and rock. The ion tail and dust tail are made of ice and dust. Comets become visible as they near the sun and burn off their outer layers. Comets can come from the Kuiper Belt, or the Oort Cloud.
A meteoroid is a rocky body that travels through space. If that rocky body burns up in Earth’s atmosphere, it becomes a meteor. If any piece of that rocky body lands on Earth without burning up, it is called a meteorite.
An asteroid is a large, irregularly shaped, rocky object that orbits the sun. Most asteroids are located between the orbits of Mars and Jupiter.
Most Kuiper Belt Objects, or KBOsare minor bodies found in the Kuiper Belt. The composition of the KBOs are similar to that of comets. Four of the five dwarf planets are located in the Kuiper Belt.
The OortCloud is a large spherical region that surrounds the solar system and extends almost halfway to the nearest star.