MODULE; 20 UNDERSTANDING THE SOLAR SYSTEM

MODULE: 20

Understanding the Planets in the Solar System

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By Arvie Alvarez

LESSON OBJECTIVES:​

​At the end of the lesson, you should be able to:

a. understand the Planets in the Solar System

b. characterize the planets in the solar system

By Arvie Alvarez

​KNOWING OUR PLANETS

• In our Solar System, astronomers often divide the planets into two groups — the inner planets and the outer planets.

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•A planet (meaning “wandering star”) is an astronomical object orbiting a star (The Sun– in the solar system) that has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape and has cleared the neighborhood around its orbit.​

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By Arvie Alvarez

By Arvie Alvarez

MERCURY

✓The smallest terrestrial planet with thin atmosphere which causes it to swing between burning and freezing

temperatures. Its surface is similar to the Earth’s moon; it has many deep craters and is covered by a thin

layer of tiny silicates (most important class of rock-forming mineral).​

VENUS

✓Has about the same size as Earth; the hottest planet due to its thick toxic atmosphere that traps heat. Much

of its surface is marked with volcanoes and deep canyons. The third brightest object in the sky.​

EARTH

✓Largest among the inner planets and its atmosphere contains water vapor which helps to moderate daily

temperatures, and the lone planet that has liquid water which is necessary for life. Like the other inner

terrestrial planets, it has rocky surface and heavy metal core.​

MARS

✓Smaller than Earth with cold, thin atmosphere which means liquid water currently cannot exist for any length

of time. The bright rush color is due to iron-rich minerals in its regolith (the loose dust and rock covering its

surface).​

​JUPITER

✓Largest planet with a very stormy atmosphere (with one major storm-GREAT RED SPOT – as big as the Earth.​

SATURN

✓The planet that is hard to miss because of its distinctive large rings.​

URANUS

✓Little bigger than Uranus but with the smallest mass of the outer planets. The only planet to have tilted axial

rotation.​

NEPTUNE

✓Final outer planet with blue colored atmosphere containing significant amounts of what astronomers call ices.​