Name The Terrestrial Planets - Unit 3. Lesson 5 - page Essential Question: ENGAGE YOUR BRAIN-Circle the term that best completes the sentence 1 Venus/Earth/Mars is the largest terrestrial planet 2 MercuryNenus/Mars has clouds that rain sulfuric acid on the planet 3. Huge dust stoms sweep across the surface of Mercury Venus Mars 4. Venus/Earth/Mars is the most geologically active of the terrestrial planets 5 Mercury/Venus/Earth has the thinnest atmosphere of the terrestrial planets planets that orbit . What are the terrestrial planets? a The terrestrial planets are the to the sun In order by distance the sun, these planets are and They have similar compositions and consist of an and a that lies between the and What is known about Mercury? We know the about this planet Until 1974, the planet was seen as a dark ball of rock Now known that the planet's heavily cratered, surface is composed largely of and hides a massive Orbits only AU from the sun AU stands for and is used to measure distance in the solar system. One astronomical unit equals the average distance between the sun and the Earth It lies nearly halfway between the and . Mercury has the most extreme temperature range in the solar system A day lasts almost Earth days When it is day on Mercury, temperatures can rise to hot enough to melt certain metals When it is night, it can drop to Temperatures can change by as much as between day and night and is the greatest difference between and temperatures in the solar system Mercury has a large iron core planet in the solar system Has a diameter of only at its equator Its central core is thought to be around in diameter, which accounts for most of the planets Originally thought that it had a core of However, by observing changing in its spin as it orbits the sun, astronomers think that the core is at least partially Why is the core so large? Some scientists think that Mercury may have struck by another in the distant and lost most of the rock that the core Other scientists think that long ago the sun the planet's surface and it away into space Sulfuric acid rain falls on a surface that is not much different from the inside of an What is known about Venus? Venus is similar to Earth in Size and mass Often been called At diameter of Venus is 95% the diameter of It's mass is the around of Earth's The gravity that you would experience on venus is of the gravity on The of Venus is different from the of Earth Earth has a rotation spin of a planet about its axis as seen from