The Terrestrial Planets Topic #2 Term #2 The Local System The solar system The Terrestrial Planets Topic #2 Term #2 The Local System

Discovery of the solar system We have neighbors!! Up until the 17th century, the universe was though to have only 8 bodies. These included the planets Earth, Venus, Mercury, Mars, Jupiter, Saturn and the moon. These bodies were the only ones that can be seen with the naked eye.

The Great invention The telescope!!! In the 17th century Galileo Gallilei invented the telescope. By the end of the 17th century, moons of Jupiter and Saturn were discovered. By the end of the 18th century, the planet Uranus and other moons were found. The end of the 19th century Neptune was discovered.

The Inner solar system Looking at the inner planets… The solar system can be divided into two main parts. The inner system includes the sun and the four inner planets. These inner planets are more closely spaced together than the outer planets.

The Inner planets Let’s rock!!! The inner solar system, contains the some of the hottest places, as well as the only planet known to support life. These planets are called “terrestrial planets” because their surfaces are dense and rocky.

Mercury… The messenger, a strange world… The planet that is closest to the sun. Second smallest planet in our system. A Mercury year is 88 Earth days long. Rotates more slowly than Earth. One rotation takes 59 Earth days. Mercury fully rotates 3 times in two years!!

Mercury… A look at the planet’s features… Mercury has a very thin atmosphere made of H, He and Na gas. Temperature differences on Mercury differ dramatically; dayside (805 F), nightside (-275 F) There is also a magnetic field around Mercury, not as strong as Earth’s though. May have a large core made of Ni and Fe.

Mercury… A look at the planet’s features… The surface of Mercury is covered with craters. The Carloris Basin is 812 miles across, the result of a huge impact. This impact created terrain on the other side of the planet! Has cliffs several miles high and hundreds of miles long called scarps. Mercury has no natural satellites, or moons.

Venus… Goddess of love, Planet like Hell… The second planet from the Sun. Sometimes called Earth’s twin. One Venus year equals 224 E. days. Venus actually rotates backwards!! The sunrises in the west and sets in the east!!

Venus… A look at the Planet’s features… Of the terrestrial planets, Venus has the densest atmosphere. 90 times the pressure of Earth’s atmosphere. Consists of mostly CO2 and deadly acids. A runaway greenhouse effect. (464 C) Has the hottest surface of any planet.

Venus… A look as the Planet’s features… Venus has severe weather conditions winds up to 200 mph. Has a surface of rolling plains (hills & valleys). Has one mountain range Maxwell Montes. There seems to be no plate tectonic activity on Venus. Venus has no magnetic field nor does it have any natural satellites.

Earth… Mother of life, Planet of change. The third planet form the sun. Has day that is 23 hr 56 min long. One year equals 356 days & 6 hrs. The tilt of the Earth on it’s axis allows for it to have seasons. Temperatures on the surface ranges from 0 C to 100 C.

Earth… A look at the Planet’s features… Earth has an atmosphere of 78% N, 21 % O2 and < .8% CO2. Has an Ozone layer that protect life from UV rays. Winds around the Earth move in distinctive patterns. The climate of the Earth changes over time due to rotational effects.

Earth A look at the Planet’s features… Earth’s surface is shaped by geological forces found no where else in the solar system. (Plate Tectonics) Has active volcanoes & Earthquakes. The face of the planet has been changed many of times due to weathering.

Earth… A look at the Planet’s features… Earth has one feature that is most important for life… LIQUID WATER Having conditions that are right for life, Earth is in a “Safe Zone”. Life has risen from single cells to multi-cellular organisms with intelligence.

Mars… Bringer of war… Planet of possibilities! The 4th planet from the sun, it is 1.5 more time farther from the sun than Earth. A day on Mars is 24 hr 40 min. A Mars year is 687 Earth days. Surface temperatures range from –123 C to 37 C

Mars… A look at the Planet’s features… Because of the thinner atmosphere and greater distance from the sun, Mars is a cold planet. Air pressure is very low on Mars, any liquid water on Mars would boil away! Only water found on Mars is frozen. Liquid water did at one time flow on Mars!!

Mars… A look at the Planet’s features… Mars has a rich volcanic history. The largest volcanic mountain in the solar system, Olympus Mons. Mars has two polar ice caps like Earth. Mars has two satellites, Deimos and Phobos.

Looking back… Viewing the terrestrial planets from the middle of the system The first four planets of our system all have rocky surfaces that have been changed over time by planetary activity. These planets have dense structures but not the size of what is to come. We now will be gin our journey to the outer planets!!!

Planetary review… A look at the inner planets… What invention lead to greater understanding of the universe? Which two planets have natural satellites? Name them. What is unique about Mercury’s day as compared to its year? Describe the similarities and differences between Venus and Earth. What is the single most important substance that life requires? Why is there no life on Mars? On Venus? On Mercury? Which planet is the hottest? Which is the smallest? Which has the largest volcanic mountain? Name it!!!