1. 1. What is a terrestrial planet? 2. Mercury 3. Venus (Earth’s Twin)
ENTRY 36: The Inner Planets
2/12/2019
Key Points:
1. What is a terrestrial planet?
2. Mercury
3. Venus (Earth’s Twin)
4. Earth
5. Mars

2. 1. What is a terrestrial planet?
A. A dense and rocky planet with a solid surface. B. The four inner planets closest to the sun are terrestrial planets. C. Composed of rocks and metals that can be a solid at high temperatures.

4. 2. Mercury
A. Big, gray rock made of iron that lacks a protective atmosphere B. 2nd Hottest planet (-173°C to 427°C) C. No moons

5. 1 Revolution = 88 days, 1 Rotation = 58 days
Mercury
1 Revolution = 88 days, 1 Rotation = 58 days
In Roman mythology Mercury is the god of commerce, travel and thievery, the Roman counterpart of the Greek god Hermes, the messenger of the Gods. The planet probably received this name because it moves so quickly across the sky.

6. 3. Venus (“Earth’s Twin”)
A. Dense nickel and iron planet with a liquid core
Covered by shield volcanoes
B. Hottest planet (464°C)
C. No moons
D. Has a very thick atmosphere made of carbon dioxide and sulfuric acid

7. Venus PERIOD OF ROTATION- 243 DAYS PERIOD OF REVOLUTION- 224 DAYS
Venus (Greek: Aphrodite; Babylonian: Ishtar) is the goddess of love and beauty. The planet is so named probably because it is the brightest of the planets known to the ancients.
It is the brightest object in the sky except for the Sun and the Moon.
PERIOD OF ROTATION- 243 DAYS
PERIOD OF REVOLUTION- 224 DAYS

8. 4. Earth
A. Made completely of rock with a core made of iron and nickel B. Has one moon (Luna) C. Only planet that supports life (has water) D. Densest planet in the solar system

9. Earth Rotation-24 hours…. Revolution every 365 days
Earth is the only planet whose English name does not derive from Greek/Roman mythology. The name derives from Old English and German.
In Roman Mythology, the goddess of the Earth was Tellus - the fertile soil (Greek: Gaia, terra mater - Mother Earth).
It was not until the time of Copernicus (the sixteenth century) that it was understood that the Earth is just another planet.

10. Earth’s Moon: Luna (384,400 km from Earth)
As the Moon orbits around the Earth once per month, the angle between the Earth, the Moon and the Sun changes; we see this as the cycle of the Moon's phases. The time between successive new moons is 29.5 days .

11. 5. Mars A. The red planet 1. Red from rust
2. Rust indicates that water was on the planet at one time
B. Has 2 volcanoes, including the largest volcano in the solar system – Olympus Mons

12. 5. Mars C. Has two moons Phobos and Deimos
D. Has a thin atmosphere and cold climate (-123°C to 37°C)