Planets: Comparing their structure. Earth Science

Transcription

1 Planets: Comparing their structure Earth Science

2 Objectives To compare and contrast Terrestrial and Jovian planets in terms of: Formation temperature What types of materials they are made of (solids, liquids, or gases) Size Location in the solar system

3 All 8 Planets must: Have an elliptical orbit around the Sun Are spherical in shape Have completed accretion cleared their neighborhood No more dirty rings

4 What about Pluto? When Pluto was discovered in the 1940s, it was the largest thing in its orbit. With better equipment, we now know that it is one of hundreds of things in the Kuiper belt Because Pluto is not accreting, or cleaning up it s neighborhood, it is classified as a Dwarf Planet.

5 What about Pluto? When Pluto was discovered in the 1940s, it was the largest thing in its orbit. We didn t t see anything else there. With better equipment, we now can see that it still travels through a part of a dirty ring called the Kuniper belt Because Pluto has not completed accretion, it is now classified as a Dwarf Planet.

6 Planets Our 8 planets can be divided into two major groups based on their size, location in the solar system, & what they are made of: Terrestrial Planets: the 4 planets closest to the sun. They are small and made of solids, like rocks. Jovian planets: the 4 planets that are the farthest from the sun. They are large gas giants, all have rings (Jupiter is the dimmest, Neptune the brightest) The two types of planets are separated by the asteroid belt

7 MVEM and JSUN Terrestrial Planets Jovian Planets

8 Terrestrial vs. Jovian Group Distance from sun Temp for formation Type of Material Size Terrestrial M,V,E,M Close High (forms at high temp) Solid Small Jovian: J,S,U,N (jason) Far Low (forms at cold temp) Gas Large

9 Why Why do terrestrial planets form at high temperatures? Because they are closest to the sun, they form at higher temperatures. Why are terrestrial planets smaller than jovian planets? 1. As the gas changes into a liquid and eventually into a solid, it shrinks! 2. Terrestrial planets are smaller because the sun took so much of the dust and gas around it, leaving little to form the Terrestrial planets.

10 Why? Why are jovian planets larger? 1. Jovian planets are so far away from the sun that there was a lot more dust and gas available to accrete and form the planet. 2. Jovian planets are made of gases, mostly hydrogen and helium gas. Gases expand to fill the available space.

11 Scale of Planets It would take 1 million Earths to be the same size as the sun. The distance from the Earth to the sun is called 1 AU or astronomical unit. This is equal to light years.. It takes years for light to travel from the Sun to Earth 1 AU X 1,000,000

12 Terrestrial Planets: Mercury Closest to the sun Barely bigger than the Earth s s moon Moon like surface with craters Greatest temperature extremes From -100 to 400 degrees Celsius

13 Terrestrial Planets: Venus The Veiled planet Atmosphere like Earth s 97% of atmosphere is CO 2 so light can t t get through Extreme levels of volcanoes and tectonic activity Hot gassy atmosphere Very high temperatures (~900 ºF) Trapped gases can t t get out! Increased heat due to Greenhouse effect US & Russian probes have landed on Venus

14 Terrestrial Planets: Earth Our home Is defined to be 1 Astronomical Unit (AU) from the sun We will learn in great detail later 1 AU

15 Terrestrial Planets: Mars The red planet Has massive dust storms on its surface Has water Very old the highly cratered southern hemisphere is 3.5 to 4.5 billion years old!

16 Jovian Planets: Jupiter The largest planet Is 2 ½ times larger than all the other planets combined! Atmosphere is made of Hydrogen & Helium Has convection currents like the sun from internal heat that produces colored bands.

17 Jovian Planets: Saturn Rings! Has the lowest density of any planet Surrounded by moonlets Surface winds up to 1600 feet/sec

18 Jovian Planets: Uranius The sideways planet It rotates parallel to its orbital plane.

19 Jovian Planets: Neptune Has the Great Dark Spot Large Storm that is the size of the entire Earth Winds up to 1600 mi/hr

20 Planetary Data