Ag Earth Science Chapter 23

Transcription

1 Ag Earth Science Chapter 23

2 Chapter 23.1 Vocabulary

3 Any of the Earth- like planets, including Mercury, Venus, and Earth terrestrial planet

4 Jovian planet The Jupiter- like planets: Jupiter, Saturn, Uranus, and Neptune; These planets have relatively low densities and are huge gas giants

5 A cloud of gas and/or dust in space nebula

6 Small, irregular shaped body formed by colliding matter planetesimal

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8 The Planets: An Overview Terrestrial planets (Earth- like) Mercury, Venus, earth, and Mars Small and rocky Jovian planets (Jupiter- like) Jupiter, Saturn, Uranus, and Neptune huge gas giants

9 The Planets: An Overview Size is the most obvious difference between the terrestrial and Jovian planets Density, chemical makeup, and the rate or rotation are the other ways in which the two groups of planets differ.

10 The Interiors of Planets The substances that make up planets are divided into three groups. The classification of these substances is based on their melting points. The gases hydrogen and helium are those with melting points near absolute zero (- 273 C) The rocks are mainly silicate minerals and metallic iron which have melting points above 700 C The ices include ammonia, methane, carbon dioxide, and water. (intermediate melting points)

11 The Atmospheres of the Planets The Jovian planets have thick atmospheres (hydrogen, helium, methane, and ammonia) Terrestrial planets have meager atmospheres A planet s ability to obtain an atmosphere depends on its mass and temperature

12 Forma8on of the Solar System Nebula a cloud of dust and gas in space Nebular Theory According to the nebular theory, the sun and planets formed from a rotating disk of dust and gases As the speed of rotation increased, the center of the disk began to flatten out. Matter became more concentrated in the center, where the sun eventually formed

13 Forma8on of the Solar System Planetesimals As solid bits of matter began to collide and clump together and eventually grew to become planet

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15 Chapter 23.2

16 Mercury: The Innermost Planet Mercury is the innermost planet (closest to the sun) and second smallest Surface Features Cratered highlands and some smooth terrains Very dense planet (large iron core)

17 Mercury: The Innermost Planet Surface Temperature Revolves around sun quickly, but has a very slow rotation. One rotation of Mercury takes 59 Earth- days 3 months night and 3 months day Night temperatures = C and Daylight temperatures are 427 C

18 Mercury: The Innermost Planet Mercury has the greatest temperature extremes of any planet

19 Venus: The Veiled Planet Venus is covered in thick clouds that visible light cannot penetrate

20 Venus: The Veiled Planet Surface Features Data has confirmed that basaltic volcanism and tectonic activity shape Venus s surface Based on low density of impact craters, these forces must have been very active during the recent geologic past. 80% of Venus s surface consists of plains covered by volcanic flows

21 Venus: The Veiled Planet Surface Temperature Greenhouse effect has heated the planet s atmosphere to 475 C

22 Mars: The Red Planet The Martian atmosphere has only 1 percent the density of Earth s. Although the atmosphere of Mars is very thin, extensive dust storms occur and may cause the color changes observed from Earth. Hurricane- force winds up to 270km per hour can persist for weeks.

23 Mars: The Red Planet Surface Features Numerous large volcanoes Mars may have been the most able to support life because it may have had liquid water on its surface

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25 Chapter 23.3

26 Jupiter: Giant Among Planets Jupiter is only 1/800 as massive as the sun, however it is by far the largest planet in the solar system. Jupiter has a mass that is 2 ½ times greater than the mass of all the other planets and moons combined.

27 Jupiter: Giant Among Planets Structure of Jupiter Jupiter has a primary hydrogen- helium atmosphere that also has small amounts of methane, ammonia, water, and sulfur. Jupiter s interior heat produces large confection currents in the atmosphere

28 Jupiter: Giant Among Planets Jupiter s Moons Jupiter has 28 moons

29 Jupiter: Giant Among Planets Jupiter s Rings Rings were discovered around Jupiter during the Voyager I mission. Thought to be made up of fine, dark particles.

30 Saturn: The Elegant Planet The most prominent feature of Saturn is its system of rings

31 Saturn: The Elegant Planet Features of Saturn Saturn s atmosphere is very active (winds roaring at up to 1500 km/ hr) Large cyclonic storms similar to Jupiter Saturn has 31 moons The rings on Saturn are very complex

32 Uranus: The Sideways Planet A unique feature of Uranus is that it rotates on its side Instead of being generally perpendicular to the plane of its orbit like the other planets, Uranus s axis of rotation lies nearly parallel with the plane of its orbit.

33 Neptune: The Windy Planet Winds exceeding 1000 km/ hr encircle Neptune, making it one of the windiest places in the solar system. Neptune has 13 known moons Triton, Neptune s largest moon, is nearly the size of Earth.

34 Pluto: Planet X Pluto is 40 times farther from the sun than the Earth It is 10,000 too dim to be visible to the unaided eye It takes Pluto 248 Earth- years to orbit the sun

35 Pluto: Planet X Pluto s orbit is highly eccentric, causing it to occasionally travel inside the orbit of Neptune, where it has resided from 1979 through February For reasons such as it being the smallest of the other planets and because of its distance from the sun, Pluto is no longer considered an official planet.

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37 Count the number of faces Chapter 23.4

38 asteroid A small, rocky body, which can range in size from a few hundred kilometers to less than a kilometer. Asteroids orbits lie mostly between those of Mars and Jupiter

39 comet A small body made of rocky and metallic pieces held together by frozen gases. Comets generally revolve about the sun in an elongated orbit

40 coma A fuzzy, gaseous component of a comet s head

41 meteoroid A small, solid particle that travels through space

42 meteor The luminous phenomenon observed when a meteoroid enters Earth s atmosphere and burns up, popularly called a shooting star

43 meteorite Any portion of a meteoroid that reaches Earth s surface

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45 Asteroids: Microplanets Asteroids small rocky bodies that have been likened to flying mountains Most asteroids lie between the orbits of Mars and Jupiter. They have orbital periods of three to six years.

46 Comets Comets are among the most interesting and unpredictable bodies in the solar system Comets are pieces of rocky metallic materials held together by frozen gases, such as water, ammonia, methane, carbon dioxide, and carbon monoxide.

47 Comets Coma the glowing of the comet head A small glowing nucleus with a diameter of only a few kilometers can sometimes be detected within a coma. As comets approach the sun, some, but not all, develop a tail that extends for millions of kilometers.

48 Comets Comets apparently originate in two regions of the solar system Beyond Neptune in a region called the Kuiper belt Oort Cloud

49 Comets Halley s Comet Most famous short- period comet Orbit is 76 years

50 Meteoroids Meteoroid a small particle that travels through space Shooting Star

51 Meteoroids Most meteoroids originate from three sources: Interplanetary debris that was not gravitationally swept up by the planets during the formation of the solar system Material from the asteroid belt The solid remains of comets that once traveled near Earth s orbit

52 Meteoroids Meteors Those that enter the Earth s atmosphere and burn up Meteorites A meteoroid that reaches (hits) the Earth s surface

53 Meteorites and the Age of the Solar System Radiometric dating of oldest meteorites is around 4.54 billion years moon rocks is 4.5 billion years Earth rocks is about 4.3 billion years old

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