Chapter 23: Touring Our Solar System

Transcription

1 Chapter 23: Touring Our Solar System The Sun The is the center of our solar system. The Sun makes up of all the mass of our solar system. The Sun s force holds the planets in their orbits around the Sun. The Planets: An Overview Mercury, Venus, Earth, and Mars are relatively small and rocky. Jupiter, Saturn, Uranus, and Neptune are huge gas giants. Differences between the Terrestrial and Jovian planets,,, and. The Terrestrial planets are, consisting mostly of rock and metallic substances, and only minor amounts of gas and ices. Jovian planets are less dense and contain large amounts of and. Formation of the Solar System a cloud of dust and gas in space. the sun and the planets formed from a rotating disk of dust and gases. solid bits of matter collided and clumped together through a process called accretion forming small, irregular shaped bodies. Section 23.2 The Terrestrial Planets Mercury Planet closest to the. planet in the solar system. Has an orbit period of days. The shortest of any planet. Takes days to rotate once on its axis.

2 Temperature may reach as high as during the day (hot enough to melt lead) and plunge to at night. Mercury has the greatest extremes of any planet. Venus Second planet from the sun called twin. Orbit period of days. Rotates once on its axis every days! Rotates the of all the other planets. The Sun rises in the west and sets in the east. Average surface temperature is making it the hottest planet. Atmospheric pressure is about that of Earth. Venus s atmosphere is 97%. Earth Our planet, the planet from the sun. Orbit period is days. Completes one rotation in hours and minutes. Only known planet with. Average surface temperature of. Only planet known to. Mars planet from the sun. Orbit period of days. Rotates on its axis once in hours minutes. Mars has like Earth. Mars has two moons, and

3 Mars has the largest known volcano in the solar system,, which is three times higher than Mt. Everest. Mars also has the largest canyon,, which is as long as the United States. Evidence has been found on Mars of erosion by. Water is in the Martian soil and icecaps. Temperatures range from in the summer to in the winter. Section 23.3 The Outer Planets (and Pluto) Jupiter planet from the sun. By far the of all planets. Its mass is times greater than all of the other planets and moons combined! Orbit period is about years, but it rotates faster than any other planet once every hrs and minutes! Jupiter has at least moons and counting! The 4 largest moons, Europa, Io, Ganymede, and Callisto, are called the, because they were discovered by Galileo. Temperatures in the interior of Jupiter may raise as high as It is composed of mostly and, much like that of the sun, but Jupiter was not massive enough for nuclear fusion to begin. The on Jupiter is a giant rotating storm in the atmosphere that has been raging for several hundred years. Wind speeds reach as high as. Saturn planet from the sun. The largest planet. Average temperature is.

4 Has at least moons and provisional moons and an immense, complex ring system. Orbit period of years Rotates once every hrs and minutes The least planet in the solar system. It would float in water!! Its largest moon is, which is larger than Mercury and has an. Uranus planet from the sun Discovered in. Orbit period of years Has at least moons and at least small rings. The only planet in the solar system that rotates to its plane of orbit, like a rolling ball! Rotates once in hr min Average surface temperature is about Neptune planet from the sun. Orbit period of years Rotates once in hrs min Neptune has moons and possibly rings The largest of these moons is. The upper atmosphere is composed of white clouds of frozen. Has an Earth sized storm called the with winds exceeding km/hr. Average surface temperature is about.

5 Pluto: Dwarf Planet Pluto has actually been recently from the list of planets. planet from the sun discovered in discovered Pluto by accident. Orbit period is years Rotates once every days Has one large moon called. Average surface temperature of. Dwarf Planets Along with Pluto, there are other dwarf planets: Eris, Ceres, Haumea, and Makemake. Section 23.4 Minor Members of the Solar System Asteroids small rocky bodies that have been likened to flying mountains Most asteroids lie between the orbits of and. They have orbital periods of 3 to 6 years. Some have very orbits, a few regularly pass Earth and our moon Many asteroids have shapes, and some planetary geologists believe the asteroids are of a broken planet (pulled apart by the immense gravity of Jupiter) Comets pieces of rocky and metallic materials held together by frozen gases Most comets travel in orbits, taking them past Pluto and take hundreds of thousands of years to go around the sun. glowing head of a comet, caused by the solar energy vaporizing frozen gases

6 A small glowing with a diameter of only a few kilometers can sometimes be detected within a coma. As comets approach the sun, some develop a that extends for millions of kilometers. The of the comet always points away from the sun, this is accounted for by the and Comet Origins where most short-period comets are thought to originate from, it is a belt of material orbiting outside the orbit of Neptune. Unlike the Kuiper Belt comets, these comets have longer orbital periods and aren t confined to the plane of the solar system. The Oort Cloud appears as a spherical shell of comets and other materials surrounding our solar system. Meteoroids a small solid particle that travels through space Most meteoroids originate from any one of the following sources: (1) that was not gravitationally swept up during the formation of the solar system, (2) material from the, or (3) the solid remains of that once traveled near Earth s orbit meteoroids that enter Earth s atmosphere and burn up, a shooting star The light that we see is caused by the between the meteor and the air a meteoroid that reaches Earth s surface A few meteorites have blasted out on Earth s surface Meteorites and the Age of the Solar System How did scientists determine the age of the Solar System? They use to determine that the oldest meteorites found on Earth formed more than 4.54 billion years ago Scientists believe that the of these meteorites is similar to the composition of other materials in the inner solar system during its formation

7 The oldest moon rocks are believed to be ~ The oldest known Earth rocks are found in Canada ~