Astronomy 8-4.1 Summarize the characteristics and movements of objects in the solar system (including planets, moons, asteroids, comets, and meteors).
Our Solar System • Objects found in the solar system are characterized based on surfacefeatures and atmosphere (if there is one) • Objects in the solar system also move in an orbit or some type of rotation.
Planets • May have a terrestrial (rocky) surface or a gaseous surface. • Can also be classified by how they move. (Rotation on their axis and Revolution around the sun) • May have rings.
Inner Planets • The four inner planets are small, have rocky surfaces and iron cores. • Mercury • Venus • Earth • Mars
Mercury • Closest planet to the Sun • Very small (not much bigger than our moon) • Thin to no atmosphere • Extreme range of temperatures; greater than any other in our solar system.
Venus • 2nd planet from the Sun. • Similar in size to Earth. • Venus revolves around the sun in 7.5 Earth months. • It takes 8 months for it to rotate on it’s axis ( its day is longer than its year!) • Very thick atmosphere (cloudy). • Surface temperature is hot enough to melt lead. (Hottest planet in the Solar System)
Earth • 3rd planet from the Sun. • Only inhabitable planet in our solar system. (that we know of?) • 70% covered in water. • One moon.
Mars • 4th planet from Sun. • Called the “red planet” because of how it looks from the sky. • Seasons similar to Earth’s. • Two small moons. • Polar Ice Caps
Planets • The four outer planets are much larger than Earth and have a gaseous atmosphere (also called the Gas Giants) • They all have rings! • Jupiter • Saturn • Uranus • Neptune
Jupiter • Most massive planet (300 times more massive than Earth) • Unique feature: Giant Red Spot – a giant area of swirling clouds larger than Earth. • 63 moons • A few of the moons have volcanoes, ice and craters. • 5th planet from the Sun.
Saturn • 2nd largest planet. • Less dense than water. • Has rings around it (over 100 rings) • Largest moon is Titan (larger than Earth’s moon). • Over 33 moons. • 6th planet from the Sun.
Uranus • 7th planet from the Sun. • Axis is tilted at an angle of about 90 degrees. • Rotates on its side. • 27 moons. • Has rings. • Revolution is 84 years.
Uranus with its RingsThis is the highest resolution image of Uranus with its rings ever assembled. Four separate images were mosaicked together to create the picture of Uranus. The rings were made from two high resolution images of Uranus's rings in which a strip was cut out and projected for a full 360 degrees. The rings and planet are to scale and shows the view Voyage 2 had of at the time the images were taken. The rings shown in the picture are Epsilon, Delta, Gamma, Eta, Beta, Alpha, 4, 5, and 6. Although there are other rings, these are the ones that could be seen on the Voyger 2 images at the point in time in which the pictures were taken
The Interior of UranusOur knowledge of the internal structure of Uranus is inferred from the planet's radius, mass, period of rotation, the shape of its gravitational field and the behavior of hydrogen, helium, and water at high pressure. Its internal structure is similar to that of Neptune except for the fact that it is less active in terms of atmospheric dynamics and interior heat flow. This cut-away view shows Uranus composed of an outer envelope of molecular hydrogen, helium and methane roughly the mass of one to two Earths. Below this region Uranus appears to be composed of a mantle rich in water, methane, ammonia, and other elements. These elements are under high temperatures and pressures deep within the planet. The mantle is equivalent to 10 to 15 earth masses. Uranus's core is composed of rock and ice, and is likely no more than one Earth mass.
Neptune • 8th planet from the Sun. • Blue atmosphere with visible clouds. • 8 moons. • Giant “blue” spot • Strongest Winds over 1200 mph!!
Moons • A moon is a natural satellite rotating around a planet. • Almost 140 moons are known in the Solar System. • Moons are studied in relation to the planet they orbit. (revolution)
Moons • Several moons are larger than Pluto and two moons are larger than the planet Mercury. • Mercury and Venus do not have any moons. • By comparison, Earth has one moon and Mars has two.
Moons Some moons have unique characteristics such as: • Large mountains • Volcanoes • Craters • Icy surfaces • Most moons are airless (no atmosphere).
Moons with atmospheres • Triton • Moon of Neptune. • Thin layer of methane and nitrogen • Icy surface • Io • Moon of Jupiter • This sulfurous moon is the most volcanic world in our Solar System. • Titan • Moon of Saturn • Titan appears to have an organic chemistry in its atmosphere. • Very thick nitrogen atmosphere • May even have liquid water!
Asteroids • Most revolve around the sun between the orbits of Mars and Jupiter. • This region of the solar system is called the ASTEROID BELT. • Come in all shapes and sizes. • Movement based on their revolution around the Sun. • Scientists monitor asteroids that have orbits that cross Earth’s orbit. Why?