Astronomy
Mr. Miller Science
Astronomy: A study of everything that exists outside of the Earth's atmosphere, including data about the Earth gathered from space.
A solar eclipse happens when the Moon passes between the Earth and Sun, casting a shadow on our planet.
A Lunar eclipse occurs when the Moon passes through the Earth's shadow. It appears red or orange because the Earth's atmosphere filters out all the blue light.
Why is the sky blue in the daytime and red at sunrise and sunset?
Oxygen in the Earth's atmosphere scatters blue light. This is what makes the sky blue, and sunrises and sunsets red...all the blue light has been filtered out by the Oxygen.
The Planets and the Solar System
The Solar System includes everything that orbits the Sun ("Sol" is Latin for "Sun." Sol-ar, get it?)
Mercury is the planet closest to the Sun. It is shown here in relation to the size of the Earth.
Venus is the second planet from the Sun. It is nearly the same size as the Earth, but has an atmosphere of Carbon and Sulfur oxides. This causes an out of control "greenhouse" effect which makes the planet hot enough to melt rocks. It also rains sulfuric acid. It's not a habitable planet for life as we know it here on Earth.
Mars is slightly more than half the size of Earth. It's gravity is only 38% that of Earth, and it's atmosphere is less than 1/100 of Earth and is composed of mostly Carbon Dioxide. You could not survive on Mars without a supply of oxygen and a heated space suit since the pressure and temperature are too low to support life as we know it.
The Asteroid Belt is an area between Mars and Jupiter that contains rocky material that is left over from the formation of the Inner Planets. It is not as densely packed as this photo suggests, the individual asteroids are much further apart.
Jupiter is the largest planet in the Solar System and is made of gases such as Methane and Ammonia. The "Great Red Spot" is a giant cyclonic storm (think hurricane) that has been visible for at least 300 years. The storm is about 3 times larger than Earth. Jupiter has at least 53 moons. It also has faint, thin rings made of dust and rock.
Saturn is the second gas giant (of the outer gas planets), and is the 6th planet from the sun. This picture shows how much larger than the Earth it is (no, the Earth is NOT that close to Saturn!) Saturn is famous for its dramatic rings made of ice and dust. It has at least 62 moons, and 9 of them haven't been named yet. It's largest moon, Titan, is larger than the planet Mercury.
Uranus is the 7th planet from the sun, and the 3rd of the gas giants. It has 27 moons. It has 13 known rings, but they are faint and dark like those of Jupiter. This picture shows the relative size of the Earth to Uranus.
Neptune is the last of the gas giants, planet number 8. It is also the last planet in the Solar System, and furthest from the sun.
Pluto is only a fraction the size of the Earth and is considered to be a "Dwarf Planet." It resides in the Kuiper Belt beyond the orbit of Neptune. Discovered in 1930 by Clyde Tombaugh, it was formerly considered to be the 9th planet. It has at least five moons; Charon, Styx, Nix, Kerberos, and Hydra.
Just as asteroids are leftovers from the formation of the inner planets, comets are the leftovers from the formation of the outer, or gas giant planets. They are made up of frozen gas and dust, and orbit in highly elliptic paths, sometimes taking hundreds of years to circle the sun.
Questions to think about:
1. How long does it take the moon to orbit the Earth?
2. How long does it take the earth to orbit the Sun?
3. How long does it take for the Earth to rotate on its axis?
4. What is gravity, and how does it affect the objects in the solar system?
5. Could you live on Mars without a space suit? Why or why not?
6. What would happen to you if you landed on the surface of Venus?
7. What is a "light year?"