Natural Objects in the Sky

• Natural Objects in the Sky are visible in both the day and night sky.

Natural Objects in the Day Sky

• The Sun is one of many stars in the solar system.
• The Sun is 4.5 billion years old.
• The Sun will continue shining for another 5 billion years.
• The Sun has average size with a life span of 10 billion years.
• The sun is a big ball of gas that emits light and heat.

Natural Objects in the Night Sky

• The moon is Earth's only natural satellite.
• A natural satellite orbits a planet, a planet-like object, or an asteroid.
• The Moon is 1/3 the size of Earth.
• The Moon does not have its own light; it reflects light from the Sun.
• The Moon's shape changes every night due to its phases.
• Galileo Galilei discovered the Moon.
• Galileo Galilei made the first telescopic observation of the Moon in 1610.
• The phases of the Moon are caused by the changing positions of the Moon, Earth, and the Sun.
• On July 20, 1969, American astronauts Neil Armstrong and Edwin "Buzz" Aldrin became the first humans to land on the moon.
• About six-and-a-half hours after landing on the moon, Armstrong became the first person to walk on the moon.
• Armstrong famously said, "That's one small step for man, one giant leap for mankind."
• Apollo 14, Apollo 15, Apollo 16, and Apollo 17 were the other manned moon landing missions.
• Gene Cernan was the last man to step off the lunar surface during the Apollo 17 mission on December 14, 1972.
• Solar and Lunar Eclipses are optical phenomena involving the Sun, Moon and Earth.
• A solar eclipse occurs when the Moon passes between the Sun and the Earth, casing a shadow
• A lunar eclipse occurs Earth passes between the Sun and the Moon, casuing a shadow

The Stars

• Stars are big balls of gases that emit light and heat.
• Stars appear small because they are very far away.
• The Sun is the closest star to Earth.

Planets

• Mercury's diameter is 4,879.4 km.
• Mercury has no moons.
• Mercury's distance from the Sun is 58 million km.
• The length of a year on Mercury is 88 days.
• The length of a day on Mercury is 58 days, 15 hours, and 30 minutes.
• The temperature on Mercury ranges from -180°C to 430°C.
• Mercury's atmosphere contains hydrogen, helium, oxygen, sodium, and potassium.
• Venus' diameter is 12,104 km.
• Venus has no moons.
• Venus is 108 million km from the Sun.
• A year on Venus lasts 225 days.
• A day on Venus lasts 116 days, 18 hours.
• The temperature on Venus is around 475°C.
• Venus' atmosphere consists of carbon dioxide (96.5%), nitrogen, and sulfur dioxide.
• Earth's diameter is 12,742 km.
• Earth has 1 moon.
• Earth is 150 million km from the Sun.
• A year on Earth lasts 365 days.
• A day on Earth lasts 24 hours.
• Earth's temperature ranges from -88°C to 58°C.
• Earth's atmosphere is made up of 78.08% nitrogen, 20.95% oxygen, 0.93% argon, and 0.04% carbon dioxide.
• Mars' diameter is 6,779 km.
• Mars has 2 moons: Phobos and Deimos.
• Mars is 228 million km from the Sun.
• A year on Mars is 687 days.
• A day on Mars lasts 1 day and 37 minutes.
• The temperature on Mars ranges from -153°C to 20°C.
• Mars' atmosphere contains 0.13% O2, 95.32% CO2, 0.08% CO, 2.7% N2, and 1.6% Ar.
• Jupiter's diameter is 142,984 km.
• Jupiter has 79 moons.
• Jupiter is 778 million km from the Sun.
• A year on Jupiter lasts 12 Earth years.
• A day on Jupiter is 9 hours and 56 minutes.
• The temperature on Jupiter is about -110°C.
• Jupiter is made up mostly of hydrogen and helium, with traces of ammonia, sulfur, and water vapor and Jupiter's Moons.
• Io, Europa, Ganymede and Callisto are Jupiter's four Galilean moons of most interest to scientists.
• Saturn's diameter is 116,460 km.
• Saturn has 82 moons.
• Saturn is 1.4 billion km from the Sun.
• A year on Saturn lasts 29 Earth years.
• A day on Saturn is 10 hours and 42 minutes.
• The temperature on Saturn is -140°C.
• Saturn is made up mostly of hydrogen (~75%), helium (~25%), and traces of methane and water.
• Uranus diameter is 50,724 km.
• Uranus has 27 moons, including Titania, Oberon, Miranda, Ariel, and Umbriel.
• Uranus is 2.9 billion km from the Sun.
• A year on Uranus lasts 84 Earth years.
• A day on Uranus is 17 hours and 14 minutes.
• The temperature on Uranus is around -224°C.
• Uranus’ atmosphere is made up mostly of hydrogen and helium, with traces of ammonia, water, and methane.
• Uranus is the third largest planet in the Solar System.
• Uranus is the seventh planet from the Sun, positioned 2.6 billion kilometers away from Earth.
• Neptune's diameter is 49,244 km.
• Neptune has 14 moons.
• Neptune is 4.5 billion km from the Sun.
• A year on Neptune lasts 165 Earth years.
• A day on Neptune is 16 hours and 6 minutes.
• The temperature on Neptune is around -210°C.
• Neptune’s atmosphere is made up mostly of hydrogen, helium, and methane.

Dwarf Planets

• Dwarf planets are smaller objects in our Solar System.
• Dwarf planets are neither full-sized planets nor moons.
• Ceres, Pluto, Eris, Makemake, and Haumea are five recognized dwarf planets.
• Hundreds of other objects are at the edge of our Solar System in an area known as the Kuiper Belt, and some are suspected to be dwarf planets.
• The dwarf planet Ceres is found in the asteroid belt between Mars and Jupiter, and is the only dwarf planet closer to the Sun than Neptune.
• A day on Ceres lasts nine hours, one of the shortest in the Solar System.
• A year on Ceres is 4.6 Earth years.
• Pluto is found at the very edge of the Solar System in the Kuiper Belt.
• Pluto is the largest dwarf planet.
• Originally thought to be the ninth planet in the Solar System, Pluto was reclassified as a dwarf planet in 2006.
• Charon, Styx, Nix, Kerberos and Hydra are Pluto's five moons, Charon is the largest, about half the size of Pluto.
• A day on Pluto is about 6 Earth days.
• A year on Pluto is 248 Earth years.
• Pluto's orbit differs from other planets and dwarf planets, taking it closer to the Sun than Neptune.
• Eris is the largest of the known dwarf planets andwas discovered in the Kuiper Belt in 2003.
• Eris is about the same size as Pluto but three times further away from the Sun.
• Eris has a small moon, Dysnomia.
• A year on Eris lasts 557 Earth years.
• Eris' discovery caused a debate over the definition of a planet versus a dwarf planet.
• In 2006, Eris was named after the Ancient Greek goddess of discord because of the arguments its discovery caused.
• Makemake is located in the Kuiper Belt along with Pluto and Eris.
• Makemake was discovered in 2005 and opened up the debate over whether something is a planet or a dwarf planet.
• A year on Makemake lasts 305 Earth years.
• Makemake is named after the god of creation from Rapa Nui mythology.
• Haumea is located in the Kuiper Belt alongside Eris, Pluto, and Makemake.
• It takes Haumea 285 years to orbit the Sun.
• A day on Haumea is 4 hours, causing it to have an elongated elliptical shape.
• Haumea is named after the Hawaiian goddess of fertility and has two moons named after her children, Hi'iaka and Namaka.

The Milky Way Galaxy

• A galaxy is a large collection of stars, gas, and dust bound by gravity.
• The Sun is part of the Milky Way Galaxy.
• The Milky Way holds 100 to 400 billion stars.
• Earth is in the Orion Arm, located about halfway between the center of the Milky Way and its outer edge.
• The Milky Way is a large barred spiral galaxy that includes the sun.
• There is a central section with arms of stars that are curved and extended outward.