The Moon

The Moon is Earth's nearest natural satellite. Our Moon is bigger than Planet Pluto. It can be seen clearly with your eyes. For better viewing you can use binoculars, or a telescope.  Galileo in 1609 was the first to look at it through a telescope. The Moon is about 4 and a 1/2 billion years old. It is the only object in the solar system visited by humans.

The moon is about one quarter the size of Earth and it has about one-sixth of the Earth's gravity. It has a black sky, has almost no atmosphere due to its weak gravity. Without an atmosphere, there is no wind, no clouds and no rain. 

* Distance: Mean distance from Earth to the Moon is 384,000km (238,900 miles)

* Diameter: 3,476km (2,160 miles)

* Mass: 7.35 X 10²² kg. This about one-eightieth of the Earth's mass.

* Moon's rotation: Rotates about its own axis in 27 days and 8 hours, which is about the same time it takes to orbit the earth. Hence the same face of the moon is always facing the Earth. The far side always faces away and cannot be seen from Earth. It has been photographed by spacecraft.

* Escape velocity: 2.38 km/sec

* Moon Surface: It is covered with craters, lava plains, mountains and valleys. No active volcanos.

* Temperature: Ranges from -171?C to 111?C.

* Mass: 0.012 (Earth = 1)

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Phasing of our Moon

Our Moon goes through phases during the lunar month. The lunar month is the 29.53 days it takes to go from one new moon to the next. The moon phase is the shape you see which follows the same pattern every four weeks.

Asteroid Belt

The Asteroid Belt is the region of interplanetary space between Mars and Jupiter where most asteroids are found. It contains irregularly shaped chunks of debris called asteroids

The Space Asteroids are made of rock and metal, mostly nickel and iron. Contrary to popular imagery, the asteroid belt is mostly empty.
 

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Facts about the Asteroid Belt
* Area: The main asteroid belt extends from 255 to 600 million km (2.15 to 3.3 astronomical units) from the Sun and may contain over a million objects bigger than 1 km across.
* Diameter: The largest objects are Ceres (1,003 km), Pallas (608 km) and Vesta (538 km).
* Total Mass: The total mass of all the asteroids is less than that of the Moon. There are 26 known asteroids larger than 200 km across.
* Location: The Asteroid Belt is a region between the inner planets and outer planets where thousands of asteroids are found orbiting around the Sun.

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Size

How big are the asteroids? Ceres is the largest asteroid in the asteroid belt and is the only dwarf planet in the belt. Pallas is second largest and the second asteroid to have been discovered. More than half the mass of the main belt is contained in the four largest objects: Ceres, Vesta, Pallas and Hygiea.

Planet Saturn

The Planet Saturn is the second largest planet. It is the next planet after Jupiter. Saturn is named after a Roman God and is famous for its beautiful rings

It has at least 31 moons. These include Titan, Hyperion, Mimas, Enceladus, Rhea, and Phoebe.

Facts about Planet Saturn
* Diameter: 120,660 km. It is about 10 times larger than our Earth
* Temperature: –178°C
* Distance from Earth: At its closest, Saturn is 1190.4 million km * Atmosphere: Hydrogen and helium
* Surface: consists of liquid and gas.
* Rotation of its axis: 10 hours, 40 min, 24 sec
* Rotation around the Sun: 29.5 Earth years

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Planet Mars

Planet Mars is also called the Red Planet or Red World.
Mars is reddish in colour and was named after the god of war of the ancient Romans. Mars is the only planet whose surface can be seen in detail from the Earth. Mars is the fourth closest planet to the Sun and the next planet beyond the Earth.
Planet Mars Facts:
Number of Satellites: 2 (Phobos and Deimos)

Rotation Period: 24 hours and 37 minutes
Temperature: -140 to 20 degrees celsius (-220 to 60 fahrenheit)
Length of Year: About 1 Earth-year and ten and a half months (687 days)
Diameter: 6796 Kms (4223 Miles)
Axial Tilt: 25.19 degrees

Atmosphere: Mainly Carbon Dioxide
 

Planet Neptunus

The Planet Neptune is the eighth planet from the sun. It is also known as the Blue Giant. Neptune is the fourth and outermost of the gas giant planets and also has rings. Its atmosphere is mostly hydrogen and helium. In Roman mythology Neptune was the god of the Sea

Neptune has been visited by only one spacecraft, Voyager 2 on Aug 25 1989. It was the last stop in 1989 for the Voyager 2 spacecraft on its grand tour of the solar system.
Recent knowledge has been gained by ground-based telescopes and the Hubble Space Telepscope.
Due to Pluto's eccentric orbit, Neptune at times becomes the most distant planet from the Sun for a few years.
Planet Neptune Facts:
Mass: 17.15 Earth-masses
Number of known satellites: 8
Length of Year: 164.8 Earth-years
Mean Distance from the Sun: 4,500 million kilometers

Mean Orbital Velocity: 5.4 kilometers per second

Length of Day: 16.11 hours, 0.67 Earth-day

Equatorial diameter: 49,500 kilometers Atmospheric components: 74% hydrogen, 25% helium, 1% methane

Moons of Planet Neptune
Neptune has 8 known moons: Triton, Thalassa, Naiad, Despina, Galatea, Larissa, Proteus and Nereid

Planet Pluto

Pluto is the farthest known planet from the Sun. It the only one planet that has not been visited by spacecraft. It has one moon called Charon

Pluto was discovered in 1930 by Clyde W. Tombaugh. The planet is named Pluto after the God of the Underworld in Roman mythology. In Greek mythology the equivallent god is Hades.
Facts about Planet Pluto
* Diameter: 2324 km (1444 miles).
* Surface composition: Nitrogen, carbon monoxide, methane and water ices

* Average surface temperature: -233ºC (-382ºF)

* Mass: 0.002 (Earth = 1)
* Gravity: 0.07 (Earth = 1)
* Average distance from the Sun: 5.9 billion kilometres.

* Rotation Period: 6.39 Earth days (length of day)

* Orbital period around the sun: 248 Earth years (length of year)
* Rings = 0
* Moons =  1
* Average distance between Pluto and Charon: 19,600 Kms
The Orbit of Planet Pluto

Pluto's orbit from the Sun varies from 4.4 to 7.7 billion kms and for the most of its orbit it is the outer most planet. Between 1979 and 1999 Pluto was actually closer to the Sun than Neptune and the closest approach to the sun (perihelion) was in September 1989.

Due to the changes in orbit in time, Pluto has a unique atmsophere that transforms at various stages of its orbit. As its orbit approaches the Sun, its atmosphere begins to form. The frozen atmosphere melts as it comes closer. As Pluto moves further out its atmsophere will freeze

Planet Jupiter

The Planet Jupiter is the LARGEST PLANET in our Solar System. Jupiter has at least 63 moons and they include: Europa, Io, Callisto and Ganymede.
Jupiter was explored in flybys in the 1970s by NASA's Pioneer 10 and 11 and Voyager 1 and 2 spacecraft, and is currently being studied by the Galileo spacecraft

Facts about Planet Jupiter
* Diameter: 85,788 miles the largest planet - more than 12 Earths could line up across it
* Temperature: Range -163° C to >-121° C
* Distance from Sun: Approximately 466 million miles
* Atmosphere: Mostly hydrogen and helium
* Surface: A giant ball of mostly hydrogen and helium
* Rotation of its axis: 9 hours, 55 minutes in Earth time (the length of one rotation)
* Rotation around the Sun: 12 Earth years
* Magnetic Field: Yes
* Number of Moons: 63 moons have been identified Ganymede is the largest moon - it is bigger than both Mercury and Pluto