Download Space Revision Answers File

Space Revision Solutions
Answer the following questions in your exercise books or on your laptops
The Moon
1. Why is the moon called a satellite? Define ‘satellite’
Anything that goes around a planet is called a satellite. The moon is called a
satellite as it orbits the Earth.
2. Why is it a natural satellite?
Moons are natural satellites, as they are not man made yet they orbit the
Earth.
3. What keeps the moon in orbit?
The motion of the Moon is affected by the gravity of the Sun AND the Earth.
The moon is in free fall around the Earth with a velocity of 3682 kilometers per
hour. Much faster and it could escape Earth-orbit; much slower and it would
crash into the Earth.
4. Does the moon produce light? Why/Why not?
Yes, the moon does produce light. The moon shines because its surface
reflects 3% to 12% of light from the sun that hits it.
5. Why are stars called luminous?
Luminous means to give off light, which stars do (like our Sun). When
astronomers speak of the luminosity of a star, they’re speaking of a star’s
intrinsic brightness, how bright it really is. A star’s apparent magnitude – its
brightness as it appears from Earth.
Phases of the Moon
1. How long does it take the Moon to orbit the Earth?
The sidereal month is the time it takes to make one complete orbit around
Earth with respect to the fixed stars, it is about 27.32 days. The synodic
month is the time it takes the Moon to reach the same visual phase. This
varies notably throughout the year, but averages around 29.53 days.
2. Why do we see phases of the Moon?
The phases of the Moon depend on its position in relation to the Sun and
Earth. As the Moon makes its way around the Earth, we see the bright parts
of the Moon's surface at different angles.
3. What do we see when there is a full moon?
When there is a full moon, the whole of the moon is illuminated. Therefore we
see a complete circle illuminated. This occurs when the moon is in opposition
to the Sun (opposite side of the Earth to the Sun).
4. Write the phases of the moon in order starting with New Moon.
Draw a picture next to each
Eclipse of the Moon
1. What common mistakes do people make about the phases of the Moon?
A common mistake is to think that the phases of the Moon happen because
the Earth gets in the way, and casts its shadow onto the Moon. That is not
how the phases are caused.
( http://moon.nasa.gov/moonmisconceptions.cfm )
Go to the above link if you would like to see more common mistakes.
2. When do we get an eclipse of the moon?
When the Earth’s shadow falls upon the moon, we then get an eclipse of the
moon.
3. What is the difference between a solar eclipse and a lunar eclipse?
A lunar eclipse occurs when the Earth passes between the Moon and the
Sun, and the Earth's shadow obscures the moon or a portion of it. A solar
eclipse occurs when the Moon passes between the Earth and the Sun,
blocking all or a portion of the Sun.
The Night Sky
1. List the:
Rocky Planets: Mercury, Venus, Earth, and Mars
Gas Giants: Jupiter, Saturn, Uranus, and Neptune
Dwarf Planets: Ceres, Pluto, and Eris
2. What are the four different types of galaxy shapes? Also define ‘galaxy’
The four different types of galaxy shapes are spiral, elliptical, lenticular,
and irregular. A galaxy is a system of millions or billions of stars, together
with gas and dust, held together by gravitational attraction.
3. What is the difference between a meteor, meteorite, and meteoroid?
It depends on their position at the time.
Meteoroid - A small particle from an asteroid or comet orbiting the Sun.
Meteor - A meteoroid that is observed as it burns up in the Earth's
atmosphere – a shooting star. Meteorite - A meteoroid that survives its
passage through the Earth's atmosphere and impacts the Earth's surface.
4. Explain the difference between an asteroid and comet
Asteroids are made up of metals and rocky material, while comets are made
up of ice, dust and rocky material.
Another difference between comets and asteroids is in their orbital patterns.
Comets tend to have very extended and elongated orbits, many times
going more than 50,000 AU from the sun (1 AU, or astronomical unit, equals
the distance from the Earth to the sun).
Asteroids tend to have shorter, more circular orbits and they seem to want
to group together in belts.