1. Astronomy
What You Really Need To Know
Accompanied by a Worksheet
2. • Nebula: clouds of gas and dust.
• Mercury has the smallest diameter and
greatest average density.
• Rocky object known as asteroids are located
between Mars and Jupiter.
• Mercury travels around the Sun in less time
than it take for Earth to make one complete
revolution.
• Absolute Magnitude: a measurement
scientists use to compare brightness of stars.
• At any given time 50% of Earth is illuminated
by the Sun.
3. • Earth is an inner planet.
• The corona is the layer of the sun seen
during a solar eclipse.
• Jupiter has a fierce hurricane-like storm that
is several times the size of Earth.
• Life has flourished on Earth because we
have liquid water.
• Hydrogen is the main element of most stars.
• The presence of sand dunes on Mars
indicate the presence of winds on Mars.
• When Earth’s orbit passes through the
remains of a comet spectacular meteor
showers are observed.
4. • Apollo 11 was the first manned-mission to
land on the moon.
• Fusion is the process by which the sun emits
energy by converting hydrogen into helium.
• The core of the sun is the most dense layer
of the sun.
• Venus is referred to as “Earth’s twin”.
• One year equals one complete revolution of
a planet around the sun.
• Gravitational attraction between Earth and
an object depends on distance and mass.
5. • Weight is dependent on gravity.
• Mercury has no atmosphere and little gravity
and is closest to the sun.
• The gravitational pull of the moon causes
tides on Earth.
• The rotation of the Earth causes the sun to
appear to rise and set.
• Planets usually contain an atmosphere.
• Solar winds blow a comets tail away from the
sun.
• Earth’s tilt causes seasons.
6. • We live in the Milky Way Galaxy.
• The Milky Way Galaxy is a Spiral Galaxy.
• Stars appear to change position during the
night because the Earth is rotating on its
axis.
• Erosion does not occur on the Moon
because there is no wind or rain.
7. 1. Why does a comet's tail
point away from the Sun?
– The solar wind blows the
tail away from the Sun.
– The comet's tail is following
the path of Jupiter.
– The Moon's light only
shines on part of the comet.
– It is being pulled by a
nearby black hole.
8. 2. Earth's axis of
rotation is tilted
23.5° relative to the
plane of its orbit,
which helps to
cause –
– high and low tides
– the lunar phases
– the seasons
– day and night
9. 3. In addition to Earth's
orbit, which planets'
orbits are shown?
– Mercury and Venus
– Venus and Mars
– Mars and Jupiter
– Jupiter and Saturn
10. 4. Which planet has the shortest day?
– Mercury
– Venus
– Jupiter
– Saturn
11. 5. Based on the drawing above,
what is the main reason that
Venus would appear brighter at
point Q rather than at point R as
seen from the Earth?
– More of the visible side of the
planet is illuminated at point Q
than at point R.
– Light from the planet at point Q is
less affected by the sun's gravity
than at point R.
– The planet is closer to the Earth
at point Q than at point R.
– The planet appears overhead
against a dark sky when it is at
point Q but not at point R.
12. 6. In the late 1920s, Edwin Hubble
and Milton Humason determined
the distance to a number of
galaxies and the velocity of those
galaxies relative to the Earth. The
graph shows the early results that
were obtained. What approximate
ratio did the scientists calculate
between velocity and distance
based on these early findings?
– 450 kilometers per second per one
million light years
– 150 kilometers per second per one
million light years
– 600 kilometers per second per one
million light years
– 300 kilometers per second per one
million light years
13. 7. In 1912, an astronomer at Arizona's Lowell
Observatory noticed that the lines in the spectra of
most galaxies shifted toward the red end of the
spectrum. Another American astronomer, Edwin
Hubble, later interpreted this discovery as evidence
that –
– the largest galaxies are slowly engulfing their smaller
neighbors
– galaxies are moving away from each other in a constantly
expanding universe
– galaxies were once part of one
huge megagalaxy
– an explosion will one day result from the pressure building as
the galaxies expand
14. 8. At what position would Earth be found in the solar
system diagram shown below?
– 1
– 2
– 3
– 4
15. 9. Which of the above evolutionary stages of a
massive star is called a supernova?
– 1
– 2
– 3
– 4
16. 10. According to this diagram, a lunar eclipse
occurs only when the –
– sun's rays are directly overhead
– Earth is between the sun and the moon
– moon is in the new moon phase
– moon is between the sun and the Earth
17. 11. According to this chart, which planet will most
likely have the highest temperatures?
– Mars
– Earth
– Mercury
– Venus
