Tuesday, October 27, 2009
SES4U
Solar System Test (Version A)
Name: ___________________________
Knowledge/Understanding – 27 Marks
Thinking/Investigation – 9 Marks
/55
Communication – 14 Marks
Application – 5 Marks
Section I – Multiple Choice (10 Marks –K)
Choose the best answer for each of the following.
1. The apparent backward movement of a planet is called:
a. Planetary motion
b. Sidereal motion
c. Retrograde motion
d. Copernican motion
2. Which of the following astronomers did not make a significant contribution to dispelling the
geocentric model of the solar system?
a. Nicolas Copernicus
b. Johannes Kepler
c. Galileo Galilei
d. William Herschel
3. Which of the following would not be considered a terrestrial planet?
a. Earth
b. Saturn
c. Mercury
d. Venus
4. Which of the following statements is not true about dwarf planets?
a. It orbits the Sun
b. Due to its own gravity, it is spherical in shape
c. It can be a satellite of a larger, nearby planet
d. It has not cleared the area of its orbit of smaller debris.
5. The layer of loose, ground-up rock on the surface of the Moon is referred to as:
a. Highland breccia
b. Regolith
c. Lunar maria
d. Lunar silica
6. Which of the following types of electromagnetic radiation would likely emit ionizing
radiation?
a. X-rays
b. Visible light
c. Infrared light
d. Radio waves
7. Determine which of the following statements about the vernal equinox are true.
i. The vernal equinox signals the start of spring.
ii. The Sun is directly overhead at 12:00 noon on the day of the vernal equinox at the Tropic
of Capricorn.
iii. During the vernal equinox, along the equator there are exactly 12 hours of sunlight and 12
hours of darkness.
iv. The Sun is directly overhead at 12:00 noon on the day of the vernal equinox at the Tropic
of Cancer.
a.
b.
c.
d.
Statements i, ii, and iii are correct.
Statements ii, and iii are correct.
Statements i, and iv are correct.
Statements i, and iii are correct.
8. Which of the following would not be considered a dwarf planet?
a. Ceres
b. Deimos
c. Eris
d. Pluto
9. Determine which of the following statements about the Moon is correct.
a. It is thought that the Moon formed 2 billion years ago after the Earth captured a
stray asteroid due to its strong gravitational attraction.
b. The dark side of the Moon faces away from Earth due to the Moon’s synchronous
rotation.
c. The Moon is much closer to Earth than other moons are to their respective
planets.
d. A lunar eclipse can only occur when there is a new moon.
10. Foucault is famous around the World because:
a. He showed that the Earth has a nearly circular orbit around the Sun.
b. He discovered that Uranus spins on an almost 90 degree axis (from the ecliptic
plane).
c. He created a simple device to show that the Earth is rotating on its axis.
d. He proved that the Earth is tilted at 23.5 degrees relative to the ecliptic plane.
Section II – Matching (10 Marks –K)
Match the term on the left with the appropriate definition on the right.
1
Johannes Kepler
A
An area beyond Neptune where there are thought to
be many dwarf planets.
2
Isaac Newton
B
The Moon, Earth, and Sun are all aligned.
3
Venus
C
4
Neptune
D
5
Meteorite
E
The Moon, Earth, and Sun form a 90-degree angle.
6
Meteoroid
F
Interplanetary material that is entering Earth’s
atmosphere.
7
Kuiper Belt
G
Has a rich methane gas atmosphere.
8
Oort Cloud
H
A piece of interplanetary material found on the
surface of Earth.
9
Spring Tide
I
Developed the three laws of planetary motion.
10
Neap Tide
J
Thought to be the place where comets congregate
K
A streak of light seen from the surface of the Earth.
L
His Law of Universal Gravitation helped to explain
planetary orbits.
Has a thick atmosphere of carbon dioxide and
nitrogen.
An asteroid-rich area found between Mars and
Jupiter.
Section III – Diagrams and Calculations (10 Marks)
1. Create a simple diagram that shows how a comet appears as it approaches the Sun.
Underneath the diagram, explain why this happens. (3 Marks – 1K/2C)
2. Using a set of diagrams, show how a lunar eclipse is different from a solar eclipse. Also,
show both the umbra and penumbra of a solar eclipse. (3 Marks – 1K/2C)
F=
Gm1m2
r2
G = 6.67 × 10 −11 m 3 /kg • s2
P 2 = a3
3. Dr. Fantastic is just about to unveil his latest dastardly creation: the gravity gun. If it has a
simulated mass €
of 4.7 × 10 25 kg , what would the gravitational
force be between it and a
€
€
car ( m = 2000kg ) that is parked 10m away? (2 Marks – T/I)
€
€
4. A new comet, TPS, has just been discovered. If its Semimajor axis is 24AU, what would its
orbital period be? (2 Marks – T/I)
Section IV – Short Answer (25 Marks)
1. Read the following article and then answer the questions that follow. (8 Marks)
Space radiation hits record high September 2009 - New Scientist (David Shiga)
Like a wounded Starship Enterprise, our solar system's natural shields are faltering, letting in a flood of cosmic rays.
The sun's recent listlessness is resulting in record-high radiation levels that pose a hazard to both human and robotic
space missions.
Galactic cosmic rays are speeding charged particles that include protons and heavier atomic nuclei. They come from
outside the solar system, though their exact sources are still being debated.
Earth dwellers are protected from cosmic rays by the planet's magnetic field and atmosphere. But outside Earth's
protective influence, cosmic rays can play havoc with spacecraft electronics – they may be responsible for some recent
computer glitches on NASA's Kepler spacecraft, which temporarily halted its planet-hunting observations. They can
also damage astronaut DNA, which can lead to cancer.
Now, the influx of galactic cosmic rays into our solar system has reached a record high. Measurements by NASA's
Advanced Composition Explorer (ACE) spacecraft indicate that cosmic rays are 19 per cent more abundant than any
previous level seen since space flight began a half century ago.
Solar minimum
"The space era has so far experienced a time of relatively low cosmic ray activity," says Richard Mewaldt of Caltech,
who is a member of the ACE team. "We may now be returning to levels typical of past centuries."
The sun's magnetic field normally blocks some of the cosmic rays, preventing them from entering the solar system. But
that protection has weakened of late. The solar wind, which helps project the sun's magnetic field out into space, has
dropped in pressure to a 50-year low. And the strength of the magnetic field in interplanetary space is down to just 4
nanoTesla, compared to the more typical 6 to 8 nanoTesla.
The recent weakening of the shield is due to cycles in solar activity. The sun is at a minimum in its 11-year cycle of
magnetic activity, and this particular dip is deeper than any other seen in nearly a century.
Extra shielding
That may be a sign that the unusually active sun of the past 100 years or so is returning to the historical norm of lower
activity, or even entering a so-called grand minimum of exceptionally low activity that could last centuries.
Scientists can infer variations in the sun's magnetic activity over the past 10,000 years from the abundance of rare
isotopes in Greenland ice cores.
If the increase in cosmic rays is here to stay, it could make long-duration human missions in space more challenging.
Astronauts aboard the International Space Station are still close enough to enjoy protection from Earth's magnetic field,
but any sent in future to the moon or beyond will be outside that field.
"The increase is significant, and it could mean we need to re-think how much radiation shielding astronauts take with
them on deep-space missions," Mewaldt says.
Down time
If there's a long-term increase, it might also make sense to design future robotic missions for extra robustness against
radiation, says Roger Hunter of NASA's Ames Research Center in Moffett Field, California, who manages NASA's
planet-hunting Kepler mission.
It is not clear whether Kepler's temporary computer glitches were due to cosmic-ray hits, he says. But the spacecraft is
designed to be able to recover from such events, going into a safe mode while mission controllers work to restore it to
normal operation, he adds.
"Our only concern is will we see more events as a result of the cosmic-ray increase," he says. Since its launch in
March, Kepler has lost 3.5 days of observing time due to glitches that put it into safe mode. However, the mission team
always planned for occasional days lost to glitches, and considers up to 12 lost days per year to be acceptable.
a. What is our solar systems’ natural defense shield and why is it faltering? (2 Marks
– C)
b. How has the space era (1950-Present) been somewhat lucky in terms of space
radiation? (2 Marks – C)
c. How will the current levels of solar activity affect future space missions? (2 Marks
– C)
d. What do you think needs to happen in order for future space missions to be both
effective and safe? (2 Marks – A)
2. In your own words, briefly explain how our solar system formed. In your answer, be sure to
indicate why the gas giants formed further away from the Sun than the terrestrial planets.
(3 Marks – 2K/1C)
3. Answer the following questions about Earth’s elliptical orbit. (4 Marks)
a. Using a simple diagram, explain the difference between the Earth’s aphelion and
perihelion (2 Marks – 1K/1C)
b. If the Earth’s eccentricity were to increase dramatically, how would this affect our
orbit? (2 Marks – 1K/1C)
4. Why is it hotter in July rather than in January in Toronto? In your answer, you may wish to
include a simple diagram. (2 Marks – T/I)
5. Briefly explain the formation of our Moon. (2 Marks – 1K/1C)
6. Based on your knowledge of planetary motion, predict how the average temperature of the
Earth would be different if Kepler’s second law was not true. (3 Marks – T/I)
7. Do you think that, despite the high cost, governments should continue to fund space
missions? Provide three reasons why they should or should not continue to do so. (3
Marks – A)