Download The Planets

The Planets
Part A: In your Space Journal answer the following questions:
1. Compare and Contrast the geocentric and heliocentric models.
2. What evidence supports the heliocentric model over the geocentric model?
1. The geocentric model came before the heliocentric model, but the heliocentric model
ended up being the simpler, more accurate model of the two. The geocentric model was
a model that was Earth-centered. It was developed first by Aristotle, and was very
complex as well as contained some flaws. For example, one of the problems was
explaining why Mars, Jupiter, and Saturn seemed to occasionally reverse their direction
of orbit. An even more complex arrangement resulted in order to solve this; however, the
whole system seemed to make sense despite the complications. Models could be built
based on the geocentric model that could show things such as phases of the Moon,
when Mars would pass Jupiter, etc. However, the system we currently use is the suncentered model called the heliocentric model. It is a far more simple model where the
Earth rotated while travelling westward around the Sun. The heliocentric model also
included the solar plane- a non-existent flat disk stretching out from all sides of the Sun’s
equator on which the orbits were arranged. The planets orbited the Sun on this solar
plane. This composition helped to explain the retrograde motion of some of the planets,
and was much easier to understand compared to the geocentric model as well.
2. The heliocentric model is the model we use today for many reasons. One of the main
reasons is that it is far less complex than the geocentric model, making it easier to
understand. For example, the geocentric model was complicated enough before the
retrograde motion problem was solved. However, after epicycles were introduced in
order to solve the retrograde confusion, the geocentric model became even more
complex. It was so complex that it became hard to make sense of it, although it did make
sense despite the complexity. However, the heliocentric model wasn’t only simpler but it
explained the retrograde motion in a better way as well. For example, when all of the
planets can be seen orbiting around the Sun, it is easy to see what is happening when
retrograde motion occurs because we get a different perspective. But when everything
revolves around the Earth, the retrograde motion will look almost the same as it does
from our point of view. Another thing that supports the heliocentric model over the
geocentric is the fact that in the geocentric model cannot show things such as moons
orbiting around their planets. If moons orbited around planets like Jupiter, this meant that
everything did not orbit the Earth. This is another flaw of the geocentric that proves how
the heliocentric model is much more efficient and accurate than the geocentric model.
Part B: Create a chart in your Space Journal to record 5 significant features for each of the
planets.
Mercury
-closest planet to the
Sun
-rocky/terrestrial
planet
-no rings
-no moons
-only a little larger
than Earth’s moon
Jupiter
Venus
-only a little smaller
than Earth
-second closest
planet to the Sun
-rocky/terrestrial
planet
-no moons
-no rings
Saturn
Earth
-third planet from the
Sun
-rocky/terrestrial
planet
-ocean planet: 70% of
the surface is oceans
-no rings
-one moon
Uranus
Mars
-rocky/terrestrial planet
- thin atmosphere mainly
made of carbon dioxide,
nitrogen, and argon
-two moons: Phobos and
Deimos
-no rings
-currently cannot support
life as we know it
Neptune
Pluto (Dwarf
Planets)
-fifth planet from
-sixth planet from -seventh planet
-eighth planet
-solid, rocky
the Sun
the Sun
from the Sun
from the Sun
and/or icy bodies
-one day on
-gas-giant planet
-one day on
-one day on
-most dwarf
Jupiter=10 hours
-53 known moons Uranus= 17 hours Neptune= 16
planets have
-faint ring system -seven rings
-gas giant
hours
moons
-currently cannot
-atmosphere
-atmosphere
-gas giant
-cannot support
support life as we made up of
made up of
-13 moons
life as we know it
know it
mostly hydrogen
mostly hydrogen, -six rings
-no known rings
-gas-giant planet
and helium
helium, and a bit
-days and years
-50 known
of methane
vary on dwarf
moons
-27 moons
planets
Then use the site to help you answer the following 6 questions in your Space Journal:
1. Which planets are most unlike Earth? Why?
2. Which planets are most similar to Earth? Why?
3. Why does Venus have a higher surface temperature than Mercury?
4. Venus is considered Earth's twin, yet we would probably not survive on Venus. Why? Explain
using specific data gathered from the site.
5. If a planet were discovered beyond Pluto, speculate about what features it might have.
Include at least 5 features.
6. What is your favorite planet? Use 5 reasons/facts to support your answer.
7. Explain the differences between planets, moons, comets and asteroids. A chart may work
best for this.
1. The gas giant planets are the most unlike Earth. This includes Jupiter, Saturn, Uranus
and Neptune. They are the most unlike Earth because they do not have a solid surface,
while Earth is a rocky/terrestrial planet with mountains, valleys, canyons, etc. Also, none
of the gas giant planets can support life as we know it (although the same thing goes for
all of the other planets). Another fact is that they all have at least 10 moons, while Earth
only has one (Saturn has 53 known moons). Saturn is also very much unlike earth
because it has seven rings, while Earth has none. They all take a different amount of
time to rotate once in comparison to Earth as well. In terms of comparison to Earth,
Jupiter, Saturn, Uranus, and Neptune are also much larger in size.
2. Venus and Mars are most similar to Earth. This is partly because Venus and Earth are
very similar in size; however, Mars is only around half the size. All three of these planets
are rocky/terrestrial planets, which is something that they all have in common. It has also
been taken into consideration that Mars was possibly once able to support life in the
past, and may have the potential for it as well; this has not happened with any other
planet, other than Earth, which can currently support life. Another similarity between
Mars and Earth is the day length. While Earth’s days last for 24 hours, Mars’ days last
for about only a little over 24 hours. Venus, on the other hand, does not share this
similarity. However a similarity that all three planets share is their material makeup, they
are all made up of similar elements.
3. Venus has a higher surface temperature than Mercury because Venus is covered by a
thick, quickly spinning atmosphere which creates extremely hot temperatures and also
traps the Sun’s heat. No very much water has been detected in Venus’ atmosphere.
Mercury has no atmosphere at all to retain heat, so at night, the temperature can drop.
4. We would almost surely not survive on Venus, firstly, because of the scorching
temperature. As described in Q#3, Venus’ atmosphere causes the temperatures to rise
to even higher than 470 degrees Celsius. The probes that have landed on Venus never
lasted more than 2 hours against the heat. Also, Venus’ clouds drip with sulfuric acid,
and it does not seem likely that any human being would survive that.
5. It would probably be generally similar to most of the planets in terms of life, meaning that
it would most likely not be able to support life as we know it. I think it would be a gas
giant or a terrestrial planet, but not a dwarf planet because many dwarf planets have
already been taken account for. I also believe that it would have quite a few moons
because many of the planets have a lot of moons, although some do not have any at all.
I’m not completely sure as to what else it may be like, but I assume if there was a planet
discovered beyond Pluto, it would be generally cold. I would assume this because any
planet that far away from the sun cannot be very heated (does not receive much heat
from the sun), even with a thick atmosphere to contain the heat. I also think that this
planet would be found in the Kuiper Belt, because that is where Pluto is situated; if this
planet was discovered just beyond Pluto, it would probably be located in the Kuiper Belt.
6. My favorite planet is Saturn. The main reason I’m so interested in this planet is because
of the rings system; Saturn has a complex ring system that contains seven rings. Also,
Saturn has 53 moons and even more to be discovered. I just find it fascinating how our
one moon is so bright and seems so spectacular, but on Saturn where there are 53
known moons, it must look really amazing. Another thing I like about Saturn is how large
it is compared to the Earth. Earth alone already seems so large, but with how large
Saturn is, Earth seems tiny. One more thing that interests me about Saturn does not
have a solid surface, it seems like a giant solid sphere from the pictures, but it is actually
made of gases. Another reason that my favorite planet is Saturn is the fact that it takes
10.7 hours to make a full rotation. Despite the fact that days would be less than half the
time they are on Earth, I think it would be nice to see so many sunrises/sunsets in such
a short period of time (if I were on the planet itself). The last reason that Saturn interests
me so much is that it takes 29 Earth years in order to make a complete orbit. I don’t think
it would be very entertaining to endure a year that actually lasted 29 years; however, I
still find it interesting.
7.
Planets
-orbit around the
sun
-has enough mass
to take a roughly
round shape
-not a satellite/moon
-has cleared the
neighborhood
around its orbit
Moons
-orbit around
planets
-no rings
-come in many
shapes, sizes, and
types
-cannot support life
as we know it
Comets
-cosmic balls of
frozen gases, rock,
and dust
-no rings
-no moons
-short-period
comets are found in
the ‘Kuiper Belt’
-long-period comets
are found in the
‘Oort Cloud’
Asteroids
-orbit around the
sun (mostly)
-orbit on the
‘Asteroid Belt’
-solid, rocky,
irregular bodies
-no rings
-cannot support life
as we know it