Module 3: The Solar System
Likely, when you were a child, you learned some little saying to help you remember the order of the planets from the innermost planet to the outermost planet. Probably one of the most common one was "My very elderly mother just saw us near Pluto". The first letter of each gives you the clue. Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and the now demoted Pluto which has been reclassified as a dwarf planet.
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CC3.1 Explain the origin and properties of the celestial bodies in our solar system
★ LO3.1.1 Describe each of the planets in the solar system
LO3.1.2 Distinguish between comets, asteroids, and meteors in the solar system
LO3.1.3 Describe the origins of the solar system
Read Chapter 15, Sections 1-2 of Physical Science, 13th edition by Bill Tillery McGraw Hill Education
NASA: About the Planets, Planet Sizes, Moons of Mars
Lowell Observatory: The Dwarf Planets of the Solar System
Let's begin by looking at the terrestrial planets: Mercury, Venus, and Mars. This page has several Sketchfab interactive models to explore. They may look small imbedded on the page, but if you load them up by clicking the play button, you can then expand them to full screen. This will let you move the model and explore annotations to learn more about the planet.
This is the smallest and closest planet to the sun. It has a "year" of 88 Earth days, but a very long single day - about 59 Earth days. The planet has two peculiar features: a magnetic field and a dark surface. The planet's surface is dark because the planet's surface is covered in graphite; which is an allotrope of carbon, and is commonly found in pencils. Because of the high carbon content, it is suspected that there may be a thick layer of diamonds (another allotrope of carbon) far below the planet's surface. The magnetic field suggests that the planet has a metallic core despite its small size and lack of volcanoes.
This is a 3D model that lets you rotate the view of the planet from any angle. Just click/hold and move the cursor.
Venus is the second planet from the sun, and is often referred to Earth's sister planet because it is also a terrestrial planet of similar size. This planet's atmosphere is 98% carbon dioxide and contains clouds of sulfuric acid; this is in contrast to Earth's atmosphere which is around 400 parts per million carbon dioxide and our clouds are made of water. This type of atmosphere has caused a runaway greenhouse effect that has made the planet's surface the hottest in our solar system (after the sun). Unlike Earth, Venus does not have a moon.
This is a 3D model that lets you rotate the view of the planet from any angle. Just click/hold and move the cursor.
Time: 15:57
ASL version of Venus May Have Life
Channel: PBS Space Time
The third terrestrial planet from the sun is our home planet, Earth, and it has one moon. It will be covered in more depth in the next module.
Now let's look at Mars, the fourth planet from the Sun. It is fairly small, and approximately twice the size and has twice the twice the gravitational strength of the Moon. Oxidized iron-rich basalt rock gives the planet its red color; however, blue rocks have recently been found on the planet's surface. It has two moons, Phobos and Deimos, that are so small that they don't have enough gravity to mold them into spheres like our Moon.
This is a 3D model that lets you rotate the view of the planet from any angle. Just click/hold and move the cursor.
Time: 12:26
ASL Version of A Natural History of Mars - What Happened to Mars?
Channel: PBS Eons
Study these images from the exploration of the four terrestrial planets of our solar system to learn more about them.
After the four terrestrial planets is the Asteroid Belt, which is home to a dwarf planet, and then there are four gas giant planets which we will look at next. These planets are different from the first four because they aren't made of rock, but instead gas. They are all interesting in their own right; however, in many ways their moons are just as interesting if not more so, because several of them could potentially support life. None of the gas giants can support life as we know it.
By far this is the largest planet in our solar system, and it is sometimes described as a failed star. If it were about 80 times more massive it would have been a star. Currently, it doesn't have enough mass to cause thermonuclear fusion of hydrogen in its core as stars do, but it does have enough gravity to have a core made of metallic hydrogen. Jupiter is known as the guardian of the inner solar system because its gravitational field protects Earth from comets and asteroids; its high gravitational field strength can either deflect comets and asteroids out of our solar system or pull them into the planet destroying them.
Currently, there are 95 known moons of Jupiter, and the four large ones were discovered by Galileo Galilei in 1610. These are called the Galilean moons: Io, Europa, Ganymede, and Callisto. There is some evidence that significant amounts of water maybe present on Europa, making this moon a good candidate to explore for possible life. Io is the most volcanically active world in our solar system. Ganymede is the largest moon in the solar system, and it is larger than Mercury and Pluto; additionally, it is the only moon in our solar system to have its own magnetic field.
This is a 3D model that lets you rotate the view of the planet from any angle. Just click/hold and move the cursor.
Time: 13:27
ASL version of Juno to Reveal Jupiter's Violent Past
Channel: PBS Space Time
Saturn is the sixth planet from the sun, and is most famous for its rings. Saturn is mostly made of hydrogen and helium giving the planet an average density less than that of water. The rings are made of billions of fragments ice, metal, and rock that were from comets, asteroids, or shattered moons that broke up before they reached the planet. These rings are at most 400 million years old, making them younger than life on Earth.
Saturn has more moons than any other planet in the solar system; currently, the planet has 274 known moons. Most notably are Titan and Enceladus. Titan is Saturn's largest moon, and it is bigger than Mercury. Titan is the only moon of Saturn with a substantial atmosphere, and the only place in the solar system other than Earth known to have water in the form of rivers, lakes, and seas on its surface; these factors make it a good candidate for life to exist. Enceladus is a small, icy world that has oceans of water beneath the surface and geyser-like jets eject water vapor and ice particles into space. Most of the ingredients for life similar to Earth have been found in these water jets.
This is a 3D model that lets you rotate the view of the planet from any angle. Just click/hold and move the cursor.
Uranus, pronounced "YOOR-un-us", is the seventh planet from the solar system. Although less visible, this planet has two sets of rings. Uranus is one of two ice giants in the outer solar system (the other is Neptune). Most (80% or more) of the planet's mass is made up of a hot dense fluid of "icy" materials – water, methane, and ammonia – above a small rocky core. Uranus gets its blue-green color from methane gas in the atmosphere. Sunlight passes through the atmosphere and is reflected back out by Uranus' cloud tops. Methane gas absorbs the red portion of the light, resulting in a blue-green color.
This is a 3D model that lets you rotate the view of the planet from any angle. Just click/hold and move the cursor.
Neptune is the eighth and last planet of our solar system, and the second ice giant. It is very similar to Uranus: it has rings, is made of dense fluid of "icy" materials – water, methane, and ammonia above a rocky core, and it has an atmosphere of hydrogen and helium with just a little bit of methane that give it its blue color.
This is a 3D model that lets you rotate the view of the planet from any angle. Just click/hold and move the cursor.
Study these images from the exploration of the four outer gas giants of our solar system to learn more about them.
Dwarf planets are relatively large objects that orbit the sun, but aren't quite planets because they don't have enough gravity to clear their orbit of other objects. Currently there are five known dwarf planets in our solar system. There is one in the Asteroid Belt - Ceres, and there are four in the Kuiper Belt: Pluto, Eris, Makemake, and Haumea.
This is probably the most famous dwarf planet, because it was reclassified as one in 2006. It has five moons, the largest of which, Charon, has about half the size and gravitational strength as Pluto.
This is a 3D model that lets you rotate the view of the planet from any angle. Just click/hold and move the cursor.
Study these images from the exploration of our solar system's dwarf planets to learn more about them.
Recall the planets of our solar system and what type of planet each one is.
Answer
M - Mercury (terrestrial)
V - Venus (terrestrial)
E - Earth (terrestrial)
M - Mars (terrestrial)
J - Jupiter (gas giant)
S - Saturn (gas giant)
U - Uranus (gas giant)
N - Neptune (gas giant)
Recall at least one notable property of each planet.
Answer
Some examples: