Astronomy Chapter 7

How many stars does the solar system contain? (Enter a number)

1

How many planets are in the solar system? (Enter a number)

8

How many dwarf planets are in the solar system? (Enter a number)

5

How many moons does the solar system contain? (Enter two words and a number)

More than 150

What are the big rocky objects found in our solar system?

Asteroids

What kind of dust/gas does the solar system contain?

Interplanetary dust/gas

What belt objects does the solar system contain?

Kuiper belt objects

What icy object does the solar system contain?

Comets

What objects of the solar system did we “know” in ancient times? (One has been deconfirmed!)

Sun, stars, Five planets, One moon, Meteors, Comets

What percentage of mass of the solar system does the Sun take up/contain?

99.8%

What two planets take up most of the remaining matter, and what percent of that remaining matter do they take up? (Write your answer as Planet, Planet, #%

Jupiter, Saturn, 90%

What percentage of mass remains for everything else after The Sun, Jupiter, and Saturn took up most of it?

0.02%

What defines a planet?

It orbits the Sun, is massive enough for its gravity to pull it into a spherical/ellipsoidal shape, and has cleared its orbit of debris.

What does a moon do that defines it as a moon?

It orbits a planet or other larger object

What are dwarf planets?

Objects that orbit the Sun and are spherical/ellipsoidal, but don’t meet all of the conditions required to make it a real planet.

What do Asteroids/Meteoroids/Comets/Kuiper belt objects do and are that classifies them as they are?

They orbit the Sun, but don’t qualify as dwarf planets nor real planets.

What are planets/moons named after? What is the exception?

They were named after gods and heroes from Greek and Roman mythology, with the exception of Uranus which was named after English literature.

What are comets named after?

The discoverer.

What decides the names of asteroids?

They are named by the discoverer?

How are features on other objects named?

By a naming convention set by the International Astronomical Union (IAU).

What are Terrestrial planets?

Planets that are Earthlike.

What are Jovian planets?

Planets that are Jupiterlike.

What are the size and mass of Terrestrial and Jovian and planets in comparison to each other?

Terrestrial planets are small in size and mass, while Jovian planets are larger in size and mass.

How do Terrestrial planets compare to Jovian planets in terms of their contents?

Terrestrial planets are rocky while Jovian planets are gaseous.

How do the surfaces of Terrestrial and Jovian planets compare?

Terrestrial planets have solid surfaces while Jovian planets don’t.

How do the densities of Terrestrial and Jovian planets compare to each other?

Terrestrial planets have high density while Jovian planets have low density.

How do the rotation speeds of Terrestrial and Jovian planets compare to each other?

Terrestrial planets have a slow rotation while Jovian planets have a fast rotation.

How do the magnetic fields of Terrestrial and Jovian planets compare to each other in terms of strength?

Terrestrial planets have weak magnetic fields while Jovian planets have strong magnetic fields.

How do the statistics in terms of rings and moons compare in terms of Terrestrial and Jovian planets? (Which type has what and how much?)

Terrestrial planets have no rings and few moons, while Jovian planets have rings and many moons.

How do Terrestrial and Jovian planets compare regarding their distance from the Sun?

Terrestrial planets are close to the Sun while Jovian planets are far away from the Sun.

What statistic or property determines which type of the two types of planets form?

Temperatures.

Why do Terrestrial planets only form when close to the Sun?

Because rocks and metals could only condense to form solids when close to the Sun due to them having higher temperatures when closer.

Why do Jovian planets only form when farther away from the Sun?

Because when further away from the Sun, ices could condense as well, which gives far more material for planets to form with, allowing larger planets to form.

What is differentiation?

The separation of materials by density.

How does differentiation apply to Earth’s layers? What are the layers in order from most to least dense? (On part 2, just list the layers with a comma between them.)

Differentiation separates Earth’s layers from each other. Metallic core, rocky mantle/crust, gaseous atmosphere

On what objects does geological activity occur?

Objects with hot interiors.

What do impacts do?

They change the surface appearance via heavy object collisions on that surface.

What are relative ages and how do they work?

Relative ages are the ages of solid objects in space based on their crater count; The more craters an object has, the older it is.

What are absolute ages, and what do they work for compared to Relative Dating?

Absolute ages are ages based on the radioactive materials within rocks. This works for all rocks, not just objects in space.

How are relative ages determined?

By counting the amount of craters on a planet or rocky surface.

What does the amount of craters on a surface mean?

How long it has been exposed.

What do geological and weathering effects do to craters?

They slowly wipe out the evidence of them.

What are Maria on the moon?

Dark regions of the moon that have fewer craters and thus a younger surface.

What are highlands on the moon?

Lighter regions on the moon that have more craters and thus an older surface.

How are absolute ages determined, and how does it work?

Get a sample of a rock from the surface being aged; All rocks have some radioactive minerals that decay over time. The relative concentrations of these tell us the age of that rock, which gives us the absolute age of the surface.

What is a half-life? (Not the game) How does it help us determine absolute age?

The amount of time required for 1/2 of the original (parent) atoms of the radioactive minerals to decay into the new (daughter) atoms. Comparing the ratio of parent to daughter atoms gives us the absolute age of the rock and the surface it came from.

Give an example of a half life. (The one from the slideshow. Remove the bullets and make it all into one sentence.)

Potassium-40 has a half-life of 1.3 billion years, so every 1.3 billion years, half of the Potassium-40 will have decayed into Argon-40.

How can we learn about the origins of the solar system? (First term on the PowerPoint)

By looking at the patterns in it that remain today.

How do the planets in orbit compare in terms of the plane(s) they orbit in? What does this mean?

They all orbit in approximately the same plane. This means that the solar system is flat.

How do the directions of the orbits of the planets around the Sun compare to each other?

They all orbit around the Sun in the same direction.

How do the directions of the rotations of the planets on their axes compare to each other?

They rotate on their axes in the same direction.

What are the two types of planets that the planets are separated by and categorized in?

Terrestrial and Jovian

How many objects of other sized bodies are there in the solar system besides the big ones? Give two examples with an etc, as shown in the PowerPoint.

There are many small bodies in the solar system - asteroids, comets, etc.

What did the solar system form from?

A large cloud of gas and dust (primarily hydrogen gas) that started collapsing about 5 billion years ago.

How does the rotation of the cloud relate to the rotations and orbits of the planets in our solar system?

Its rotation is reflected in the rotations and orbits of the planets in our solar system.

What would have happened with materials near the Sun, and why? (The “Why” should go first, think of the powerpoint)

The hotter temperatures near the Sun would have caused different types of materials to condense.

What are the small bodies in our solar system derived from?

The small bodies are the left over remnants of planetary formation.

What happens as the nebula cools/begins to cool?

As the nebula begins to cool, particles begin to coalesce into larger objects - grains of sand, pebbles, small rocks, larger rocks, etc.

What happens to the particles that coalesce during nebula cooling?

Eventually they become planetesimals, which are precursors to actual planets, that are no larger than 100 km in diameter. 

What happens to planetesimals over millions of years?

They slowly grow larger, eventually becoming the planets we see today.

What do planets do to debris as they form? What happens to the debris?

As planets form, they clear out the remaining debris, with some becoming part of the planet and others being ejected out into interstellar space.

What happens to the rest of the stray gas and dust when the Sun fully forms?

The solar wind and radiation pressure will clear out the remaining gas and dust.

What is solar wind?

An outflow of particles from the Sun.

What is radiation pressure?

The pressure provided from the light from the Sun.

• We now know of many planetary systems outside our own

  • Planetary systems are ______!

common

What do dusty disks around stars let us observe?

The process of planet formation.