Astro 100 exam 2

The inner planets are made mostly of rocks and metal because :

It was so hot where the inner planets formed that the lighter materials evaporated

A planet in our solar system whose composition resembles that of our sun is

Jupiter

Which of the following in NOT a terrestrial planet ?

Jupiter

The environment depends on a delicate balance between __________ light coming in from the sun and _________ light escaping back into space ( select the answer that fills the Blanks above in the correct order

Visible ; infrared

Much of what we have learned about the jovian planets and their satellites has come from the work of two spacecrafts called:

Voyager

Which of the following statements about the tails of comets is FALSE?

a comet always has a nice long tail, even when it is far from the sun

The rings of the outer planets consists of:

Billions of chunks (of various sizes) that all orbit the equator of each planet

One piece of evidence that can help astronomers sort out how the planets in our solar system formed is

Finding circumstellar disks of material around nearby stars

The four large moons of Jupiter were first discovered by:

Galileo with his early telescope

The element that can act like a metal when it is under tremendous pressure and is probably responsible for Jupiter and Saturns magnetism is:

hydrogen

A main difference between asteroids and comets is that asteroids are mostly made of rock and comets are mostly made of

ice

The lakes found in the north polar region of Titan are filled with liquid:

methane

The upper clouds in the atmosphere of Neptune are composed of:

methane

Some objects in space just don't have what it takes to be a star. Which of the following is a "failed star", an object with too little mass to qualify as a star?

A brown dwarf

According to the fossil records, how old is the oldest evidence of life forms on the surface of the earth ?

About 3.5 billion years

Which of the following is a way we believe that the early atmosphere of the Earth differed from the atmosphere we have today?

All of these answers

A planet in the "habitable zone"

Is at a distance where liquid water can exist in the surface

The same gas makes up most of the atmosphere of Mars and Venus. This gas is:

Carbon dioxide

The average temperature on planet Earth is higher than you would expect just from the heating of sunlight alone. What is the explanation for this?

Carbon dioxide (and other gases) in the atmosphere cause a greenhouse effect

The main greenhouse gases in the atmospheres of the terrestrial planets are

Carbon dioxide and water vapor

Pluto's big satellite is called

Charon

The smaller objects in the solar system composed mainly of ices (frozen gases) that usually orbit far from the Sun are called:

Comets

The satellite whose surface is characterized by a smooth icy crust with a complex network of cracks is:

Europa

If you were to take a large sample of the four giant planets, the most common element you would find in them is :

Hydrogen

The world in the solar system that is the most active volcanically is:

Io

The spectroscopic radial velocity method preferentially detects

Large planets close to the central star

The jovian planets that has the longest year (period of revolution) is:

Neptune

The moon Titan orbits which of the planets?

Neptune

When a star or galaxy is moving away from us, we observe the Doppler effect by seeing the lines in its spectrum

Red-shifted (shifted toward the red end of the light spectrum)

Which of the following is NOT a method for detecting extrasolar planets

The Jovian method

Our Modern understanding of Pluto is that it is a member of :

The Kuiper Belt (of trans -Neptunian objects)

Which of these is NOT a result of Global Warming ?

The Ozone hole

Which is the following does the composition of a planet like Jupiter resemble:

The Sun

What planet can come closest to the Earth in its orbit and look brightest in our skies?

Venus

Why does Mars have an overall reddish color when we see it's surface from afar?

The material of Mars' surface contains a lot of iron oxide, the same chemistry that makes rusting metals look reddish

Our best evidence and theoretical calculations indicate that the solar system began with a giant spinning system of gas and dust that scientists call:

The solor nebula

What do astronomers think is the origin of the many irregular moons around the outer planets (irregular meaning they are orbiting backwards and /or have eccentric orbits)

These moons were likely formed elsewhere and captured by the giant planets

Which of the following characteristics do all four terrestrial planets have in common?

They all have solid surfaces with signs of geological activity on them

The satellite which has the thickest atmosphere (so thick that it's quite a surprise for a satellite )is:

Titan

The planet that orbits "on its side" ( ie. has it's rotation axis perpendicular to the plane of its orbit) is:

Uranus

If our estimates of the number of comets in every part of the solar system are correct, the total mass contained in comets must be:

about the mass of the earth

When the solar system was forming, the building blocks from which the protoplanets gathered together were the:

about the mass of the earth

All the planets (without exception)

revolve around the Sun in the same direction

Since angular momentum is conserved, an ice-skater who throws her arms out will

rotate more slowly