Astronomy Final Part 1

Astronomers have found that the level of the Sun's activity varies over the centuries. How did they come to realize that this is so?

All of the above.

If there are at least a million asteroids, how did spacecraft like Galileo survive their trip through the asteroid belt?

Although there are many asteroids, there is a lot of space between them.

Solar wind particles can be captured by the Earth's magnetosphere. When these particles spiral down along the magnetic field into the atmosphere, they are responsible for_______.

Aurorae (northern and southern lights).

Different asteroids reflect different percentages of the light falling on them. This is due to the fact that they have different_______.

Compositions.

The Sun's chromosphere and corona were discovered_____.

During total eclipses of the Sun.

The two asteroids from which close-up images and data have been returned by the Galileo spacecraft are____.

Gaspra and Ida.

The granulation pattern that astronomers have observed on the surface of the Sun tells us that____.

Hot material must be rising from the Sun's hotter interior.

The most common element in the Sun is_____.

Hydrogen.

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

Ice.

In the far future, an entrepreneur with a large fleet of space ships decides to capture and bring to Earth some valuable asteroids. If at that time there is a shortage of usable metals on Earth, what type of asteroids should his employees search for?

M asteroids.

Comets get significantly brighter in our skies as they approach the Sun because______.

More than one of the above.

Today we realize that the source of energy for the Sun is a process called______.

Nuclear fusion.

Where in the Sun does fusion of hydrogen occur?

Only in the core.

When two light elements undergo nuclear fusion, ____.

Some of the energy in their mass is released.

How do astronomers know how strong the magnetic field of the Sun is?

The measure the Zeeman effect (the splitting of spectral lines).

Which part of a comet is the DENSEST?

The nucleus.

In the formula E=mc2, the letter c stands for __.

The speed of light.

Sunspots are darker than the regions of the Sun around them because______.

They are cooler than the material around them (although still very hot compared to Earth temperatures).

Several hundred asteroids have been found in the same orbit around the Sun as the planet Jupiter, in two stable areas ahead of and behind Jupiter. These asteroid groups are called_____.

Trojan asteroids.

The process of fusion that keeps our Sun shining begins with which building blocks?

Two protons.