Astronomy test 4

We receive a radio message from a civilization around a star about 40 lightyears from Earth? If we reply right away, how long will it be between the time THEY sent the message and the time they receive our reply?

80 years

According to our textbook, roughly what percent of the mass and energy contents of the universe is made up of dark matter plus dark energy?

95 percent

Astronomers today know a lot about the size and shape of the Milky Way Galaxy. Which of the following common objects most resembles the shape of our Galaxy?

A cD or DVD

What does the Fermi Paradox say?

Given all the time since the Big Bang and all the stars, why has some form of intelligent life in the Galaxy not established a network throughout the Galaxy and visited us?

The astronomer who assisted Edwin Hubble at the Mount Wilson Observatory and helped him establish the expansion of the universe was:

Milton Humason

Your weird cousin, who is really into astronomy, decides that the return address he uses on his letters is incomplete! To his city, state, and country, he begins to add: "North America, Earth, Solar System..." If he now wants to include the name of the Galaxy's spiral-structure feature in which the Earth is located, how should his address end?

Orion Spur

Photosynthesis releases a particular gas as a byproduct. This gas is:

Oxygen

The two scientists who first discovered the cosmic microwave background radiation were:

Penzias and Wilson

The very strong source of radio waves at the center of our Galaxy is called

Sagittarius A

Compared to the mass of the Milky Way Galaxy, the mass of the Andromeda Galaxy is

Somewhat bigger

Edwin Hubble was able to show that (with the exception of our nearest neighbors) the farther a galaxy is from us, the

The father it is moving away from us

Edwin Hubble developed a classification scheme for galaxies. By what characteristic did he classify galaxies?

Their shape

The Andromeda Galaxy (our nearest spiral neighbor) has spectral lines that show a blue shift. From this we may conclude that:

This particular nerdy Galaxy is moving toward us

The central region of our Galaxy is not as flat as its main disk of stars. Which of the following has roughly the same shape as our central region of stars?

a peanut

Factoring in everything we currently know about the history of the universe, our best estimate for the age of the universe is

about 13.8 billion years

In our modern view of the expansion of the universe, we understand that it is space that is stretching; individual galaxies don't speed away from each other as if they were rockets. In that case, why do galaxies show a red-shift?

as space stretches, the waves of radiation in space also stretch and their wavelength increases

Scientists are impressed with extremophiles, life forms that can survive under what seems to humans to be extremely unpleasant conditions. In which of the following environments have we not found life:

conditions resembling the photosphere of the Sun

What method would astronomers use to find the distance to a galaxy so far away that individual stars are impossible to make out (resolve)?

finding the redshift and using Hubble's Law

Which of the following is the Earth not located

globular cluster M-13

Scientists looking at an overview of physics today understand that there are four forces that govern all action in the universe. These four forces are the strong nuclear force, the weak nuclear force, electro-magnetism and

gravity

Where would you look for the youngest stars in the Milky Way Galaxy?

in the disk

According to astronomers, which of the following places in the outer parts of our solar system might be a reasonable place for life to exist?

on the surface of some of the smaller members of the Kuiper belt

Our Milky Way Galaxy is what type of galaxy?

spiral

The type of galaxy that sometimes has a distinct bar of stars running across the central region is

spiral

Which of the following is pretty good evidence that the universe began with a Big Bang?

the 3-degree cosmic microwave background radiation

After the Big Bang, in order for the universe to become transparent to light and other electro-magnetic radiation, what had to happen?

the density of the universe had to decrease (to 1000 nuclei per cubic centimeter or less)

The Drake Equation allows astronomers to estimate

the number of civilizations out among the stars with which we might communicate

Which of the following objects is considered useful to astronomers as a "standard bulb" for determining distances?

type Ia supernovae

For the complex biochemical reactions of life (as we know it) to happen, a solvent is required. What is that solvent for life on Earth?

water

From a scientific perspective, which of the following statements about life elsewhere in the universe is best supported by current evidence?

while we have evidence of the building blocks of life elsewhere in the universe, we have no definite evidence about life around other stars at this time