astro 1 exam 2

If no one has ever visited the core of the Earth, how do we know that it is made of metals?

circulating liquid metals in the core set up a large (measurable) magnetic field

Which of the following is NOT a correct statement about the rotation of Venus?

Venus rotates in roughly the same time period as Earth

Which of the following statements about the seasons on Jupiter is correct? Jupiter has seasons pretty much like the Earth; its axis has the same tilt, and each season is about the same length Jupiter has the same axis tilt as the Earth, but each season on Jupiter is much longer Jupiter's axis is tilted much more than the Earth's so its seasons are much more intense Jupiter's axis is hardly tilted so it has no real seasonal variations Jupiter's orbit brings it much closer to the Sun in summer and much farther from the Sun in winter

Jupiter's axis is hardly tilted so it has no real seasonal variations

The gas giants are

Jupiter, Saturn, Uranus, Neptune

Which of these stars would have the biggest redshift?

a star moving at high speed away from you

Which of these objects would emit an absorption spectrum?

a thin, cool gas cloud that lies in front of a hotter blackbody

During the process of differentiation,

heavier materials sink to the centers of molten planets

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

hydrogen

Which of the following characteristics distinguishes Uranus from every other planet in our solar system? it has more than one moon its atmosphere is made of gases it rotates on an axis tilted almost 90 degrees to the circle of its orbit its orbit is significantly tilted relative to the orbits of the other planets its magnetic axis does not lie in the same direction as its rotation axis

it rotates on an axis tilted almost 90 degrees to the circle of its orbit

Which of the following points about our planet's atmosphere is FALSE? 1. it is slowly leaking atoms into space from its outermost regions 2. its mass is a substantial part of the mass of the Earth 3. warm air rises and cool air descends within it, setting up circulating currents` 4. it is made mostly of nitrogen 5.one of its layers helps keep much of the ultraviolet radiation from space from reaching the surface

its mass is a substantial part of the mass of the Earth

The Moon is heavily cratered, but the Earth which "lives next door" is NOT. Why?

the active geology and weather on Earth destroy traces of impacts over millions of years

For scientists, one bar is

the pressure with which 1 square centimeter of the Earth's atmosphere presses down at the surface

The process by which Venus became so much hotter than the Earth is called:

the runaway greenhouse effect

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 solar nebula

At the moment when the Voyager spacecraft got closest to Uranus, the Sun was shining directly on the planet's south pole. Uranus takes about 17 hours to rotate once on its axis. If Voyager took a photo of the south pole 8.5 hours later, what would it observe?

the south pole was brightly lit, with the Sun shining down on it

Which of the following is NOT a way that Venus resembles the Earth? its size (diameter) its overall density the surface gravity (which tells us how much we would weigh there) the thickness and pressure of its atmosphere you can't fool me; Venus resembles Earth in all of the above ways

the thickness and pressure of its atmosphere

The rate at which a collection of the same radioactive atoms will decay depends on:

only on internal processes within the atoms; nothing external matters

These days the theory of the Earth's Moon's origin that best fits with the facts we have about the Moon is:

a large object hit the Earth and the collision produced a filament of material that condensed to make the Moon

A spot where magma rises to the surface can be seen as a

volcano

The color of visible light is determined by its

wavelength

You are using a radioactive isotope to measure the age of a rock in your lab. The half-life of the isotope is 300 million years and the ratio of parent to daughter particles is 1/4. How old is the rock?

600 million years

What makes astronomers believe that Mars once had rivers and running water?

Images from orbiting spacecraft reveal ancient channels that look like dried-up river beds on Earth

If the Sun instantaneously stopped giving off light, what would happen on the day-side of Earth?

It would get dark 8.3 minutes later.

Why does Mars have an overall reddish color when we see its surface from afar?

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

Which of the following photons carries the smallest amount of energy?

a microwave photon, whose wavelength is 10-2 m

A spaceship is traveling toward Earth while giving off a constant radio signal with a wavelength of 1 meter (m). What will the signal look like to people on Earth?

a signal with a wavelength less than 1 m

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

carbon dioxide

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

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

How do astronomers learn what elements are present in a given star?

look at the absorption lines in its spectrum

As a blackbody's temperature increases, it also becomes _________ and _________.

more luminous; bluer

A crucial difference that helps explain why Venus is so hot and the Earth isn't is that:

on Venus, there was eventually no ocean to remove carbon dioxide from the atmosphere

The Doppler shift can be used to determine the _________ of an object.

radial velocity

All of the inner planets are

rocky

In 1980, scientists suggested that the great mass extinction of 65 million years ago (which ended the reign of dinosaurs) may have been caused by a large impact from space. What discovery gives a big boost to this idea?

the discovery of a buried crater (about 200 km across) near Chicxulub, Mexico

the composition of a planet like Jupiter resemble:

the sun

Jupiter has enough mass to make 318 Earths. In contrast, Uranus and Neptune have only enough mass to make

15 Earths

Compare two blackbody objects, one at 200 K and one at 400 K. How much larger is the flux from the 400 K object compared to the flux from the 200 K object?

16 times larger

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

3.5 billion years

Which lists the terrestrial planets in the correct order?

Mercury, Venus, Earth, Mars

Which of the following statements about NEO's (Near Earth Objects) is TRUE? we have identified just about all NEO's with diameters greater than 1 km no NEO has passed closer to the Earth than the orbit of the Moon it is unlikely that any NEO's have hit the Earth during our planet's history NEO's can include both asteroids and comets that cross the Earth's orbit we are not able to obtain information about the shape or size of any of the NEO's at present

NEO's can include both asteroids and comets that cross the Earth's orbit

The largest volcano on Mars is called:

Olympus Mons (Mt. Olympus)

Consider an incandescent lightbulb. If you wanted to turn a 10-W lightbulb into a 100-W lightbulb, how would you change the temperature of the filament inside the bulb?

Raise its temperature by a factor of 1.8.

How do the wavelength and frequency of red light compare to the wavelength and frequency of blue light?

Red light has a longer wavelength and lower frequency than blue light.

Why do some stars in the sky appear blue, whereas other stars appear red?

The blue stars have higher surface temperatures than the red stars.

If the wavelength of a beam of light were to double, how would that affect its frequency?

The frequency would be two times lower.

The fact that each type of atom has a unique pattern of electron orbits helps explain why

each type of atom shows different absorption or emission spectra

If you observe an isolated hot cloud of gas, you will see

an emission spectrum.

The Kelvin temperature scale is used in astronomy because

at 0 K an object has absolutely zero energy.

Why are almost all the craters we see on the Moon circular?

because the rocks and icebergs that hit the Moon are moving so fast, they explode on impact, making a circular hole

Where is the asteroid belt located?

between Mars and Jupiter

Light has aspects of

both a particle and a wave.

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

small body in the solar system that is made of rock, ice and dust and has a tail when it gets close to the sun is ________________.

comet

Which part of the Earth has the greatest density?

core

As wavelength increases, the energy of a photon _________ and its frequency _________.

decreases; decreases

Which of the following statements about the Earth's magnetosphere is FALSE? it contains particles that come mainly from the solar wind it is generated by circulating liquid metal inside the Earth's core it was first detected in space by the Explorer 1 satellite it extends into space over a region much bigger than the diameter of the Earth its shape and size are the same on the sides facing toward and away from the Sun

its shape and size are the same on the sides facing toward and away from the Sun

Which of the following statements about Valles Marineris, the great "grand canyon system" on Mars is true? it is much shorter than the Grand Canyon in Arizona, but much much wider it was discovered by Giovanni Schiaparelli in the 19th century it was hard to photograph because it is always covered by wind-blown dust landslides have helped broaden the canyons since they were first formed although the canyons are long and wide, they are very shallow, only a few feet deep

landslides have helped broaden the canyons since they were first formed

What have astronomers and geologists studied to arrive at the same conclusions about Earth's origins?

meteorites

Individual "particles" of light are called

photons

I want to examine the surface of a planet which is completely covered by a thick layer of clouds all the time. What wavelength of electromagnetic radiation would I be smartest to use: visible light x-rays radio waves (like radar) any of the above would work none would work

radio waves

How fast do electro-magnetic waves travel?

speed of light

The ground state in an atom is

the electron orbit with the lowest possible amount of energy

One way in which Mars closely resembles the Earth is:

the length of its day (period of rotation)

One reason that we have such a complex system of belts/zones/storms in Jupiter's atmosphere is that:

the planet rotates very rapidly

Which of these did the June 1908 impact event in Siberia and the 2013 event in the Russian city of Chelyabinsk have in common?

they both exploded high in the atmosphere and produced a shock wave that reached the ground

The inner planets are rocky, relatively closely spaced and dense. True False

true

Which planet could be considered Earth's twin because of its similar size and mass?

venus