Astrology Mid 2

What are Maria? I basaltic "seas" on the moon II old lunar mountains III a remnant of the Late Heavy Bombardment

I and III

Suppose scientists detected a massive planet in another star system 100 times the mass of Earth and 8 times its radius. What is it's composition ?

Icy volatile

What is the composition of the planet in the previous problem ?

Icy volatile

Which is a true statement about the asteroid Oumuamua

It can be interpreted as evidence that other planetary systems fling out material through gravity

Venus may have had oceans long ago. What happened to all that water?

It evaporated to the upper atmosphere where ultraviolet radiation broke the water molecule allowing the hydrogen atom to escape.

How can Mercury have ice?

It exists in deep craters near Mercury's poles

What does current evidence indicate about the Earth's magnetic field in the past?

It has undergone drastic changes and reversals

When scientists say that an element has a half-life of say 3 hours, this means that

It will take 12 hours for most of the element to decay such that only 1/16th of it remains

In what way is Mars similar to Earth?

Its length of day

What role does a planet's size play in its geological activity?

Larger planets are more geologically active �because they take longer to cool off

Which mission made a radar map of Venus?

Magellan

Which is the most likely moon formation scenario?

Object passed Earth and gravitationally pulled material from a molten Earth

The encephalization level is

The ratio of theorized brain size to actual brain size

Mars appears to have long branching channels that have the appearance of being formed by a flowing liquid. Yet we know that liquids would not stay liquid in the very thin atmosphere we have on the Martian surface? So how can we explain the channels?

Mars had a thicker atmosphere long ago when the channels formed

In 2013, a small stony asteroid collided with the Earth above the Russian city of Chelyabinsk. What were the results?

-Meteorite on the ground -shock waves that cracked windows and caused buiding damage -A fireball briefly brighter than the Sun could be seen in the sky

What is the density of a planet that has 1/10 the Earth's mass and 1/2 the radius?

.1/.5^3 *5.5 = 4.4

How is the planet Mercury similar to Earth's moon? I Both surfaces appear heavily cratered by impacts. II Weird Terrain is seen on the surfaces of both objects. III Their rotational periods are equal to their orbital periods.

1

Which real characteristic(s) of Mercury seems/seem unlikely given it's small size? I. a global magnetic field II. The existence of an exosphere III. Mercury's close proximity to the Sun IV. Evidence of Volcanic eruptions

1 and 4

At what size does a planetesimal start to have a sizable gravitational field that influences other objects?

10 kilometers

In general, how large is a crater in comparison to the impactor that created it?

10 times larger

Large quantities of new lava rock are emerging from the mantle to form new portions of the crust. Where does this occur? I along the tops of major continental mountain ranges II along the length of the submarine ridges in the middle of the major oceans III along the continental shelf adjacent to the continents

2

Suppose a future astronaut travels to a distance planet around a distant star. They collect rocks for dating the age of the planet and system. The astronaut compares the abundance of a certain radioactive element (half life of element = 500 million years) in the collected rocks to the abundance of the same element in a newly formed rock. They measure that there are 1/16th the number of radioactive atoms in the collected sample. How old is this planet?

2 billion -- 500 million *4

What is the density of a planet that has 1/45th the Earth's mass and 1/3rd the radius?

3.3

What is a possible theory as to why Venus doesn't have a magnetic field? I It is too small and the planet quickly cooled after formation II The dense atmosphere cancels out the magnetic field III Venus rotates backwards thus the liquid interior can't induce a magnetic field. IV The interior solidified after a global volcanic event long ago

4

What is the density of a planet with a volume 12 times the volume of Earth and 5 times the mass of Earth?

5/12 *5.5 =2.23

What is the density of a planet that has 5 times the mass of the Earth and 3 times the radius as Earth?

5/3^3 *5.5 = 1g/cc

How many times larger is the volume of a planet in comparison to Earth's volume if it has radius 6 times larger than Earth's radius?

6^3 =216

According to the video "The whole saga of the supercontinents" embedded in your readings, What is the future of Earth continents?

Australia will move north, The mediterranean ocean will disappear, South America will move west

According to the video "The whole saga of the supercontinents" embedded in your readings, approximately how many supercontinents were there prior to Pangea?

Between 5-8

Which are greenhouse gases?

CO2 (carbon dioxide), H2O (water), Methane

What causes a runaway greenhouse effect?

The surface temperature of a planet with an atmosphere is at least the boiling point of water

What is true about mass extinction events in Earth's history?

There have been several mass extinctions in Earth's history

How have astronomers learned what composes different asteroids?

They examine the spectrum of the sunlight that reflects from the asteroid

Venus doesn't have global plate tectonics like Earth. Which statement below points to this conclusion?

Venus lacks plate boundaries

Given what we know about the planets in our own solar system, what could we assume about this distant planet from the previous problem?

it's day is much less than 24 hours, has many moons

In general, the further planets are from the Sun, the cooler they are. What other factor can have a significant influence on a planet's surface temperature?

its atmosphere (whether it has one and how thick it is)

Most of Venus' surface can be described as... jungles

lowland lava plains

Why do you think astronomers know more about the solar system in the last 40 years than all of history before then?

many spacecraft have been sent to gather information about the solar system in the last 40 years

Which of the following observations led astronomers in the early 1900's to suspect that there might be life on Mars?

seasonal variations in dark surface markings

Why are there so few smaller craters on Venus?

smaller objects are most likely destroyed by the atmosphere before they reach the ground

Which property of the solar nebula cloud was responsible for creating the observed composition? Another way to think about this is: Why are all the terrestrial worlds near the sun and the gas giants located far from the sun?

temperature

The fact that densest materials are in the center of terrestrial planets and not evenly distributed throughout the planets leads scientists to conclude that

terrestrial planets must once have been hot enough to be molten (like a liquid)

What kind of surface features may result from tectonics?

vocanoes, mountains, rift valleys, cliffs

Even though we don't exactly know how the Moon formed, the best theory of the Moon's origin based on the data is:

A giant Mars sized object pulling Earth's mantle off from a distance forming the moon

When the Earth passes through a cometary dust tail we would expect...

A meteor shower

Walter and Luiz Alvarez...

Discovered a connection between a mass extinction in Earth's history and an impact event that covered much of the Earth

Schiaparelli

Drew detailed maps of Mars' surface

Which of the following is most likely the cause of the formation of Valles Marineris?

Early tectonics

Which statement is not true about Mars?

Mars used to have an atmosphere with a composition and density similar to Earth's present atmosphere

Which is a true statement about the Viking experiments looking for life on Mars?

Microbial life was never found, One experiment strongly reacted to the topsoil

How do we know the Earth has a liquid outer core?

S waves from earthquakes disappear when travelling through the outer core.

Given the following choices, which object has a composition most similar to the Sun?

Saturn

Suppose we could stand on Mercury and not move from our position.Initially we are facing the sun and it is noon. Mercury now moves through 1 1/2 (1.5) orbits around the sun. What is the time of day for us on Mercury?Have we experienced a full day on Mercury (as defined as the time it takes to get from noon to noon the next day)?

Sunrise, no

What happens when two continental plates of different densities collide?

The denser plate slips under the less dense plate, creating mountain ranges

NASA's Spaceguard Survey concluded that astronomers had now identified 90% of the asteroids with diameters greater than 1 km. How could astronomers know that they had reached this goal?

The people doing the survey began to find the same objects over again, indicating they were reaching the limits of their survey

Which statement is true about how astronomers measure the size or volume of planets?

We can never know the true size of a planet if the distance to the planet is unknown

How is it that we know so much about the composition dwarf planet Vesta and little about Ceres, the other dwarf planet in the asteroid belt?

bits of Vesta have landed on Earth

Which was not accomplished by the Apollo missions?

detected water under the surface

Check all that apply: Mars has...

frozen water, atmosphere, moon(s), weather, evidence of floods

What is the only ongoing geological process on the Moon today?

impacts by micrometeroids and very occasionally larger meteoroids

The rate at which radioactive atoms in a rock decay depends upon...

internal processes within the atoms

In studying the surfaces of terrestrial bodies in the solar system, astronomers have learned that the number and size of craters (per unit area):

is roughly proportional to the age of the surface we are examining

From Einstein's point of view, what does mass do to space?

it creates new paths

Which of the following ways that jovian (gas giant) planets differ from the terrestrial planets is NOT CORRECT?

jovians rotate significantly more slowly than terrestrials

What is true about craters?

older surfaces have a much larger number of both big and small craters than newer surfaces

The material that would eventually make all the major bodies in our solar system first gathered together as smaller pieces which astronomers call:

planetesimals

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

Mars rovers (such as Opportunity and Curiosity) have identified evidence that their landing sites were once under water. Which of the following is among the kinds of evidence they have identified?

they found rock formations that show the area was under water and also minerals that only form in water