MIDTERM 3

In the far future, a visiting tourist from another planetary system asks to see the most massive object in our solar system. Where would you take him/her/it?

the Sun

Physicists Kelvin and Helmholtz in the last century proposed that the source of the Sun's energy could be:

a slow contraction

Which of the following places is most likely NOT to be differentiated?

a small asteroid

What relatively recent event shows that impacts continue to happen in our solar system even today?

a comet (which broke into more than 20 pieces) hit the planet Jupiter in 1994

Which of the following particles has the lowest mass?

a neutrino

The Van Allen belt is

a region of trapped charged particles in the Earth's magnetosphere

In radioactive dating, the measure scientists use to note how long (on average) a particular radioactive nucleus will take to decay is called its

half-life

During the process of differentiation,

heavier materials sink to the centers of molten planets

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

jovians (being larger) rotate significantly more slowly than terrestrials

In a bad late-night science fiction film, a villain is using a large collection of rare radioactive atoms as energy for a weapon to threaten the good guys. The atoms have a half-life of 1 hour. The villain has 4 kilograms of the radioactive material now, and he needs a minimum of 1 kg. for his weapon to work. After how much time will the weapon

just a little after 2 hrs

An important way that scientists have been able to study the interior of the Earth is by:

measuring how seismic waves are transmitted through the Earth

When we use the light of atoms such as hydrogen and calcium to examine the Sun's outer layers, we can see bright "clouds" in the chromosphere right around the location of sunspots. These bright clouds are given the name:

plages

the antimatter version of an electron is called a

positron

Rocks that have not been chemically modified by being significantly heated are called

primitive

All the planets (without exception)

revolve around the Sun in the same direction

Regions where the continents or the sea floor are pulling apart are called

rift zones

One way to find a new meteorite is to:

search the area beneath or close to the point where a bright fireball was seen to burn out

According to the theory of plate tectonics,

slow motions within the mantle of the Earth move large sections of the crust around

The Sun's chromosphere contains many jet-like projections that stick up into the transition region. These spikes of gas are called:

spicules

Which of the following is a way for astronomers to learn more about the interior of the Sun?

study the oscillations (pulsations) of the Sun's surface

In the four terrestrial planets, the densest, heaviest materials are at the center and not evenly distributed throughout the planet. Scientists interpret this observation to mean that:

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

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

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)

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

A key difference between the protoplanets that formed in the outer solar system and those that formed in the inner solar system was that

those in the outer solar system included far more metal and rock, and thus the outer planets could be denser

What mechanisms do astronomers believe is responsible for making the Sun's outer atmosphere so much hotter than its photosphere?

the Sun's magnetic field interacting with the charged particles that make up the atmosphere

Which of the following is NOT evidence that objects from space collide with the Earth?

the crater at the top of the Mount St. Helens volcano

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

Scientists now understand that the Earth consists of layers, with the densest materials in the core. What allowed the differentiation of the Earth's layers to happen?

the early Earth must have been so hot it was like a liquid and heavier things sank to the middle

Mountains on Earth often have sharp peaks and edges to them, while mountains on the Moon look smooth and kind of dull in comparison. What gives the Earth's mountains their dramatically sharp shapes?

water and ice flow over the Earth's mountains and erode them

Which of the following statements about antimatter is true ?

when a particle of matter and the corresponding particle of antimatter meet, they become pure energy

Which planet in the solar system has not been examined by spacecraft instruments that have either flown by or orbited them?

you can't fool me, spacecraft have visited all the planets in our solar system

When a chunk of cosmic material the size of a golf ball or a baseball hits the Earth's atmosphere it makes a

fireball

The type of rock we find predominant in the crust of the Earth's continents is called:

granite

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)

In the Sun, when a positron and an electron collide, they will produce:

energy in the form of a gamma ray

The person who came up with the continental drift theory that led to our modern understanding of plate tectonics was

Alfred Wegener

What is the best reason astronomers have come up with to explain why sunspots are cooler and look darker?

Sunspots are places where the strong magnetic fields in the Sun resist the upward motion of bubbling hot gases from underneath

Which statement about the Sun's rotation is TRUE?

The Sun rotates at different rates at different latitudes on the Sun

How can astronomers measure the age of a meteorite that fell from the skies?

They measure the amount still left of radioactive materials in the meteorite, and how much has turned into decay products

When did scientist begin to understand how the Sun produces all the energy that it does?

The process was not well understood until the 1930's

One way in which the ozone layer is useful for life forms on the Earth's surface is that it

absorbs ultra-violet light, preventing much of it from reaching the surface

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

all the options

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

comets

Which part of the Earth has the greatest density?

core

The ten million tons of particles that escape the Sun each year in the form of the solar wind get out mainly through regions called

coronal holes

Any rock in the Earth's crust that has cooled from an originally molten state is called

igneous

As astronomers have learned more about the structure of the Sun, they have found that it

is made entirely of hot gas

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

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

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

Which of the following points about our planet's atmosphere is FALSE?

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

Which of the following statements about the Earth's magnetosphere is FALSE?

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

Chunks of solid material that survive passing through the Earth's atmosphere and are found on the Earth's surface are called

meteorites

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

nuclear fusion

The Sun is an enormous ball of gas. Left to itself, a ball of so many atoms should collapse under its own tremendous gravity. Why is our Sun not collapsing?

nuclear fusion in the core keeps the temperature and the pressure inside the Sun at a high enough level so that gravity is balanced

A future interplanetary tourist whose parents kept him too warm as a baby asks for your help to find a "really cold place" in the solar system. Which of the following would be the coldest place to take him?

the moons of Neptune

A college friend of yours who has been postponing taking any science courses hears you talking about the generation of nuclear energy in the Sun and makes the following observation: "The whole idea of the atomic nucleus is pretty ridiculous. If an oxygen nucleus consists of eight protons and eight neutrons, the charge on that nucleus is positive. Since even I learned in high school that like charges repel, such a nucleus would find all its positive protons repelling and quickly fall apart." How would you answer his argument?

the nuclear force, which is attractive over short distances like the nucleus, and stronger than electricity, holds the nucleus together

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

The region around the Earth where charged particles are trapped and spiral around is called

the spirosphere