WorksheetsAstro 115 Ch7
Total questions: 60
Worksheet time: 30mins
If life does indeed exist elsewhere in our solar system it will most likely take the form of
human beings
plants
birds
microbes or other simple life
Habitability generally refers to an environment capable of sustaining
human life
plant life
microbial life only
any kind of life
The necessary chemical elements of life should
only be found on the Earth and Mars
be widespread in the solar system but not elsewhere in our Milky Way galaxy
be widespread throughout the universe
be widespread in our Milky Way galaxy but not in other galaxies
Given that organic molecules need to react in order to produce life, this suggests we should search for worlds in the solar system that have
either an atmosphere, or a surface or subsurface liquid medium such as water, or both.
organic molecules on their surfaces
an atmosphere
rocky surfaces
The planet Saturn is approximately 10 times farther away from the Sun than the Earth is. Given this, how much sunlight does it receive compared to the Earth?
1/1,000th
1/10,000th
1/100th
1/10th
A newly discovered asteroid of the Aten family is found to be 50% closer to the Sun than the Earth is. Given this, how much sunlight does it receive compared to the Earth?
half as much
four times as much
twice as much
about the same
Photosynthetic life existing on a planet farther from the Sun than the Earth would most likely be
smaller, less efficient at collecting solar radiation or have a faster metabolism than photosynthetic life on Earth
identical to photosynthetic life on Earth
larger, more efficient at collecting solar radiation or have a slower metabolism than photosynthetic life on Earth
impossible
All of the most likely alternatives to water as a biological solvent are liquids at
higher temperatures
lower temperatures
lower pressures
similar temperatures
Which of the following is an advantage that liquid water has as a biological solvent compared to other alternatives?
when it freezes it becomes less dense
it is a liquid over a wide temperature range and remains liquid at higher temperatures
it is able to dissolve many things
all of these are advantages
Which one of the following properties is unique to water?
it has a high heat capacity
it is a good solvent
it is a liquid over a wide temperature range
it expands on freezing
If ice were denser than water, during winter lakes and ponds would
completely freeze
remain liquid
freeze on the surface but remain liquid beneath
freeze on the bottom but remain liquid at the surface
Which of the following alternatives to water has a wider temperature range over which it is a liquid?
ammonia
methanol
methane
ethane
Even though ethane (C2H6) has a liquid temperature range almost as wide as water, it is not as good a biological solvent as water because it is a liquid at what?
much higher temperatures which would result in the breakdown of fragile biological molecules
very high pressures that are unlikely to be found elsewhere
very low pressures that are unlikely to be found elsewhere
much lower temperatures which would result in extremely slow metabolic reactions
What happens to the rate of most chemical reactions as the temperature decreases?
the rate of reaction drops rapidly
the rate of reaction drops only slightly
the rate of reaction increases rapidly
the rate of reaction stays the same
Molecules like water in which electrons are distributed unevenly within the molecule are referred to as what?
bipolar
ionic
charged
polar
The strong forces of attraction that exist between water molecules and are responsible for many of its unique properties as a solvent are called what?
dispersion forces
ionic bonds
hydrogen bonds
covalent bonds
If we place living cells in a nonpolar solvent like methane or ethane, what will happen?
their membranes will thicken, preventing molecular transport across the membrane
they will rapidly explode due to pressure caused by the solvent building up inside the cell
their membranes will most likely dissolve as cell membranes are also nonpolar
they will function in much the same way as they do in water
Which of the following is NOT a basic requirement for chemically based life?
a liquid medium to transport biological molecules
a source of molecules from which to build living cells
oxygen from photosynthesis
a source of energy to fuel metabolism
In searching for life in the solar system, which basic requirement of life is the most fundamental and the one we always look for?
the presence of organic matter
the presence of an energy source
the presence of a liquid medium, most likely water
the presence of oxygen
The search for life in the solar system that is similar to life on Earth is essentially a search for
organic molecules
liquid water
molecular oxygen
energy sources
Mercury and the Moon are probably the least-habitable bodies in the solar system because they
are unlikely to have liquids anywhere
have never had carbon compounds on their surfaces
do not have atmospheres containing oxygen
do not receive any sunlight
Mercury and the Moon do not have atmospheres because
their surfaces are so cold that any atmospheric gases freeze out onto their surfaces
charged particles from the Sun have stripped away their atmospheres
they are rotating too rapidly, causing their atmospheres to be thrown out into space
their gravities are too weak to prevent atmospheric gases escaping into space
Water is present on the Moon and Mercury in the form of
liquid water present just beneath the surface
ice in polar craters
vapor in the atmosphere
oceans of liquid water on the surface
The planet Venus is often referred to as the Earth's "sister planet" because
it is almost the same size and density
it looks like the Earth through a telescope
its atmosphere has the same composition
its surface is very similar
Based on its distance from the Sun, we would expect the surface of Venus to be:
much hotter than the Earth
much colder than the Earth
a little hotter than the Earth
the same temperature as the Earth
The surface of Venus is much hotter than the Earth because it:
has no magnetic field
has a very thick atmosphere of carbon dioxide
has a much higher rate of volcanic activity
is closer to the Sun
How does the surface temperature and atmospheric pressure on Venus compare with the Earth?
higher temperatures and pressures
lower temperatures but higher pressures
lower temperatures and pressures
higher temperatures but lower pressures
Most of the carbon dioxide on the Earth:
is dissolved in the oceans, forming carbonate rocks
has frozen out in the polar regions
has escaped into space
is still present in the atmosphere
Most of the carbon dioxide on Venus:
has frozen out in the polar regions
is dissolved in oceans of liquid water, forming carbonate rocks
is still present in the atmosphere
has escaped into space
Venus may have been more Earth-like in the past because:
it was rotating more rapidly
the Sun was dimmer, putting out less solar radiation
it was not as close to the Sun
its atmosphere was thinner
Although very unlikely, if life exists on Venus today, it will most likely be found
at the center of the planet
just beneath the surface
on the surface
floating high in the atmosphere
If life exists on Mars today, it will most likely be found
on the surface
at the center of the planet
beneath the surface where liquid water may still exist
floating high in the atmosphere
Mars may have been more Earth-like in the past because
its atmosphere was thicker and warmer
it was rotating more rapidly
the Sun was dimmer, putting out less solar radiation
it was not as close to the Sun
What would probably be the most likely source of energy for life in Jovian atmospheres?
sunlight
chemical reactions powered by lightning
meteoroid impacts
solar wind particles from the Sun
The biggest obstacle to life being present in the atmospheres of Jupiter and Saturn is the
absence of liquid water in their atmospheres
high levels of solar radiation that would destroy any biological molecules
strong vertical wind speeds that would rapidly carry organisms into the hot interior where they would be destroyed
very low temperatures at the tops of the clouds where water would not be liquid
In order for life to survive in the atmospheres of Jupiter and Saturn it would have to
be high in the atmosphere where it could collect solar radiation
be at the center, close to the rocky core where a rocky surface exists
be large and buoyant, allowing it to maintain a stable altitude in the atmosphere
float on the surface of the layer of liquid metallic hydrogen
If life exists in Uranus and Neptune, it will most likely be found
In the oceans of liquid ices beneath the surface
Floating on the surface of a layer of liquid metallic hydrogen
High in the atmosphere where it could collect solar radiation
At the center, close to the rocky core where a rocky surface exists
Some Jovian moons may have liquid water
Beneath their surfaces
At their centers
On their surfaces
In their atmospheres
Europa may have a subsurface ocean of liquid water due to
The insulating properties of its icy surface
Tidal heating from Jupiter and the other Galilean moons
Internal heat left over from its formation
Tidal heating from the Sun
Which of the following is NOT property of a dwarf planet?
Symmetrical shape
Orbits the Sun
Intermediate in size between an asteroid and a small terrestrial planet
Irregular shape
Dwarf planets are very similar to
Larger Jovian moons
The Earth's moon
Smaller Jovian moons
Comets
Which dwarf planet did the NASA Dawn spacecraft enter into orbit around in 2015?
Pluto
Eris
Ceres
Haumea
Which dwarf planet did the NASA New Horizons spacecraft flyby in 2015?
Pluto
Eris
Ceres
Haumea
An extrasolar planet in the HD 4308 system orbits its parent star at a distance of 17.1 million kilometers and takes 15.56 Earth days to complete one orbit. Given this and assuming that the planet has a very low mass compared to the parent star, what is the mass of the parent star? Assume G=6.67x10^-11 m^3/kgs^2. P^2=a^3(4π^2/GM) and M=4π^2a^3/GP^2.
3.25 x 10^30 kg
2.00 x 10^30 kg
1.25 x 10^30 kg
1.64 x 10^30 kg
Small bodies like asteroids and comets are unlikely to harbor life because they:
are constantly colliding with each other, sterilizing any life that may be present
have not had liquid water inside them for extended periods now or in the past
do not contain any organic molecules
are so far from the Sun that any water would be permanently frozen
Most of the detailed information about the planets in our solar system comes from:
telescopic observations from Earth
robotic spacecraft
human visits
meteorites
Which kind of robotic space mission enables us to take a quick look at a planet?
sample return
flyby
orbiter
lander/probe
Which kind of robotic space mission enables us to study a planet for an extended period of time?
lander/probe
sample return
flyby
orbiter
Which kind of robotic space mission enables us to determine the chemical composition of a planet's surface and atmosphere remotely?
sample return
lander/probe
orbiter
flyby
Which kind of robotic space mission enables us to determine the chemical composition of a solar system body in a laboratory?
sample return
flyby
lander/probe
orbiter
A common way a robotic spacecraft can be accelerated and have its trajectory changed without the use of any fuel is via
a gravitational slingshot from another spacecraft
radiation pressure from the Sun
the ejection of mass from the probe
a gravitational slingshot from another planet
Voyagers 1 and 2 were examples of which kind of space mission?
flyby
orbiter
sample return
lander/probe
Which of the following planets has NOT yet been studied with an orbiter?
Saturn
Mars
Uranus
Venus
The Rosetta mission to the comet 67P/Churyumov-Gerasimenko is an example of which kind of robotic space mission?
lander/probe
flyby
sample return
orbiter
Which spacecraft dropped a probe into the atmosphere of Jupiter in 1995?
Galileo
Cassini
Voyager 2
Pioneer 10
The Huygens probe is an example of which kind of robotic spacecraft?
orbiter
sample return
lander
flyby
The Curiosity rover is an example of which kind of robotic spacecraft?
flybys
sample return
landers
orbiters
Hayabusa was an example of which kind of mission?
lander
flyby
sample return
orbiter
Stardust was an example of which kind of mission?
lander
flyby
sample return
orbiter
The Mars Curiosity rover, landed on the surface of Mars using
balloons
a skycrane
parachutes
airbags
