ACT Science : Earth and Space Sciences

Study concepts, example questions & explanations for ACT Science

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Example Questions

Example Question #101 : Earth And Space Sciences

One night there was a meteor shower and scientists in four different regions, A, B, C and D, observed and counted the number of meteors seen. The scientists noted the duration of the meteor shower and the visibility of the stars. 

Act 2

In which of the regions is there the least amount of light pollution? 

Possible Answers:

Cannot be determined from the given information

D

C

B

A

Correct answer:

Cannot be determined from the given information

Explanation:

Light pollution will reduce visibility of the night sky. The scientists do not note the weather conditions in their respective regions. It can be cloudy in Region C or it could have a large amount of light pollution. It cannot be determined which region has the most light pollution. Be careful when the question is asking for inference leaps that are too far outside the scope of the information presented in the table and passage.

Example Question #21 : How To Find Synthesis Of Data In Earth And Space Sciences

Researchers are curious about the effects of large amounts of steam released by a power plant. They hypothesize that the large amounts of moisture might affect precipitation in the area. They record yearly rainfall at multiple locations at various distances from the power plant and find the results below:

Distance from Power Plant (kilometers) Yearly Rainfall (inches)
1999 2000 2001 2002
1 40.2 44.3 45.1 38.8
5 38.6 42.8 44.1 37.5
10 37.3 41.2 43.7 37.1
20 36.9 40.5 42.3 36.8

How many inches of rainfall would you expect a farm  from the power plant to get in the year 2000?

Possible Answers:

Around 37 inches

Around 40 inches

Around 41 inches

Around 43 inches

Around 44 inches

Correct answer:

Around 41 inches

Explanation:

A farm  from the plant is closest to the measurement at . In the year 2000, this location received 41.2 inches of rainfall, which is closest to 41 inches.

Example Question #28 : How To Find Synthesis Of Data In Earth And Space Sciences

Explorers have discovered a new planet, Planet K. It is known that Planet K has magnetic poles to similar to those of Earth, so the explorers decide that using a compass to navigate is possible. When navigating Planet K's surface, it is discovered that the compass points north for a distance then flips so that it points north in the opposite direction for a distance, before returning to pointing north in the original direction. It is known that the magnetic poles of the planet flip every 100 years. Weather is recorded on the planet for 250 years. 

Capture 2

If the explorers are scouting planets for humans to live on, is Planet K a good planet for humans to settle on? Why?

Possible Answers:

Cannot be determined from the given information

Planet K is a good planet to settle because it has a similar magnetic field to Earth

Planet K is not a good planet to settle due to cold climate without precipitation every 100 years 

Planet K is a good planet to settle because it has a similar climate to Earth

Planet K is not a good planet as it has a magnetic field similar to Earth's magnetic field

Correct answer:

Planet K is not a good planet to settle due to cold climate without precipitation every 100 years 

Explanation:

Planet K is not a good planet to settle. Every 100 years the magnetic poles flip which could cause navigation to be difficult, but that is not the major concern. The major concern is that when the magnetic poles flip, the temperature drops to below zero and there is little precipitation. This would make it difficult to grow crops and even obtain water (provided there is water on the planet's surface) that would not make Planet K a good candidate for a settlement. 

Example Question #21 : How To Find Synthesis Of Data In Earth And Space Sciences

Explorers have discovered a new planet, Planet K. It is known that Planet K has magnetic poles to similar to those of Earth, so the explorers decide that using a compass to navigate is possible. When navigating Planet K's surface, it is discovered that the compass points north for a distance then flips so that it points north in the opposite direction for a distance, before returning to pointing north in the original direction. It is known that the magnetic poles of the planet flip every 100 years. Weather is recorded on the planet for 250 years. 

Capture 2

If the compass cannot be utilized to navigate on Planet K, in what other ways can the explorers navigate the planet? 

Possible Answers:

The explorers can use Planet K's sun for navigation 

The explorers can use any landmarks observed from space to navigate

The explorers can use landmarks on the surface of Planet K that they observe as they travel

All of the other options

The explorers can use constellations and stars to navigate

Correct answer:

All of the other options

Explanation:

It is possible and has be performed on Earth that people have navigated by using the stars, constellations, and the sun. Therefore any of these options can be used by the explorers on Planet K. Additionally if the explorers have traveled from Earth, landmarks have been noticed on the surface of Planet K that will be helpful in navigating. Therefore all of the options can be used in navigating the planet's surface. 

Example Question #21 : How To Find Synthesis Of Data In Earth And Space Sciences

Scientists have long debated the origin of organic molecules on Earth. Organic molecules are those based on the atom carbon, which can form four distinct bonds in contrast to the fewer number allowed in most other non-metals. As a result of this property, carbon can give rise to the enormously complex molecular shapes necessary for life to arise.

Some scientists argue that organic matter was dissolved in water ice on comets, and brought to Earth early in its history. These comets crashed into the early Earth, and deposited carbon-based molecules in copious quantities to the Earth’s surface as their water melted.

In 2014, the first space probe landed on the comet 67P/Churyumov-Gerasimenko. Suppose that scientists find the following information from 5 distinct samples after landing on the comet. Each sample was taken at a single geographical location, but 5 meters deeper than the last. Sample 1 was taken at a depth of 1 meter below the surface.

Sample #

Water Ice?

Concentration of Organics

1

No

N/A

2

Yes

1 mg/L

3

No

N/A

4

Yes

4 mg/L

5

Yes

10 mg/L

These samples were compared to 5 similar samples from the surface of Mars. Scientists posited that this comparison would be meaningful because we know that life does not exist on Mars the same way that it does on Earth. Thus, they are comparing a known non-biological celestial body, Mars, with another celestial body, the comet, which may be seeding life on suitable plants.

Sample #

Water Ice?

Concentration of Organics

1

No

N/A

2

No

N/A

3

No

N/A

4

No

N/A

5

Yes

1 mg/L

The purpose of the sample from Mars as described in the passage is most likely to act as:

Possible Answers:

a negative control group for the experimental sample from the comet.

a balancing group to balance data from the comet.

a standard group to allow for standardization of data from the comet.

an experimental group for the negative control group from the comet.

Correct answer:

a negative control group for the experimental sample from the comet.

Explanation:

The passage indicates that Martian soil was chosen as it is known to be non-biological. As a result, it is being used as a negative control to compare the concentration of organic molecules on comets to known non-biological samples from another celestial body.

Example Question #101 : Earth And Space Sciences

Scientists have long debated the origin of organic molecules on Earth. Organic molecules are those based on the atom carbon, which can form four distinct bonds in contrast to the fewer number allowed in most other non-metals. As a result of this property, carbon can give rise to the enormously complex molecular shapes necessary for life to arise.

Some scientists argue that organic matter was dissolved in water ice on comets, and brought to Earth early in its history. These comets crashed into the early Earth, and deposited carbon-based molecules in copious quantities to the Earth’s surface as their water melted.

In 2014, the first space probe landed on the comet 67P/Churyumov-Gerasimenko. Suppose that scientists find the following information from 5 distinct samples after landing on the comet. Each sample was taken at a single geographical location, but 5 meters deeper than the last. Sample 1 was taken at a depth of 1 meter below the surface.

Sample #

Water Ice?

Concentration of Organics

1

No

N/A

2

Yes

1 mg/L

3

No

N/A

4

Yes

4 mg/L

5

Yes

10 mg/L

These samples were compared to 5 similar samples from the surface of Mars. Scientists posited that this comparison would be meaningful because we know that life does not exist on Mars the same way that it does on Earth. Thus, they are comparing a known non-biological celestial body, Mars, with another celestial body, the comet, which may be seeding life on suitable plants.

Sample #

Water Ice?

Concentration of Organics

1

No

N/A

2

No

N/A

3

No

N/A

4

No

N/A

5

Yes

1 mg/L

How far below the surface of the comet was the third sample measured?

Possible Answers:

10 meters

12 meters

11 meters

15 metes

Correct answer:

11 meters

Explanation:

The passage indicates that the samples are taken 5 meters below the sample above them. The first sample was taken at 1 meter below the surface, the second was taken at 6 meters below the surface, and the third was taken at 11 meters below the surface.

Example Question #101 : Earth And Space Sciences

Global warming is defined as the slow increase in the temperature of the earth’s atmosphere and is caused by pollutants and carbon dioxide (CO2). While the gradual increase in temperature cannot be refuted, scientists argue over the cause.

 Scientist 1:

Global warming is caused by increases in atmospheric CO2, which is directly created by humans and their consumption of fossil fuels. The natural CO2 released from carbon sinks has a different isotopic ratio from the CO2 released from fossil fuels. Current measurements of the radioactive isotopes of CO2 show that it is from human activity, not from nature. The Earth’s carbon sinks cannot absorb these large amounts of unnatural CO2 emissions. About fifty percent of the CO2 produced by mankind remains in the atmosphere, unable to be absorbed.

Scientist 2:

The rise in atmospheric CO2 levels are a result of global warming, not the cause of it. When the temperature increases, the CO2 in carbon sinks is released. While humans do cause release of CO2, the carbon sinks absorb it. The activity of the carbon sinks increases to allow for higher levels of CO2 absorption. Proponents for human causation of global warming point to the warming and cooling of the stratosphere, however, these temperature fluctuations are caused by changes in the sun’s heat. These proponents also look at the acidity of the ocean as evidence of human causation, however, the rise in ocean acidity is within the normal range of fluctuations over the past ten thousand years.

What new evidence would support the argument made by Scientist 2?

Possible Answers:

Evidence showing the release of CO2 from carbon sinks directly increases the atmospheric temperature

Evidence showing that temperature increase predated the release of CO2 from carbon sinks

A studying showing that carbon sinks can only absorb a finite amount of CO2

An experiment suggesting that 83% of CO2 remaining in the atmosphere is caused by humans

Evidence showing temperature fluctuations cause the sun's heat to increase in intensity

Correct answer:

Evidence showing that temperature increase predated the release of CO2 from carbon sinks

Explanation:

Evidence showing that temperature increase predated the release of CO2 from carbon sinks would support the theory of Scientist 2. Scientist 2 argues that the rising temperature led to an increase in atmospheric CO2, rather than CO2 leading to an increase in temperature. An increase in temperature before an increase in CO2 would be consistent with this reasoning.

Example Question #1 : How To Find Research Summary In Earth And Space Sciences

The origin of the universe has been a highly debated topic among physicists. In the middle of the twentieth century, there were two prevalent models regarding the origin of the universe. The first model, called the Big Bang Theory, suggests that the universe was spontaneously created approximately 14 billion years ago. The second model, called the Steady State Theory, suggests that the universe contains no beginning or end, is always expanding, and contains a constant density.

Initially, the Big Bang Theory was widely disregarded by physicists and astronomers. In fact, the name “Big Bang” was coined by Fred Hoyle, a supporter of the Steady State Theory, who used the term in a derogatory manner. The Big Bang Theory suggests that prior to the creation of matter, a physical object that occupies space and possesses mass, the universe was filled homogenously with high-energy density and very high temperature and pressure. The universe was rapidly expanding and cooling resulting in the creation of atoms. The initial atoms that were produced were much lighter than the atoms currently found on earth, the lightest of which are hydrogen, helium, and lithium. After this initial creation of the universe, it continued to expand.  The Big Bang Theory is now the prevalent theory for the origin of the universe.

The Steady State Theory suggests that there is no start or end to the universe in time or space, yet the universe is always expanding. Furthermore, the Steady State Theory states that new stars and galaxies replace old stars and galaxies and the overall appearance of the universe does not change over time.

Two sources of evidence are used to support or refute the discussed hypotheses. The first piece of data is the presence of primordial gas clouds, pockets of the universe that contain gases lighter than those found in the current universe. The second piece of evidence is that other galaxies are “red shifted”. The term red-shift indicates that as objects move farther away, the light they emit changes wavelength and appears to be more red.

The Steady State Theory states:

Possible Answers:

The universe originated from light

All of the other choices

The universe was created 14 billion years ago

The overall appearance of the universe does not change

Correct answer:

The overall appearance of the universe does not change

Explanation:

The Steady State theory claims the the universe has always existed in time and space and that its overall appearance does not change. This indicates that things may be created and destroyed, but new and old galaxies will appear identical.

Example Question #1 : How To Find Research Summary In Earth And Space Sciences

The origin of the universe has been a highly debated topic among physicists. In the middle of the twentieth century, there were two prevalent models regarding the origin of the universe. The first model, called the Big Bang Theory, suggests that the universe was spontaneously created approximately 14 billion years ago. The second model, called the Steady State Theory, suggests that the universe contains no beginning or end, is always expanding, and contains a constant density.

Initially, the Big Bang Theory was widely disregarded by physicists and astronomers. In fact, the name “Big Bang” was coined by Fred Hoyle, a supporter of the Steady State Theory, who used the term in a derogatory manner. The Big Bang Theory suggests that prior to the creation of matter, a physical object that occupies space and possesses mass, the universe was filled homogenously with high-energy density and very high temperature and pressure. The universe was rapidly expanding and cooling resulting in the creation of atoms. The initial atoms that were produced were much lighter than the atoms currently found on earth, the lightest of which are hydrogen, helium, and lithium. After this initial creation of the universe, it continued to expand.  The Big Bang Theory is now the prevalent theory for the origin of the universe.

The Steady State Theory suggests that there is no start or end to the universe in time or space, yet the universe is always expanding. Furthermore, the Steady State Theory states that new stars and galaxies replace old stars and galaxies and the overall appearance of the universe does not change over time.

Two sources of evidence are used to support or refute the discussed hypotheses. The first piece of data is the presence of primordial gas clouds, pockets of the universe that contain gases lighter than those found in the current universe. The second piece of evidence is that other galaxies are “red shifted”. The term red-shift indicates that as objects move farther away, the light they emit changes wavelength and appears to be more red.

A primordial gas has less mass than ________.

  

Possible Answers:

Hydrogen

An atom

Light

Energy

Correct answer:

Hydrogen

Explanation:

The primoridal gases at the creation of the universe contained less mass than the elements on earth today. Hydrogen is the smallest element, therefore, primordial gases must comprise less mass than hydrogen. Atoms can vary in size and mass based on the type. Energy and light do not contain mass.

Example Question #1 : How To Find Research Summary In Earth And Space Sciences

The origin of the universe has been a highly debated topic among physicists. In the middle of the twentieth century, there were two prevalent models regarding the origin of the universe. The first model, called the Big Bang Theory, suggests that the universe was spontaneously created approximately 14 billion years ago. The second model, called the Steady State Theory, suggests that the universe contains no beginning or end, is always expanding, and contains a constant density.

Initially, the Big Bang Theory was widely disregarded by physicists and astronomers. In fact, the name “Big Bang” was coined by Fred Hoyle, a supporter of the Steady State Theory, who used the term in a derogatory manner. The Big Bang Theory suggests that prior to the creation of matter, a physical object that occupies space and possesses mass, the universe was filled homogenously with high-energy density and very high temperature and pressure. The universe was rapidly expanding and cooling resulting in the creation of atoms. The initial atoms that were produced were much lighter than the atoms currently found on earth, the lightest of which are hydrogen, helium, and lithium. After this initial creation of the universe, it continued to expand.  The Big Bang Theory is now the prevalent theory for the origin of the universe.

The Steady State Theory suggests that there is no start or end to the universe in time or space, yet the universe is always expanding. Furthermore, the Steady State Theory states that new stars and galaxies replace old stars and galaxies and the overall appearance of the universe does not change over time.

Two sources of evidence are used to support or refute the discussed hypotheses. The first piece of data is the presence of primordial gas clouds, pockets of the universe that contain gases lighter than those found in the current universe. The second piece of evidence is that other galaxies are “red shifted”. The term red-shift indicates that as objects move farther away, the light they emit changes wavelength and appears to be more red.

A red-shift can be used to estimate_________.

Possible Answers:

The size of the universe

The intensity of light

Whether an object is moving away.

Color

Correct answer:

Whether an object is moving away.

Explanation:

From the text: The term red-shift indicates that as objects move farther away, the light they emit changes wavelength and appears to be more red.  

 

Therefore, an object that has a red-shift is moving farther away from the observer. This phenomenon can be used to determine if galaxies are moving farther away.

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