Analyzing New Evidence

Analyzing New Evidence

Middle School

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Learning Objectives

• Define claim, evidence, and reasoning as parts of a scientific argument.

• Use evidence to build an argument explaining how a channel formed on Mars.

• Tell the difference between rocks formed by water and rocks formed by lava.

• Explain habitability and how it relates to the presence of water on Mars.

Key Vocabulary

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Claim

A statement or conclusion that answers a question or explains a particular phenomenon.

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Evidence

Scientific data that is collected to support or refute a previously made claim.

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Reasoning

The process of using evidence and scientific principles to explain why evidence supports a claim.

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Landform

A natural feature of the surface of the Earth or any other solid planet.

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Geologic Process

A natural process that is responsible for shaping the many physical features of a planet.

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Conglomerate

A type of rock that is formed from rounded pebbles and sediment cemented together.

Key Vocabulary

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Basalt

A dark-colored volcanic rock that forms from the rapid cooling of lava on the Earth's surface.

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Habitable

Describes a place that is suitable for organisms to live in and is capable of supporting life.

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Model

A representation of an object or system used to explain or predict how something behaves or works.

Claim, Evidence, and Reasoning

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Claim

• ​A claim is a direct answer to a scientific question.

• ​It is the starting point that the rest of the argument supports.

• ​For example: Flowing water formed the large channel on Mars.

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Evidence

• ​Evidence is scientific data you use to back up your claim.

• ​This data must always be observable and measurable to be valid.

• ​For instance, photos of the channel or special rock samples.

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Reasoning

• ​Reasoning connects your evidence to the claim you have made.

• ​It explains why your evidence supports the claim being made.

• ​This is the logical bridge between the data and your conclusion.

Multiple Choice

In a scientific argument, what is the primary role of a claim?

• A direct answer to a scientific question that the rest of the argument supports.

• The observable and measurable data used in an investigation.

• A logical explanation that connects scientific data to a conclusion.

• The final conclusion reached after an experiment is completed.

Multiple Choice

What is the relationship between evidence and reasoning in a scientific argument?

• It presents the scientific data that has been collected.

• It states the initial answer to the scientific question.

• It ensures that all data is observable and measurable.

• It explains the logical connection between the evidence and the claim.

Multiple Choice

A student makes the claim that a large rock on a hill is slowly moving. Which of the following could be used as valid scientific evidence to support this claim?

• A popular opinion that the rock has been in the same place for years.

• A statement explaining that gravity causes all objects to move downhill.

• A log of daily measurements of the rock's slow movement down the hill.

• A question about what might have originally pushed the rock.

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The Big Question: Water or Lava on Mars?

Claim 1: Water

• Mars may have once had liquid water flowing on its surface, similar to the rivers we see on Earth.

• This flowing water could have eroded the Martian land over a very long period, carving out the channels.

• The water would have carried away loose sediment, creating a path for itself just like a river does.

Claim 2: Lava

• The channels could be the result of hot, flowing lava from ancient volcanic activity on the planet.

• This molten rock would have carved a path for itself as it moved across the Martian surface.

• Once the lava flow cooled and hardened into solid rock, it left behind the empty channels we see today.

Multiple Choice

What are the two competing theories that could explain how channels formed on the surface of Mars?

• Flowing water and flowing lava

• Shifting sand dunes and powerful winds

• Melting glaciers and freezing ice

• Asteroid impacts and ancient earthquakes

Multiple Choice

How are the processes described in the water and lava theories similar?

• A flowing material carved a path for itself on the surface.

• Underground caves collapsed and created trenches.

• The ground cracked open due to the planet's cooling.

• Glaciers slowly scraped away the rock over millions of years.

Multiple Choice

If scientists discovered that the channels on Mars are lined with hardened, solid rock, which claim would this evidence most strongly support?

• The claim that the channels were formed by lava flows.

• The claim that the channels were formed by water erosion.

• A new theory that the channels were formed by wind.

• A new theory that the channels were formed by ice.

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Evidence in the Rocks: Conglomerate vs. Basalt

Conglomerate

• This sedimentary rock forms when rounded pebbles, sand, and smaller sediments get cemented together over time.

• The rounded pebbles are a key clue, shaped by the tumbling action of flowing water in rivers.

• Finding this rock on Mars is strong evidence that liquid water once flowed on the planet’s surface.

Basalt

• This is a dark-colored igneous rock that is formed from the rapid cooling of lava on a surface.

• When lava flows from a volcano, it spreads and hardens into a rock with a fine-grained texture.

• Finding basalt on a planet is considered direct and clear evidence of past volcanic activity.

Multiple Choice

What is the primary difference in the formation of conglomerate and basalt rocks?

• Conglomerate is dark-colored, while basalt is light-colored.

• Conglomerate is found on Mars, while basalt is found on Earth.

• Conglomerate is an igneous rock, while basalt is a sedimentary rock.

• Conglomerate forms from cemented sediments, while basalt forms from cooled lava.

Multiple Choice

What do the rounded pebbles in conglomerate rock indicate about their history?

• They were broken apart by volcanic eruptions.

• They were tumbled and smoothed by the action of flowing water.

• They were shaped by wind and sand over a long period.

• They were melted and reformed by intense heat from lava.

Multiple Choice

A planetary rover discovers a large deposit of rock containing rounded pebbles and sand cemented together. What is the most logical conclusion that can be drawn from this discovery?

• The planet must have active volcanoes on its surface.

• The planet likely had rivers or streams in its past.

• The planet's surface is formed only from cooled lava.

• The planet has a very fine-grained, dark-colored surface.

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Building the Argument: From Evidence to Conclusion

• Claim: A channel on Mars was formed by flowing water long ago.

• Evidence: Scientists found a rock called a conglomerate inside the channel.

• Reasoning: On Earth, flowing water tumbles rocks, making their edges smooth and round.

• This suggests flowing water on Mars also created these smooth, rounded rock pieces.

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Multiple Choice

In a scientific argument, what is the role of evidence?

• To provide facts or data that support a claim.

• To state the main conclusion of an experiment.

• To offer a personal opinion about the topic.

• To ask a question that needs to be answered.

Multiple Choice

Why does finding a conglomerate rock with smooth, rounded pieces suggest that water once flowed on Mars?

• A similar process of flowing water on Earth creates smooth, rounded rocks.

• Conglomerate rocks are only found on planets with water.

• The wind on Mars is not strong enough to shape rocks.

• All channels on all planets are formed by water.

Multiple Choice

Based on the connection between conglomerate rocks and flowing water, what is the most logical conclusion?

• The rocks on Mars are identical to the rocks on Earth.

• The presence of flowing water in Mars' past is a likely explanation for the channel's formation.

• Life must have existed on Mars long ago.

• Mars and Earth have the exact same environment.

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Implications: A Habitable Past and Future Exploration

• Water joined energy and chemicals, completing Mars's basic habitability requirements.

• Ancient riverbeds and lakebeds suggest early Mars once hosted liquid water.

• Curiosity and Perseverance examine rocks for chemical traces of possible ancient microbes.

• Future missions will drill deeper, hunting preserved evidence to answer life's big question.

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Multiple Choice

What three things completed the basic requirements for Mars to be considered habitable?

• Water, energy, and chemicals

• Ancient riverbeds, lakebeds, and rocks

• Curiosity, Perseverance, and future missions

• Microbes, plants, and animals

Multiple Choice

What key evidence supports the idea that Mars once had liquid water, a component needed for habitability?

• The red color of the planet's surface

• The discovery of chemical traces in rocks

• The presence of ancient riverbeds and lakebeds

• The data from deep drilling missions

Multiple Choice

Given the focus of the Curiosity, Perseverance, and future missions, what is the ultimate question scientists are trying to answer?

• To determine the exact age of Martian rocks

• To find out if life ever existed on Mars

• To map the locations of all ancient riverbeds

• To prepare the planet for future human settlement

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Common Misconceptions

Misconception	Correction
A single piece of evidence proves a scientific claim.	Scientific conclusions require multiple lines of evidence pointing to the same conclusion.
A scientific 'argument' is a disagreement or fight.	It's a collaborative process where claims are tested against evidence to find truth.
A river-like channel must have been formed by water.	Similar landforms can be created by different processes, like flowing lava.
Mars is red because of fire or lava.	The red color comes from iron oxides (rust) in its soil.

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Summary

• A scientific argument uses evidence and reasoning to support a claim.

• Geologists debated if Mars channels were from water or lava.

• Conglomerate rock suggests ancient water, while basalt rock points to past volcanic activity.

• Past water suggests Mars may have been habitable, meaning it could support life.

Poll

On a scale of 1-4, how confident are you in your ability to construct a scientific argument using claim, evidence, and reasoning?

• 1 - Not confident at all

• 2 - A little confident

• 3 - Mostly confident

• 4 - Very confident