Grade: Grade 5 Subject: Science Unit: Solar System Lesson: 5 of 6 SAT: Information+Ideas ACT: Science

Claim-Evidence Writing: Solar System

Learn to write scientific arguments about space using the CER framework: Claim, Evidence, and Reasoning.

Learn

Scientists communicate their discoveries through clear, organized writing. The CER framework (Claim, Evidence, Reasoning) helps you write persuasive scientific arguments about topics like our solar system.

Why Use CER for Space Science?

Space scientists can't always directly visit the planets and moons they study. Instead, they collect data from telescopes, space probes, and mathematical calculations. CER helps them present their conclusions based on this evidence in a clear, logical way.

The CER Framework

C - Claim

What do you think?

Your answer to a question or your main conclusion about a space phenomenon.

E - Evidence

What data supports it?

Specific measurements, observations, or facts from space missions, telescopes, or calculations.

R - Reasoning

Why does it matter?

Explains how your evidence connects to your claim using scientific principles like gravity, orbital mechanics, or planetary formation.

Example: Why Does Earth Have Seasons?

Question: What causes the seasons on Earth?

Claim

Earth's seasons are caused by the tilt of its axis as it orbits the Sun, not by changes in distance from the Sun.

Evidence

Earth's axis is tilted at 23.5 degrees. When the Northern Hemisphere tilts toward the Sun, it receives more direct sunlight - up to 15 hours of daylight in summer versus only 9 hours in winter. Also, Earth is actually closest to the Sun (147 million km) in January, which is winter in the Northern Hemisphere.

Reasoning

If distance from the Sun caused seasons, both hemispheres would have the same season at the same time. Instead, when it's summer in the Northern Hemisphere, it's winter in the Southern Hemisphere. This happens because the tilted axis causes one hemisphere to receive more direct sunlight (summer) while the other receives less direct sunlight (winter). More direct sunlight means more energy hitting each square meter of surface, resulting in warmer temperatures.

Writing Tip: For space science, include specific numbers like distances (in km or AU), temperatures (in Celsius or Fahrenheit), or time measurements (days, years). These make your evidence stronger!

Practice Writing Prompt

Question: Why is Mars called the "Red Planet"?

Write a CER response explaining what causes Mars' distinctive color.

Your Claim:

0 words

Your Evidence:

0 words

Your Reasoning:

0 words

Practice Quiz

Test your understanding of the CER framework and solar system concepts.

1 In a CER response, which part answers the question directly?

A Claim

B Evidence

C Reasoning

D Data

View Explanation

The Claim is your answer to the question. It states what you believe to be true based on the evidence.

2 "Jupiter's diameter is 139,820 km, making it 11 times wider than Earth" is an example of:

A Claim

B Evidence

C Reasoning

D Question

View Explanation

This is evidence because it contains specific numerical data and measurements that can be verified.

3 What makes the Moon appear to change shape during its phases?

A Earth's shadow on the Moon

B The Moon moves closer and farther from Earth

C We see different amounts of the Moon's sunlit side as it orbits Earth

D The Moon generates its own light

View Explanation

Moon phases occur because we see different portions of the Moon's sunlit half as it orbits Earth. The Moon doesn't make its own light - it reflects sunlight.

4 Which inner planet is closest to the Sun?

A Venus

B Earth

C Mercury

D Mars

View Explanation

Mercury is the closest planet to the Sun at an average distance of about 58 million km (0.39 AU).

5 Why do the outer planets (Jupiter, Saturn, Uranus, Neptune) have many moons while inner planets have few or none?

A Outer planets are closer to the asteroid belt

B Outer planets have stronger gravity due to their larger mass

C Inner planets are too hot for moons

D The Sun pushed all the moons away from inner planets

View Explanation

The outer planets are much more massive than inner planets, giving them stronger gravitational pull. This allows them to capture and hold more moons in orbit.

6 A statement that explains HOW your evidence supports your claim using scientific principles is called:

A Claim

B Evidence

C Reasoning

D Hypothesis

View Explanation

Reasoning is the part that explains WHY your evidence supports your claim. It connects data to scientific concepts.

7 How long does it take the Moon to complete one full orbit around Earth?

A 24 hours

B About 7 days

C About 29.5 days

D 365 days

View Explanation

The Moon takes about 29.5 days to complete one orbit around Earth. This is why we see a complete cycle of moon phases roughly once a month.

8 Which is the BEST example of a claim about the solar system?

A Mars has two moons named Phobos and Deimos.

B Venus is the hottest planet because of its thick atmosphere.

C The temperature on Venus is 465 degrees Celsius.

D Scientists use telescopes to study planets.

View Explanation

A claim states a conclusion that can be supported with evidence. "Venus is the hottest planet because of its thick atmosphere" is a claim that explains a phenomenon.

9 What type of planets are Mercury, Venus, Earth, and Mars?

A Gas giants

B Ice giants

C Terrestrial (rocky) planets

D Dwarf planets

View Explanation

Mercury, Venus, Earth, and Mars are terrestrial (rocky) planets. They have solid, rocky surfaces and are relatively small compared to the gas giants.

10 What is the most important characteristic of strong evidence in a CER response?

A It uses long, complicated words

B It is specific, measurable, and verifiable

C It is written by a famous scientist

D It is the longest paragraph

View Explanation

Strong evidence is specific (includes exact numbers), measurable (can be quantified), and verifiable (can be confirmed by others). This makes your argument more convincing.

Check Your Understanding

C = Claim

Your answer or conclusion about a space phenomenon.

E = Evidence

Specific data from observations, measurements, or space missions.

R = Reasoning

Explains HOW evidence supports claim using scientific principles.

Key Takeaways

CER helps organize scientific arguments clearly
Include specific measurements and numbers in evidence
Reasoning connects data to scientific concepts like gravity, orbit, and light
This framework is used on standardized science tests

Next Steps

Practice writing CER responses about other planets
Research data about planets from NASA's website to use as evidence
Complete the Unit Checkpoint to test your solar system knowledge