Peering into the Past: The James Webb Space Telescope
Lexile: 1080 | Grade: 10
Passage
Launched in December 2021, the James Webb Space Telescope (JWST) is the most powerful telescope ever sent into space. It was designed to explore some of the oldest and most distant parts of the universe, helping scientists look billions of years into the past.
Unlike the Hubble Space Telescope, which sees mostly visible and ultraviolet light, the JWST focuses on **infrared light**. Infrared light has longer wavelengths, which allows it to pass through clouds of gas and dust that often block other forms of light. This ability makes JWST perfect for studying the formation of stars, galaxies, and planets that formed shortly after the Big Bang.
JWST orbits far beyond Earth—about 1 million miles away. At this distance, it avoids the heat and light from Earth and the Moon, which can interfere with its sensitive instruments. To keep cool, the telescope carries a massive sunshield the size of a tennis court. This shield protects its mirrors and sensors from the Sun’s heat, allowing it to operate at temperatures near absolute zero.
One of JWST’s key goals is to study the **atmospheres of exoplanets**—planets that orbit stars outside our solar system. By analyzing how starlight passes through a planet’s atmosphere, JWST can detect gases like water vapor, carbon dioxide, or even methane. These gases could provide clues about whether a planet might support life.
In addition to studying exoplanets, JWST is helping astronomers answer big questions: How did the first galaxies form? What are black holes really like? How common are solar systems like ours? The telescope’s high-resolution images and deep sensitivity are already transforming what we know about the cosmos.
But building and launching the JWST was no small feat. It took over 20 years of planning, international collaboration, and billions of dollars. Engineers had to fold the telescope to fit inside a rocket and then unfold it in space—a process that involved over 300 possible failure points.
Despite the challenges, JWST has become a symbol of scientific ambition and cooperation. Its mission is far from over, and the data it collects may change how we think about the universe—and our place in it—for decades to come.
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Questions
Q1: What is the central purpose of the James Webb Space Telescope?
- A. To take close-up photos of Earth
- B. To replace satellites used for communication
- C. To explore the early universe and study distant planets
- D. To help astronauts live in space
Q2: What makes JWST different from the Hubble Space Telescope?
- A. It uses radio waves instead of light.
- B. It sees in infrared light, allowing it to see through cosmic dust.
- C. It’s designed only for viewing stars in our galaxy.
- D. It orbits much closer to Earth.
Q3: Why is the telescope’s location important for its mission?
- A. It keeps the telescope hidden from enemy satellites.
- B. It allows it to orbit the Moon.
- C. It protects the telescope from Earth’s heat and light.
- D. It makes it easier to launch astronauts to repair it.
Q4: What does the passage suggest about the search for life on other planets?
- A. JWST can take photos of aliens.
- B. JWST analyzes gases in exoplanet atmospheres to look for signs of habitability.
- C. JWST travels to other planets to collect samples.
- D. JWST replaces the need for rovers on Mars.
Q5: What does the phrase 'over 300 possible failure points' in paragraph 6 emphasize?
- A. That the telescope is highly dangerous to use
- B. That many people doubted the telescope would be useful
- C. That building and launching JWST was complex and risky
- D. That JWST was poorly designed
Q6: What tone does the author use when describing JWST’s impact?
- A. Sarcastic and critical
- B. Playful and humorous
- C. Serious and admiring
- D. Uncertain and doubtful
Q7: Which of the following best supports the idea that JWST is transforming our understanding of space?
- A. It cost billions of dollars.
- B. It orbits 1 million miles from Earth.
- C. It is helping scientists learn how galaxies formed and study atmospheres of exoplanets.
- D. It is bigger than the Hubble Space Telescope.
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Answers & Reasoning
Q1: What is the central purpose of the James Webb Space Telescope?
✅ Correct Answer: C
💡 Reasoning: The passage explains that JWST is designed to look far back in time and study exoplanets and galaxy formation.
Q2: What makes JWST different from the Hubble Space Telescope?
✅ Correct Answer: B
💡 Reasoning: JWST detects infrared light, which helps it see objects blocked by gas and dust.
Q3: Why is the telescope’s location important for its mission?
✅ Correct Answer: C
💡 Reasoning: The telescope orbits far from Earth to avoid interference from heat and light.
Q4: What does the passage suggest about the search for life on other planets?
✅ Correct Answer: B
💡 Reasoning: The passage states that JWST looks for gases like water vapor or methane that could suggest life.
Q5: What does the phrase 'over 300 possible failure points' in paragraph 6 emphasize?
✅ Correct Answer: C
💡 Reasoning: This detail highlights the technical difficulty and risk involved in deploying JWST.
Q6: What tone does the author use when describing JWST’s impact?
✅ Correct Answer: C
💡 Reasoning: The author describes the telescope as ambitious and transformative, reflecting respect and wonder.
Q7: Which of the following best supports the idea that JWST is transforming our understanding of space?
✅ Correct Answer: C
💡 Reasoning: This directly relates to the telescope’s ability to provide new information that changes scientific knowledge.
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