What meteorites, Moon rocks and ancient crystals tell us
Grade 9 Science Worksheet - Challenge Me
Circle the best answer.
Read this first
Table, Sample ages (USGS), with columns Sample, Age (billion years)
Meteorites, 4.53 to 4.58; oldest Moon rocks, 4.4 to 4.5; oldest zircon crystals (Western Australia), 4.3 to 4.4; oldest Earth rocks (Acasta Gneiss, Canada), 4.03.
Why does USGS base Earth's 4.54-billion-year age on meteorites rather than on Earth rocks, by Esme's reading?
- Meteorites are pieces of Earth
- Earth and meteorites formed together, and Earth's first rocks are gone
- Earth rocks are too young to date
- Earth's oldest rock is 4.54 billion years old
Captured-Moon prediction; giant-impact prediction. If the Moon had been captured from elsewhere, what would scientists expect its rocks to show, by Kira's reading?
- Exactly the same as meteorites
- A makeup matching Earth's outer layers
- A makeup unlike Earth's
- Ages younger than Earth's oldest rocks
Table, Sample ages (USGS), with columns Sample, Age (billion years)
Meteorites, 4.53 to 4.58; oldest Moon rocks, 4.4 to 4.5; oldest zircon crystals (Western Australia), 4.3 to 4.4; oldest Earth rocks (Acasta Gneiss, Canada), 4.03.
Luz's friend says Earth must be 4.03 billion years old, the age of its oldest rock. Which response is best (USGS)?
- Disagree: Earth is a few thousand years old
- Agree: the oldest rock is Earth's age
- Disagree: early rocks were recycled; meteorites give about 4.54 billion
- Agree: zircons are younger than Earth's rocks
Milo's cousin says the Moon was a wandering body that Earth captured. Which response is best (NASA)?
- Disagree: Apollo evidence points to a giant collision
- Agree: the Moon formed far away
- Disagree: the Moon formed from a piece of the Sun long ago
- Agree: capture explains the Moon
Noah's friend says after two half-lives a sample has no parent left, since half goes each time. Which response is best?
- Agree: decay stops after two half-lives, so the parent is gone
- Agree: half plus half makes the whole
- Disagree: the parent does not decay
- Disagree: each half-life halves what is left, leaving 1/4
Half-life 1.1 billion years; 1/16 left. A Moon rock has 1/16 of a parent left (half-life 1.1 billion years). About how old is it, and does that fit the Moon's oldest rocks, by Pia's math?
- About 1.1 billion years
- About 4.4 million years
- About 4.4 billion years, which fits
- About 17.6 billion years, older than the universe
Each half-life halves what is left. How many half-lives leave about 3% of the parent, by Ren's math?
- 5 half-lives
- 3 half-lives
- 97 half-lives
- 32 half-lives
Two meteorites dated about 4.56 billion years. An iron meteorite and a stony meteorite both date to about 4.56 billion years. What does that suggest, by Zee's reading?
- They fell to Earth 4.56 billion years ago yesterday
- Iron meteorites came from the Sun
- Earth is older than both
- Their parent asteroids formed near the solar system's start
Table, Sample ages (USGS), with columns Sample, Age (billion years)
Meteorites, 4.53 to 4.58; oldest Moon rocks, 4.4 to 4.5; oldest zircon crystals (Western Australia), 4.3 to 4.4; oldest Earth rocks (Acasta Gneiss, Canada), 4.03.
Which statement about the Moon's oldest rocks is best supported, by Ari's reading (USGS)?
- They show the Moon is at least 4.4 billion years old
- They show the Moon is 4.03 billion years old, like Earth's rocks
- They show the Moon is older than the meteorites
- They show the Moon was captured
Four clue cards, labeled A to D. Which set of clues best dates Earth's early history, by Bo's reading?
- Meteorites from the Sun date the Sun
- Fossils alone date Earth's formation
- Meteorites for the start, zircons and old rocks for the crust
- Earth's oldest rock alone dates Earth