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
The Moon has a small iron core for its size (NASA). How does that support the giant-impact idea, by Jun's reading?
- The Moon's iron floated away
- It shows the Moon is older than the meteorites
- A captured Moon would have had no iron core of any kind
- The debris came mostly from iron-poor outer layers
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?
- Ages younger than Earth's oldest rocks
- Exactly the same as meteorites
- A makeup unlike Earth's
- A makeup matching Earth's outer layers
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)?
- Agree: zircons are younger than Earth's rocks
- Disagree: early rocks were recycled; meteorites give about 4.54 billion
- Disagree: Earth is a few thousand years old
- Agree: the oldest rock is Earth's age
Milo's cousin says the Moon was a wandering body that Earth captured. Which response is best (NASA)?
- Agree: capture explains the Moon
- Agree: the Moon formed far away
- Disagree: Apollo evidence points to a giant collision
- Disagree: the Moon formed from a piece of the Sun long ago
Noah's friend says after two half-lives a sample has no parent left, since half goes each time. Which response is best?
- Disagree: the parent does not decay
- Agree: half plus half makes the whole
- Disagree: each half-life halves what is left, leaving 1/4
- Agree: decay stops after two half-lives, so the parent is gone
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.
Earth is about 4.54 billion years old and the oldest zircons about 4.4 billion. About how soon after Earth formed did solid crust exist, by Tala's math?
- Before Earth formed
- About 1.4 billion years after Earth formed
- About 14 years later
- Within about 140 million years
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?
- Their parent asteroids formed near the solar system's start
- Iron meteorites came from the Sun
- They fell to Earth 4.56 billion years ago yesterday
- Earth is older than both
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 was captured
- They show the Moon is older than the meteorites
Four clue cards, labeled A to D. Which set of clues best dates Earth's early history, by Bo's reading?
- Earth's oldest rock alone dates Earth
- Fossils alone date Earth's formation
- Meteorites for the start, zircons and old rocks for the crust
- Meteorites from the Sun date the Sun
