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?
- 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
- Meteorites are pieces of Earth
The Moon has a small iron core for its size (NASA). How does that support the giant-impact idea, by Jun's reading?
- It shows the Moon is older than the meteorites
- The Moon's iron floated away
- 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?
- A makeup unlike Earth's
- A makeup matching Earth's outer layers
- Ages younger than Earth's oldest rocks
- Exactly the same as meteorites
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: the oldest rock is Earth's age
- 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
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
- Agree: decay stops after two half-lives, so the parent is gone
- Disagree: each half-life halves what is left, leaving 1/4
Each half-life halves what is left. How many half-lives leave about 3% of the parent, by Ren's math?
- 5 half-lives
- 32 half-lives
- 3 half-lives
- 97 half-lives
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
- Within about 140 million years
- About 1.4 billion years after Earth formed
- About 14 years later
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?
- Iron meteorites came from the Sun
- Earth is older than both
- Their parent asteroids formed near the solar system's start
- They fell to Earth 4.56 billion years ago yesterday
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 4.03 billion years old, like Earth's rocks
- They show the Moon is at least 4.4 billion years old
- 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?
- Fossils alone date Earth's formation
- Earth's oldest rock alone dates Earth
- Meteorites from the Sun date the Sun
- Meteorites for the start, zircons and old rocks for the crust