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's oldest rock is 4.54 billion years old
- Earth rocks are too young to date
- Earth and meteorites formed together, and Earth's first rocks are gone
- 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?
- 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
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: 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
- 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
- Disagree: the Moon formed from a piece of the Sun long ago
- Agree: capture explains the Moon
- Agree: the Moon formed far away
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 17.6 billion years, older than the universe
- About 4.4 billion years, which fits
Each half-life halves what is left. How many half-lives leave about 3% of the parent, by Ren's math?
- 3 half-lives
- 5 half-lives
- 97 half-lives
- 32 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?
- Within about 140 million years
- About 1.4 billion years after Earth formed
- Before 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?
- Earth is older than both
- They fell to Earth 4.56 billion years ago yesterday
- Their parent asteroids formed near the solar system's start
- Iron meteorites came from the Sun
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 was captured
- They show the Moon is at least 4.4 billion years old
- They show the Moon is older than the meteorites
- They show the Moon is 4.03 billion years old, like Earth's rocks
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
- Meteorites for the start, zircons and old rocks for the crust
- Fossils alone date Earth's formation
- Meteorites from the Sun date the Sun