Howardites

A printable worksheet for the lesson The journey through the atmosphere (Start here: Explorer). It prints on A4 without the website around it. The answers are on a separate sheet for the teacher.

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Start here: Explorer · Ages 10 and upHowardites worksheet

The journey through the atmosphere

Name:Class:Date:

Key words

Meteorite
A meteorite is a piece of space rock that has survived its fall through the air and landed on Earth.
Meteoroid
A meteoroid is a small piece of rock or metal travelling through space.
Asteroid belt
The wide ring of space between Mars and Jupiter where most known asteroids travel around the Sun.
Ablation
Ablation is the melting and vaporising of a meteoroid's surface as it speeds through the atmosphere.
Fusion crust
Fusion crust is the thin, dark skin that forms on a meteorite as its surface melts during its fall.
Dark flight
Dark flight is the last part of a meteorite's fall, after it has slowed down and stopped glowing.

Choose the right answer

Circle the letter of the right answer.

  1. In what form is the melted surface carried away during ablation?
    • ATiny droplets
    • BLarge slabs
    • CThick sheets of lava
    • DIce crystals
  2. How is the top entry speed of about 72 km/s worked out?
    • AEarth's 11 km/s gravity speed multiplied by seven
    • BThe speed at which the fastest stones start to glow
    • CEarth's 30 km/s added to the 42 km/s solar-orbit limit
    • DThe speed of the fastest comet ever seen, doubled
  3. A meteoroid enters at about 11 km/s. What does that suggest about how it was moving beforehand?
    • AThe same way as Earth, at nearly the same speed
    • BFaster than anything else in the Solar System
    • CRound the Sun the opposite way to Earth
    • DStraight towards Earth, head-on, very fast
  4. Why does the pressure on a meteoroid's front face rise as it plunges deeper?
    • AThe rock speeds up as it falls lower
    • BIt is ploughing into thicker and thicker air
    • CGravity gets much stronger near the ground
    • DThe air gets hotter near the ground
  5. Sonic booms from a meteorite fall are often mistaken for what?
    • AAircraft landing
    • BExplosions or thunder
    • CBird calls
    • DWaves breaking on a shore

True or false?

Is the answer given right? Tick True or False.

  1. Why do many stony meteoroids break apart in the air?

    Answer given: Old cracks weaken them until air pressure exceeds their strength TrueFalse

  2. A 100 kg meteoroid enters the atmosphere. Which result on the ground is most likely?

    Answer given: Less than half of it survives as meteorites TrueFalse

Write your answer

Answer in a word or a short sentence.

  1. What causes the sudden bright flares seen in many fireballs?
  2. What is the bright meteor we actually see?
  3. What pushes falling fragments sideways during dark flight?

Task

Next time there is a reported fireball in the news, look at the map of where it was seen. Notice how the track runs in one direction. Where along that track would you expect the biggest pieces to land, and why?

Howardites · free to copy for use in your classroom · answers are on the separate teacher's answer sheet