Question 1

What do we call a space rock that lands on Earth?

Accepted Answer

A meteorite. A meteorite is a space rock that survives its trip through the air and lands.

Question 2

What is a shooting star really?

Accepted Answer

A tiny space rock burning up in the air. Shooting stars are meteors: little bits of space dust glowing as they rush into our air.

Question 3

Which planet has sent rocks to Earth?

Accepted Answer

Mars. Big crashes on Mars threw rocks into space, and some landed on Earth.

Question 4

What will stick to most meteorites?

Accepted Answer

A magnet. Most meteorites have metal inside, so a magnet sticks to them.

Question 5

Where do most meteorites come from?

Accepted Answer

The asteroid belt. Most come from the asteroid belt between Mars and Jupiter.

Question 6

Space rocks made almost all of metal are called…

Accepted Answer

Irons. Iron meteorites are made of nickel and iron metal.

Question 7

What colour is the outside of a fresh meteorite?

Accepted Answer

Black. The outside melts as it falls and makes a thin black skin called fusion crust.

Question 8

Where is a great place to find meteorites because the ground is white?

Accepted Answer

Antarctica. Dark rocks are easy to spot on the white ice of Antarctica.

Question 9

A super-bright shooting star is called a…

Accepted Answer

Fireball. Fireballs are very bright meteors. Some drop meteorites!

Question 10

The biggest meteorite ever found weighs about as much as…

Accepted Answer

10 elephants. The Hoba meteorite in Namibia weighs about 60 tonnes, about as much as 10 elephants.

Question 11

A meteorite from the Moon is called a…

Accepted Answer

Lunar meteorite. "Lunar" means to do with the Moon.

Question 12

When is the best time to see shooting stars?

Accepted Answer

On a dark, clear night. Go somewhere dark, look up, and be patient.

Question 13

What are chondrules?

Accepted Answer

Tiny round grains that were once molten droplets. Chondrules formed as melted droplets in space about 4.6 billion years ago.

Question 14

Which type of meteorite is seen to fall most often?

Accepted Answer

Ordinary chondrites. Ordinary chondrites (H, L and LL) make up most falls.

Question 15

Which spacecraft orbited the asteroid Vesta?

Accepted Answer

Dawn. NASA's Dawn orbited Vesta in 2011–2012.

Question 16

Howardites come from which asteroid?

Accepted Answer

Vesta. Howardites, eucrites and diogenites (HED) come from Vesta.

Question 17

What is the difference between a 'fall' and a 'find'?

Accepted Answer

A fall was seen coming down. Falls are seen landing. Finds are discovered later.

Question 18

The thumbprint-like dents on some meteorites are called…

Accepted Answer

Regmaglypts. Regmaglypts form when hot air carves the surface during the fall.

Question 19

The thin black skin on a fresh meteorite is the…

Accepted Answer

Fusion crust. It forms when the outside melts during the fiery fall.

Question 20

Pallasites contain beautiful crystals of which mineral?

Accepted Answer

Olivine. Golden-green olivine crystals sit inside nickel-iron metal.

Question 21

Meteorites are usually named after…

Accepted Answer

The place they were found. For example, Allende is named after a village in Mexico.

Question 22

Which of these is NOT a type of meteorite?

Accepted Answer

Granite. Granite is an Earth rock formed in Earth's crust.

Question 23

In which country did the huge Chelyabinsk fireball explode in 2013?

Accepted Answer

Russia. It exploded over Chelyabinsk, Russia, on 15 February 2013.

Question 24

About how old are most meteorites?

Accepted Answer

About 4.5 billion years. Most formed when the solar system was young.

Question 25

What does a Widmanstätten pattern in an iron meteorite tell us?

Accepted Answer

The metal cooled extremely slowly. The criss-cross pattern grows only during extremely slow cooling over millions of years.

Question 26

Roughly what share of meteorites seen to fall are chondrites?

Accepted Answer

About 86%. Chondrites dominate falls. Irons are only about 5%.

Question 27

A rock leaves a red-brown streak on an unglazed tile. That usually means…

Accepted Answer

Hematite, an Earth rock. Meteorites usually leave little or no streak. A red-brown streak points to hematite.

Question 28

How were Martian meteorites confirmed to come from Mars?

Accepted Answer

Trapped gases match Mars's atmosphere. Gas bubbles in the glass match what the Viking landers measured on Mars.

Question 29

Which was the first meteorite recognised as coming from the Moon?

Accepted Answer

Allan Hills 81005. ALH 81005 was found in Antarctica in 1982.

Question 30

Allende, which fell in Mexico in 1969, is classified as…

Accepted Answer

CV3 carbonaceous chondrite. Its white inclusions (CAIs) are among the oldest solids in the solar system.

Question 31

The Murchison meteorite (Australia, 1969) is famous for…

Accepted Answer

Organic compounds such as amino acids. Murchison is a CM2 chondrite rich in organic molecules.

Question 32

Why was the L'Aigle fall of 1803 important?

Accepted Answer

It convinced scientists that meteorites fall from the sky. Jean-Baptiste Biot's report on thousands of stones settled the debate.

Question 33

Where is the largest known meteorite?

Accepted Answer

Namibia (Hoba). Hoba, an iron of about 60 tonnes, still lies where it was found.

Question 34

Roughly how thin is a standard geological thin section?

Accepted Answer

30 micrometres. At 30 µm, most minerals let light through and show colours in polarised light.

Question 35

What type of meteorite fell on Winchcombe, England, in 2021?

Accepted Answer

A carbonaceous chondrite. Winchcombe is a CM carbonaceous chondrite, recovered within days.

Question 36

Which of these is NOT part of the HED group from Vesta?

Accepted Answer

Ureilite. Ureilites are carbon-rich achondrites from a different parent body.

Question 37

In an ordinary chondrite, petrologic type 3 indicates…

Accepted Answer

The least thermal metamorphism (unequilibrated). Types 4 to 6 show increasing metamorphism. Type 3 is the most primitive.

Question 38

The H, L and LL groups of ordinary chondrites differ mainly in…

Accepted Answer

Total iron and metal content. H = high iron, L = low iron, LL = low iron, low metal.

Question 39

What are CAIs?

Accepted Answer

Calcium-aluminium-rich inclusions. CAIs are the oldest dated solids, about 4.567 billion years old.

Question 40

Hexahedrites are iron meteorites made almost entirely of…

Accepted Answer

Kamacite (low-nickel iron). They have low nickel and often show fine Neumann lines instead of a Widmanstätten pattern.

Question 41

Ataxites show no visible Widmanstätten pattern because they…

Accepted Answer

Are very high in nickel. High nickel makes the structure too fine to see.

Question 42

SNC meteorites (shergottites, nakhlites, chassignites) come from…

Accepted Answer

Mars. SNC is the classic name for the main Martian meteorite groups.

Question 43

Ureilites are unusual because they contain…

Accepted Answer

Carbon as graphite and tiny diamonds. The diamonds probably formed by shock or high pressure on the parent body.

Question 44

In meteorite naming, 'paired' stones are…

Accepted Answer

Separate pieces from the same fall. Pairing is common in Antarctica and the Sahara, where many fragments are found.

Question 45

In the Antarctic newsletter, weathering grades A, B and C describe…

Accepted Answer

How much rust and oxidation there is. A is minor rustiness and C is severe. An 'e' means evaporite deposits are visible.

Question 46

Shock stages S1 to S6 measure…

Accepted Answer

Shock metamorphism from impacts. Higher stages show stronger shock effects, such as melt veins and mineral changes.

Question 47

Which iron meteorite group is considered 'non-magmatic' and often contains silicate inclusions?

Accepted Answer

IAB. IAB irons didn't form by simple fractional crystallisation of a core.

Question 48

Kamacite and taenite are…

Accepted Answer

Nickel-iron alloys. Kamacite is low in nickel and taenite is high in nickel. Their intergrowth makes the Widmanstätten pattern.

Questions & answers