Guided Exploration: Center Area
Overview: The centerpiece of this hall is Ahnighito, one of the three Cape York meteorites on display here. Touchable specimens and text panels explain the characteristics of stony, stony-iron, and iron meteorites, and the history of meteorite science.
1. Thirty-Four Tons of Iron
Because it’s made of iron-nickel alloy, Ahnighito is much heavier than it looks. Touch and examine the meteorite. What do you feel and see? Tip: Look for the two polished spots; the criss-crossing pattern shows how the crystals grew. Note the difference between a meteor (an object that enters Earth’s atmosphere, usually disintegrating) and a meteorite (material that survives the intense heat and pressure to land on Earth’s surface).
2. Fragments of Cape York
Along with Ahnighito, these two meteorites, known as the Woman and the Dog, are fragments of a much larger meteorite that landed in Greenland thousands of years ago. Watch the video to learn how they reached the Museum.
3. Stone and Iron from Space
The most common type, stony meteorites are made of minerals that are similar to those in rocks on Earth. Iron meteorites are more than 98% metal. Stony-irons are a mixture of metal and rock. Compare the polished surface of Estacado (stony) and Ahnighito (iron). Notice that the different-sized grains of the stony meteorite and the regular pattern of the iron.)
4. What Does a Meteorite Look Like?
During a meteorite’s fall through the atmosphere, it heats up and melts on the outside. Its appearance depends on what it’s made of, how it came through the atmosphere, and what happened after impact. Compare the meteorites’ external appearances to explore the effects of their high-speed journeys. For example, one side of Miller stayed oriented towards Earth as it passed through the atmosphere. It eroded into an aerodynamic “nose cone” shape, and molten rock formed flow lines from front to back. Modoc’s broken surface high-lights its dark fusion crust, a thin, glassy coating that formed as its molten surface solidified before hitting the ground.
5. Looking Inside Meteorites
Scientists often cut meteorites into thin sections to study their internal structure. Examine the slices and read about what they reveal.