Oldest Igneous Meteorite May Reveal Secrets of Our Early Solar System

SCIENCE

A 4.565-billion-year-old space rock hints at the way Earth and other rocky planets took shape. (Phys.org)

What is a meteorite? Use our introductory reference to learn more.

Teachers, scroll down for a quick list of key resources in our Teachers Toolkit.

NWA 11119 is a 453-gram (nearly 1-pound), baseball-sized meteorite found in Mauritania in December 2016.
Photograph © 2017 B. Barrett/Maine Mineral & Gem Museum. From “Silica-rich volcanism in the early solar system dated at 4.565 Ga.” Nature Communications volume 9, Article number: 3036 (2018). https://doi.org/10.1038/s41467-018-05501-0

Discussion Ideas

  • NWA 11119 is the oldest igneous meteorite yet dated. What does NWA stand for?
    • Northwest Africa. The space rock was discovered in a sand dune in the west African nation of Mauritania in 2016. Thousands of meteorites are classified as “NWA,” as the Sahara Desert is one of the richest repositories of meteorites on Earth. (The Antarctic Desert is another.)
      • Although the meteorite was discovered in 2016, no one knows when it actually fell to Earth—the rock could have been in the sand for weeks or for centuries.

 

  • NWA 11119 is the oldest igneous meteorite yet dated. What is an igneous meteorite?
    • Igneous rocks are formed by the cooling of magma or lava. Meteorites are space rocks that fall to Earth’s surface. So, igneous meteorites formed from some type of volcanism on an extraterrestrial body, such as a planet, moon, or asteroid.

 

  • NWA 11119 is older than our solar system’s rocky inner planets and moons. So where did it form?

 

  • Scientists have tentatively linked the formation of NWA 11119 to a specific process associated with planetary formation. What is this process?
    • planetary differentiation. Planetary differentiation describes the process by which heavy elements sink to the center of protoplanets through 1) continual impacts and collisions with other protoplanets and asteroids, 2) radioactive decay, and 3) gravitational pressure. These heavier elements evolve into a planetary core and mantle, while lighter elements evolve into a planetary crust.
      • The new research indicates NWA 11119 was formed in the crust of a differentiated protoplanet. (That’s the big takeaway here.)

 

 

 

  • How does the mineralogy of NWA 11119 help us understand the early solar system?
    • This research is key to how the building blocks of planets formed early in the solar system,” says one scientist. “When we look out of the solar system today, we see fully formed bodies, planets, asteroids, comets and so forth. Then, our curiosity always pushes us to, to ask the question—How did they form? How did the Earth form? This is basically a missing part of the puzzle that we’ve now found that tells us these igneous processes act like little blast furnaces that are melting rock and processing all of the solar system solids. Ultimately, this is how planets are forged.”

 

TEACHERS TOOLKIT

Phys.org: Researchers uncover remnants of early solar system

The Meteoritical Society: NWA 11119

Nat Geo: What is a meteorite?

Nat Geo: Diamonds from Space Hint at a Long-Lost Planet

(extra credit!) Nature Communications: Silica-rich volcanism in the early solar system dated at 4.565 Ga

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