Earhart, Hiding in Plain Sight


Scientists have identified a large crater on the near side of the moon—the first detection of its kind in at least a century. The structure has been provisionally named after aviation pioneer Amelia Earhart. (BBC)

What’s a moon? What’s a crater? Who’s Amelia Earhart? Use our resources to find out.

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

Earhart, a new crater of the moon, is just north of Serenitatis, the dark lunar mare (sea) at center left in this typically gorgeous NASA mosaic culled from Galileo images in 1992. Photograph by NASA/JPL/USGS
Earhart, a newly discovered crater of the moon, is just north (which is actually the upper right in this image) of Serenitatis, the dark lunar mare (sea) at center left in this typically gorgeous NASA mosaic culled from Galileo images in 1992.
Photograph by NASA/JPL/USGS

Discussion Ideas



  • Our encyclopedic entry says “Because the moon has almost no atmosphere, there is hardly any wind, erosion, or weathering. Craters and debris, called ejecta, from millions of years ago are still crystal-clear on the moon’s surface.” So, how was a 200-kilometer-wide (124-mile-wide) crater “hiding in plain sight”?
    • The Earhart crater was mostly buried by ejecta from a bigger, more recent impact. (That impact created the Mare Serenitatis, or “Sea of Serenity.”) So, the older crater isn’t really visible, much less “in plain sight.” It’s barely “in plain gravity.” (See next question.)


  • How did scientists discover the Earhart crater?
    • They examined data from NASA’s GRAIL mission. (NASA loves acronyms: This one stands for Gravity Recovery And Interior Laboratory.)
    • The GRAIL data tracked tiny gravitational anomalies on the moon. The mission did this through the use of two probes—Ebb and Flow. (Tidal swelling of love for NASA nomenclature!) As Ebb and Flow orbited the moon, instruments kept track of minute changes in the gravitational pull of the moon on each probe. Differences in gravity directly relate to differences in the density of the interior lunar crust. The circular outline of the Earhart crater only became apparent when scientists evaluated the density of the subsurface lunar crust, not the surface topography of the moon. (Whew.) (FYI: Ebb and Flow are now a permanent part of the lunar landscape.)


  • Why have scientists named the new crater Earhart?
    • Well, they haven’t, officially. All new astronomical objects and features need to be approved by the folks at the International Astronomical Union. (They’ll probably go for it, though.)
    • Legendary pilot Amelia Earhart was a visiting faculty member at Purdue University College of Technology. (She advised women on careers in aviation. What a great guidance counselor to have!) Earhart was flying a Purdue-funded Lockheed Model 10 Electra at the time of her disappearance. And . . . the new crater was identified by H Jay Melosh (an earth, atmospheric, and planetary science professor), Rohan Sood, and Loic Chappaz—a trio of researchers from Purdue. Nice.
    • Do we need a reason to honor Amelia Earhart? Says Dr. Melosh: “Craters are named after explorers or scientists, and Amelia Earhart had not yet received this honor. She attempted a flight around the world, and we thought she deserved to make it all the way to the moon for inspiring so many future explorers and astronauts.”



BBC: New lunar crater named after aviation pioneer Earhart

Nat Geo: What is a moon?

Nat Geo: What is a crater?

NASA: GRAIL mission overview

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