← Another date

Birthday · May 23, 2001

Strange Orange Soil on the Moon

May 23, 2001

When you were born, the Sun rose on a world that had never seen you before. Since then, every dawn has arrived in a universe subtly altered...

Strange Orange Soil on the Moon

A little universe, just for you

Your date.
Ready to give.

Free PNG · 1080 × 1350 · No account needed

Image rights and credit requirements apply when sharing or reusing imagery.

Change the year

APOD published May 23, 2001. Full image credits are on the original APOD entry below. A publication-date match, not a photo taken on your date. Independent of NASA.

Behind the image

Strange Orange Soil on the Moon

Original APOD · May 23, 2001

How did orange soil appear on the Moon? This mystery began when astronaut Harrison Schmidt noticed the off-color patch near Apollo 17's Taurus-Littrow landing site in 1972. Schmidt and fellow astronaut Eugene Cernan scooped up some of the unusual orange soil for detailed inspection back on Earth. Pictured above is a return sample shown greatly magnified, with its discovery location shown in the inset. The orange soil contains particles less than 0.1 millimeter across, some of the smallest particles yet found on the Moon. Lunar geologists now think that the orange soil was created during an ancient fire-fountain. Detailed chemical and dating analyses indicate that during an explosive volcanic eruption 3.64 billion years ago, small drops of molten rock cooled rapidly into the nearly spherical colored grains. The origin of some of the unusual elements found in the soil, however, remains unknown.

Explore May 23 in other years