Houston, we have a question: What are these weird spiky shapes we're seeing as we fly over Siberia?
That's what astronauts were asking this June, when the sight of strange, dark-green features running along Siberia's Kulunda Steppe left them stumped, according to NASA's Earth Observatory. The curving features streak across the plain near the Ob River, and can be seen from the International Space Station (ISS) when it flies over the Northern Hemisphere's 52nd parallel, the highest latitude of its orbit.
Fortunately for the ISS astronauts' burning curiosity, researchers at NASA Johnson Space Center in Houston had answers. The spikes are a side effect of the geology of the region: Folded surface rocks (shaped by tectonic forces) dip lower than the surrounding land, creating long, linear valleys filled with pine forests. From space, the pines appear as a darker shade of green than the surrounding agricultural fields, according to the Earth Observatory.
The spikes also appear in a winter scene snapped by an ISS astronaut more than a decade ago, in 2003. In that image, snow covers the fields surrounding the folds, doubly highlighting the pine forests within. [Photos: The 10 Strangest Places on Earth]