It's hard to believe that an ancient structure larger than several football fields could go unnoticed for 8,000 years, but that's exactly what happened with Kazakhstan's Steppe Geoglyphs. The enormous earthworks are almost impossible to decipher from ground level. In recent years, however, satellite imagery has allowed researchers to identify hundreds of mysterious designs. Now, reports Ralph Blumenthal for the New York Times, NASA is giving researchers access to a trove of high-resolution footage of the site.

Like Peru's famous Nazca Lines, the Steppe Geoglyphs are best seen from above. That's how the Neolithic structures were actually discovered: In 2007, a Kazakh economist and archaeology fan named Dmitriy Dey was exploring Google Earth when he stumbled across the earthworks, Blumenthal writes. "There are pyramids all over the earth," Dey recalls, according to Blumenthal. "In Kazakhstan, there should be pyramids, too."

While Dey didn't find any pyramids, he discovered something just as surprising. He found hundreds of earthworks covering Kazakhstan's' remote plains. Since then, Dey has logged 260 unique earthworks of different shapes and sizes—from a giant square composed of dots to a massive, three-armed, swastika-like structure—none of which had been discovered before, Blumenthal writes.

The earthworks are made of dirt mounds that measure three feet high and 40 feet wide. Unlike the Nazca Lines, which depict pictures of birds, insects and plants, it's unclear what purpose the Steppe Geoglyphs served. Though archaeologists have dug up spear points and other artifacts—evidence of a Neolithic settlement that existed 6,000 to 10,000 years ago—excavations haven't uncovered enough artifacts to suggest they are tombs or memorials, Blumenthal reports. Dey suspects that the earthworks may have been designed as solar observatories by a sun cult, but more research needs to be done before researchers can propose a solid theory.

This isn't the first time NASA has stepped in to help earthbound archaeologists. Since the 1980s, the space agency has trained its equipment on sites across the planet, uncovering treasures like "ancient watercourses" in Sudan and Mayan settlements, Kelsey Campbell-Dollaghan reports for Gizmodo. NASA's satellite images will help archaeologists as they attempt to understand the site—and also protect it. According to Dey, a road builder demolished one of the earthworks earlier this year, even though he and his colleagues notified Kazakh officials of their discovery. "We cannot dig up all the mounds. That would be counterproductive," Dey tells Blumenthal. "We need modern technologies, like they have in the West."