Providence, RI [Brown University] – At first, Dave Scott and Jim Irwin, the Apollo 15 astronauts, could not believe what they were seeing. During a cruise on their lunar rover – the first vehicle deployed to the moon – the astronauts observed the green twigs breaking the grayish-white uniformity of the lunar surface.

“[Are you] Are you sure it’s green and not white albedo again? Irwin asked, referring to the tactics that sunlight can play on the lunar surface.

“No, it’s green,” Scott confirmed.

Knowing they had something interesting, Scott and Irwin added a few samples to their collection that returned to Earth with the Apollo 15 crew 50 years ago.

More than 35 years later, those green spots that turned into pearls of volcanic glass found their way to a lab in Brown, where geologist Alberto Sal showed that they contained amazing amounts of water. That was the first Clear evidence The interior of the moon, although some water was thought to have been removed during formation, was not so dry.

“It completely revolutionized our thinking about how the moon formed and how the solar system interacts,” said Jim Head, a professor of geological sciences at Brown who worked on the Apollo program and worked inside NASA’s mission control center when Scott and Irwin explored. Chandran “It was a very important discovery made by Dave and Jim on that mission.”

It was the discovery that Head said was one of the most productive scientific missions in the history of space travel.

“Everyone knows about the historic Apollo 11, but most people don’t know about the subsequent missions,” Head said. “Apollo 15 was the first real scientific expedition to the moon, and it was incredibly successful.”

The Apollo 15 missions were the first to be described by NASA as J-type missions. Apollo 11, the first lunar landing, proved to be a safe landing on the moon. The next two landings, Apollo 12 and 14, touched down rough terrain. Those technological achievements set the stage for a strategic Apollo 15 landing in an area of ​​high technological interest: a place between the high Apennine Mountains and the Hadley Reel, with ancient lunar lava flowing carvings.

Head, lunar, expert in planetary geography, first job after earning a PhD. Brown was on the Apollo program and was instrumental in choosing that landing site.