Scientists have found evidence for an accessible cave conduit beneath the moon's surface. The location of the underground cave is not far from Apollo 11's landing site. It's 250 miles (400 kilometers) from where Neil Armstrong and Buzz Aldrin landed 55 years ago.
Researchers analysed radar measurements by NASA's Lunar Reconnaissance Orbiter, and compared the results with lava tubes on Earth. Their findings appeared in the journal Nature Astronomy.
The finding suggests that the cave is a "promising site for a lunar base" as it offers shelter from the harsh surface environment and could support long-term human exploration of the Moon.
The cave is accessible from the deepest known pit on the moon. It's located at the Mare Tranquillitatis (Sea of Tranquility)
The pit, like the more than 200 others discovered up there, was created by the collapse of a lava tube.
NASA is aiming to build a semi-permanent crewed base on the moon, China and Russia have also announced interest in creating lunar research outposts. But, a permanent lunar base can only be set up in environments protected from cosmic radiation and with stable temperatures.
Such caves could form an emergency lunar shelter because the astronauts would be naturally shielded from harmful cosmic rays, solar radiation and micrometeorites.
Lunar orbiters first spotted pits on the moon more than a decade ago. Many are thought to be "skylights" that connect to underground caves such as lava tubes, giant underground tunnels that form through volcanic processes, reported The Guardian.