article_snippet: Nasa's Lunar Prospector spacecraft first spotted the volcanic site in 1999 by detecting an isolated deposit of thorium - which is associated with volcanic activity.
article_snippet: Since Nasa's Lunar Prospector spacecraft discovery, an isolated deposit of thorium - which is associated with volcanic activity had been hard to study because an isolated deposit of thorium - which is associated with volcanic activity is hidden beneath debris from meteorite impacts.
article_snippet: But the Lunar Prospector was also able to detect gamma rays emitted by the thorium that can pass through up to 3.3 feet (one metre) of rock.
article_snippet: Based on this information, the Durham-led team used a 'pixon' image enhancement technique, originally designed to peer into the distant universe, to sharpen the map and reveal the enormous size of an isolated deposit of thorium - which is associated with volcanic activity from a lunar volcanic eruption.
article_snippet: first spotted the volcanic site in 1999 by detecting an isolated deposit of thorium - which is associated with volcanic activity. 
article_snippet: This map of the Moon shows gamma-spectrometric data collected by Nasa's the Lunar Prospector spacecraft, specifically thorium in surface rocks.
article_snippet: Rather than the radioactive element thorium, the researchers will be looking for hydrogen and the possible remnants of water ice from glaciers on the high slopes of the red planet.