Breaking through a popular perception of moon being a geologically inert place for the last three billion years, Indian scientists have found new evidence of the recent volcanic activities inside a lunar crater, opening up a new window for research.
The discovery of a 2-km high peak with large boulders comfortably sitting atop inside a crater and signatures of strong volcanic activities all around the peak may eventually aid scientists to solve one of the long-standing lunar mysteries – what is the moon made of?Analysing data collected by Chandrayan-I and USA’s Lunar Reconnaissance Orbiter, a team at the Physical Research Laboratory (PRL) in Ahmedabad, found evidences of volcanic vent, lava pond and lava channels as recent as 100 million years old inside the ‘impact crater’, thus implying that the moon was not a geologically quiet, rather, it was an active place.
The lunar volcano was different from the volcanoes seen on earth. Possibly, there was no explosive eruption. The magma may have oozed out silently through the vents. The discovery – if supported by further studies in future – has the potential to change the commonly held belief on geological history of moon, the team claimed. Instruments on board Chandrayaan-II, to be launched in 2013, will take a closer look at the peak.
Constantly bombarded by asteroids and meteors, moon has many scars on its face – the impact craters. The high-velocity collisions with lunar surface creates “impact-induced” mounds. The 2-km high peak in Tycho – a 110 million year old crater, is one such peak.
The fresh evidence of volcanic activity suggests magma may have been released from the interior as a consequence of the impact that led to the formation of the crater in the first place. This suggests that the moon was geologically active from inside when the carter was formed.
“Either the signatures were made post formation of the crater or sub-surface solidified magma which was released due to the impact. We can’t be sure at this point, therefore, require more studies from other craters.
“But unlike on earth, we cannot have a deep drilling project on moon to understand its deeper crust,” J N Goswami, PRL director and lead scientist of Chandrayaan told Deccan Herald.
“We found the inner crustal material exposed on the central peak of Tycho,” said Prakash Chauhan, a PRL scientist. The study, he claimed, changed views about geological history of the moon and brought out details of more recent modifications of the lunar surface.
“A surprise findings revealed the presence of large boulders–about 100 meter in size –on top of the peak. Nobody knew how did they reach the top,” Chauhan said. The findings were reported in the April 10 issue of ‘Current Science’.
Composition of lunar core and the nature of materials present on the surface remains one of the unsolved scientific problems. The evidence so far, has come mainly from the analysis of lunar rocks collected by Apollo missions, and analysis of images collected by a handful of spacecraft within the last six years including Chandrayaan-I.