From Apollo sample distribution and crater counts , we know that the volume of volcanism on the lunar month occurred from 3.9 to 3.1 billion years ago , and we ’ve long conceive that all volcanic natural process shut off around a billion years ago . But now , scads of freshly detected topographical anomaly discover that volcanic activity did n’t stop on the moon abruptly when we thought it did – rather , it ’s slowed gradually , and it may not even be done yet .
The discovery of these rock deposits suggests that volcano were erupting on the moon within the last 100 million years – during the Cretaceous when dinosaurs roamed the Earth – build the moon much , much warmer than we recollect . It may be time to rewrite the textbooks . Thefindingswere write inNature Geosciencethis week .
These rock deposits , ring " irregular female horse patches ” ( IMPs ) , are characterized by a distinct compounding of textures : politic , rounded , shallow cumulus next to patches of rough , blocky terrain . They ’re the remnants of modest basaltic eruptions , and they ’re dust all across volcanic plains . Until late , these features were count very uncommon : Only one , named Ina , was been spotted by Apollo 15 in the seventies .
Turns out , Ina is n’t a one - off oddity . Using NASA’sLunar Reconnaissance Orbiter Camera(LROC ) , researchers from Arizona State University and Westfälische Wilhelms - Universität Münster spot 70 unpredictable mare speckle on the near side of the moon . These are too little to see from Earth , and in fact , most of the lava flow that make up the dark plains seeable to us ( including the face of the “ serviceman on the moon”)erupted between 3.5 and 1 billion eld ago .
Their wide distribution powerfully evoke that former - degree volcanic activity was not an anomalousness . And their sharp nature and the absence seizure of encroachment craters greater than 20 metre in diameter indicate that at least three of these IMPs formed in the last 100 million years , accord to an LROC liberation .
Ina may be less than 50 million years old , they rule , and volcanic activity at another IMP called Sosigenes only ended about 18 million years ago . Sosigenes ( pictured , correct ) is only about 300 meters deep , 3 kilometer wide , and 7 kilometers long . you could see how thin the number of Crater on the lava flow are .
Because these IMPs forge mode after the well - established volcanic shutdown a billion yr ago , the findings evoke that the DoI of the moon is hotter than antecedently thought . Our cold , utter moon ’s still get some heating system in it . “ The existence and age of the irregular mare patch severalize us that the lunar mantle had to remain spicy enough to render magma for the low - volume eruptions that created these strange young features,”Sarah Braden of ASUsays in aNASA release . “ immature volcanism indicates perhaps more magma , or magma at higher temperatures , or magma at shallower depths , or all of the above,”she tells New Scientist .
“ The big story is that the moon is quick than we thought,”ASU ’s Mark Robinsontells Science . And with lava course that young , irruption are apt to happen again .
Images : NASA / GSFC / Arizona State University
