India's pioneering mission strengthens the theory that the moon surface had melted.

The Chandrayaan 3 mission India has provided the first measurements to composition the soil near the south pole of the moon 1 . The minerals found offer further indications that the lunar surface had completely melted shortly after the moon was formed.

The Vikram-Lander the Chandrayaan-3 landed on the surface on August 23, 2023. He dropped a rover named Pragyan, which collected data from temperature to seismological measurements for over 10 days.

Pragyan also examined the chemical composition of the regolith: the fine material that covers a large part of the lunar surface. The rover stopped 23 times and used an instrument called Alpha particle X-ray spectrometer (APXS).

Santosh Vadawale, an X -ray generony at the Physical Research Laboratory in Ahmedabad, India, and his colleagues analyzed the radiation data that was collected by the APX, and used this information to identify the elements in the regolith and its relative frequencies, which in turn revealed the mineral composition of the soil. The team found that all 23 rehearsals consisted mainly of Ferroanorthosite, a frequent mineral on the moon. The results were published in Nature today.

"" It is, so to speak, what we expected based on orbital data, but it is always good to get the real truth, "says Lindy Elkins-Tanton, a planetary scientist at Arizona State University in Tempe.

earlier landers achieved similar results. However, the rehearsals of the Chandrayaan-3 are the First from the subpolar region : Earlier landers visited equatorial and mid-pleated zones. Together, this indicates that the composition of the regolith is uniform across the entire lunar surface.

Vadawale says that this is the direct confirmation that the lunar surface was a melted magma lean immediately after its formation. The theory of the Lunar MagmameER was first proposed by two independent groups in 1970 after rocks that were collected in the landing of Apollo 11 in 1969 were analyzed.

origin of the moon

The best model for the origin of the moon says that the new earth was hit by a large impactor called Theia, which evaporated the surface of the planet and hurled a large amount of material into the orbit. The distributed material quickly clumped and formed the moon. This impact theory explains why Lunare has an isotope composition similar to that on earth.

The material that formed the moon had a lot of energy that had to be dissipated. This escaped in the form of heat and had the surface of the young moon melt into a Magmameer. Dense mafic rocks, rich in metals such as magnesium, sank into the interior of the moon. Lighter rocks, including anthosite, swam upwards and formed Hochländer, similar to those visited by Chandrayaan-3.

"It continues the hypothesis of the Lunar Magmameer," says Mahesh Anand, a planetary scientist at the Open University in Milton Keynes, Great Britain.

Vadawale and his colleagues found that their rehearsals contained increased amounts of magnesium compared to the values ​​of calcium. This indicates that deeper mafic materials were mixed into the regolith.

The researchers attribute this to the events that formed an enormous impact crater called Südpol-Aitken basin, the edge of which is 350 kilometers from the landing point of Chandrayaan-3. "If such a big impact crater is created, it should dig up a few deeper materials," says Vadawale because the impactor penetrates deeply into the crust. This deeper, magnesium -rich material would have been distributed over a large area and would have slightly changed the composition of the regolith that Pragyan examined.

A problem with this idea, however, is that the Südpol-Aitken basin is apparently dominated by a mineral called Pyroxen, which does not quite fit the data from Pragyan, says Anand. To clarify it, it will probably be necessary to bring samples back to earth, he says.

The next Chandrayaan mission, which is located in an early stage of development, intends to do that.

"For me this is a story about the Success of the Indian Space Program ", says Elkins-Tanton.