The Chinese outreach publication Our Space announced the findings last month by using a term translated as “gel-like.” This notion sparked wide interest and speculation among lunar scientists. Researchers have now received a look at that strange lunar material, following an Our Space post released over the weekend.
Accompanying the new images of the Moon material were details about how the Yutu-2 team managed to overcome risks to analyse the specimen.
The clearest photo depicts two of the Yutu-2 rover’s six wheels and a seven foot-wide (2m) crater’s contents.
The compressed, black-and-white shot comes from an obstacle-avoidance camera on the rover.
The green, rectangular area and red circle within are thought to relate to the field of view of the Visible and Near-Infrared Spectrometer (VNIS) instrument, rather than the strange subject matter itself.
VNIS detects light scattered or reflected off material to reveal its chemical composition.
Because VNIS has a narrow field of view, the Yutu-2 team needed to carefully navigate the lunar rover to make a detection without stumbling into the crater.
After obtaining the first data set collected at the crater in July, the Yutu-2 team deemed it to be unsatisfactory due to shadows
The team consequently attempted a another approach and measurement during the proceeding lunar day last month.
According to Our Space, a satisfactory detection was made — but the results have yet to be released.
Professor Clive Neal, a University of Notre Dame lunar scientist, told Space.com how although the resulting photo is not perfect, it may yet offer clues about the unexpected discovery.
Professor Neal said that the material found in the crater’s centre resembles a sample of impact glass found during the Apollo 17 mission in 1972.
Sample 70019 was collected by astronaut Harrison Schmitt, a trained geologist, from a crater, similar to that found by Yutu-2.
The lunar expert described 70019 as being made of dark, coherent microbreccia — broken fragments of minerals cemented together — and black, shiny glass.
He said: “I think we have an example here of what Yutu-2 saw.”
High-speed impacts on the lunar surface melt and redistribute rock across the craters they make and can create glassy, igneous rocks with crystalline structures.
As for being unusual and “mysterious,” as described by the initial Chinese account, “having craters looking like those from Yutu-2 and where 70019 was collected is to be expected,” Professor Neal said.
The initial observation that captured the attention of the Chang’e-4 researchers was obtained by Yutu-2’s Panoramic Camera (PCAM).
Its predecessor Yutu-1, which landed on the near side in 2013, returned impressive, high-resolution colour vistas of the Moon’s desolate landscape using its PCAM.
The Yutu-2 team will have great images to work with, and these may suggest something different.
However, photos from the Chang’e-4 mission may not be released for up to a year.