I am shamelessly starting with one of my own finds as I have only just realised what it is after a tip off from Katie from the Moon Zoo Team. I was looking out for this particular feature too and didn't spot it when it came up as it was rotated and so not the usual view. The Moon Zoo image also looked slightly different and my brain had settled on completely the wrong zoom level.
I'll just put it down to a bad day! IMAGE OF THE WEEK - MONDAY 17 MAY 2010
Ina (named after a lunar goddess in Polynesian mythology) is an odd looking “D shaped” lunar geological feature about 2 kilometres wide which was first spotted by the Apollo Astronauts. It can be found in Lacus Felicitatis (Lake of Happiness) a lake of ancient, hardened lava located in between Mare Vaporum (Sea of Vapours) and Mare Serenitatis (Sea of Serenity) at lunar coordinates 19 degrees North, 5 degrees East.
From the Apollo pictures it was first identified as a Volcanic caldera. Ina is thought to be a fairly recent volcanic feature (millions rather than billions of years old) as it still has sharp edges which have not been worn away by impacts and appears to host very few craters. It also has two distinct types of terrain: rough jagged rubble-like brighter areas and smoother, darker mounds. No-one knows for certain what caused these two different types of terrain. One view is that it is the result of a recent gaseous outburst which has removed part of the top layer of regolith. This paper
states that “Ina is fresh in appearance both photographically and spectrally.” And this article
tells us “the colors of Ina, measured by a spectrometer on the Clementine spacecraft, are similar to the colors of the Moon's youngest craters. Yet Ina is not an impact crater.”
Having got used to reading galaxy spectra (within limits!) over on Galaxy Zoo
I am quite intrigued at the thought of getting my hands on some lunar spectra!
However, it’s not all plain sailing as recent images from LROC
have shown that crater numbers in the mounds and surrounding Mare are very similar implying that Ina might not be quite as young as originally thought. More research is needed before the final verdict!
The great news is that there are likely to be similar features as yet undiscovered in other parts of the Moon and finding the unexpected is one of the things Moon Zoo will be good at.
|Caro found this in Boulder Wars in |
the same area. Looks like part of Ina.
|And Geoff found this close to Mare Imbrium in the same region. |
Is this also part of the Ina structure?
Here's the NAC strip: M113921307RE
So what are you waiting for? Get looking!!