Cool image time! The image on the right, reduced and rotated 180 degrees to post here, comes from a recent release for Lunar Reconnaissance Orbiter (LRO). It shows a flow of lava that partly covers an older terrain.
Some scientists propose that Ina formed as very young (less than 100 million years) volcanic eruptions because only a few larger impact craters (>20 m) have formed on its surface. Others believe it is quite ancient (3.5 billion years), possessing highly unusual physical properties that stifle the formation of normal impact craters. At least everybody agrees it was formed as basalt was erupted to the surface! But how and when Ina formed remains open.
Ina’s morphology is so unusual that it is easy to see inverted topography – that is, craters appear as bubbles rather than bowls! Think of Ina as a cast iron frying pan with freshly poured pancake batter; the wiggly textured material is the frying pan and the bulbous smoother mounds are the batter.
The image to the right has been rotated 180 degrees so that my mind at least can see it with the craters as bowls and the uplifted smooth lava as uplifted. If this doesn’t work for you, click on the link and look at the original image.
While some scientists think the lava flows are recent, no one knows at present the origins of the rougher terrain that the lava has partly obscured.
Please consider donating to Behind the Black, by giving either a one-time contribution or a regular subscription, as outlined in the tip jar below. Your support will allow me to continue covering science and culture as I have for the past twenty years, independent and free from any outside influence.
Regular readers can support Behind The Black with a contribution via paypal:
If Paypal doesn't work for you, you can support Behind The Black directly by sending your donation by check, payable to Robert Zimmerman, to
Behind The Black
c/o Robert Zimmerman
Cortaro, AZ 85652