Ghost craters on the Moon!

Here is a ghost crater, can you see it?

Ghost crater Lambert R, captured from orbit by NASA’s Apollo 17. Source: NASA

A ghost crater is a crater buried in lava, with only the crater rim visible. How do they form? Say a regular crater forms by an asteroid/meteor impact at some point. After that, during the time of active volcanism on the Moon, lava eruptions in the area may fill the crater to the brim, leaving behind just the rim. Many such ghost craters have been spotted on the Moon. My favorite is this one where the crater is fully submerged in lava, but the bright ejecta from the impact is still visible!

A 650-700 m ghost crater with visible ejecta. Credit: NASA Lunar Reconnaissance Orbiter (LRO)

Long-time Moon Monday readers will get reminded of the previously covered Lunar Kipuka, which is a similar feature. One of the ways scientists know these ghost craters really are craters is by imaging them from orbit at low-sun angles. Their rim, if it is a crater, casts a long shadow in such cases and makes its nature apparent.

More complex ghost craters have been observed on Mercury from past missions, decorated with graben and ridges! Fascinating stuff.

KNOW MORE


EXPLORE ON A MAP

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

Powered by WordPress.com.

Up ↑