It Looks So Familiar

Where in the Solar System is It?

What planet do we know of that has deserts and crater fields and looks rather reddish?  Where the sands of time have covered up any traces of water that may have flowed across the surface? That has scenes like this one?

Where is this?
Where is this?

One of the most intriguing things about studying the surfaces of other worlds is figuring out just how they came to be the way they are. Planetary scientists know of several processes that shape solid surfaces: cratering (made by incoming projectiles), weathering (caused by liquid or wind erosion (which is itself often termed “aeolian”)), volcanism (molten materials from deep beneath the surface that flow across terrains and cover over what was there before, or disrupt the landscapes with calderas and pits), and tectonism (the processes that fault and fold the surface of a planet or moon (such as earthquakes, mountain-building)).

So, if you look at a surface like the one shown above, you see no water, but you do see dunes and fields of sand and  dust. This tells you that at least wind-blown erosion and deposition are taking place.  You can also see some circular impressions that turn out to be the ancient, eroded remains of impact craters. Erosion takes time, which means that this surface is not  young and fresh. Weathering and deposition are covering up what’s left of these craters and various surface measurements give an estimated age of the craters themselves at about 140 million years old. And so we ask again: what planets in the solar system have evidence of aeolian (wind-blown) weathering and ancient impact cratering?  And, whose sands look some what reddish?

What does scene this tell you about the planet where this terrain lies? What assumptions can you make to help you guess where this scene is?  Think about it before dragging your pointer across the blank-looking area between the ( ) for the answer.

(It’s on Earth — in a desert area in Libya (northern Africa), that sports a pair of ancient impact sites called the Arkenu craters. This image was provided by astronauts aboard the International Space Station.)

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.