Welcome to the Planet Four: Terrains Spotter's Guide
Having trouble distinguishing between spiders, baby spiders, and channel networks?
Remember that one of the defining features for spiders is that they have channels originating from a center pit/point. Then use the following guidelines to help you decide:
- Legs longer than the size of the center pit: It's a spider
- Only a pit or has tiny legs shorter than the size of the center pit: It's a baby spider
- No discernible pit and no centralized pattern but more grid or network like: It is a channel network
Spiders
Radially converging channels that are often branching and often hosting a visible central pit.
Baby Spiders
A spider without 'legs.' A central pit dominates, either without any branching channels associated or with very tiny ones. If channels are present, they will be short in comparison to the size of the central pit.
Channel Network
Where the spider channels are not radially organized (no central pit visible). They might form a dense tangled network of twisting strands and often times the channels outline closed shapes.
Swiss Cheese Terrain
Flat-floored, circular-like depressions in relatively thin carbon dioxide ice layer on top of the permanent polar cap.
Craters
A bowl-shaped cavity in the surface of Mars, typically caused by the impact of a meteorite. Typically much larger than the central pit of a spider or baby spider.
More Examples
Keep in mind that more than one of the features (spiders, baby spiders, channel networks, swiss cheese, and craters) we ask you to identify can be visible in an image.
Channel networks and baby spiders
Craters
Spiders
Spiders and baby spiders
Swiss Cheese Terrain
Channel network and spiders
None of the features (spiders, baby spiders, channel networks, swiss cheese, and craters) are present
Spiders and baby spiders
Swiss Cheese Terrain
Channel Network
Channel networks, spiders,and baby spiders
None of the features (spiders, baby spiders, channel networks, swiss cheese, and craters) are present
None of the features (spiders, baby spiders, channel networks, swiss cheese, and craters) are present
Other Surface Features You Might Encounter
Although we're not explicitly looking for these types of terrains below, you might encounter them in the images you review. You can identify these and any other interesting features you find in Talk with a hashtag or you can start a collection.
