Mars’ “spiders” are not living creatures at all. They are dark, branching surface features on the planet’s south polar terrain, and they form when seasonal carbon dioxide ice cracks and vents gas through the ice below.
If you want the short answer to where the spiders from Mars come from, they appear in Mars’ southern polar region, especially the area around Angustus Labyrinthus. Springtime carbon dioxide activity carves spider-like patterns into the ground there.
ESA’s Mars Express captured striking views of these features. The European Space Agency’s 2024 report explains how the process works.
The name can sound like a joke, since it echoes the famous “Spiders from Mars” phrase tied to David Bowie. On the planet itself, the real features are a seasonal geologic mystery that keeps teaching us more about Martian ice, dust, and polar weather.
Where On Mars These Spider Features Appear
These formations show up in Mars’ southern polar region. Winter layers of carbon dioxide ice build up and then change quickly as spring arrives.
The strongest concentrations appear near a region called Angustus Labyrinthus, also known as Inca City.
Mars’s Southern Polar Region
The southern pole gives the right mix of seasonal carbon dioxide frost, low temperatures, and surface dust. That combination makes the spider effect possible each spring.
Inca City And Angustus Labyrinthus
Inca City is the informal name for Angustus Labyrinthus, a maze-like area of ridges and valleys. ESA notes that the dark spots linked to these spiders cluster around the edge of this region, where the terrain looks almost geometric.
Why The Clusters Stand Out In Orbital Images
From orbit, the dark spots and branching patterns stand out against lighter ice and dust. The shapes are large enough to be seen in spacecraft images, making them easier for scientists to track across different seasons.
What The “Spiders” Really Are
The name sounds biological, yet these features are part of Mars’ surface geology. They are tied to araneiform terrain, a term for the spider-like branching patterns made by gas moving under ice.
Araneiform Terrain
Araneiform terrain is a network of channels that spreads outward like legs from a central point. Erosion and cracking under seasonal ice create the shape, not anything living.
Not Animals
These are not spiders or other creatures. They are geological marks, formed by pressure, cracking, and dust movement on a cold polar surface.
How Carbon Dioxide Ice Triggers Seasonal Gas Eruptions
Spring sunlight warms the ground under carbon dioxide ice. The ice turns to gas, builds pressure, and bursts through the surface, carrying dark dust upward in geyser-like plumes.
Why Dark Spots And Branching Channels Form Together
The dark spots show where dust lands back on the surface after the gas escapes. The branching channels form below the ice as the gas carves paths outward, so both the spots and the spider-like pattern come from the same process.
How Scientists Captured And Studied Them
Spacecraft imaging gave scientists the first clear look at these formations. Lab work helped test how they form.
Mars Express, the ExoMars Trace Gas Orbiter, and NASA-backed experiments each added a different piece to the puzzle.
Mars Express Surface Views
Mars Express used its High Resolution Stereo Camera, or HRSC, to capture broad views of the southern polar region and the edge of Angustus Labyrinthus. Those images showed the dark surface spots spread across hills, plateaus, and troughs.
ExoMars Trace Gas Orbiter’s Clearer Channel Detail
The ExoMars Trace Gas Orbiter gave a closer look at the tendril-like channels under the ice. ESA reports that the orbiter showed the spider-like patterns especially clearly, which helped connect the surface spots to the hidden channels below.
Lab Tests Led By NASA’s Jet Propulsion Laboratory
NASA’s Jet Propulsion Laboratory recreated spider-like araneiform terrain in Earth-based tests. Those experiments helped show that carbon dioxide gas escaping from under ice can produce the same branching shapes seen from orbit.
Why This Region Matters To Mars Science
This region gives a rare look at how Mars behaves near its poles today. It also offers clues about older landscapes, buried layers, and how impacts may have shaped the area.
What Inca City May Reveal About An Ancient Crater
ESA says the walls of Inca City seem to trace part of a large circle, which suggests the region may sit inside an old impact crater. If that idea is right, the ridges and swirls seen today may reflect a long history of impacts, lava, erosion, and possible fault lines.
Why These Features Are Rare On Mars
These spiders need a very specific setting, carbon dioxide ice, seasonal sunlight, and fine dust near the pole. That makes them rare compared with many other Martian surface shapes.
What Researchers Still Do Not Know
Scientists still do not know every detail of how Angustus Labyrinthus formed.
Researchers also wonder why some spider patterns are more visible than others.
Mars keeps changing in ways that are still hard to predict.
These features remain useful for study.
