Credit: ESA/DLR/FU Berlin (G. Neukum)

What looks like a gaggle of Martian tadpoles turns out to be a series of lava tubes on Pavonis Mons, a volcano on Mars, in this image from the European Space Agency’s Mars Express spacecraft.

Explore the series of channels as you travel across Mars. What other stories and pictures do you see in this image? Share a note below.

Rising more than 39,000 feet (12 kilometers) above the surrounding plains, Pavonis Mons is the central volcano of three that make up the Tharsis Montes. Called shield volcanoes, these three gently sloping mountains, dwarfing the largest mountains on Earth, look like flattened domes and are built mostly of thick, slow-moving lava over a long period of time.

Scientists found what they think are lava tubes along the south-west flank of the volcano. Lava tubes are formed by hot flowing lava. As the surface cools, a crust forms on top. Lava continues to flow beneath the hardened surface. When lava stops flowing and the tube is empty, the roof collapses leaving long, wormlike depressions. The longest tube in this image extends for about 36 miles (59 kilometers) and is more than a mile wide in some places. Lava tubes are well-known features here on Earth and have been found on the Moon as well.

Mars Express launched in 2003 as part of a series of probes sent to explore the Red Planet. Mars Express carries a wide variety of instruments to explore the planet. The greatest strength of the mission is its High Resolution Stereo Camera. The camera has a two-meter resolution; meaning objects as small as two meters can be seen in the images. Scientists are using it to image the entire planet in full color.