In the photo: Astronomers named the Dark Spots "Seven Sisters" and gave them names: Dena, Chloe, Wendy, Annie, Abby, Nicky and Jenna. The average size of the circles is about the size of a football field. Click to enlarge. Here are a few more photos.
A year ago, images of Mars brought another mystery. On the slopes of the Martian volcano, objects very similar to the passages into the caves were discovered. Perhaps these are not the only dungeons on the Red Planet, and perhaps Martian life lurks in their depths
Deep dark rounded spots ranging in diameter from 99 to 250 m, spotted by Mars Odyssey and Mars Global Surveyor, immediately attracted the attention of researchers. Using infrared sensors on board the Mars Odyssey, they measured the day and night temperatures of these spots and concluded that they were not just specifically colored ground, but real underground tunnels - or rather, a submarine.
Indeed, during the day (after local noon), that at night (shortly before dawn) their temperature changed about 3 times less than the temperature of the surrounding rock. Moreover, during the day they turn out to be cooler, and at night - warmer than the surface of the planet next to them.
Such a regime is not as stable as that of large cave dips on Earth, which keep the temperature practically constant - but nevertheless, it is difficult to offer another explanation for it. “Whether it's funnels of vertical mines or entrances to winding underground labyrinths, they are all surely paths deep into the planet,” says researcher Tim Titus. missions.
The holes, which have already received the poetic nickname "Seven Sisters", are located in extremely high latitudes, on the slopes of the volcano Arsia Mons. So other experts express serious doubts: even if the simplest life on Mars once existed, it was unlikely to be able to master these homeless areas. And the place is not very suitable for a space base. Apparently, the dips were the result of the volcano's own activity, as evidenced by the fact that some of the dark spots lie in line with traces of frozen lava on the slopes.