Cool to find what I assume are big-ass lava tubes, but I was amused to see how the first thing the press had to bring up was LIFE! I.e., that if there is life it'll be underground, and a cave is underground, and so this somehow makes us vaguely more hopefully about LIFE! True, I'm not sure why you'd think a good habitat for life or even spot for fossils would be a lava tube in what must be relatively recent basalt (post any "wet" period at least), way up on the flanks of a huge volcano, well above any likely aquifers and up where it's even colder and drier than most of the planet, but even so it's a cave, it's LIFE!

(*) I'm being slightly unfair -- eruptions could release volatiles, there's been some indications of glaciers and thus snow (CO2 or H2O?) on the big Tharsis cones, etc. But even so, other than proving that there isn't some strange Martian warp in the laws of physics that prevents caves from forming, I'm not sure why lava tubes on Arsia -- however neat if unsurprising a find -- makes LIFE! somehow likely.