Check out a photo of Mars processed from Viking 1 that literally made me gasp when I enlarged it

This is amazing, and a little scary. We need to avoid infecting Mars accidentally.

Take, for example, the argument over humans vs. robots. Given the success of the robotic missions to Mars and other bodies, many people ask why we should bother to send people to any of those places. Tyson himself estimates the cost of sending a human to be around fifty times the cost of sending a robot, and says that "if my only goal in space is to do science, and I'm thinking strictly in terms of the scientific return on my dollr, I can think of no justification for sending a person into space." But then, he turns around and tries to justify it on fairly standard grounds: that humans are more flexible, while a robot can only "look for what it has already been programmed to find." Having humans on the scene would enable faster and more "revolutionary" discoveries.

This is an argument that sounds fairly convincing on a surface level, but on closer inspection it breaks down in two ways: it's too generous to humans, and too hard on the robots.

Both the presence of zinc deposits and veins of gypsum are very suggestive—water was likely once present in the Endeavour Crater region. Comparison with sandstone found elsewhere on Mars hints that Cape York's water was transitional. The hydrothermal deposits mark the early period, when volcanic activity was more common, while the evaporative deposits show a later period, when seas covered much of the Martian surface. The warm water required to form and precipitate gypsum hints that perhaps transient pools may have been habitable

HiView is the best way to explore HiRISE images of the Martian surface at the full resolution of the imagery. Tracks of boulders that have fallen down crater walls, delicate rays of ejecta from fresh impact craters, and the unearthly formations created by carbon dioxide ice on the Martian south pole are just a few of the things that are waiting to be discovered by anyone using a tool like HiView with HiRISE imagery.

wow: "More than 10 million square kilometers of landscape on the surface of Mars, a region nearly the size of Europe, is made of glass—specifically volcanic glass, "a shiny substance similar to obsidian that forms when magma cools too fast for its minerals to crystallize."