After the tantalizing discoveries from Mariner 9, the United States launched a pair of ambitious spacecraft, to go study Mars, map it in detail, and not land just once, but twice, on the surface. These are the Viking spacecraft. And in 1976, the two Viking spacecraft went into orbit around Mars, and two landers landed on Mars. I like to think this is the moment when Mars went from prehistory to, to modern science then modern maps that came from Viking are the ones that we see, we talk about when we talk about what Mars looks like as a globe. One of my very favorite mosaics put together shows the view that you would have if you were coming in right over the top of Valles Marineris. Which, as you remember from Mariner 9, we just had this sort of ghostly view of all these things happening around here and now you can see this beautiful crack in the surface. There the volcanoes that had originally been above the, the dust clouds that they were identified for the first time. You see, up through here, these magnificent, you'll, we'll talk about these later, outflow channels that go off in through here. And views like this cover the entire globe and really show us what Mars is now. In addition, there were the landings, the two Viking landers. And the part that I remember the most about the Viking landers is this picture. This was not just the first color image returned from a spacecraft that had landed on the surface. It was also, of course, the first spacecraft that had landed successfully on the surface of a different planet. But this was also the first color photograph that was published in my home town newspaper, 1976. Before this moment, there had never been a color picture in the newspaper. I'm sure that they had developed the color capabilities and they were waiting for some excuse to use it the very first time. And what better excuse the mess, the pic, first picture coming back from Mars, in color. Now, if you look at this again, you might even say it doesn't look very exciting. It looks like a, a, a debris field, rocks strewn everywhere, dust all over the place, and, you'd be absolutely right. We'll talk a lot more about rovers and landing, and what you see on the surface of Mars, but I want to back, back out to the global view, and just do a quick overview of all of the missions that have happened since that time of the Viking. Because from now on in the class, we're not going to go historically one by one and talk about each mission as it happens. I'm going to now use these global data sets that have been done. But I want to tell you a little bit where they came from. So after Viking, there was actually a hiatus for about 20 years before anything successfully made it to Mars. There were two spacecraft that tried to go. There was the Mars Observer that in 1992 made it to Mars. And it's thought that it exploded when it was trying to go into orbit. And the, the rockets, fired to put it into orbit, exploded the whole thing. Bummer. In September of 1999, there was a spacecraft called Mars Climate Orbiter, which made it to Mars. It was supposed to go in orbit around Mars and this is the one which has perhaps the most embarrassing reason for failing ever. The computer software used the wrong units when calculating how much force that the rocket should, should produce. As it entered Mars, it encountered Mars at the wrong angle and burned up in the atmosphere. [SOUND] There are a lot of really sad, tragic things. Mars is hard to get to. It's hard to go into orbit around another planet, but, that one's pretty pathetic. Other than those two failures, and they were depressing failures, people who studied Mars were desperate to get back and, and understand what was happening there. And they just didn't seem to be able to get there. But other than those two failures, there has been now a string of missions to Mars that have successfully been in orbit. Successfully landed, successful roved around. And we now have an incredible fleet that's there still taking data. There was the Mars Global Surveyor, which was up for about six or seven years in orbit mapping Mars at much higher resolution, measuring magnetic field on Mars. It was Mars Odyssey which was looking at the spectra, the reflective light coming off the surface Mars trying to understand what the compositions were. It was also using this fantastic technique of gamma-ray spectroscopy, which we'll talk about in the future. Trying to understand where there currently is water underneath the surface of Mars. There was, oh and I should have told you about the back on Mars Global Surveyor, I think that one of the most interesting things on Mars Global Surveyor was a laser altimeter. A laser altimeter which used the timing of the laser light going up and back down again to figure out precise elevations on Mars, which led to incredible revolutions in our understanding of the planet. There was Mars Express, the first one from the European Space Agency, which also mapped out spec, spectroscopic regions on Mars. And it also had a lander, the Beagle 2 lander, which sadly, did not seem to survive landing on Mars. Currently in orbit, there's a Mars reconnaissance orbiter, which has very high resolution camiters, cameras can see rocks down to centimeter sizes in limited areas of the planet. It has one of the coolest things, it has a radar so it can see through the polar ice caps, and it has found also other regions where there's ice. We'll talk about that in the future. And it has additional spectroscopic capabilities. There are of course the landers. We'll talk about the landers in detail. And then there are two recent arrivals. My favorite one is this one, it's called the Mars Orbiter Mission. Or MOM, it actually has a name that I can't pronounce because it's, the first interplanetary mission from India. It was launched as, sort of a demonstration mission, they tried to downplay it very carefully just in case things didn't work out. And, things worked out great, it's in orbit around Mars, it's, it doesn't have a, a very large complement of scientific instruments, but the fact that it's there, I think is a harbinger of things to come from India. And finally, there's one more in orbit that just went into orbit that we'll talk about later. It's called the Maven spacecraft. And it is studying the atmosphere of Mars. So we are, have no shortage of orbiters around Mars. As we'll see, we'll have no shortage of things on the surface of Mars. There's an incredible amount of data, an amount of information that people are still making sense out of today from all of these different regions on Mars. We'll use all of these data sets now to try to answer some of these questions. Some of the questions that were hinted at even in just those very earliest days of the Mariner 9 images.
