Nov 13: Mariner 9 Enters Mars Orbit, LCROSS Finds Water on the Moon

Host 1 Welcome to This Day in Space and Astronomy. On this day, November 13th, well, we are taking a five minute look at this day in space exploration and astronomy for anyone who looks up at the night sky and wonders. So imagine flying millions of miles through the void only to arrive and find your destination entirely erased from view.

Host 2 Yeah, that is exactly what happened.

Host 1 Yeah.

Host 2 To date, we're doing a deep dive into two times NASA had to violently punch through the veil, you know, to rewrite our solar system's history.

Host 1 Right. One being a Martian dust storm and the other a lunar crater.

Host 2 So back in 1971, Mariner 9 reached Mars. and a quick note on the date the history books log its arrival on November 13th for US calendars but the actual orbit insertion slipped into the 14th on UTC time at 0042

Host 1 oh so it just barely crossed over midnight

Host 2 exactly and after a 167 day trip it became the first spacecraft to ever orbit another planet

Host 1 and it was carrying double the workload right because its twin Mariner 8 was lost during a launch failure

Host 2 yeah all the pressure was on Mariner 9. But when it got there, well, it couldn't see a thing.

Host 1 I always think of it like driving through blinding fog. You can't see the road or the landscape. But suddenly you look up and spot just the very tip of an enormous skyscraper protruding through the clouds.

Host 2 That is a great analogy. It flew right into the middle of a global dust storm. It's this phenomenon where solar heating whips up the thin Martian atmosphere until dust hides almost the entire planet.

Host 1 Just completely blankets the whole globe.

Host 2 Yep. And that skyscraper poking through the dust, that was Olympus Mons, rising 16 miles high with a base roughly the size of Arizona.

Host 1 Unbelievable.

Host 2 It is. And when the dust finally settled weeks later, Mariner 9 also revealed Valles Marineris, you know, a canyon system stretching 2,500 miles across the surface and plunging up to 23,000 feet deep.

Host 1 Wow. So if Mariner 9 found canyons and volcanoes of that scale, I mean, that shatters the 1960s assumption that Mars was just a dead cratered rock like the moon.

Host 2 It changed everything. It shifted the paradigm to a dynamic world with a history of volcanism and ancient surface water carving out those valleys.

Host 1 and it paved the way for future missions right

Host 2 definitely by mapping 85 of the planet mariner 9 provided the crucial topography needed to select safe landing sites for the subsequent viking landers it proved mars had an active past which uh sparked a continuous line of mars orbiters we rely on today

Host 1 okay so mariner 9 gave us ancient signs of water on Mars but in 2009 we searched for actual frozen water much closer to home on the moon

Host 2 the L cross mission yes

Host 1 but I really have to push back on the method here on October

Host 3 Ninth of that year, NASA crashed a spent Centaur rocket stage into the Cabeus crater.

Host 4 That the lunar south pole, yeah.

Host 3 Right. But is slamming debris into the moon really the most scientific way to search for water?

Host 4 Well, it sounds aggressive, I know, but think about the environment. A standard rover's drill couldn't survive the temperatures in a permanently shadow crater.

Host 3 Because they sit near absolute zero. Right.

Host 4 Right. So a kinetic impactor was our only viable option to excavate that deep. Lcross directed that spent rocket stage into the crater, while a trailing probe watched the impact and gathered four minutes of crucial data.

Host 3 And then it crashed itself.

Host 4 Yep, it also crashed.

Host 3 So instead of gently landing a rover with a tiny drill, NASA just used a rocket stage like a cosmic sledgehammer to blast the evidence up into the sunlight where we could actually see it.

Host 4 Pretty much. That initial impact created a crater 20 to 30 meters across and it threw a plume of debris 20 kilometers high.

Host 3 20 kilometers.

Host 4 Yeah. We were talking about material from the crater floor that hadn't seen sunlight in billions of years. By throwing that plume up into the solar glare, Lcross allowed its spectrometers to catch the ultraviolet light bouncing off the debris.

Host 3 which revealed hydroxyl right?

Host 4 Yeah.

Host 3 The chemical fingerprint of water molecules breaking apart in the sun.

Host 4 You got it. It confirmed about 100 liters of water in that impact zone alone.

Host 3 So if we can prove those permanently shadowed craters hold ice, water, becomes a resource. I mean, we can use it for drinking or we can split it into hydrogen and oxygen for rocket fuel.

Host 4 Which explains why the moon's south pole is the primary target for modern lunar exploration.

Host 3 This date really has a habit of pushing our boundaries off world.

Host 4 It definitely does. Whether it was Buzz Aldrin proving we could work in space without exhaustion during a tethered Gemini 12 spacewalk in 1966, though sources debate if that lasted two hours and six minutes or just nine minutes.

Host 5 That is quite a discrepancy.

Host 4 Yeah. Or witnessing a total solar eclipse cross the South Pacific in 2012 beginning November 13th universal time but hitting Cairns locally on the 14th.

Host 5 oh another time zone technicality

Host 4 yep and even looking ahead to 2025 with blue origin landing a booster after launching NASA's twin escapade Mars probes November 13th consistently proves the impossible is just an engineering problem

Host 3 so consider that the next time you look at the moon it's no longer just a beautiful dead rock in the sky it is a gas station waiting to fuel our next jump to deep space

Host 4 it really changes how you see things

Host 3 it does we went from just trying to reach these celestial bodies to viewing them as resources holding the ancient history of our solar system if we can mine that ice you know where do we go next

Host 4 it is an exciting thought

Host 3 thanks for tuning in see you back here tomorrow