S27E142: Martian Moon Origins, Starship's Sixth Triumph, and Earth's Ore Age Revelation

[00:00:00] This is SpaceTime, Series 27, Episode 142, for broadcast on the 25th of November 2024.

[00:00:07] Coming up on SpaceTime, how the red planet Mars got its moons, our full report on Starship Test Flight 6, and a billion year shift in the formation of planet Earth's largest ore deposits.

[00:00:21] All that and more coming up on SpaceTime.

[00:00:26] Welcome to SpaceTime with Stuart Gary.

[00:00:45] A new study suggests that Mars got its two moons, Phobos and Deimos, after a passing asteroid was ripped apart by the red planet's gravity.

[00:00:54] The findings reported in the journal Icarus are based on new supercomputer simulations by NASA.

[00:01:00] Besides the Earth's moon, Phobos and Deimos are the only moons in our solar system that orbit a terrestrial planet.

[00:01:07] Previous hypotheses have suggested that the two tiny moons were either captured main-built asteroids, or the result of a major asteroid impact on the Martian surface, possibly on the planet's northern hemisphere lowlands.

[00:01:20] That latter explanation better accounts for the paths the moons travel today, in these circular orbits that closely align with the Martian equator.

[00:01:28] The problem is, a giant impact usually ejects material into a disk that mostly stays close to the planet.

[00:01:35] And the Martian moons, especially Deimos, are orbiting quite a bit further out from the planet, and so probably formed at their current distance.

[00:01:43] The new study, using a series of supercomputer simulations, suggests another option.

[00:01:48] The destruction of an asteroid that ventured too close to Mars, pushing through its Roche limit, where gravitational tidal disruptions tore the asteroid apart.

[00:01:58] The new modelling shows the resulting rocky fragments from the asteroid's destruction would have been strewn into a variety of orbits around Mars.

[00:02:06] More than half of those fragments would have escaped the Mars system completely, but others would have stayed in orbit.

[00:02:13] Tugged by the gravity of both Mars and the Sun, some of these remaining pieces would have collided with one another,

[00:02:19] and every encounter would have further ground them down, turning them into even more debris.

[00:02:25] Many collisions later, smaller chunks from the former asteroid would have settled into a debris disk circling the planet like a ring.

[00:02:32] And over time, some of this material would eventually have coalesced, accreting to ultimately form Phobos and Deimos.

[00:02:40] To assess whether this was a realistic chain of events, the authors explored hundreds of different close encounter simulations,

[00:02:47] varying the asteroid's size, spin, speed and distance at its closest approach to the red planet.

[00:02:53] Now in many of these scenarios, enough asteroid fragments survived and collided in orbit to serve as the raw material to form the two moons.

[00:03:01] The study's lead author, Jakub Kogaris from NASA's Ames Research Center in California's Silicon Valley,

[00:03:07] says this new model makes different predictions about the two moons' properties,

[00:03:11] and these can be tested against standard ideas for this key event in Martian history.

[00:03:15] The new hypothesis also allows for a more efficient distribution of moon-making material to the outer regions of the debris disk.

[00:03:22] And that means a much smaller pair of an asteroid could still deliver enough material

[00:03:27] to send the moon's building blocks to the right place.

[00:03:31] Testing different ideas about the formation of the two Martian moons

[00:03:34] is the primary goal of the upcoming Martian moons exploration or MMX sample return mission,

[00:03:40] which should be led by JAXA, the Japanese Aerospace Exploration Agency.

[00:03:44] The spacecraft will survey both DEMOS and Phobos before eventually collecting samples from the surface of Phobos

[00:03:51] to bring back to Earth for study.

[00:03:53] A NASA instrument aboard the spacecraft called MEGAIN, short for Mars-Moon Exploration with Gamma Rays and Neutrons,

[00:04:00] will identify the chemical elements Phobos is made of and help select sites for the sample collection.

[00:04:06] And some of these samples will be collected by a pneumatic sampler also provided by NASA

[00:04:11] as a technology demonstration contribution to the mission.

[00:04:15] Understanding what the Martian moons are made of

[00:04:17] is one clue which could distinguish between the moons having an asteroid origin or a planet plus impactor origin.

[00:04:23] This is Space Time.

[00:04:26] Still to come, SpaceX undertakes a successful sixth test flight of its Starship mega rocket

[00:04:32] and a new study shows a billion-year shift in the formation of planet Earth's largest ore deposits.

[00:04:39] All that and more still to come on Space Time.

[00:04:41] SpaceX has undertaken a successful sixth test flight of its Starship mega rocket

[00:05:02] with United States President-elect Donald Trump joining SpaceX boss Elon Musk

[00:05:07] to witness the spectacular launch first-hand.

[00:05:10] Flight directors go for launch.

[00:05:12] All right, we're now T-minus 20 seconds until liftoff of Starship Flight 6.

[00:05:17] 9, 2, 7, 6, 5, 4, 3, 2, 1.

[00:05:34] Vehicle is pitching downrange.

[00:05:35] Booster Raptor, chamber pressure nominal.

[00:05:37] Booster and ship, avionics power and telemetry nominal.

[00:05:40] All right, we're just a little over a minute into flight.

[00:05:42] Maximum dynamic pressure.

[00:05:43] We're about six miles away so all the sound's still hitting us here.

[00:05:47] Hearing good call-outs at power telemetry nominal that's flying straight and true.

[00:05:51] We do see all 33 Raptor engines lit up on telemetry screens.

[00:05:56] At this point, we've passed through that point of maximum aerodynamic pressure, that max Q.

[00:06:01] Now, coming up in just a little over a minute from now is going to be hot staging.

[00:06:07] So we're going to see the six engines on the ship ignite while still attached to the booster.

[00:06:12] Just before that, we'll see all but three center engines on the booster shut down.

[00:06:17] In what we call MECO, it's most engines cut off instead of main engine.

[00:06:20] A lot of our flight controllers looking at all the systems around the tower.

[00:06:25] Again, we have to send a manual command.

[00:06:27] We heard the tower is go for catch.

[00:06:30] Booster engine cut off.

[00:06:31] The return flag is set for true.

[00:06:34] Ship engines start up. Stage separation.

[00:06:36] All right, hot staging confirmed.

[00:06:38] Six out of six lit on the ship.

[00:06:40] Booster boost back going.

[00:06:41] We heard that we are go for catch.

[00:06:43] Kate, Jessie, take other views.

[00:06:45] Hopefully I got a booster coming home real soon.

[00:06:47] Right now it is performing the boost back burn.

[00:06:49] Phenomenal.

[00:06:50] Good news there telling us that the pressures inside the ship are good.

[00:06:55] That is the second stage or the upper portion of the vehicle.

[00:06:58] Yeah, booster is currently a super heavy is currently in its boost back burn.

[00:07:02] This boost back burn.

[00:07:03] Ameonics power telemetry nomine.

[00:07:04] This boost back burn lasts just a little bit over a minute.

[00:07:08] However, a loss of communication with the launch tower computer at the Boca Chica starbase in Texas meant they were prevented from seeing a repeat of the previous test spectacular super heavy booster returning to the launch pad and being captured by the launch tower's chopstick arms.

[00:07:23] So instead, the first stage was instructed to undertake a vertical landing at sea splashing down in the Gulf of Mexico.

[00:07:31] But all other aspects of the flight appear to go according to plan, with a hot staging separation of the upper starship orbital section from the booster section performing nominally.

[00:07:41] The booster then undertook its boost back re-entry burn using its underbelly heat shield to belly flop through the atmosphere to burn off speed during the re-entry and then flipping from the horizontal back to the vertical at the last minute for a perfectly executed landing burn and touchdown on the sea surface.

[00:07:58] Booster offshore divert.

[00:08:00] Booster offshore divert.

[00:08:00] The hot stage has been jettisoned.

[00:08:03] Yes, visual confirmation of that.

[00:08:05] Starship is following a nominal trajectory.

[00:08:07] The next step for booster is going into that landing burn.

[00:08:10] Again, it'll light up 13 of those engines and then pair down to three engines right before booster catch.

[00:08:17] All right.

[00:08:17] Now, just real quick.

[00:08:18] We did hear the call out booster offshore divert.

[00:08:21] Unfortunately, that means that we are no go for the catch both the tower and the vehicle as well as the operators on constant.

[00:08:28] Council have been actively evaluating the commit criteria for that return to the launch tower.

[00:08:35] And unfortunately, we did not have a pass on those commit criteria.

[00:08:39] So we are no go for tower catch.

[00:08:41] There's a lot of things that need to go well in order to line that up.

[00:08:44] Unfortunately, today we will forego booster catch today.

[00:08:48] We have an additional objective today to do an in space relight of a Raptor engine, which again will help us set us up for being able to do deorbit burns, which is.

[00:08:57] The ship chamber pressures are nominal.

[00:08:58] Which is important for orbital flights.

[00:09:00] Yeah, once again, we are attempting an offshore landing of the super heavy booster off the Gulf Coast of Texas.

[00:09:08] Those grid fins.

[00:09:09] There are four hypersonic grid fins.

[00:09:11] Oh, we can see that the landing burn for the booster.

[00:09:15] Same pattern.

[00:09:16] 13 engines will light.

[00:09:17] Gone down to three just as we expected.

[00:09:20] Splash down.

[00:09:21] Super heavy.

[00:09:21] So we'd like to confirm a water landing once again for the super heavy booster.

[00:09:27] Meanwhile, the Starship upper stage continued to climb to orbit, cruising halfway around the planet before reentering the atmosphere above the Indian Ocean off the Western Australian coastline.

[00:09:36] The test included reigniting one of Starship's Raptor engines for the first time in space.

[00:09:42] It's going to attempt to do an in space burn.

[00:09:44] We're going to light one of those Raptor engines, the sea level ones in the middle, just to help demonstrate that we can relight in that microgravity environment.

[00:09:52] Really critical for deorbit burns.

[00:09:54] So we start to do some orbital missions in the not too distant future.

[00:09:58] And then following that, we'll see a ship entry, maybe a splash down.

[00:10:02] As you guys said, we're really going to be pushing ship on this one.

[00:10:06] We're pretty much intentionally putting it in places where we expect it might not do so great.

[00:10:10] And all that's to try and help us learn, see if we're a little too conservative.

[00:10:14] And then maybe that opens up more capability for when we start catching them.

[00:10:17] The next milestone is...

[00:10:19] Starship is in terminal guidance.

[00:10:21] Starship terminal guidance referring to the upper stage.

[00:10:24] At about 8 minutes 35 seconds or so, we have ship engine cutoff, which will be the cutoff of the Raptor engines.

[00:10:33] Ship engine cutoff.

[00:10:34] And there we just heard a call out for SECO, ship engine cutoff.

[00:10:38] Everything continuing to look awesome.

[00:10:39] Ship FTS is safe. Nominal orbit insertion.

[00:10:43] There's that call out we were waiting for. Confirmation of good orbital insertion for ship today.

[00:10:48] Ship nominal orbit, so it's on its way around the planet.

[00:10:52] And trialing new heat shield materials.

[00:10:54] As a reminder, one of the main goals of today's flight test is for the ship to make it through the extreme heat of reentry and to do so in a controlled manner.

[00:11:03] Now, reentry is typically a portion of flight where we don't have communication capability with the spacecraft because it's reentering at or around orbital velocity, which is roughly 8 kilometers per second or about 5 miles per second.

[00:11:19] Now, at those speeds, yep, pretty fast.

[00:11:22] The spacecraft is moving through the atmosphere rather quickly and that results in friction and this creates a plasma field around the vehicle.

[00:11:32] That blanket of plasma distorts communication frequency, so it's not uncommon to experience brief blackouts in communication.

[00:11:39] Other thermal protection experiments saw some areas stripped of the heat tiles to see where the catch mechanisms could be positioned there on future flights.

[00:11:47] The receding tile line where we have removed a number of heat shield tiles in order to test out and push the envelope on the ship and demonstrate what its capabilities are.

[00:11:59] We are really pushing the ship today.

[00:12:00] The heat shield is not in the same configuration as it was last flight where we had a team of ship techs do just an otherworldly task replacing the entire heat shield.

[00:12:12] We have thousands of tiles installing a backup of lativ and that pretty much set us up to do a pinpoint landing on flight five.

[00:12:20] We did not do that with this one.

[00:12:22] We have some backup in those really sensitive areas around the flat, but this is an older generation heat shield.

[00:12:28] And knowing we weren't going to do that, we even went and removed some extra tiles.

[00:12:33] There are some missing tiles on the nose cone where we're testing some backups.

[00:12:37] There are some steel covered tiles in a couple of different spots.

[00:12:41] And there's also a whole lot more steel of the ship showing.

[00:12:44] A couple hundred tiles trimmed off the sides and that's where we might have catch fittings in the future.

[00:12:49] But color is starting to come in.

[00:12:51] So it looks like things are going to start heating up Kate and Jesse.

[00:12:54] Yeah, fun fact, Dan, we actually removed 2,100 heat shield tiles from Starship in order to basically present that necessary receding line.

[00:13:04] We want to test the vehicle beyond what we think it is capable of carrying based on our simulations and calculations.

[00:13:12] So once again, don't be surprised if we see some wackadoodle stuff happen here.

[00:13:18] We won't be.

[00:13:19] There are a number of things that we are testing out intentionally to see what the ship can take.

[00:13:25] Yeah, exactly.

[00:13:26] And knowing what those limits are will really help us design the vehicle of the future.

[00:13:31] Essentially, removing those tiles helps us remove a lot of weight from the vehicle, a lot of things that might potentially need refurbishment in the future.

[00:13:38] And the goal is to come up with a heat shield pattern or design that we don't have to refurbish.

[00:13:44] We can just continue to use it over and over again.

[00:13:47] And that's why we're changing some of those tiles and moving stuff around, removing a lot of those tiles, as Kate has been mentioning.

[00:13:55] Exactly.

[00:13:56] And, you know, looking forward to the Starship capability of the future, we want to be able to catch Starship like we do with boosters.

[00:14:03] And so the next flight, we want to better understand where we can install catch hardware, not necessarily to actually do the catch, but to see how that hardware holds up in those spots.

[00:14:13] And today's flight will help inform, you know, does the stainless steel hold up like we think it may based on experiments that we conducted on flight five.

[00:14:22] And Starship was also programmed to test a new more aggressive descent strategy before flipping vertically for the landing.

[00:14:29] The Starship is at 85 kilometers. Flaps now have control of the vehicle.

[00:14:33] The ship is beginning to reenter the Earth's atmosphere.

[00:14:37] The Starship is approaching the peak heating phase of entry.

[00:14:40] We've got kind of the next gen ship lined up for flight seven.

[00:14:44] It's got all of those heat shield upgrades and everything.

[00:14:47] And one of the things that we're going to be doing that's most interesting and one of the reasons we wanted daylight is we're going to be flying pretty aggressively as ship comes in.

[00:14:55] We're going to be kind of nose down. We've done it in wind tunnels. We've done it in simulations.

[00:14:59] You might see the flaps really flapping around, trying to control the vehicle.

[00:15:04] We're betting we might have a little bit more capability than think in just the analysis.

[00:15:09] But always a chance that that doesn't pay off.

[00:15:11] But that just helps us know, like, what are what are our limits?

[00:15:13] The Starship is now halfway through the peak heating phase of entry.

[00:15:16] Halfway there. Halfway home, guys.

[00:15:18] Just like the booster, it re-entered the Earth's atmosphere horizontally, bleeding off speed with its underbelly heat shield.

[00:15:24] And as we've seen on previous flights, displaying stunning plasma wave patterns as it descended through the atmosphere.

[00:15:32] Interestingly, however, sharp-eyed viewers would have noticed wrinkles or creases developing on the exposed surface of the hull midsection during the descent.

[00:15:40] It wasn't a major issue as the underlying structure kept the whole thing together.

[00:15:44] But it was an interesting point of observation.

[00:15:47] We are also testing out new secondary thermal protection materials.

[00:15:52] So basically, like if the heat shield isn't in this one spot, can this other material protect the metal is the thinking there.

[00:15:59] Also checking of the ship's structural strength in those areas where we're looking to add that ship catch hardware just to see if it survives entry.

[00:16:08] As we've been saying, we've done a lot of calculations and simulations.

[00:16:13] Similar to Flight 5, we are targeting the same splashdown location in the Indian Ocean, but we are not expecting to recover the vehicle.

[00:16:23] The flaps so far are looking pretty good.

[00:16:26] We're not seeing any burn through.

[00:16:28] Once we're subsonic, essentially.

[00:16:29] So I think that's about 1,200 kilometers an hour.

[00:16:33] Once we're down below that, that's when we're going to kind of dip our nose down and get that more aggressive angle of attack.

[00:16:38] Normally, we're just belly flop right into the water pretty much that position.

[00:16:43] But if we're going to be able to do return to launch sites, we're going to want to be able to fly with a little bit more of an angle of attack,

[00:16:50] get you a little bit more range as you're coming through.

[00:16:53] And so this will be just a test to see quite how far can we push it.

[00:16:58] And obviously, we're going to do these kind of tests way out here in super remote areas before you ever try to bring a ship back to a place like Starbase.

[00:17:05] Starship remains on a good entry trajectory.

[00:17:08] External temperatures are coming down.

[00:17:09] That tells us that we are through the phase of peak heating.

[00:17:14] So we are expecting these temperatures to continue to come down.

[00:17:18] Once again, we are targeting a soft splashdown in the Indian Ocean off the northwest coast of Australia.

[00:17:27] And as we get down a little bit lower, the Raptor engines are in their chill phase right now.

[00:17:32] So just essentially getting them primed to turn on.

[00:17:36] We're going to use those three center engines to do a landing flip and then a landing burn.

[00:17:41] So we'll come down kind of in that slightly pointed down belly flop and then fire off those engines to flip us around

[00:17:48] and do that final landing burn.

[00:17:49] Starship has passed maximum entry dynamic pressure.

[00:17:52] Do have some heating there on that looks like one of the forward flaps on Starship.

[00:17:57] This is to be expected.

[00:17:59] We knew that the vehicle would perform differently than what we had seen on Flight 5.

[00:18:05] Looks like that heating is starting to cool off there.

[00:18:08] Yeah, it's a little burn through.

[00:18:10] Again, it is important to know when we start seeing that through the ship's descent as well.

[00:18:16] Also, like Kate was saying, we're getting some really good data here.

[00:18:20] Looks like the other flaps are doing a little better than the one that has a little burn through, which is some good news.

[00:18:25] Starship is slowing down past Mach 1.

[00:18:27] And go ahead, Dan.

[00:18:28] Starship has started the subsonic belly flop.

[00:18:30] Remains on a good trajectory.

[00:18:31] This is when things will start to get a little interesting.

[00:18:34] So this is when we're moving slower than the speed of sound.

[00:18:37] Your nose slowly start to tip down.

[00:18:39] And we're going to try and maintain flap control the whole way.

[00:18:42] But we are just a couple of minutes away from hopefully doing a landing flip.

[00:18:46] Landing flip and landing burn if the flaps can hold together.

[00:18:49] This higher angle of attack, we're intentionally doing it to stress those aft flaps.

[00:18:54] And that will help inform the limits of flap control in order to collect data for future landing profiles.

[00:19:00] We're looking good so far.

[00:19:02] We've just got about five kilometers in altitude to go.

[00:19:05] We'll ignite the engines when we're still just a couple hundred meters over the ground, do that flip.

[00:19:09] Starship is passing through five kilometers altitude, remains on a good trajectory.

[00:19:13] As with previous test flights, Starship flipped back to vertical just before splashing down on target an hour and five minutes after launch.

[00:19:21] The whole thing being monitored by a pre-positioned SpaceX buoy anchored nearby.

[00:19:27] Our ship is doing great so far.

[00:19:31] There's those engines relighting.

[00:19:34] What a great reorientation by Starship.

[00:19:56] And this flight also carried Starship's first ever biological payload.

[00:20:00] It was a banana hanging all by itself in the cavernous payload bay.

[00:20:05] Exactly why it was put there has been the subject of some speculation.

[00:20:09] A camera did monitor it throughout the flight.

[00:20:12] And importantly, it didn't explode once in space.

[00:20:15] So it's fair to say the payload bay must have remained pressure tight throughout the mission.

[00:20:20] This launch also marked the quickest turnaround so far between test flights for what is the world's largest and most powerful rocket.

[00:20:28] And it was the last test flight for this specific version of Starship.

[00:20:32] The next test will involve an upgraded version 2 Starship, which will have a slightly altered design with larger fuel tanks.

[00:20:39] Now theoretically that could fly next month, although an actual launch date is yet to be set.

[00:20:45] Meanwhile work's already underway on a future third variant of Starship, which will include engines three times more powerful than those currently used.

[00:20:53] That should be ready to fly in about a year.

[00:20:56] The massive gleaming 121 meter tall stainless steel rocket is at the heart of Musk's plans to develop an interplanetary colonial transport vehicle.

[00:21:06] One capable of carrying 100 people at a time on missions to the moon, to Mars and beyond.

[00:21:11] In fact, using Starship, Musk hopes to eventually turn humanity into the first multi-planetary species.

[00:21:19] Current plans will see NASA use a version of Starship, called the HLS, the ferry astronauts and equipment between the Orion spacecraft and the lunar south pole as part of the Artemis 3 mission in September 2026.

[00:21:32] After that, it will be used to shuttle people, supplies and equipment between the Lunar Gateway space station, once it's positioned in trans-lunar orbit, and the lunar surface, helping maintain a permanent human presence on the moon.

[00:21:44] And Starship doesn't end there.

[00:21:47] Musk is also planning to fly an unmanned version of Starship to Mars on a test run, also in 2026.

[00:21:53] That will coincide with the next Mars transfer window.

[00:21:56] That's the time when the orbits of the Earth and Mars allow for journeys between the two planets to be kept down at just six or seven months each way.

[00:22:05] SpaceX sees Starship as the future of the company.

[00:22:08] Eventually, it will replace the current Falcon 9 and Falcon Heavy vehicles, as well as the Dragon capsule.

[00:22:14] And one day, it may even replace some airline services on point-to-point journeys between major cities on Earth, meaning any point on planet Earth will be no more than 90 minutes from any other point.

[00:22:27] A true glimpse into the future.

[00:22:29] This is space-time.

[00:22:31] Still to come, a new study has found that Earth's largest iron ore deposits, found in Western Australia's Pilbara, are about a billion years younger than previously thought.

[00:22:41] And later in the science report, a new study warns that global plastic waste is likely to double by the middle of this century.

[00:22:49] All that and more still to come on Space Time.

[00:23:07] A new study has found that planet Earth's largest iron ore deposits, which are found in the Western Australian Pilbara region, are about a billion years younger than what was previously thought.

[00:23:16] The latest data places the massive deposits at between 1.1 and 1.4 billion years of age, far less than the 2.2 billion years previously estimated.

[00:23:27] The findings are important because they help establish a new picture of planet Earth's geological history at a time when plate tectonic upheavals saw ancient super-continents begin to break up and subduct while new ones began forming.

[00:23:40] The discovery, reported in the Journal of the Proceedings of the National Academy of Sciences, are based on new geochronology techniques which are far more accurate at measuring the age of iron oxide minerals.

[00:23:51] The new research is able to precisely date minerals from banded iron formations which are ancient underwater layers of iron-rich rock and which provide a significant insight into Earth's deep geological past.

[00:24:03] The study's lead author, Liam Courtney Davis from Curtin University and the University of Colorado Boulder, says the energy from this epic geological activity likely triggered the production of billions of tons of iron-rich rock across the Pilbara.

[00:24:17] Western Australia is the world's leading producer of iron ore, which is Australia's largest export earner at $131 billion a year.

[00:24:26] Until now, the exact timeline of these formations changing from 30% iron, as they originally were, to more than 60% iron, as they are today, was unclear.

[00:24:35] And that hindered science's understanding of the processes that led to the formation of these huge reserves.

[00:24:41] But the discovery of a link between these giant iron ore deposits and changes in supercontinent cycles enhances science's understanding of ancient geological processes and improves geologists' ability to predict exactly where they should be exploring in the future.

[00:24:55] By using an emerging technique to date iron oxide minerals through uranium and lead isotope analysis within the mineral grains, the authors were able to directly date all the major banded iron formation deposits in the Hammersley province.

[00:25:09] Courtney Davis says the findings showed that these deposits formed in conjunction with major tectonic events, events which changed planet Earth completely, highlighting the dynamic nature of the planet's history and the complexity of iron ore mineralization.

[00:25:24] So we've been looking into redefining what is the age of the mineralization within the banded iron formations in the Pilbara.

[00:25:32] The original banded iron formations that were laid down across the Hammersley are very old.

[00:25:38] These are about 2.45 billion years old.

[00:25:41] But for them to actually be a mineral deposit or an iron ore deposit, something has to happen which transforms these banded iron formations from about 40% iron, 30% iron to about 60%, 65% iron.

[00:25:55] And this process was originally believed to have happened around 2 billion years ago based on evidence from other minerals in the ore, which were not direct indicators of the age.

[00:26:07] But now at Curtin University, we've been developing instruments and methods that have allowed us to actually date iron minerals.

[00:26:15] So this is iron oxide minerals like hematites, which are the minerals that make up the ore deposits.

[00:26:21] And through dating of these minerals in most of the major deposits within the region, we found that they're about a billion years younger than we previously understood.

[00:26:30] Why does that matter? Why is that important?

[00:26:32] So it's important because if we want to be able to actually understand where mineral deposits are sitting within the crust,

[00:26:39] and this isn't just for iron ore, this is for all commodities like gold or lithium, we need to have a really good grasp on how these ore deposits form.

[00:26:48] So what was the tectonic setting? What were the drivers for mineralisation? What were the processes?

[00:26:54] So once we can actually define how your deposit forms, that gives miners and explorers a blueprint of how they might be able to better adapt exploration to search for more of these deposits.

[00:27:05] Because a lot of these deposits are dwindling in grade, especially in the Pilbara, and we need to really be looking for bigger, better deposits.

[00:27:13] When I think of iron, I think of something condensing out of a protoplanetary nebula and then forming the core of a planet around a nascent star.

[00:27:23] I then think of something that's upwelled from deep within the Earth in the form of basalt in a craton or something,

[00:27:30] and basically sitting in the lithosphere. There's a third way iron ore can form, and that is it's excreted by some microorganisms in the sea.

[00:27:39] Yeah, so in simplest terms, back in the day before there was a lot of oxygen in the atmosphere, the oceans were very iron-rich,

[00:27:46] and a lot of that iron would have come from hydrofermal vents in the oceans.

[00:27:50] So we had a really iron-rich ocean. Then we had a period called the Great Oxidation Event,

[00:27:56] which is where bacteria started reacting, creating oxygen, which reacted with iron,

[00:28:02] and that iron then settled on sea floors to create bands of iron.

[00:28:07] These would have been layers of Cherty silica-rich rocks and then layers of more iron-rich rocks that were forming.

[00:28:14] And this is what we see in Karajini National Park today, these nice interlayered rocks of silica to iron-rich material.

[00:28:21] So those rocks are the host of what is being mined, but those rocks aren't iron-rich enough to actually be mined.

[00:28:30] So there's a later process which happens which upgrades the banded iron formations to be a lot more iron-rich.

[00:28:37] And this is a hydrofermal process which will basically leach out all that silica and introduce more iron,

[00:28:43] and basically concentrate iron within certain areas of the Pilbara.

[00:28:48] This is different from the vast oceans of iron coming through great magma flows.

[00:28:53] Yeah, yeah, completely different, because they would be igneous deposits.

[00:28:58] You do get, in places like Karuna in Sweden, you do get magmatic rocks, which are very iron-rich, which are mines.

[00:29:05] Those are called iron oxide apatite deposits.

[00:29:08] But these are sedimentary deposits, which are then silicified and then transformed to be more iron-rich.

[00:29:16] So yeah, nothing to do with mantle upwelling or igneous magmatic activity.

[00:29:20] You used a new geochronology process in order to determine the age of these rocks.

[00:29:25] So there's an instrument called a laser ablation inductively coupled plasma mass spectrometer.

[00:29:31] And with this instrument, you can put in small polished pieces of rock into the sample's chamber.

[00:29:38] This will then shoot a laser beam down onto the sample material.

[00:29:42] And in our case, that laser beam is about 50 microns in diameter.

[00:29:46] That will ablate a little top section of that mineral, so in our case hematite.

[00:29:52] It will transport the ablated material to the mass spectrometer.

[00:29:56] And that mass spec will then separate out different elements and isotopes.

[00:30:01] So what we're looking for is to be able to measure the ratio between the uranium and the lead

[00:30:05] within that tiny little bit of the mineral grain, because uranium decays to lead.

[00:30:10] So if we know the ratio of that, we can work out what was the exact time that that mineral grain crystallized.

[00:30:16] So this is a uranium-led dating technique, which we've now been able to develop and adapt to use with iron oxide minerals.

[00:30:25] Because previously, a lot of the time, people date zircons and other minerals which are more amenable to uranium-led.

[00:30:31] So this is a new technique which we're applying here, but then we're hoping to use in all different types of environments.

[00:30:37] There was a lot of continental shifting going on.

[00:30:40] Tectonic plates were moving, and that aided in this process.

[00:30:43] Yeah, so we've been able to correlate the periods of their iron ore formation or their economic mineralization

[00:30:50] with different episodes of continental breakup and coming together.

[00:30:55] And we've noticed, and it's not just with iron ore, it's with a lot of different commodities.

[00:31:00] In Western Australia, there seems to be a time period around 1.3 billion years ago

[00:31:05] when different parts of Australia were amalgamating into more like the continent we see today.

[00:31:10] And it's this tectonic force or drivers that provide the energy and hydrothermal fluid

[00:31:16] that we need to actually transform the banded iron formation from just rock into ore.

[00:31:22] We talk about banded iron formations. What are they?

[00:31:26] These are sedimentary deposits, and they have a distinctive rhythmic banding of reddish iron and paler silica.

[00:31:33] And these elements were ultimately laid down on the seafloor seasonally during the Great Oxidation event

[00:31:40] when oxygen was reacting with iron in the ocean,

[00:31:44] then allowing it to settle out as iron oxide minerals on the ocean floor.

[00:31:48] These rocks are in the Pilbara, about 2.45 billion years old.

[00:31:53] And they're an archive between Earth's continents, oceans and atmosphere through time.

[00:31:59] And they're the rocks which we now mine for iron once they've been upgraded.

[00:32:02] If they're younger, what does that mean, other than the fact they were laid down more recently?

[00:32:07] Well, if the iron in the rock is younger than the actual timing that it was laid down,

[00:32:13] it means that there was some kind of event which concentrated iron within these rocks to an economic level

[00:32:20] which made it viable for the big exploration companies to go out there and mine.

[00:32:25] And that's where the plate tectonic movements come in.

[00:32:27] Yes.

[00:32:27] Where does this take us?

[00:32:28] For us, something interesting would be to be able to further correlate this with banded iron formations across the world.

[00:32:36] Because they're not just in Western Australia.

[00:32:38] There's huge deposits of these formations in South Africa, Brazil, Lake Superior region in North America, Ukraine and China.

[00:32:46] So we really want to be able to understand when all these deposits were turning into the iron ore that we see today.

[00:32:53] And there's lots of different connections.

[00:32:55] Like the banded iron formations in the Pilbara and South Africa, at the same age,

[00:32:59] they were laid down at the same time when these two countries were joined together as continents.

[00:33:03] So we want to be able to work out when iron ore was forming across the world, not just within the Pilbara.

[00:33:08] That's Liam Courtney Davis from Curtin University and the University of Colorado Boulder.

[00:33:14] This is Space Time.

[00:33:31] And time now to take a brief look at some of the other stories making use in science this week with a science report.

[00:33:37] A new study shows that if you're over the age of 40, taking an hour-long walk every day could add years to your life.

[00:33:44] The findings reported in the British Journal of Sports Medicine looked at physical activity and life expectancy,

[00:33:50] showing that if people over the age of 40 were as physically active as the top 25% of the population,

[00:33:56] they could expect to live an extra five years on average.

[00:33:59] Or to put it more simply, for every one-hour-long walk you take, it adds an extra three hours to your life.

[00:34:06] The study also found that the impact of exercise was greatest for the least active people,

[00:34:10] who could add an extra six hours to their lives simply by taking that one-hour walk.

[00:34:15] The authors say the study proves that the costs of physical inactivity are far greater than previously thought.

[00:34:22] A new study has shown that global plastic waste will double by the middle of the century if humans stick to business as usual.

[00:34:31] However, researchers also found that a mix of policies could slash plastic waste by up to 90%.

[00:34:36] The study, reported in the journal Science, also found that greenhouse gas emissions from plastic production and waste management

[00:34:44] are set to grow by at least 37% over the same period.

[00:34:48] However, an intelligent mix of policies could slash plastic waste by up to 90%.

[00:34:53] To reach their conclusions, the authors simulated eight interventions currently being considered

[00:34:58] by the United Nations Plastic Pollution Treaty,

[00:35:01] finding that implementing just four could reduce mismanaged plastic waste by roughly 91%

[00:35:06] and plastic-related emissions by a third.

[00:35:11] A new study has found that switching to a vegan diet could lower your food costs by 19%.

[00:35:16] On the other hand, switching to a Mediterranean diet is unlikely to have any impact on the cost of your groceries.

[00:35:23] The study, reported in the Journal of the American Medical Association,

[00:35:27] compared 30 people who started a vegan diet and 30 people who started a Mediterranean diet.

[00:35:33] And they estimated their food costs, based on several three-day records of what the participants ate during the study.

[00:35:39] Researchers found the lowered costs of the vegan diet were mainly associated with savings on meat and added fats.

[00:35:46] And these savings clearly outweighed the increased spending on vegetables, grains, fruits and meat alternatives.

[00:35:53] The 2024 Ben Spoon Award, the glittering highlight of the Australian Skeptical Calendar,

[00:35:59] has been awarded to the Cancer Council of Western Australia

[00:36:02] for its endorsement of the pseudo-medical and unscientific practices of Reiki and reflexology.

[00:36:07] The award's presented annually at the Australian Skeptic Skepticon Conference,

[00:36:11] which this year was held in Sydney.

[00:36:13] It's presented to the perpetrator of the most preposterous piece of paranormal or pseudo-scientific piffle.

[00:36:19] The Western Australian Cancer Council is a registered charity.

[00:36:23] It has the stated purpose of working with the community to reduce the incidence and the impact of cancer

[00:36:28] based on the most solid foundations of evidence available.

[00:36:33] However, the Western Australian Cancer Council says that complementary therapies such as massage,

[00:36:38] beauty treatments and Reiki, used in conjunction with conventional medical treatments,

[00:36:42] are increasingly considered an important part of supportive care,

[00:36:46] which helps people address a wide range of challenges beyond medical treatment or cancer.

[00:36:51] The inclusion of Reiki, which is a system in which the practitioner passes their hands through the air over a patient,

[00:36:57] often without touching them, supposedly helps balance their energy flows.

[00:37:01] And that's especially concerning for an organisation like the Cancer Council,

[00:37:05] which is designed to help people during and after their diagnosis for cancer

[00:37:09] and subsequent evidence-based treatments.

[00:37:11] Tim Mendham, Executive Officer for Australian Skeptics, says for an organisation like the Western Australian Cancer Council

[00:37:19] to endorse and add its imprimatur to pseudo-scientific practices in the name of wellbeing is disappointing,

[00:37:25] especially when some elements of the industry, such as the International Centre for Reiki Training,

[00:37:29] wrongly claim that Reiki can actually cure cancer.

[00:37:32] Mendham says opening the door to pseudo- and unscientific medical treatments in the name of wellbeing

[00:37:38] is simply not acceptable.

[00:37:40] Reiki and reflexology were both recently included in the list of therapies no longer covered by the NDIS.

[00:37:48] Runners-up for this year's Bent Spoon included Ellie McPherson for her own treatment for cancer

[00:37:52] and especially her medical consultant, Simone Lubbshire,

[00:37:56] the latter claiming a string of spurious medical qualifications.

[00:37:59] A dishonourable mention went to Channel 7 News for endorsing astrology,

[00:38:04] weather control and unsubstantiated autism treatments.

[00:38:08] The Western Australian Cancer Council now joins an illustrious rogues' gallery of past Bent Spoon winners,

[00:38:14] including Walkley Award-winning journalist and UFO proponent Ross Coulthard,

[00:38:18] former celebrity chef Pete Evans, who's actually won the award twice,

[00:38:21] the Australian Vaccination Network, which opposes vaccinations,

[00:38:25] a psychic dentist and both the broadcasting networks ABC and SBS.

[00:38:31] My, how the once great have fallen.

[00:38:33] This is Space Time.

[00:38:35] And that's the show for now.

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[00:39:44] You've been listening to Space Time with Stuart Gary.

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