00:00:00 --> 00:00:03 this is spacetime series 27 episode 154
00:00:03 --> 00:00:06 for broadcast on the 23rd of December
00:00:06 --> 00:00:09 2024 coming up on SpaceTime new studies
00:00:09 --> 00:00:11 showing the moon's actually a lot older
00:00:11 --> 00:00:13 than we thought nessa's perseverance
00:00:13 --> 00:00:16 Rover finally crests the top of jro
00:00:16 --> 00:00:19 crater's rim and understanding the
00:00:19 --> 00:00:21 tectonic mystery behind South
00:00:21 --> 00:00:24 Australia's strange pink beat Sands all
00:00:24 --> 00:00:27 that and more coming up on
00:00:27 --> 00:00:30 SpaceTime welcome to space time with
00:00:30 --> 00:00:40 steuart
00:00:40 --> 00:00:46 [Music]
00:00:47 --> 00:00:49 Gary new researchers discovered that the
00:00:49 --> 00:00:52 Earth's Moon may be an awful lot older
00:00:52 --> 00:00:54 than we thought scientists found
00:00:54 --> 00:00:55 evidence suggesting that the moon's
00:00:55 --> 00:00:58 crust underwent extensive remelting
00:00:58 --> 00:01:01 around 4.35 billion years ago and that
00:01:01 --> 00:01:04 would have masked a far older history
00:01:04 --> 00:01:06 the moon thought to have been formed
00:01:06 --> 00:01:08 when a mars-sized planet which
00:01:08 --> 00:01:10 scientists have named Thea collided with
00:01:10 --> 00:01:12 the early Proto Earth around 4 and A2
00:01:12 --> 00:01:15 billion years ago the Colossal impact
00:01:15 --> 00:01:17 turned both bodies into a magma ocean of
00:01:17 --> 00:01:20 melted rocks which eventually coales and
00:01:20 --> 00:01:23 solidified to form the Earth however
00:01:23 --> 00:01:25 some of the ejected debris from that
00:01:25 --> 00:01:26 impact was thrown up into orbit around
00:01:27 --> 00:01:29 the Earth and it gradually accreted and
00:01:29 --> 00:01:32 sidif fight to form the moon however
00:01:32 --> 00:01:33 this new research argues that there was
00:01:33 --> 00:01:35 a period Well after that when the moon's
00:01:35 --> 00:01:38 surface was melted again and changed the
00:01:38 --> 00:01:39 appearance of certain Rock samples that
00:01:39 --> 00:01:41 made them look younger than what they
00:01:41 --> 00:01:44 really were now if this evidence is
00:01:44 --> 00:01:45 accurate it means the Earth's moons
00:01:46 --> 00:01:49 actually around 4.53 billion years old
00:01:49 --> 00:01:52 it's all very confusing previous
00:01:52 --> 00:01:54 attempts to uncover the moon's true age
00:01:54 --> 00:01:56 have vied at estimates that lie several
00:01:56 --> 00:01:58 hundred million years apart while some
00:01:58 --> 00:02:00 researchers suggest that our Cosmic
00:02:00 --> 00:02:02 companion was formed 4.35 billion years
00:02:03 --> 00:02:06 ago others date the birth at 4.51 and
00:02:06 --> 00:02:07 now
00:02:07 --> 00:02:09 4.53 one of the most striking
00:02:09 --> 00:02:12 inconsistencies is of a Stony nature you
00:02:12 --> 00:02:14 see almost all the lunar Rock samples we
00:02:14 --> 00:02:16 have here on Earth point to the younger
00:02:16 --> 00:02:19 age in the millions of years that
00:02:19 --> 00:02:20 followed the giant impact the newly
00:02:21 --> 00:02:23 formed Moon cooled and moved further and
00:02:23 --> 00:02:25 further away from the earth until it
00:02:25 --> 00:02:26 reached its current orbit at a distance
00:02:26 --> 00:02:30 of around 384 km
00:02:30 --> 00:02:31 it's still moving away from the earth
00:02:31 --> 00:02:33 today at a couple of centimeters every
00:02:33 --> 00:02:36 year the study's lead author Francis
00:02:36 --> 00:02:38 neemo from the University of California
00:02:38 --> 00:02:40 Santa Cruz says his team were especially
00:02:40 --> 00:02:42 interested in the phase when the
00:02:42 --> 00:02:43 distance between the Earth and the moon
00:02:43 --> 00:02:46 was just a third of today's distance now
00:02:46 --> 00:02:48 at that time there were various
00:02:48 --> 00:02:50 differences in the position and shape of
00:02:50 --> 00:02:52 the moon's orbit now among other things
00:02:52 --> 00:02:55 it became far more elliptical so that
00:02:55 --> 00:02:56 the orbital speed of the moon at its
00:02:56 --> 00:02:58 distance from the earth varied
00:02:58 --> 00:03:01 considerably within each orbit and the
00:03:01 --> 00:03:02 thing is that would have generated an
00:03:02 --> 00:03:05 awful lot of gravitational tidal heating
00:03:05 --> 00:03:08 partially melting the lunar interior now
00:03:08 --> 00:03:09 all this is similar to what we see today
00:03:10 --> 00:03:12 with Jupiter's moon IO which travels
00:03:12 --> 00:03:13 around the gas giant in a slightly
00:03:13 --> 00:03:16 elliptical orbit the enormous tidal
00:03:16 --> 00:03:18 forces of Jupiter together with that of
00:03:18 --> 00:03:20 io's other companion moons causes the
00:03:20 --> 00:03:22 moon to be constantly stretched and
00:03:22 --> 00:03:24 squeezed generating friction and
00:03:24 --> 00:03:27 consequently heat and all that makes IO
00:03:27 --> 00:03:29 the most volcanically active body in the
00:03:29 --> 00:03:30 solar system
00:03:30 --> 00:03:33 and based on this new study Earth's Moon
00:03:33 --> 00:03:35 went through a similar phase Nemo and
00:03:35 --> 00:03:37 colleagues calculations suggested the
00:03:37 --> 00:03:39 heat flow from the lunar interior was
00:03:39 --> 00:03:41 sufficient to melt and churn through the
00:03:41 --> 00:03:44 entire mantle now while a magma ocean
00:03:44 --> 00:03:46 never covered the entire lunar surface
00:03:46 --> 00:03:48 over the course of several million years
00:03:48 --> 00:03:50 the heat from the interior gradually
00:03:50 --> 00:03:51 reached pretty well every part of the
00:03:52 --> 00:03:54 surface liquefying most of the crust
00:03:54 --> 00:03:56 possibly several times over now the
00:03:56 --> 00:03:58 authors say that in some places the hot
00:03:58 --> 00:04:00 lava penetrated right through to the
00:04:00 --> 00:04:03 surface in others magma was injected
00:04:03 --> 00:04:05 beneath the surface heating the Rocks
00:04:05 --> 00:04:08 around it and this volcanic history is
00:04:08 --> 00:04:10 decisive for determining the age of
00:04:10 --> 00:04:13 crustal rocks now when they form rocks
00:04:13 --> 00:04:15 including those on the moon contain
00:04:15 --> 00:04:17 various radioactive isotopes Isotopes
00:04:17 --> 00:04:19 are variations of certain atoms that
00:04:19 --> 00:04:21 differ in the number of neutrons they
00:04:21 --> 00:04:23 have in their nucleus now as long as the
00:04:23 --> 00:04:26 Rock's hot it can exchange isotopes with
00:04:26 --> 00:04:28 its surroundings but as it cools those
00:04:28 --> 00:04:30 Isotopes become locked in and the
00:04:30 --> 00:04:33 composition becomes set then the trapped
00:04:33 --> 00:04:36 Isotopes begin to radioactively Decay
00:04:36 --> 00:04:38 and so the geological clock starts
00:04:38 --> 00:04:41 ticking lunar Rock samples therefore
00:04:41 --> 00:04:43 don't reveal their original age but only
00:04:43 --> 00:04:45 the age when they were last strongly
00:04:45 --> 00:04:48 heated however there are some unique
00:04:48 --> 00:04:50 crystals in rocks known as zircons that
00:04:50 --> 00:04:52 are extremely tough and heat resistant
00:04:52 --> 00:04:55 and uranium atoms trapped inside these
00:04:55 --> 00:04:57 crystals Decay into lead atoms at a set
00:04:57 --> 00:05:00 rate so by comparing the ratio of
00:05:00 --> 00:05:02 uranium to Le inside ziron crystals
00:05:02 --> 00:05:04 astronomers can determine the exact age
00:05:05 --> 00:05:06 when the ziron crystals were first
00:05:06 --> 00:05:09 formed and they showing a more distant
00:05:09 --> 00:05:11 earlier history than other crustal rocks
00:05:11 --> 00:05:14 and so are telling a different story the
00:05:14 --> 00:05:16 violent volcanism shaped the moon's
00:05:16 --> 00:05:19 crust around 4.35 billion years ago but
00:05:19 --> 00:05:22 the zircons are much older at 4.53
00:05:22 --> 00:05:25 billion years and the story doesn't end
00:05:25 --> 00:05:27 there these new findings are also
00:05:27 --> 00:05:29 resolving many other contradictions that
00:05:29 --> 00:05:32 had previously puzzled astronomers for
00:05:32 --> 00:05:34 example the comparatively few crators on
00:05:34 --> 00:05:37 the moon argues against the to age in
00:05:37 --> 00:05:39 such a long time astronomers think our
00:05:39 --> 00:05:40 Cosmic neighbor should have witnessed
00:05:40 --> 00:05:44 more impacts Luna volcanism now offers
00:05:44 --> 00:05:46 an explanation lava from the moon's
00:05:46 --> 00:05:48 interior would have filled the early
00:05:48 --> 00:05:50 impact creators and thus made them
00:05:50 --> 00:05:52 unrecognizable the composition of the
00:05:52 --> 00:05:55 lunar mantle also posed a problem this
00:05:55 --> 00:05:57 is the layer of rock that lies directly
00:05:57 --> 00:05:59 beneath the moon's crust and its
00:05:59 --> 00:06:01 composition I differs from that of the
00:06:01 --> 00:06:03 Earth in several key aspects however if
00:06:03 --> 00:06:06 the moon's interior melted a second time
00:06:06 --> 00:06:08 round as this new study would indicate
00:06:08 --> 00:06:10 some substances could have sunk from the
00:06:10 --> 00:06:13 metal down to the iron core below and
00:06:13 --> 00:06:14 that would explain the compositional
00:06:14 --> 00:06:16 differences between the Moon's mantle
00:06:16 --> 00:06:19 and parts of the Earth the new results
00:06:19 --> 00:06:21 mean that all the pieces of the puzzle
00:06:21 --> 00:06:23 that previously didn't fit together are
00:06:23 --> 00:06:25 now forming a coherent overall picture
00:06:25 --> 00:06:29 of our Luna Partners formation it puts a
00:06:29 --> 00:06:32 full stop at the end of the story this
00:06:32 --> 00:06:35 is spacetime still to come NASA's
00:06:35 --> 00:06:37 perseverance Rover finally crested the
00:06:37 --> 00:06:40 top of jezo crater's rim and planetary
00:06:40 --> 00:06:43 plate tectonics are solving the mystery
00:06:43 --> 00:06:45 of South Australia's strange pink Beach
00:06:45 --> 00:06:48 Sands all that and more still to come on
00:06:48 --> 00:06:53 SpaceTime
00:06:53 --> 00:07:05 [Music]
00:07:05 --> 00:07:07 there are celebrations at JPL today with
00:07:07 --> 00:07:09 NASA's M perseverance Rover finally
00:07:09 --> 00:07:12 cresting the very top of gzro crater's
00:07:12 --> 00:07:15 rim and Mission managers say the road
00:07:15 --> 00:07:17 ahead will be even more scientifically
00:07:17 --> 00:07:19 intriguing and the good news is it'll
00:07:19 --> 00:07:22 probably somewhat easier going now that
00:07:22 --> 00:07:24 the six whe car siiz mobile laboratory
00:07:24 --> 00:07:27 has completed its long climb to the top
00:07:27 --> 00:07:29 perseverance crested the top of gzro Rim
00:07:29 --> 00:07:32 at a location known as Lookout Hill and
00:07:32 --> 00:07:33 it's now rolling towards what will be
00:07:33 --> 00:07:35 its first new science stop following its
00:07:35 --> 00:07:38 monthlong climb the Rover made the
00:07:38 --> 00:07:40 ascent in order to explore a region of
00:07:40 --> 00:07:43 Mars unlike anywhere it had investigated
00:07:43 --> 00:07:45 before taking about 3 and a half months
00:07:45 --> 00:07:47 and ascending over half a kilometer in
00:07:47 --> 00:07:50 elevation the Rover climbed 20° grades
00:07:50 --> 00:07:53 often in Slippery Sandy conditions
00:07:53 --> 00:07:55 making stops along the way for
00:07:55 --> 00:07:56 scientific
00:07:56 --> 00:07:59 observations since Landing in jro crat
00:07:59 --> 00:08:01 back February 2021 the mass perseverance
00:08:01 --> 00:08:04 Rovers completed four science campaigns
00:08:04 --> 00:08:07 there was the crater floor then the fan
00:08:07 --> 00:08:09 front the fan being the buildup of river
00:08:09 --> 00:08:11 DOTA sediment then the upper fan and
00:08:11 --> 00:08:14 finally the margin unit the science team
00:08:14 --> 00:08:16 are calling what will be perseverance
00:08:16 --> 00:08:18 fifth scientific campaign the northern
00:08:18 --> 00:08:20 Rim that's because the route will cover
00:08:20 --> 00:08:22 the northern part of the southwestern
00:08:22 --> 00:08:25 section of jrose Rim perseverance Deputy
00:08:25 --> 00:08:27 project manager Steven Lee from nass's
00:08:27 --> 00:08:29 jet propulsion laboratory in Pas
00:08:29 --> 00:08:31 California says that over the first year
00:08:31 --> 00:08:33 of the northern Rim campaign The Rovers
00:08:33 --> 00:08:35 expected to visit four sites of
00:08:35 --> 00:08:37 geological interest take several samples
00:08:37 --> 00:08:41 and drive about 6.4 km the northern Rim
00:08:41 --> 00:08:43 campaign brings completely new
00:08:43 --> 00:08:46 scientific riches as perseverance robes
00:08:46 --> 00:08:48 into fundamentally new geology that's
00:08:48 --> 00:08:50 because it marks the transition from
00:08:50 --> 00:08:52 rocks that were partially filled in jro
00:08:52 --> 00:08:54 Crater when it was formed by a massive
00:08:54 --> 00:08:56 impact about 3.9 billion years ago to
00:08:57 --> 00:08:59 the rocks from deep inside Mars there
00:08:59 --> 00:09:01 ejected upwards from the Crater Rim as a
00:09:01 --> 00:09:04 result of that impact scientists believe
00:09:04 --> 00:09:06 that these new rocks will represent
00:09:06 --> 00:09:08 pieces of the early Martian crust and
00:09:08 --> 00:09:10 therefore will be among the oldest rocks
00:09:10 --> 00:09:12 found anywhere in the solar system
00:09:12 --> 00:09:15 investigating them could help science
00:09:15 --> 00:09:16 understand what Mars and for that matter
00:09:16 --> 00:09:18 the Earth may have looked like just
00:09:18 --> 00:09:20 after the solar system formed and
00:09:20 --> 00:09:23 planets began to solidify 4.6 billion
00:09:23 --> 00:09:25 years ago with Lookout hill now in its
00:09:26 --> 00:09:27 rear viw mirror perseverance is headed
00:09:27 --> 00:09:29 for a scientifically significant Rock
00:09:29 --> 00:09:32 outcrop about 450 M down the other side
00:09:32 --> 00:09:34 of the rim known as witch hazel Hill
00:09:34 --> 00:09:37 witch hazel Hill represents over 100 m
00:09:37 --> 00:09:39 of layered outcrop where each layer is
00:09:39 --> 00:09:41 like a page in a martian geological
00:09:41 --> 00:09:44 history book so as perseverance drives
00:09:44 --> 00:09:46 down the hill it's sort of going back in
00:09:46 --> 00:09:48 time investigating the ancient
00:09:48 --> 00:09:50 environments of Mars recorded in the
00:09:50 --> 00:09:53 Crater Rim then after a steep descent
00:09:53 --> 00:09:54 perseverance will turn its Wheels away
00:09:54 --> 00:09:56 from the Crater Rim and head towards
00:09:57 --> 00:10:00 lact shames about 3 km further south
00:10:00 --> 00:10:03 like the shamz intrigued scientists
00:10:03 --> 00:10:04 because being located on the planes
00:10:04 --> 00:10:06 Beyond The Rim it's far less likely to
00:10:06 --> 00:10:08 have been significantly affected by the
00:10:08 --> 00:10:11 formation of jezzro crater after leaving
00:10:11 --> 00:10:13 lactic chames the Rover will Traverse
00:10:13 --> 00:10:16 about 1.6 km back to the rim in order to
00:10:16 --> 00:10:18 investigate a stunning outcrop of large
00:10:18 --> 00:10:21 blocks known as Mega breia these blocks
00:10:21 --> 00:10:24 may represent ancient Bedrock broken up
00:10:24 --> 00:10:26 during the acidious impact a planet
00:10:26 --> 00:10:28 altering event that likely excavated
00:10:28 --> 00:10:30 deep into the Martian C trust as it
00:10:30 --> 00:10:32 created an impact Basin some 1200 km
00:10:32 --> 00:10:36 wide 3.9 billion years ago needless to
00:10:36 --> 00:10:39 say it means interesting times ahead
00:10:39 --> 00:10:42 this is spacetime still to come the
00:10:42 --> 00:10:44 mystery of South Australia's strange
00:10:44 --> 00:10:46 Pink Sands and later in the science
00:10:46 --> 00:10:48 report a new study shows that guys tend
00:10:48 --> 00:10:50 to head to the bar faster when the women
00:10:50 --> 00:10:53 are scarce all that and more still to
00:10:53 --> 00:11:07 come on SpaceTime
00:11:07 --> 00:11:10 [Music]
00:11:10 --> 00:11:12 deposits of strange deep pink sand
00:11:12 --> 00:11:15 washing up on South Australian beaches
00:11:15 --> 00:11:16 is shedding new light on when the
00:11:17 --> 00:11:19 Australian tectonic plate began to
00:11:19 --> 00:11:21 subduct beneath the Pacific Plate and
00:11:21 --> 00:11:23 the findings reported in the journal
00:11:23 --> 00:11:25 Communications Earth and environment are
00:11:25 --> 00:11:27 also exposing the existence of a
00:11:27 --> 00:11:29 previously unknown ancient anti IC
00:11:29 --> 00:11:32 mountain range the Pink Sands are
00:11:32 --> 00:11:34 composed of a mineral called Garnet now
00:11:34 --> 00:11:36 garnets known to have formed locally
00:11:36 --> 00:11:39 during the Delian orogy an event which
00:11:39 --> 00:11:42 created the Adelaide fold Bel around 514
00:11:42 --> 00:11:44 to 490 million years ago and also during
00:11:44 --> 00:11:46 the formation of the Galler Craton in
00:11:46 --> 00:11:49 Western South Australia between 3.3 and
00:11:49 --> 00:11:52 1.4 billion years ago the problem is
00:11:52 --> 00:11:53 these ages don't match up with the
00:11:53 --> 00:11:56 garnet Sands now being found on South
00:11:56 --> 00:11:58 Australian seash Shores one of the
00:11:58 --> 00:12:00 studies's authors show jine verad from
00:12:00 --> 00:12:01 the University of Adelaide says new
00:12:02 --> 00:12:04 dating shows that the garnet grains are
00:12:04 --> 00:12:07 around 590 million years old it's too
00:12:07 --> 00:12:09 young to have come from the garet Craton
00:12:09 --> 00:12:11 and far too old to have come from the
00:12:11 --> 00:12:14 eroding Adelaide fold belt the authors
00:12:14 --> 00:12:15 were able to establish the new date
00:12:15 --> 00:12:18 using a new Lum hafnium laser Mass
00:12:18 --> 00:12:20 spectrometer technique gner requires
00:12:20 --> 00:12:22 high temperatures to form and is usually
00:12:22 --> 00:12:24 associated with the formation of large
00:12:24 --> 00:12:27 mountain belts but the 590 million year
00:12:27 --> 00:12:29 old age window was a time when the South
00:12:29 --> 00:12:32 Australian crust was comparatively cool
00:12:32 --> 00:12:34 and non-mountainous and vattan
00:12:34 --> 00:12:35 colleagues wrote to establish that this
00:12:35 --> 00:12:37 Garnet didn't originate from local
00:12:37 --> 00:12:40 Source rocks the thing is it must have
00:12:40 --> 00:12:42 originated nearby because Garnet is
00:12:42 --> 00:12:43 typically destroyed through prolonged
00:12:44 --> 00:12:46 exposure to Marine environments now the
00:12:46 --> 00:12:48 authors have discovered that the glacial
00:12:48 --> 00:12:50 sedimentary deposits of the cape Jervis
00:12:50 --> 00:12:52 formation outcropping along the South
00:12:52 --> 00:12:54 Australian shorelines contains layers of
00:12:54 --> 00:12:56 sand which also contain garard that's
00:12:56 --> 00:12:59 also around 590 million years old
00:12:59 --> 00:13:02 and Ice Flow indicators in these glacial
00:13:02 --> 00:13:03 sedimentary deposits suggest that the
00:13:03 --> 00:13:05 garnet Rich glacial Sands were brought
00:13:05 --> 00:13:08 to Australia by a northwesterly moving
00:13:08 --> 00:13:10 ice sheet during the late Paleozoic Ice
00:13:10 --> 00:13:13 Age when Australia and Antarctica were
00:13:13 --> 00:13:15 attached as part of the supercon
00:13:15 --> 00:13:17 gondwana and here's where it gets really
00:13:17 --> 00:13:19 interesting Ghana dating back to the
00:13:20 --> 00:13:22 same period has also been found in an
00:13:22 --> 00:13:24 outcrop in the transantarctic mountains
00:13:24 --> 00:13:26 in East Antarctica right at the edge of
00:13:26 --> 00:13:28 a colossal area completely concealed by
00:13:28 --> 00:13:31 a thick ice sheet and researchers
00:13:31 --> 00:13:33 believe that this area contains evidence
00:13:33 --> 00:13:36 for a 590 milliony Old Mountain belt
00:13:36 --> 00:13:39 hiding below the Antarctic ice now while
00:13:39 --> 00:13:40 it's not currently possible to sample
00:13:40 --> 00:13:42 directly under this ice sheet it's
00:13:42 --> 00:13:44 conceivable that millions of years of
00:13:44 --> 00:13:46 ice transport eroded the Bedrock
00:13:46 --> 00:13:48 underneath and transported the garnet
00:13:48 --> 00:13:50 northwestwards towards the conjugate
00:13:50 --> 00:13:53 Antarctic Australian margin the garnet
00:13:53 --> 00:13:55 deposits werein locally stored in
00:13:55 --> 00:13:57 glacial sedimentary deposits along the
00:13:57 --> 00:13:59 southern Australian margin until fresh
00:13:59 --> 00:14:01 erosion liberated them and waves and
00:14:01 --> 00:14:03 Tides concentrated them on South
00:14:03 --> 00:14:06 Australian beaches so these findings are
00:14:06 --> 00:14:08 suggesting the discovery of a major
00:14:08 --> 00:14:10 mountain building event that redefines
00:14:11 --> 00:14:13 the timing of the onset of convergence
00:14:13 --> 00:14:15 in the Pacific Ocean the Hut says it's
00:14:15 --> 00:14:17 fascinating to think scientists were
00:14:17 --> 00:14:19 able to trace tiny grains of sand on a
00:14:19 --> 00:14:21 beach in Australia to a previously
00:14:21 --> 00:14:23 undiscovered mountain range buried deep
00:14:23 --> 00:14:26 below the Antarctic Ice usually if we
00:14:26 --> 00:14:29 see pink Beach Sands that con of garnets
00:14:29 --> 00:14:31 the garnets must have been eroded from
00:14:31 --> 00:14:34 somewhere it could be if there's like a
00:14:34 --> 00:14:36 mountain belt close by for example if
00:14:36 --> 00:14:38 you would go to the Himalayas and you
00:14:38 --> 00:14:39 would walk through the Himalayan
00:14:39 --> 00:14:41 florland Basin and you'd be walking
00:14:41 --> 00:14:43 along the rivers and the beaches you
00:14:43 --> 00:14:44 might find a lot of gars in there
00:14:45 --> 00:14:47 because they usually occur in highly
00:14:47 --> 00:14:50 metamorphic mountain ranges such as the
00:14:50 --> 00:14:52 Himalayas so in the case of South
00:14:52 --> 00:14:54 Australia and we were walking along the
00:14:54 --> 00:14:56 beaches and we saw that the beaches
00:14:56 --> 00:14:58 contain a lot of those pink garet we
00:14:58 --> 00:15:00 were just wondering where could they be
00:15:00 --> 00:15:01 coming from because we don't really have
00:15:02 --> 00:15:04 a big existing mountain range nearby
00:15:04 --> 00:15:06 here in South Australia we do have the
00:15:06 --> 00:15:09 adelade small belt which contains garnet
00:15:09 --> 00:15:12 and um it it has some form of topography
00:15:12 --> 00:15:14 but it isn't really a big impressive
00:15:14 --> 00:15:16 mountain range or anything and there
00:15:16 --> 00:15:19 isn't a large volume of gret in the
00:15:19 --> 00:15:21 elade fall belt not large enough for it
00:15:21 --> 00:15:24 to erode that many Gs along all the
00:15:24 --> 00:15:26 beaches around South Australia so we're
00:15:26 --> 00:15:29 like how can we try to solve this
00:15:29 --> 00:15:31 problem and at the time when we found
00:15:31 --> 00:15:34 those P garnets on the beach we actually
00:15:35 --> 00:15:38 were developing a new dating method that
00:15:38 --> 00:15:41 we could apply to garet as well so at
00:15:41 --> 00:15:42 the time when we found those garnets we
00:15:42 --> 00:15:44 were like why don't we just try to
00:15:44 --> 00:15:47 analyze those GRS and see what age we
00:15:47 --> 00:15:49 get from them because that's the easiest
00:15:49 --> 00:15:52 way to match certain grars to certain
00:15:52 --> 00:15:55 basement blck once we got our ages back
00:15:55 --> 00:15:58 from our laser sessions we realized that
00:15:59 --> 00:16:00 that just gave us another question
00:16:00 --> 00:16:02 because the ages we got from those Gars
00:16:02 --> 00:16:04 didn't line up with anything so they
00:16:04 --> 00:16:06 were too young to be from the aday G
00:16:06 --> 00:16:09 crat and then they were too old to come
00:16:09 --> 00:16:11 from the F belt so we were wondering
00:16:11 --> 00:16:13 what could be another source for those
00:16:13 --> 00:16:16 garnets and the only possible option
00:16:16 --> 00:16:19 close by was the buring glacial
00:16:19 --> 00:16:21 sediments that are also cropping out
00:16:21 --> 00:16:24 along South Australia which we found out
00:16:24 --> 00:16:27 also contain a lot of G so we decided to
00:16:27 --> 00:16:30 sample those glacial Sands as well so we
00:16:30 --> 00:16:32 scooped some sand from the gracial Sands
00:16:32 --> 00:16:34 which had a lot of granet in them and we
00:16:34 --> 00:16:36 tried to analyze those as well and then
00:16:36 --> 00:16:38 when we got our results back we realized
00:16:38 --> 00:16:41 that the garnets from the glacial sand
00:16:41 --> 00:16:42 had the same age as the garet on the
00:16:42 --> 00:16:44 beach so we found our mat and where
00:16:44 --> 00:16:45 would they have come from that's the
00:16:45 --> 00:16:47 problem with glacial sediments so we
00:16:47 --> 00:16:49 know that glacial sediments if there's
00:16:49 --> 00:16:51 indicators that they were deposited by
00:16:51 --> 00:16:54 large ey sheet we know that they aren't
00:16:54 --> 00:16:56 originally from this location so a big
00:16:56 --> 00:16:58 massive eye sheep must have brought them
00:16:58 --> 00:17:01 to South Australia during the glaciation
00:17:01 --> 00:17:03 of that ice sheet so the glaciation
00:17:03 --> 00:17:06 we're talking about is the late bosic I
00:17:06 --> 00:17:08 age which occurred around the Buran
00:17:08 --> 00:17:11 carbonis first time zon so at that time
00:17:11 --> 00:17:13 looking at all BL tectonic
00:17:13 --> 00:17:15 reconstructions we know that South
00:17:15 --> 00:17:17 Australia was connected to East
00:17:17 --> 00:17:19 Antarctica back in the days so if we're
00:17:19 --> 00:17:21 thinking about ey sheet movement you can
00:17:21 --> 00:17:23 look at the Sands and you can look at
00:17:23 --> 00:17:25 the Pebbles and see what the lithologies
00:17:25 --> 00:17:27 of these Pebbles are so are they
00:17:27 --> 00:17:30 Sandstone are they metamorphic rocks
00:17:30 --> 00:17:31 where could they be coming from and then
00:17:31 --> 00:17:33 those Pebbles they can have marks in
00:17:33 --> 00:17:36 them G marks or troughs that can
00:17:36 --> 00:17:38 indicate what way the eye sheet was
00:17:38 --> 00:17:40 flowing so in this case we found out
00:17:40 --> 00:17:42 that through other researchers who had
00:17:42 --> 00:17:44 been studying this before they concluded
00:17:44 --> 00:17:47 that the ey sheet must have come from a
00:17:47 --> 00:17:49 source somewhere Southeast to us so if
00:17:49 --> 00:17:51 you would look back at the play tectonic
00:17:51 --> 00:17:53 reconstruction and you would go
00:17:53 --> 00:17:56 Southeast from the El area you would end
00:17:56 --> 00:17:58 up in East Antartica wow that sort of
00:17:59 --> 00:18:01 puts the cherry on the cake doesn't it
00:18:01 --> 00:18:03 yeah it's a detective story isn't it it
00:18:03 --> 00:18:05 is it kind of is and we didn't expect to
00:18:05 --> 00:18:08 find an outcome as exciting as this one
00:18:08 --> 00:18:10 because once we figured out that they
00:18:10 --> 00:18:12 might have been coming from e c AR and
00:18:12 --> 00:18:14 we're pretty certain they are we
00:18:14 --> 00:18:15 realized that there isn't really
00:18:15 --> 00:18:17 anything of the same age so we're
00:18:17 --> 00:18:20 talking about an age around 590 million
00:18:20 --> 00:18:22 years ago which is in the edurent time
00:18:22 --> 00:18:25 period you don't really find any
00:18:25 --> 00:18:27 mountains or outcrops in East anartica
00:18:27 --> 00:18:29 with that age because OB viously e
00:18:29 --> 00:18:31 Antarctica is covered by a large eyce
00:18:31 --> 00:18:33 sheep and most of the geology in E
00:18:33 --> 00:18:35 Antartica is hidden beneath that ice
00:18:35 --> 00:18:37 sheet and based on I think there was one
00:18:37 --> 00:18:39 small outcrop in the transantarctic
00:18:39 --> 00:18:41 mountains where they got a similar age
00:18:41 --> 00:18:44 for the gr but it's so far away so we
00:18:44 --> 00:18:46 assume or we suspect that there might be
00:18:46 --> 00:18:48 a large geological Pro Province
00:18:48 --> 00:18:50 underneath the a sheep an old ancient
00:18:51 --> 00:18:52 Mountain belt that was eroded by the I
00:18:53 --> 00:18:55 sheep in the late philic I age that we
00:18:55 --> 00:18:58 now find back in South Australia but
00:18:58 --> 00:19:00 that's now here in the eyes other eyes
00:19:00 --> 00:19:02 in eica and we don't know if he'd ever
00:19:02 --> 00:19:04 be able to drill into it or find it if
00:19:04 --> 00:19:06 it wasn't for this study garet when the
00:19:06 --> 00:19:08 average person thinks of garnets they
00:19:08 --> 00:19:10 think of a gemstone something pretty to
00:19:10 --> 00:19:12 put in a ring or on a necklace tell me
00:19:12 --> 00:19:14 about garnets how are they made yeah so
00:19:14 --> 00:19:16 garnets are in fact really pretty
00:19:16 --> 00:19:19 minerals so you often find them in color
00:19:19 --> 00:19:22 red or pink and they're translucent so
00:19:22 --> 00:19:24 if you find a very clear mineral that
00:19:24 --> 00:19:26 doesn't really have inclusions it's
00:19:26 --> 00:19:28 really nice to put them in jewelry as
00:19:28 --> 00:19:31 you you just said so G is a metamorphic
00:19:31 --> 00:19:34 mineral which means that it grows when
00:19:34 --> 00:19:36 deep in the Earth's crust you've got
00:19:36 --> 00:19:38 very high temperatures and pressures
00:19:38 --> 00:19:40 pushing all the Rocks together and
00:19:40 --> 00:19:42 because of this heat and this pressure
00:19:42 --> 00:19:44 your rocks will start melting and they
00:19:44 --> 00:19:47 will start forming another rock so in
00:19:47 --> 00:19:50 this case for ghas it's usually when you
00:19:50 --> 00:19:53 have old mudstones or sedimentary rocks
00:19:53 --> 00:19:55 that get buried very deep into the crust
00:19:55 --> 00:19:57 of the earth and you have an ongoing
00:19:58 --> 00:19:59 mountain building process which is
00:19:59 --> 00:20:01 pushing everything together so we've got
00:20:01 --> 00:20:04 two continents trying to mix each other
00:20:04 --> 00:20:06 that's when you start forming garet so
00:20:06 --> 00:20:08 we need pressure and temperature
00:20:08 --> 00:20:10 conditions that are high enough for gret
00:20:10 --> 00:20:12 to form and then after some time when
00:20:12 --> 00:20:14 the gr has been sitting in the Rock
00:20:14 --> 00:20:16 it'll start getting eroded so when
00:20:16 --> 00:20:19 everything or all the Rocks above the
00:20:19 --> 00:20:21 unit with the garnets is eroded away
00:20:21 --> 00:20:23 that's when you will see Garnet at the
00:20:23 --> 00:20:25 Earth's surface which isn't very common
00:20:25 --> 00:20:26 that's Charmaine verh from the
00:20:26 --> 00:20:29 University of Adelaide and this
00:20:29 --> 00:20:44 [Music]
00:20:44 --> 00:20:46 SpaceTime and time now to take a brief
00:20:46 --> 00:20:47 look at some of the other stories making
00:20:47 --> 00:20:50 news in science this week with a science
00:20:50 --> 00:20:52 report a new study has shown that
00:20:52 --> 00:20:54 ambulance and taxi drivers have the
00:20:54 --> 00:20:55 lowest levels of death due to
00:20:55 --> 00:20:57 Alzheimer's disease compared to other
00:20:57 --> 00:20:59 occupations
00:20:59 --> 00:21:00 the findings reported in the British
00:21:00 --> 00:21:02 medical journal suggest that frequent
00:21:02 --> 00:21:05 spatial processing tasks might offer
00:21:05 --> 00:21:08 some protection against the illness
00:21:08 --> 00:21:09 scientists analyzed death certificates
00:21:09 --> 00:21:12 for 443 different occupations between
00:21:12 --> 00:21:15 2020 and 2023 including cause of death
00:21:15 --> 00:21:19 usual occupation and sood demographic
00:21:19 --> 00:21:21 information after adjusting for age and
00:21:21 --> 00:21:23 sociodemographic factors the authors
00:21:23 --> 00:21:25 found that taxi drivers and ambulance
00:21:26 --> 00:21:27 drivers have the lowest proportion of
00:21:27 --> 00:21:29 deaths from Al Alzheimer of all
00:21:29 --> 00:21:31 occupations examined and also when
00:21:31 --> 00:21:34 compared with the general population but
00:21:34 --> 00:21:35 interestingly the authors noted that
00:21:35 --> 00:21:37 this trend wasn't seen in other
00:21:37 --> 00:21:39 transport related jobs such as bus
00:21:39 --> 00:21:41 drivers or aircraft Pilots possibly due
00:21:41 --> 00:21:44 to their Reliance on predetermined
00:21:44 --> 00:21:47 routes ano's opal nuclear research
00:21:47 --> 00:21:49 reactor at Lucas Heights in Sydney
00:21:49 --> 00:21:51 Southern suburbs has officially powered
00:21:51 --> 00:21:55 back on and recomen general operations
00:21:55 --> 00:21:57 it follows a several monthl long planed
00:21:57 --> 00:21:58 shutdown to carry out a Central
00:21:58 --> 00:22:01 maintenance and upgrades Central to
00:22:01 --> 00:22:02 these upgrades was the replacement of
00:22:02 --> 00:22:05 opal's cold Neutron Source located next
00:22:05 --> 00:22:08 to the reactor's core the 3M toall
00:22:08 --> 00:22:10 device slows down neutrons as they
00:22:10 --> 00:22:12 travel from the opal reactor through to
00:22:12 --> 00:22:14 the large scientific Neutron beam
00:22:14 --> 00:22:16 instruments allowing researchers to look
00:22:16 --> 00:22:18 at the structure of materials in atomic
00:22:18 --> 00:22:21 detail the plan shutdown also enabled
00:22:21 --> 00:22:23 extensive software and Hardware upgrades
00:22:23 --> 00:22:24 to opel's First reactor protection
00:22:24 --> 00:22:26 system a digital system that monitors
00:22:26 --> 00:22:29 The reactor's crucial parameters
00:22:29 --> 00:22:31 the system is the first line of defense
00:22:31 --> 00:22:33 for opal to automatically shut down
00:22:33 --> 00:22:36 safely if the parameters are exceeded as
00:22:36 --> 00:22:38 Australia's only operational nuclear
00:22:38 --> 00:22:41 reactor opal produces neutrons that form
00:22:41 --> 00:22:43 the radioisotopes required for nuclear
00:22:43 --> 00:22:45 medicines and they're used to diagnose a
00:22:45 --> 00:22:48 range of medical conditions and Cancers
00:22:48 --> 00:22:50 Opel also supplies more than half of the
00:22:50 --> 00:22:53 world's demand for IR radiated silicon
00:22:53 --> 00:22:56 that's used in electronics and green
00:22:56 --> 00:22:58 technologies now here's something that
00:22:58 --> 00:23:01 may not come as a surprise a new study
00:23:01 --> 00:23:03 has found that guys tend to head to the
00:23:03 --> 00:23:06 bar faster when women are scarce the
00:23:06 --> 00:23:08 findings reported in the journal
00:23:08 --> 00:23:10 biological letters shows that if you're
00:23:10 --> 00:23:12 out at the pub with a group of mates
00:23:12 --> 00:23:14 which include both males and females
00:23:14 --> 00:23:15 then the men will be quicker to head to
00:23:15 --> 00:23:18 the bar and buy drinks if they outnumber
00:23:18 --> 00:23:20 the women in your group the authors
00:23:20 --> 00:23:23 monitored 163 mixed sex groups out for
00:23:23 --> 00:23:25 drinks at three taverns in the Boston
00:23:25 --> 00:23:27 area over a period of seven nights good
00:23:27 --> 00:23:30 work if you can get it they found that
00:23:30 --> 00:23:31 when males outnumbered females in the
00:23:31 --> 00:23:33 group the alpha male would take less
00:23:33 --> 00:23:35 time to stride up to the bar make
00:23:35 --> 00:23:37 physical contact with it and offer to
00:23:37 --> 00:23:39 pay for the first round of drinks the
00:23:39 --> 00:23:41 researchers said that the findings
00:23:41 --> 00:23:43 suggest that just like other animals
00:23:43 --> 00:23:45 male humans tend to invest more
00:23:45 --> 00:23:47 resources when the competition for a
00:23:47 --> 00:23:49 mate is
00:23:49 --> 00:23:51 higher a recent study has been looking
00:23:51 --> 00:23:53 at the fascinating case of people who
00:23:53 --> 00:23:56 suffer from a Fantasia a characteristic
00:23:56 --> 00:23:58 some people have related to how they
00:23:58 --> 00:24:00 mind and Imagination work having a
00:24:00 --> 00:24:03 Fantasia means you either don't have or
00:24:03 --> 00:24:04 have a reduced level of visual
00:24:04 --> 00:24:06 imagination keeping you from picturing
00:24:06 --> 00:24:09 things in your mind the research by the
00:24:09 --> 00:24:12 University of Sussex found that 0.8% of
00:24:12 --> 00:24:15 the population is unable to form visual
00:24:15 --> 00:24:18 mental images and 3.9% of the population
00:24:18 --> 00:24:20 were either unable to form mental images
00:24:20 --> 00:24:22 or had only a very dim or vague mental
00:24:22 --> 00:24:25 imagery Tim menum from a strali skeptic
00:24:25 --> 00:24:27 says it's like asking someone not to
00:24:27 --> 00:24:29 think of a pink El El an well of course
00:24:29 --> 00:24:30 that's the first thing in fact the only
00:24:30 --> 00:24:32 thing you think of that is unless you
00:24:33 --> 00:24:35 suffer from a Fantasia the Pink Elephant
00:24:35 --> 00:24:37 test is basically the old story of that
00:24:37 --> 00:24:39 if I say don't think of a pink elephant
00:24:39 --> 00:24:41 you instantly do think of a pink
00:24:41 --> 00:24:42 elephant which is you know pretty normal
00:24:43 --> 00:24:45 actually don't think of a rocus please
00:24:45 --> 00:24:46 and you do think of a rhinoceros or
00:24:46 --> 00:24:48 anything else for that matter so so
00:24:48 --> 00:24:50 people sort of iMed immediately call up
00:24:50 --> 00:24:53 a visual memory and they respond in kind
00:24:53 --> 00:24:55 it's very hard to stop doing that except
00:24:55 --> 00:24:56 for people apparently who have a thing
00:24:57 --> 00:24:59 called a Fantasia who apparently cannot
00:24:59 --> 00:25:02 visualize things they cannot call up a
00:25:02 --> 00:25:04 visual image or memory or whatever of
00:25:04 --> 00:25:06 something just because it's not in their
00:25:06 --> 00:25:08 brain to do so which is interesting this
00:25:08 --> 00:25:10 is basically the whole Spectrum idea
00:25:10 --> 00:25:12 there everything that affects humans you
00:25:12 --> 00:25:14 run from people with very strong visual
00:25:14 --> 00:25:17 imagery skills or proclivities down to
00:25:17 --> 00:25:19 someone who has no visual privity at all
00:25:19 --> 00:25:20 certainly not just looking at something
00:25:20 --> 00:25:22 but actually remembering something or
00:25:22 --> 00:25:24 calling it up in their head so a
00:25:24 --> 00:25:26 Fantasia is this Condition it's like if
00:25:26 --> 00:25:28 you're reading a book and you have
00:25:28 --> 00:25:31 normal visual imagery skills you can
00:25:31 --> 00:25:32 sort of see a character doing something
00:25:32 --> 00:25:33 you have a picture of someone if you
00:25:33 --> 00:25:35 have a Fantasia you can't visualize
00:25:35 --> 00:25:38 something so basically it very difficult
00:25:38 --> 00:25:41 to survive it well they survive often
00:25:41 --> 00:25:43 quite well just as good as anybody else
00:25:43 --> 00:25:45 half the time they would not know they
00:25:45 --> 00:25:47 can't do this because they don't know
00:25:47 --> 00:25:48 what they can't do until they gradually
00:25:48 --> 00:25:49 realize that other people are calling up
00:25:49 --> 00:25:51 an image in their head it's not looking
00:25:51 --> 00:25:52 at something you can still cross the
00:25:52 --> 00:25:53 road but it's actually calling up an
00:25:53 --> 00:25:55 image in your head sometimes these
00:25:55 --> 00:25:57 people have better audio memory they can
00:25:57 --> 00:25:59 call up a someone says a trumpet so
00:25:59 --> 00:26:01 they're hearing where someone with a
00:26:01 --> 00:26:02 visual thinge might be seeing a trumpet
00:26:02 --> 00:26:04 in their head so it's a bit of swings
00:26:04 --> 00:26:05 and roundabouts and they're also
00:26:05 --> 00:26:08 suggesting that some people perhaps and
00:26:08 --> 00:26:10 this is very much perhaps people with
00:26:10 --> 00:26:12 aphantasia or aphasics as they call them
00:26:12 --> 00:26:14 might be resistant to trauma for
00:26:14 --> 00:26:16 reliving events they can't see it in
00:26:16 --> 00:26:18 their head it's like do people who have
00:26:18 --> 00:26:21 had anas Fantasia Daydream do they see
00:26:21 --> 00:26:23 things in their head Etc a memory call
00:26:23 --> 00:26:25 it up Etc so maybe it's a painful memory
00:26:26 --> 00:26:27 but they can't relive it because they
00:26:27 --> 00:26:29 can't see it in their head and they
00:26:29 --> 00:26:30 might have a better time but it's an
00:26:30 --> 00:26:32 interesting situation some people see
00:26:32 --> 00:26:34 colors they hear a word or they hear a
00:26:34 --> 00:26:36 thing a sound and they can they can see
00:26:36 --> 00:26:37 colors this is something else in the
00:26:37 --> 00:26:39 head that people can't see imagery we've
00:26:39 --> 00:26:41 got a current feature in our Magazine on
00:26:41 --> 00:26:43 psychology and all the aberations that
00:26:43 --> 00:26:45 people have and aberation might be the
00:26:45 --> 00:26:47 wrong word it's just a variation across
00:26:47 --> 00:26:49 the Spectrum in so many different areas
00:26:49 --> 00:26:50 and uh this is just one of them that's
00:26:50 --> 00:26:55 timendum from Australian Skeptics
00:26:55 --> 00:27:09 [Music]
00:27:09 --> 00:27:11 and that's the show for now SpaceTime is
00:27:11 --> 00:27:13 available every Monday Wednesday and
00:27:13 --> 00:27:16 Friday through Apple podcasts iTunes
00:27:16 --> 00:27:19 Stitcher Google podcast pocketcasts
00:27:19 --> 00:27:23 Spotify acast Amazon music bites.com
00:27:23 --> 00:27:26 SoundCloud YouTube your favorite podcast
00:27:26 --> 00:27:28 download provider and from space time
00:27:28 --> 00:27:31 with Stuart gary.com space 's Also
00:27:31 --> 00:27:33 broadcast through the National Science
00:27:33 --> 00:27:35 Foundation on science Z Radio and on
00:27:35 --> 00:27:38 both iHeart radio and TuneIn radio and
00:27:38 --> 00:27:40 you can help to support our show by
00:27:40 --> 00:27:42 visiting the SpaceTime store for a range
00:27:42 --> 00:27:45 of promotional merchandising goodies or
00:27:45 --> 00:27:47 by becoming a space-time Patron which
00:27:47 --> 00:27:49 gives you access to Triple episode
00:27:49 --> 00:27:51 commercial free versions of the show as
00:27:51 --> 00:27:53 well as lots of Burness audio content
00:27:53 --> 00:27:55 which doesn't go to air access to our
00:27:55 --> 00:27:57 exclusive Facebook group and other
00:27:57 --> 00:27:59 Rewards just go to space timewith
00:27:59 --> 00:28:03 Stewart gary.com for full details you've
00:28:03 --> 00:28:05 been listening to SpaceTime with Stewart
00:28:05 --> 00:28:07 Gary this has been another quality
00:28:07 --> 00:28:11 podcast production from bites.com