*Astronomers find the most distant stars in our galaxy halfway to Andromeda A new study shows the furthest reaches of the Milky Way galaxy – a region known as the galactic halo is so far away it almost touches the halo of our nearest galactic neighbour the Andromeda galaxy M31. *New evidence for habitability in Enceladus’s ocean The search for extraterrestrial life just got more interesting following the discovery of new evidence for a key building block for life in the subsurface oceans of Saturn’s ice moon Enceladus. *Starship could fly in a matter of weeks SpaceX boss Elon Musk says the first orbital flight of Starship – the world’s largest rocket -- could take place in either late February or March. *The Science Report A warming climate will increase the number and intensity of tropical cyclones in the North Atlantic. The link between chronic pain and poor general and mental health in later life. Uncovering 29 thousand years of aboriginal history in South Australia’s Riverland region. Skeptic's guide to reality TV ghost hunters Listen to SpaceTime on your favorite podcast app with our universal listen link: https://spacetimewithstuartgary.com/listen For more SpaceTime and show links: https://linktr.ee/biteszHQ If you love this podcast, please get someone else to listen to. Thank you… To become a SpaceTime supporter and unlock commercial free editions of the show, gain early access and bonus content, please visit https://bitesz.supercast.com/ . Premium version now available via Spotify and Apple Podcasts. Sponsor Details: This episode of SpaceTime is brought to you with the support of NordVPN…The world’s leading VPN provider. Making your online data unreadable to others. Get our Complete Security discount offer, plus one month free, plus you get to help support SpaceTime… visit www.nordvpn.com/stuartgary or use the coupon code STUARTGARY at checkout. Thank you…
[0:01] This is Space Time Series 26 Episode 9, for broadcast on the 20th of January 2023. Coming up on Space Time… Astronomers find the most distant star in our galaxy new evidence for the potential habitability of Enceladus's oceans.
And Elon Musk says Starship could be flying in a matter of weeks. All that and more coming up on Space Time. Welcome to Space Time with Stuart Gary.
[0:30] Music.
[0:47] A new study shows that the furthest reaches of our Milky Way galaxy, a region known as the Galactic Halo, is so far away It almost touches the halo of our nearest big galactic neighbor, the Andromeda Galaxy M31.
Astronomers reach their conclusions after discovering more than 200 distant variable stars known as RR Lyra stars in the Milky Way's stellar halo.
The most distant of these stars is more than a million light years from Earth. That's almost half the distance to our neighboring galaxy Andromeda, which is about 2.5 million light years away.
The characteristic pulsations and brightness of our Lyra stars makes them ideal standard candles for measuring cosmic distances.
[1:30] Of course, the sky is full of stars, some brighter than others, but a star may look bright either because it's very luminous or because it's very close, and even for astronomers it's hard to tell the difference.
But astronomers can identify our Lyra stars by their characteristic pulsations.
They can then use their observed brightness to calculate how far away they really are. These new findings are helping redefine what constitutes the outer limits of our galaxy.
It turns out the Milky Way and Andromeda are so big there's hardly any space between them. The stellar halo component of our galaxy is much bigger than the galactic disk, which is about 100,000 light years across.
Our solar system resides in one of the spiral arms of the disk, about 27,000 light years out from the galactic center. The middle of the disk is a central bulge and surrounding
it is the halo, a sphere containing some of the oldest stars in the galaxy. And this extends for hundreds of thousands of light years in every direction. The problem is the halo is the hardest part of the galaxy to study because its outer limits are so far away. And the.
[2:40] Stars there are very sparse compared to the high stellar densities seen in the galactic disc and bulge.
But the galactic halo is important because astronomers believe it's dominated by dark matter and so it actually contains most of the mass of the galaxy.
[2:56] The study's lead author Yuteng Feng from the University of California Santa Cruz says previous modelling had suggested that the stellar halo should extend out to around 300 kiloparsecs.
That's roughly a million light years from the galactic centre.
Astronomers like to measure galactic distances in kiloparsecs with 1 kiloparsec equivalent to 3,260 light years.
The 208 R.I. Lyra stars detected by Feng and colleagues ranged in distance from about 200 to 320 kiloparsecs.
And they were able to use these variable stars as reliable traces to pin down distances. The observations confirmed the theoretical estimates for the size of the halo.
The findings were based on data from the Next Generation Virgo Cluster Survey, a program using the Canada-France Hawaii telescope to study a cluster of galaxies well beyond the Milky Way known as the Virgo Cluster.
The Virgo Cluster is one of the great galactic nodes in the large-scale structure of the universe and it includes the giant elliptical galaxy M87.
Feng says to get a deep exposure of M87 and the galaxies around it, the telescope also captured the foreground stars in the same field and that was the data which they were then able to use for their HALO study.
[4:14] This is space time. Still to come, new evidence for the potential habitability of Insolidus' oceans. And Elon Musk says Starship could be flying in a matter of weeks.
All that and more still to come on Space Time.
[4:29] Music.
[4:44] The search for extraterrestrial life just got a whole lot more interesting following the discovery of new evidence for tiny building blocks of life in the subsurface oceans of Saturn's Iceman Enceladus.
The new modelling, reported in the journal PNAS, the Proceedings of the National Academy of Sciences, indicates that the Enceladian Ocean could be relatively rich in dissolved phosphorus, an essential ingredient for life.
One of the study's authors, Christopher Glenn from the Southwest Research Institute in San Antonio, Texas, says insulidus is one of the prime targets in humanity's search for life in our solar system.
It was NASA's Cassini spacecraft which first discovered that insulidus had a global subsurface liquid water ocean after detecting plumes of ice grains and water vapor erupting into,
space from geysers in the icy moon's south pole tiger stripes.
[5:39] And Glenn says that these plumes contain almost all the basic requirements for life as we know it.
He says while the bioessential element phosphorus is yet to be identified directly, his team have detected evidence of its availability in the ocean beneath the moon's icy crust.
One of the most profound discoveries in planetary science over the past 25 years is that worlds with oceans beneath a surface layer of ice are common in our solar system.
These worlds include the tiny icy moons of the giant planets like Europa, Titan and Enceladus, as well as more distant bodies like Pluto.
Worlds like the Earth with surface oceans need to reside within a narrow range of distances from their host stars, what we call the habitable zone, where it's not too hot and not too cold for water to remain in a liquid state, essential for life as we know it, on a planet's surface.
But subsurface water worlds can occur over a much wider range of distances, thereby greatly expanding the number of habitable worlds likely to exist across the galaxy.
Glenn says the quest for extraterrestrial habitability in the solar system has thus shifted focus. are now looking for the building blocks of life in different places.
[6:52] These building blocks include organic molecules, ammonia, sulfur-bearing compounds, as well as the chemical energy needed to support life.
Glenn says phosphorus presents an interesting case because previous work suggested it might be scarce in the oceans of Enceladus, and that would have been dim for the prospects of life.
Phosphorus, in the form of phosphates, are essential for all life on Earth as we know it. It's essential for the creation of DNA and RNA, energy-carrying molecules, cell membranes,
bones and teeth in animals, and even in the sea's microbiome of plankton.
Glenn says the underlying geochemistry has an elegant simplicity that makes the presence of dissolved phosphorus inevitable, reaching levels close to or even higher than those found in modern Earth sea water.
According to Glenn, the next step's clear. We need to get back to Enceladus to see if a habitable ocean is actually inhabited.
Now this all comes about because five years ago, NASA's Cassini spacecraft discovered hydrogen in a plume of gas and icy particles, spraying out from Enceladus' south pole tiger stripes.
That discovery meant the icy moon had a source of chemical energy that could be useful for microbes, if any exist there.
The finding also provides further evidence that warm mineral-laden water is pouring into the ocean from deep sea vents.
[8:17] Earth. These sort of hydrothermal events support thriving communities of life in complete isolation from sunlight. The ion and neutral mass spectrometer instrument team lead Hunter Waite from the Southwest Research Institute says Enceladus now appears to have all three of the ingredients scientists think,
life needs. Liquid water, source of energy and the right chemical ingredients like,
carbon, hydrogen, nitrogen, oxygen and now phosphorus. The instrument acts like a a human nose analyzing the smell, so to speak, or the composition of the gases in the environment.
There was a significant amount of molecular hydrogen. The existence of molecular hydrogen, at least within the Earth's ocean system, is like a food source.
It's candy for microbes.
They eat the hydrogen, they turn it into methane. With our findings, we were able to not only find out that there was H2 in the system,
but to examine the chemistry that's associated with that process of taking hydrogen and turning it into methane.
[9:26] Music.
[9:34] Here on Earth, the hydrothermal systems known as white smokers have water-rock interactions that lead to the release of molecular hydrogen in a similar fashion to apparently what's going on at Enceladus.
[9:47] Music.
[9:54] This is just the final step that shows that there's molecular hydrogen being produced by these same hydrothermal processes and that molecular hydrogen has the chemical energy to support microbial systems in the interior ocean.
It's not demonstration of finding life, but it shows the potential for the existence of life in this interior ocean.
[10:22] Of course, the wealth of discoveries now coming from Enceladus were only ever possible because of Cassini's detection of strange magnetic anomalies in the Ice Moon's vicinity.
But it took a series of close flybys of Enceladus to detect the icy plumes and understand what they meant.
This report from NASA TV.
[10:42] Music.
[10:51] We had our first close flyby of Enceladus. And the magnetometer signal saw something unusual. What a magnetometer does is it measures the magnetic field in the vicinity of the instrument.
[11:04] We had a look at the wiggles and they looked strange. The magnetic field of Saturn is moving towards it and it couldn't penetrate down onto the surface, which was pointing to an atmospheric signature of some kind.
[11:16] Here it looked like it had a tiny atmosphere.
[11:21] In March we came even closer, looking for that same strange signal. What it showed was that the signature, the atmospheric signature we were seeing was focused at the South Pole.
[11:35] It was almost like there was a cometary plume of water vapor coming off from the South Pole. People were saying, it's got to be jets, it's got to be jets, and the imaging team was saying, No, no, no, we don't want to say that until we're sure.
So we went closer. We came within 175 kilometers of Enceladus. Then we got the data back. And it was spectacular.
And then we found the evidence. Geysers coming out of the South Pole with water vapor and water ice particles.
[12:03] They were active geysers at the South Pole of Enceladus. Because we were so close, all of the other instruments were able to take really good data.
[12:13] And we put together all of this data. We saw the cracks, the tiger stripes of the South Pole. We saw heat leaking out from these tiger stripes.
On subsequent flybys, we found organic material, dust, water vapor coming out of the plume.
[12:28] The Cassini discoveries in the first three flybys were so amazing, we changed our focus and added 20 more flybys of Enceladus, including seven through the IC jets.
The surprising magnetometer reading led us to the liquid water ocean underneath Enceladus' icy crust.
[12:46] Music.
[12:57] After over a decade of research with Cassini, we now know there's a potential for the ocean on Enceladus to support life.
And that has altered the way we think about where life might be found in our own solar system and in the worlds beyond.
[13:16] And in that report from NASA TV, we heard from Cassini Project Scientist Linda Spilker and Cassini Magnetometer Principal Investigator Michelle Doherty.
This is space time. Still to come, SpaceX boss Elon Musk says the first flight of the world's largest rocket, Starship, could take place either late February or early March.
And later in the Science Report, uncovering 29,000 years of Aboriginal history in the South Australian Riverlands. All that and more still to come on Space Time.
[13:49] Music.
[14:05] SpaceX boss Elon Musk says the first orbital flight of Starship, the world's largest rocket, could take place either late in February or early March. The 120-meter-tall Starship mega-rocket towers over NASA's Artemis Orion SLS space launch system, as well as its predecessor,
the mighty Apollo's Saturn V moon rocket. When it launches, Starship will become the largest,
most powerful man-made rocket ever flown into space.
In fact, with over 17 million pounds of thrust, the Starship Super Heavy Booster will produce nearly double the power of the SLS.
It appears SpaceX have selected prototypes Super Heavy Booster 7 and Starship Variant 24 for the historic test flight, with both stages subjected to a series of tests at SpaceX's Starbase facility in southern Texas.
Both Super Heavy Booster 7 and Starship 24 have already performed static fire tests of their Raptor engines.
While Starship 24 lit up all six of its Raptor engines simultaneously, Super Heavy Booster 7 only triggered 14 of its 33 engines in a single burn.
That means additional ground testing will still be needed before any maiden flight can be considered.
[15:20] So when it does get off the ground, what will this monster rocket's mission look like? Well, the orbital test flight would see Super Heavy Booster 7 carry Starship 24 to an altitude of about 65 kilometres.
Then following main engine cut off and stage separation, the booster will return to Earth, splashing down the Gulf of Mexico off the coast of Texas.
However, the ultimate plan will see the Super Heavy Booster undertake an orientation flip, then a boost-back burn guided by nitrogen jets and aerodynamic fins back towards the launch site.
An entry burn will then slow Super Heavy down for a controlled descent before a landing burn will see the booster touch down vertically back on the launch pad, caught by a pair of mechanical arms.
Meanwhile, during this test flight, the Starship 24 upper stage will complete one full orbit around the planet before re-entry and splash down in the Pacific Ocean off the coast of Hawaii.
Eventually, Starship will also land vertically back on the ground.
The orbital trial will be the system's first test flight since May 5th, 2021. That's when Starship prototype SN15 launched from Starbase, climbing to an altitude of 10 km on three Raptor engines and undertaking a series of aerial maneuvers before landing back at Starbase.
So far all flight tests have only involved Starship prototypes. Super Heavy boosters are yet to fly.
[16:46] So, what's SpaceX's Starship program all about? Well, there are two parts to it.
There's the Starship itself and the Super Heavy booster.
[16:56] The 120-ton 50-meter tall Starship is 9 meters in diameter and constructed out of stainless steel.
It's powered by six liquid methane and oxygen-fuelled Raptor rocket engines, three configured for atmospheric flight and three for the vacuum of space.
70-meter long 9-meter diameter 230-ton super heavy booster is also constructed out of stainless steel and it's equipped with some 33 Raptor engines, all configured for atmospheric flight.
Elon Musk sees Starship as an interplanetary colonial transport system designed to establish and then supply human settlements on the Moon, Mars and across the solar system.
It'll be fully reusable, equipped with a belly heat shield and its own retractable vertical landing gear and it can be refuelled in space using unmanned versions of Starship.
Another version will be equipped with a large payload bay for the deployment of satellites.
[17:51] Further in the future Starship may even host point-to-point flights around the Earth for people allowing you to pretty well reach any destination on the planet or at least the nearby hub in under 90 minutes.
Starship's first mission is to provide the Starship Lunar Landing System or HLS, a reusable shuttle for NASA to transport people up to 100 tons of cargo between the lunar surface and orbiting spacecraft, such as Orion capsules and the Lunar Gateway Space Station.
SpaceX plan to eventually use Starship to replace all the company's existing spacecraft, including Dragon capsules and both the Falcon 9 and Falcon Heavy launch systems.
[18:31] It's all an ambitious plan right now, but SpaceX does have a proven track record.
Meanwhile, SpaceX has launched another 40 broadband internet satellites for rival company OneWeb aboard its Falcon 9 rocket from Space Launch Complex 40 at the Cape Canaveral Space Force Base in Florida.
With some 542 satellites now in orbit, OneWeb has over 80% of its first-generation constellation complete.
These satellites were originally meant to fly aboard Russian Soyuz rockets.
[19:02] Despite the European Union's ban on using Russian rockets following Moscow's invasion of Ukraine, means OneWeb's transferred its launch manifest to SpaceX and India.
The OneWeb launch was followed just days later by the safe return to Earth of a SpaceX Dragon cargo ship loaded with two tons of completed scientific experiments and equipment from the International Space Station.
The Dragon splashed down in the Gulf of Mexico off the coast of Tampa, Florida, completing the Ceres 26 mission, which had launched from the Kennedy Space Center just six weeks earlier.
The equipment brought back to Earth included hardware used to grow plants in microgravity, a bioprospecting experiment that ran aboard the space station, and the AstroRad vest, which was designed to help protect people from radiation exposure.
Crew members on station took turns in wearing the vest during their day-to-day operations and then report on how comfortable it was or wasn't and how easy it was to carry out their day-to-day working duties while wearing it.
The garment could eventually be used to help provide radiation protection for crew on Artem's Missions to the moon.
[20:08] Music.
[20:24] And time now to take another brief look at some of the other stories making use in science this week with the Science Report. A new high resolution global climate model is warning that a warming climate will increase the number and intensity of tropical cyclones in the North Atlantic Ocean,
potentially creating more and stronger hurricanes. The findings reported in the journal Geophysical Research Letters is based on work by scientists at Iowa State University and the U.S. Department of of ENERGY's Lawrence Berkeley National Laboratory.
The models show Atlantic hurricane seasons will become more active in the future and hurricanes will become even more intense.
The authors ran climate simulations using the Department of Energy's Energy Exascale Earth Systems model, finding that tropical cyclone frequency could increase by 66% during active North Atlantic hurricane seasons by the end of the century.
Now, these seasons are typically characterized by La Nina conditions, meaning unusually cool surface water in the northern and tropical Pacific Ocean and warmer surface temperatures in the northern tropical Atlantic Ocean.
The model projected that the number of tropical cyclones could also increase by 34% during inactive North Atlantic hurricane seasons, which generally occur during El Nino conditions.
That's when you have warmer surface temperatures in the eastern tropical Pacific Ocean and cooler surface temperatures in the northern tropical Atlantic.
[21:49] A new study has shown that people who suffer chronic pain at the age of 44 are far more likely to report pain, poor general health, poor mental health outcomes and joblessness in their 50s and 60s, according to international researchers.
The findings reported in the General Plus 1 is based on data from 12,037 people enrolled in the UK's National Child Development Survey, with the main data taken in 2003,
when most of the respondents were aged 44. The study pinpointed multiple factors predicting pain at that age, including a person's father's social class at birth, as well as pain in childhood.
The team also found, unsurprisingly, that chronic pain was associated with lower life satisfaction, pessimism about the future, and poor sleep at age 55, as well as a higher risk of COVID-19 infection at age 62, which suggests that pain is also associated with other health vulnerabilities.
[22:48] Archaeologists have uncovered 29,000 years of Aboriginal history in South Australia's Riverland. The findings, reported in the journal Australian Archaeology, used radiocarbon dating to analyse river mussel shells from a midden site overlooking the Pike River floodplain,
downstream from the town of Wrenmark. The research by Flinders University is the first comprehensive survey of one of the oldest indigenous sites along the 2,500 km long
Murray-Darling River system. The results include the first pre-lascalational maximum ages returned for the River Murray in South Australia and extend the known First Nations occupation of the Riverland area by approximately 22,000 years. In case you haven't noticed it,
ghost hunting programs are making a big comeback on cable TV. A lot of people, both true believers and non-believers alike enjoy them. After all, we all like getting a good scare.
[23:46] But it seems these new reality TV programs are getting so bad now that people who really are ghost hunters are now starting to complain that they're making their profession look like a.
[23:56] Joke. Notice how I said all that with a straight face. Tim Mendham from Australian Skeptics says so-called real paranormal investigators are upset because a lot of what's being seen in these reality TV shows is clearly scripted and using fake special effects.
I find most of them very unentertaining personally, not just because they're obviously picking up on things that might not be there. But also just to not, for me, great TV. They try and make it great TV and that's the problem. Actually, there's a lot of issues. This person,
who is a ghost hunter, pointing out why TV shows that have people hunting ghosts and they've always got the man, the woman, the skeptic, whatever, all wearing their camouflage suits. It's all that
finding Bigfoot formula, isn't it? It is. It's the same as finding Bigfoot. I don't know why you have to wear camouflage when you're looking for ghosts. But anyway, they've always got a team going into
of this haunted house with all their little equipment, their machines and things that go ping and suddenly getting messages from beyond the grave, etc. Why is this person here? Strange things out of the corner of their eye, etc. Now this person has written an article suggesting there's various reasons why you can spot how they cheat. One is that noises and things they get are easy to fake and fabricate. The machinery they use is very prone to interference from anything else including mobile phones. A machine that goes ping is not necessarily proof. The other things they've talked to some of the
ghost hunters there's a couple called Ed and Lorraine Wine whose exploits have.
[25:17] Been made into the Conjuring films. I say they were real hit and live.
Weren't they also the people behind the Amityville haunting etc. or curse whatever it was and they were real endorsers of all this sort of stuff because it made good sense to them. They both passed on to the other world maybe we can go and check them in the haunted house.
But they were so many conflicting accounts from various sources as to what they were finding and what they were saying and everything. This article suggests that they were sort of conscious
Of course, in the TV shows, they go into this haunted house and there they find a ghost. In reality, as ghost hunters will tell you, it's a bit more hit and miss than that. You're really not sure you're going to find something.
One issue with the course is that people often research beforehand that they find a house that is supposedly haunted, then they go in knowing what they're expecting to find, and they do find it surprisingly.
So really, people should go in their site unseen, you can use that for ghosts and check it out.
But these ghost hunters are already, they've done the research, they've probably checked through the thousands of potential places and they choose the particular ones they think they're going to get a result and what ends up doing is that they're making money out of people for doing it and people then believe in the ghost and that sets up the whole market for ghost hunting and talking to the dead and all sorts of things like that.
And finally, these articles suggest that really if you find a ghost, there's no definitive way to tell what the ghost wants or why they've stuck around.
[26:37] That's assuming there's a ghost because some people believe it and a lot of people don't. But if you want to find a ghost, you will find a ghost and this is all the ways to pretend to do it. How do you know your house is haunted? It's not.
That was Jimmy Carr's response. Jimmy Carr's response to the TV pro. How do you know your house is haunted? It's not. That's Timmendom from Australian Skeptics.
[26:58] Music.
[27:12] And that's the show for now. Spacetime is available every Monday, Wednesday and Friday through Apple Podcasts, iTunes, Stitcher, Google Podcasts, Pocket Casts, Spotify, Acast, Amazon Music, Bitesz.com, SoundCloud, YouTube, your favorite podcast download provider and from spacetimewithstuartgarry.com. Spacetime is also broadcast through the National Science Foundation on Science Zone Radio and on both iHeartRadio and TuneIn Radio.
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