Sept. 23, 2022

Counting Down to Asteroid Collision

Counting Down to Asteroid Collision

SpaceTime Series 25 Episode 100
*Counting down to asteroid collision
NASA’s Double Asteroid Redirection Test— or DART mission -- remains on target to crash into a potentially hazardous near-Earth asteroid on Monday.
*Continental plate movements...

SpaceTime Series 25 Episode 100
*Counting down to asteroid collision
NASA’s Double Asteroid Redirection Test— or DART mission -- remains on target to crash into a potentially hazardous near-Earth asteroid on Monday.
*Continental plate movements control Earth’s largest volcanic events
A new study has found a surprising link between the slowing of continental plate movements and the timing of Earth’s largest volcanic events.
*More and More Starlinks launched
SpaceX says that even though its requested authorization to launch some 42 thousand Starlink broadband satellites – it probably won’t need that many to achieve the global internet coverage its seeking.
*China launches more spy satellites
China have launched another pair of spy satellites as they continue what President Xi Jinping and the Chinese communist government refer to as preparations for war.
*The Science Report
Australia’s black summer bushfires found to be 3 times worse than any other wildfires globally.
Scientists have developed a new way to break down long lasting chemicals.
Do you suffer from doom scrolling addiction
Skeptics guide buying a legally haunted house

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Stuart: This is Spacetime Series 25, episode 100, for broadcast on 23rd September 2022. Coming up on Spacetime counting down to asteroid collision. A new study shows how continental plate movements control Earth's largest volcanic events. And China launches more spy satellites. All that and more, coming up on, um, space time.

VO: Welcome to spacetime with Stewart gary.

Stuart: NASA's Double Asteroid Redirection Test, or Dart mission, remains on target to crash into a potentially hazardous near Earth asteroid on Monday. The cosmic collision is part of a planetary defense exercise trying to determine what to do if astronomers discover a large asteroid on a collision course with the Earth. The 610 kilogram Dart spacecraft will slam into its target the 170 meters wide asteroid dimorphus at six 6. Impact will take place at approximately 07:14 p.m.. US Eastern Standard Time on the evening of September 26. That's 914 the next morning, Australian Eastern Standard Time. The massive impact should not only create a huge crater on the asteroid surface, but also slightly change its orbit in space. dimorphus is orbiting the largest 780 meters wide asteroid 6583 Diddy Moss. And the impact should push dimorphus several meters closer to Diddy Moss, possibly even slightly changing the trajectory of both bodies. Jonathan Ali, the editor of Australian Sky and Telescope magazine, says the impact will provide scientists with important details about the composition of these Earth crossing asteroids known as Apollo.

Guest: It's going to be very interesting to see what happens. Pretty certain they know what's going to happen and of course, there's no danger to anyone, m, it's not going to send anything flying towards us. But the important thing about planetary defense you just mentioned and these asteroids and things, is that if you're going to defend against something, you really have to know your enemy and go back some years. And it was probably widely thought, if not completely, mostly thought, that an asteroid was just like a huge solid chunk of rock. But now we know that many of them, some of them at least, m, and possibly many of them are actually rubble piles. They're sort of bits of stuff stuck together. And if you disturb it, it's going to sort of break into pieces. So if you've got one, if one eventually does sort of spot it's heading towards us. We need to know what happens if you smash something into one of these things, whether it's a solid one or a rubble pile one. So this one that's going to be smashed into could easily be a rubble pile one. We just don't know. And yeah, it's going to be very interesting. I want to see the images because there are two imaging systems that are going to be, um, watching this. One on the actual impactor itself and one on the little follow on spacecraft coming after us. So it should be quite amazing to see, uh, how much of a kick this impact it gives this little moonlight, um, of the asteroid and how much it affects its orbit because the impact from the thing itself will impart some force onto the little body. But when the explosion happens, when it hits, it's going to be an explosion. Any stuff that then gets flung out is also going to with the old equal opposite reaction business, that's also going to impart a bit of movement to it as well. So that's what they're really interested in seeing is how much it's orbit will be changed both by the impact on and by the force of the explosion that flings stuff in one direction and therefore the body will go in the other direction. So they don't really know yet. They've got a range of possibilities and they call it Beta or Beta is the fact that they want to measure and could change it a little bit. It could change a lot.

Stuart: It's not just the impact on the moonlight itself. It's also how the center of gravity changes and how that would affect the primary body, the one that's not being hit.

Guest: Yes, that's right. Because when you go, we tend to think of one thing, orbiting another thing. But really, when you got two things, they are actually orbiting around, uh, a common center of gravity.

Stuart: The center of gravity is called the Barry Center, wearing a safari suit.

Guest: Barry center, wearing a safari suit and his body shirt. Anyway. Barry center. Yes. So that's the center, uh, of gravity around which two objects will orbit for the Earth and the Moon. Uh, the barrier center, if I remember correctly, is actually inside the is it inside or outside the Earth?

Stuart: Just inside, isn't it?

Stuart: Otherwise the Earth and Moon would be a binary system. Like, who would want that? Pluto and Sharon. And apparently, it is sharon. I've spoken with a lot of astronomers about it, and they all call it Sharon. None of them call it Karen.

Guest: Sharon's got a Barry Center, some sort of dog called Pluto or something, and they're made Barry Center.

Stuart: Uh, Morphers will make their closest approach to Earth in years at the time of the impact, passing just 10.8 million km from the planet. In October, scientists will use ground based telescopes around the world to look for key events and calculate dimorphus new orbit, expecting that the time it takes the smaller asteroid to orbit diddymos will have shifted by several minutes. These observations will also have constrained several theories that astronomers currently have about dimorphism orbital dynamics and the rotation of both asteroids. A, uh, short time ago, a six unit Italian space Agency CubeSat was supplied from the Dart spacecraft, the Light Italian CubeSat for imaging asteroids, or the C A Cube, is designed to monitor the impact and then collect data. The C A Cube will be followed in five years time for the European Space Agency's Hera mission, which will launch in 2024 and arrive at Diamorphus in 2027. Hera will carry two six unit CubeSats. Milani will study the binaries composition and Juventus will attempt a landing on Diamorphus this report from Easter TV.

VO: The Incredible adventures of the uh Hero Mission asteroid on um collision course with Earth ah. Imagine the headlines it may sound like science fiction but to date we've discovered more than 200 asteroids whose orbits bring them dangerously close to Earth it's a hazard the dinosaurs were powerless to stop with all the advanced science and technology in our hands. Could we do better? Planetary defense requires planetary cooperation meet the Hero mission led by the European Space Agency set to rendezvous with a binary asteroid system in 2026 didymos Is orbited by a smaller asteroid dimorphus this pair poses us no risk but our experiments with them will be key to keeping Earth uh safe Demorphus is a small asteroid yet a rock of its size could devastate a small country or large metropolitan area studying asteroids like this from Earth uh. Is challenging as a matter of fact. Today we still know very little about their physical properties the only way to capture their secrets is to go and visit so we need herea to get up close and personal when Hiro reaches it demorphys will already have been impacted by NASA's double asteroid Redirection Test. Or Dart for sure this cosmic shove is expected to slightly shift the orbit of the asteroid moon Hero we'll examine the crater left by Dart the composition of Demorphus map its surface temperature and probe its internal structure similarly to an Xray meanwhile. Hiro will deploy two briefcase sized CubeSats called Juventus and Milani packed with hightech equipment such as a low frequency radar a mineral mapper. Dust analyzer and a gravy meter these minisatellites will get an even closer look before attempting to land altogether the Dart impact and Hero's data will let us understand whether this technique can be used in the future to deflect an asteroid on a collision course with Earth like an astronomical game of Billiards uh in addition to Hiro's main planetary defense quest the mission will gather invaluable bonus science new understanding of collision physics and crater creation could revolutionize our understanding about how the solar system was formed hiro will even test new techniques for autonomous deep space navigation and guidance while working in the asteroids extremely low gravity this will help pave the way for future interplanetary missions not bad for a space probe the size of an office desk the.

Stuart: Dart mission follows on from the 2000 and uh five Deep Impact mission which slammed an impactor uh. Into the comet temple one the impactor successfully collided with the comet's nucleus forming a 100 meters wide crater that was some 30 meters deep excavating debris from the cometry interior images taken by the Deep Impact spacecraft showed the comet to be more dusty and less icy than had been expected in fact. The impact generated an unexpectedly large and bright dust cloud initially obscuring the view of the impact crater xray uh observations showed the comet continued outgassing from the impact for 13 Earth days. With a peak five days after impact. A total of 5 million water and between ten and 25 million dust were ejected by the impact. Astronomers describe the debris as being as fine as talcum powder rather than sand. Spectroscopy readings of the debris cloud detected water, ice, clays, carbonate, sodium and crystalline silicates. Observations also revealed that the comet was porous about 75% empty space, very similar to a fresh snowbank. This is spacetime. Still to come, a new study shows continental plate movements control Earth's largest volcanic events and SpaceX launching more and more starlink satellites. All that and more still to come on, um, space time. A new study has found a surprising link between the slowing of continental plate movements and the timing of Earth's largest volcanic events. The findings, reported in the journal Science Advances, shed snow light on the timing unlikely cause of major volcanic events that occurred billions of years ago and caused such climatic and biological upheaval that they drove some of the most devastating mass extinction events in the planet's history. Earth's history has been marked by major volcanic events known as large igneous provinces. Using chemical data from ancient mud stone deposits obtained from a one and a half kilometer deep borehole in Wales, scientists were able to link two key events from around 183,000,000 years ago during the Torsioning period. Scientists found that this time period, which was characterized by some of the most severe climatic and environmental changes in Earth's, uh, history, directly coincided with major volcanic activity and its associated greenhouse gas release on, um, the southern hemisphere in what is now southern Africa and Arctica and Australia. Tectonic plate reconstruction models show that these are the key fundamental geological processes that control the timing of this volcanic event, as well as others of similar great magnitude. The studies lead author, Ah. Michael Ruel from the Trinity School of Natural Sciences, says researchers had long thought that the onset of upwelling of molten volcanic rock, or Magna, from deep in the, uh, Earth's interior as mantle plumes triggered this volcanic activity. But the new evidence shows that the normal rate of continental plate movements of just a few centimeters per year effectively prevents magnet from penetrating the Earth's continental crust. It seems it's only when the speed of continental plate movement slows down to near zero that magnets from mantle plumes can effectively melt their way up through the crust to the surface, causing major Large igneous province volcanic eruptions and their associated climatic, perturbations and mass extinction events. Crucially, further assessment shows that a reduction in continental plate movements likely controlled the onset, um, duration of many of the major volcanic events throughout its history, making it a fundamental process and controlling the evolution of climate and life on Earth's surface throughout the history of the planet. This is space time still to come. SpaceX says even though it's requested authorisation to launch some 420 starlink satellites. It probably won't need that many after all. And later in the Science Report do you suffer from doom scrolling addiction? Well, if you listen to us, you probably do all that and more still to come on, uh, Space Time. SpaceX says even though it's requested authorisation to launch some 420 starlink broadband satellites, it probably won't need that many to achieve the global Internet coverage it's seeking. The sheer number of satellites launched, which as of September 11 this year stood at 3293 spacecraft, is posing a serious problem for astronomers trying to undertake important scientific research. There are also growing concerns for the safety of space navigation because of the increasing congestion being caused by this massive number of satellites. And starlink satellites are also getting bigger. Uh, the first batch had a mass of just 227. Current versions weigh in at some 260. Next variant on the production line come in at around 300 kg each. But as they're increasing in mass, they're also increasing in capacity with bigger antenna and better technology. And SpaceX says that should mean that less will be needed to achieve the same level of service. Still, so far, the launch rates aren't showing any signs of decreasing. SpaceX have already undertaken, um, more rocket launches this year than anyone else. That includes China, which is engaging in a massive military buildup. In fact, just recently, SpaceX launched another 34 starling satellites aboard its Falcon Nine rocket from space launch complex 39 A at the Kennedy Space Center in Florida. Also on board was AC Space Mobile's Experimental Blue Walker Spacecraft. It's described as the largest commercial communications array ever flown in space. Blue Walker Three is actually a test satellite designed to help develop the first space based cellular broadband four G, five G network which will be accessible by standard smartphones for everyday usage rather than just for emergency messaging. HT Space Mobile has partnered with 25 cellular service providers. The satellite, which is now unfurling its giant 64 square meter array, will undertake m six months of testing with ten cell phone companies on six continents. The launch went smoothly with a Falcon Nine core stage used for the mission, undertaking a recordbreaking 14th liftoff. The core stage then successfully returned to Earth, landing on the drone ship a shortfall of gravitas which had been prepositioned down range in the North Atlantic Ocean. Just a few days earlier, another 51 starling satellites, together with an orbital transfer vehicle, were launched aboard another Falcon Nine from the neighboring Space Launch Complex 48, Cape Canaveral. The orbital transfer vehicle, named Sherpa LTC and operated by a company called Space Flight, then delivered an undisclosed payload into another orbit before being deployed. Spaceflight describes Sherpa, uh, as a mothership for small satellites that allows them to ride, chair and reduce their launch costs. Just over eight minutes after launch, the Falcon Nine core stage returned to Earth, landing on the drone ship. Just read the instructions which had also been prepositioned down range in the North Atlantic Ocean. The latest spate of the Starlink launches began with a deployment of 53 satellites from Cape Canaveral, with a Falcon Nine core stage, again landing on the drone ship a shortfall of gravitas. Meanwhile, China have launched more spy satellites, with another pair being sent into orbit as part of what President Xi Jinping and the Chinese Communist government referred to as preparations for war. The Yogon 3300 and two spacecraft were launched aboard a LONGMarch four sea rocket from the Jaquan satellite launch center in northwestern China's Gobi Desert. Beijing claimed the spacecraft will be used to monitor land use, crop yields, urban planning, and take care of natural disasters. However, military analysts say the Yoga are, uh, pure and simple military spy satellites equipped with high resolution optical and synthetic aperture radar imagery systems and electronic signals intelligence gathering technology designed to provide continuous surveillance and reconnaissance monitoring of areas of interest to China, as well as the launch vehicle's upper stage. The United States Space Force says it detected two new objects in orbit following the launch. Traveling in a 688 x 680 kilometer high near polar orbit, the flight follows the earlier launch of a quasi One A rocket also from Jaikuan, carrying the Century Space One, S Three and S Four experimental satellites into orbit. Beijing claims these two spacecraft will test out new navigation system technologies. And just hours later, Beijing launched another long March 2 D rocket, this one from the Zhaichang Satellite Launch Center in southwestern China's Sichuan province, carrying three more Yogang 35 spy satellites. Beijing has also placed a new Zion Jing One, a military telecommunications satellite, into orbit. The 5320 kilogram spacecraft was launched aboard a longmart seven. A rocket from the Wing Cheng satellite launched Saturn Hannan Island in the South China Sea. Based on a DFH four satellite bus, the spacecraft is equipped with C, Kuka and LBand transponders and is carrying enough fuel for a design service life of 15 years. China now has an estimated 539 satellites orbiting the Earth, including some 217 Earth Observation, Surveillance and reconnaissance satellites, which include some 41 Go uh things and 103 Yao gangs by satellites. This is spacetime and time. Now to take another brief look at some of the other stories making news and science this week with a science report. It's been revealed that the 2019 2020 BlackSummer Bush fires in Australia transported more smirk into the planet's atmosphere than any wildfire ever previously observed anywhere in the world. Now, two new studies led by the Lakesy Institute for Tropospheric Research have shown the global climate impact of these fires. Scientists found three times as many particles reached the upper atmosphere compared to the previous record wildfires, which occurred in Canada in 2017. The analysis, reported in the journal Atmospheric Chemistry and Physics, shows that smoked particles with a total mass of around a million tons spread across the Southern Hemisphere and affected climate for about one and a half years by warming the upper atmosphere and cooling the lower atmosphere close to the earth's, uh, surface. In fact, from the subtropics right down to the Antarctic, sunlight was dimmed even more than during the eruption of the Pinotupa volcano in 1991. The smoke probably also contributed to a record ozone hole over Antarctica in 2020, which formed a vortex 1000 km wide, which hung over the southern hemisphere for several weeks, and which is considered the first evidence that smoke from wildfires can also alter high altitude winds. In the stratosphere, uh, the black summer bushfires burnt out over 186,000 km², killing more than 3 billion vertebrate animals, including many highly endangered species, some of which have now been driven into extinction. The massive wildfires destroyed almost 6000 buildings, filling 2779 houses and killed at least 34 people. Smoke from the fire spread across the South Pacific Ocean, affecting New Zealand, Chile and Argentina. Scientists have developed a new way to break down some longlasting chemicals. These substances, known as per and polyfluor alkalis, are, ah, widely used in firefighting foams, waterproof, clothing and for nonstick cookware. But they don't break down under normal environmental conditions. And current disposal methods typically require high pressures and temperatures of more than 1000 degrees Celsius. A uh report in the journal Nature claims the new approach targets an oxygen containing chemical group to ultimately break them down into harmless products. Scientists say it's an easier, cheaper approach than existing methods. Well, if like me, you obsessively scroll through the day's latest news and have a 24 hours news channel blaring away in the background, the news isn't good. A new study in the journal Health Communications suggests our, uh, doom scrolling addiction and yes, that's what it's called is probably causing a stress, anxiety and ill health researchers surveyed one 10 adults about their connections in the 24 hours news world and then followed up with questions about their mental and physical health. They say 16 and a half percent of respondents showed signs of severely problematic news consumption. That's when someone's so immersed in news stories they dominate their waking thoughts, disrupt family time, distract from their work or school, and add to restlessness or an inability to sleep. Now, uh, among these addicted respondents, 73 6% reported experiencing mental health issues versus similar experiences being reported by only 8% of other participants. Additionally, 61% of this group reported similar responses to being physically ill compared to just 6.1% of other study participants. And time um, out, uh, for the silliest story of the week and today we couldn't go past a new legal precedent set in the United States where a house has been legally designated as being haunted. Tim Mendel from Australian Skeptic says the judge found that the homeowners should have declared their Victorian era house to be haunted prior to sale.

Stuart: This is a bit of a legal nicety, if you like. There's a house in America in a place called Nyak or nayak, whatever it is, in New York state, and it's actually not far from the town of Sleepy Hollow, which is of course, was, uh, the story of the Headless Horseman hanging around Sleepy Hollow, written about late seven hundred s, eighteen hundreds, whatever. So the ghost should feature well in this area. So what happened was that this was a house that was sort of known to be widely rumored to be haunted for some time. The owners were selling the house and all been signed up. The new buyers then pulled out because they found out that the house was supposed to be haunted. And the sellers took them to court and said, you already agreed to buy the house, you got to buy the house. And they said, no, you didn't tell us it was haunted. And so it went on a bit like this, and the arguments back and forth, and the judge was saying, well, it's been known in quotes to be haunted for some time, so therefore it is a haunted house. So the judge finding that this was a haunted house makes it a legally haunted house. Now, they added quickly that we don't necessarily endorse hauntings. They don't necessarily say that hauntings are real, but they say this one is so highly publicized that we have to say legally, you are obliged to sort of tell people that it is haunted in case they don't want to buy it, which is what stands out. So as a judicial necessity is a bit of a complexity that will sort of, no doubt the pro ghost fraternity will say, c in a court, it's accepted that houses can be haunted, not quite that way, but it is legally haunted.

Stuart: Don't we have similar laws in Australia where if there's an unusual history to the house, it's got to be disclosed?

Stuart: I think there is. It's a bit of a moot point because obviously your real estate agent is not going to tell you, oh, uh, by the way, our family was murdered in this house. The head was over there and the legs were over there, etcetera. But I think they are supposed to tell you if there is something untoward in the history of the building. I don't know how formal it is, whether it's an ethical thing. I don't know if it's a legal thing at this stage here. But um, when people find out, a lot of people will feel uneasy about, uh, living in that other place.

Stuart: Many will think it's a great selling point.

Stuart: Some might do it. If you're selling it to a family of Goths, they might quite enjoy it, actually. But this is all on the premise that these houses are haunted, right? And that's the thing you're going to get over in the first place. Um, is there such thing as a haunted house? As some British comedian once asked, how can you tell the house is haunted? It's not that's.

Stuart: Tim Mendem from Australian skeptics. And that's the show for now. Spacetime is available every Monday, Wednesday and Friday through Apple Podcast, itunes, Stitcher, Google Podcast, Pocket Casts, Spotify, Acast, Amazon Music,, SoundCloud, YouTube, your favorite podcast download provider and from Spacetime with Stewart Spacetime is also broadcast through the National Science Foundation on science owned radio, and on both iHeartRadio and Tune in radio. And you can help to support our show by visiting the Spacetime Store for a range of promotional merchandising goodies. Or by becoming a Spacetime patron, which gives you access to triple episode, commercial free versions of the show, as well as lots of bonus audio content which doesn't go to Air, access to our exclusive Facebook group, and other rewards. Just go to Spacetime with for full details. And if you want more space time, please check out our blog, where you'll find all the stuff we couldn't fit in the show, as well as heaps of images, news stories, loads of videos and things on the web I find interesting or amusing. Just go to spacetime with Stuartgarry That's all one word and that's Tumblr without the e. You can also follow us through at stuartgarry on Twitter, uh, at Spacetime with Stuart Gary on Instagram, through our, uh, Spacetime YouTube channel and, um, on Facebook. Just go to spacetime with Stuartgary and Spacetime is brought to you in collaboration with Australian Sky and Telescope magazine, Your Window on the Universe.

VO: You've been listening to Space time with Stuart Gary? This has been another quality podcast production from

Tim MendhamProfile Photo

Tim Mendham


Editor with Australian Skeptics