Transcript
[0:00] 00:00:00.017" data-end="00:00:06.670">This is Space Time Series 26, Episode 24, for broadcast on the 24th of February 2023.
00:00:07.147" data-end="00:00:08.687">Coming up on Space Time…, 00:00:09.182" data-end="00:00:15.591">A study of the complex Martian subsurface… 0:12">Astronomers angry over commercial satellite pollution…, 00:00:16.123" data-end="00:00:23.450">And China busy with spy satellites and balloons… 0:20">All that and more coming up on Space Time…, 00:00:24.017" data-end="00:00:27.916">Welcome to Space Time with Stuart Gary.
[0:28] 0:43" data-start="00:00:27.920" data-end="00:00:43.120">Music.
[0:44] 00:00:44.318" data-end="00:00:49.577">Brown penetrating radar from China's Martian rover Zhirong has revealed shallow impact, 00:00:55.183">0:50">craters and other geological structures in the top five metres of the Red Planet's surface.
00:00:55.679" data-end="00:01:02.844">0:56">Jurong was launched back in July 2020, landing on the Red Planet's Utopia Planitia region in May 2021.
00:01:03.330" data-end="00:01:08.817">Utopia Planitia is a large plain in the Martian Northern Hemisphere, near the boundary between 00:01:14.097">1:09">the Martian Northern Lowlands and the Southern Highlands. The region was chosen because it's 00:01:19.345">near the suspected ancient shoreline of what was once a vast Northern Hemisphere Ocean.
00:01:24.097">1:20">The tiny rover's primary mission was to search for evidence of water or ice.
00:01:31.097">Large reserves of underground ice were identified in a nearby part of Utopia Planitia back in 2016.
00:01:35.946">1:32">That was by radar observations taken by NASA's Mars Reconnaissance Orbiter.
00:01:36.477" data-end="00:01:44.097">After landing, Giron traveled about 1.9 km south, taking images of rocks, sand dunes and impact craters along the way, 00:01:48.097">and also collecting data from ground-penetrating radar.
[1:49] 00:01:54.097">Ground penetrating radar detects features underground by sending electromagnetic pulses into the ground, 00:01:58.097">which are then reflected back by any subsurface structures it passes over.
00:02:05.097">Chirong uses two radar frequencies, a low frequency which reaches down to around 80 meters but with less detail, 00:02:13.097">and a higher frequency which was used for the SLERDA study, which shows more detailed features but only reaches down about 4.5 meters.
00:02:18.537">Researchers hope that by imaging the subsurface of Mars, they'll shed more light on the red 00:02:24.257">2:19">planet's geologic history, its previous climatic conditions, and any water or ice the planet 00:02:26.417">may host now or in the past.
00:02:31.602">2:27">The findings reported in the journal Geology show evidence of several curving and dipping 00:02:36.402">2:32">underground structures in the Martian soil that appear to be buried impact craters, 00:02:39.442">2:37">as well as other sloping features with less certain origins.
[2:40] 00:02:40.141" data-end="00:02:45.602">Importantly, there was no evidence of water or ice, at least not in the top five meters of soil.
[2:46] 00:02:46.316" data-end="00:02:51.682">Radar images of deeper structures did reveal layers of sediment left by episodes of flooding 00:02:57.422">2:52">and deposition in the past, but also found no evidence of water in the present day.
00:03:01.662">This doesn't rule out the possibility they're being watered deeper than the 80m image with 00:03:06.310">3:02">the radar, but it does set some constraint as to what's accessible.
00:03:11.502">3:07">The study contrasts the data from Mars with ground penetrating radar previously collected 00:03:16.123">3:12">from the Earth's moon, which shows a very different shallow subsurface structure.
[3:17] 00:03:21.082">Where the shallow Martian surface contains several distinct features that show up in 00:03:26.402">radar, the top 10 meters of the Moon has fine layers but no evidence of other structures 00:03:31.265">like impact crater walls, despite also being subjected to meteorite bombardment.
00:03:36.522">3:32">The walls of impact craters are however observed at greater depths on the Moon, buried deep 00:03:39.583">3:37">beneath the 10 meter thick layer of fine debris.
00:03:40.142" data-end="00:03:46.842">The difference could be the atmosphere. 3:42">While Mars' atmosphere is only 1% as thick as the Earth's atmosphere, that's still a 00:03:50.259">3:47">lot more than the Moon, which is virtually no atmosphere at all.
00:03:55.122">3:51">So with essentially no atmospheric protection, the Moon's surface is constantly bombarded 00:03:57.641">by even the smallest micrometeorites.
[3:58] 00:03:58.322" data-end="00:04:03.295">And over billions of years they've reworked the surface, eroding small-scale features, 00:04:07.391">and leaving behind lots and lots of fine layers of ejecta.
00:04:13.728">4:08">By contrast, the surface of Mars is not being subjected to nearly as many micrometeorite impacts.
00:04:14.215" data-end="00:04:17.374">That's because the smaller objects burn up in the atmosphere.
00:04:22.682">4:18">In the regions imaged by Xeron, burial by windblown sediments may also have protected 00:04:24.482">4:23">the impact credits from erosion.
00:04:25.116" data-end="00:04:30.257">One of the craters imaged had its rim exposed to the surface, but the other crater was totally buried.
00:04:33.920">4:31">Whether we'll get more information from Zhurong is debatable.
00:04:34.398" data-end="00:04:39.529">China recently lost contact with the rover and has been unable to re-establish communications.
00:04:40.051" data-end="00:04:45.126">Zhurong, which is named after a Chinese god of fire, was placed into hibernation mode more than 00:04:49.926">six months ago in order to deal with the freezing Martian winter where temperatures commonly tip, 00:04:50.089" data-end="00:04:52.456">below minus 100 degrees Celsius.
00:04:53.046" data-end="00:04:57.446">And the area also experienced a severe regional dust storm, which may have covered the rover's 00:05:02.512">solar panels with lots of dirt, preventing it from gathering power to charge its batteries.
00:05:03.025" data-end="00:05:05.770">Xurong's mission, therefore, may be over.
00:05:06.406" data-end="00:05:13.566">This is space time. 5:08">Still to come. 5:10">Astronomers angry over the growing levels of commercial satellite pollution.
00:05:17.140">5:14">And China caught out playing with spy satellites and balloons.
00:05:19.103">5:18">All that and more still to come.
00:05:36.207">5:20">On space-time.
[5:21] 5:35" data-start="00:05:21.200" data-end="00:05:35.440">Music.
[5:37] 00:05:41.066">There's growing concern in the scientific community about the number of commercial satellites 00:05:45.846">now being launched into orbit, many of which are reflecting so much light they're destroying 00:05:47.910">5:46">important astronomical research.
[5:49] 00:05:48.606" data-end="00:05:53.870">It's now commonplace for major scientific projects to be disrupted by trains of satellites, 00:05:54.122" data-end="00:05:55.859">streaking across the skies.
00:05:56.435" data-end="00:06:00.414">The International Astronomical Union has formally warned that some of these spacecraft, such, 00:06:06.446">6:01">as the massive Blue Walker 3 telecommunications satellite, are every bit as bright as first-magnitude 00:06:10.766">stars, which puts them on par with some of the brightest stars in the sky.
[6:12] 00:06:11.595" data-end="00:06:18.581">The 1.5 ton Blue Walker III spacecraft employs a massive 64 square meter solar array, 00:06:25.531">6:19">and is designed to communicate directly with cellular devices through 3GPP standard frequencies at 5G speeds.
00:06:26.080" data-end="00:06:33.624">Orbiting at an altitude of 515 km, Blue Walker III is being controlled by a network of three tracking stations, 00:06:35.946">6:34">in Maryland, Colorado and Australia.
00:06:36.495" data-end="00:06:42.205">The satellite has a field of view covering more than 777,000 square kilometres of the 00:06:43.508">surface of the Earth.
00:06:44.021" data-end="00:06:49.005">It's currently the largest commercial telecommunications satellite in low Earth orbit, and the company 00:06:53.965">is planning to launch six of these satellites every month, building up to an eventual constellation 00:06:55.724">6:54">of over 100 spacecraft.
00:06:56.325" data-end="00:07:00.063">And it's not just the visible brightness that astronomers are finding concerning.
00:07:05.205">7:01">Blue Walker 3 also emits strong radio waves that are also interfering with the work of 00:07:12.525">astronomers. Philip Diamond, the Director-General of the 7:09">Square Kilometre Array Observatory, says the reason radio telescopes are 00:07:17.885">7:13">situated in radio-quiet areas far away from the electronic noise of civilization, 00:07:18.140" data-end="00:07:26.805">and in regions specially designated through legislation as radio-quiet 7:22">zones with no cell phone or radio coverage is to avoid the electromagnetic 00:07:31.274">7:27">pollution which can compromise an astronomer's ability to do science. He, 00:07:36.165">7:32">He says the frequencies allocated to cell phones are already challenging astronomers 00:07:40.096">to observe even in radio quiet zones created for these observations.
[7:41] 00:07:49.285">And Blue Walker 3 isn't alone. 7:43">SpaceX's Starlink now have almost 4,000 broadband satellites in 72 orbital planes at altitudes 00:07:52.525">of around 550 km.
00:07:57.219">7:53">And there are plans for an eventual constellation of around 42,000 of these satellites.
00:08:03.853">7:58">And while the first generation Starlink satellites are small, just 263306 kilograms in mass, 00:08:04.005" data-end="00:08:08.571">the larger Phase 2 versions will be well over one and a quarter tons each.
[8:09] 00:08:09.285" data-end="00:08:16.865">And Starlink isn't alone either. 8:12">OneWeb are about to complete their initial constellation of 648 satellites, with proposals 00:08:22.245">8:17">to increase that 6,372 spacecraft under Phase 2 plans.
00:08:27.381">8:23">Jonathan Nally, the editor of Australian Sky and Telescope magazine, says new satellites 00:08:32.501">such as Blue Walker 3, Starlink and OneWeb have the potential to seriously worsen the 00:08:34.901">situation, if not properly mitigated.
00:08:39.016">8:35">It's becoming a bit of a problem actually because when you look up, go back decades, 00:08:42.741">you look up at the night sky and you'd be lucky to see a satellite. You could only see them at 00:08:47.781">8:43">certain times of the day or night, usually just after sunset or just before dawn when the angle 00:08:50.143">8:48">So they were catching the light.
00:08:53.421">Decades ago, there weren't that many satellites really compared to today.
00:08:55.821">I remember back in the 80s, there were proposals.
00:09:01.021">8:56">Some people were going to put up huge billboards in space, like big glowing signs that advertise 00:09:07.781">certain cola flavored drinks or something. 9:04">People were really worried about this advertising in space, but for goodness sake, they'd have 00:09:09.804">9:08">some billboards floating over here.
00:09:12.010">9:10">Fortunately, those things didn't come to fruition.
00:09:15.790">The problem we have now is that there's this proliferation of tiny, tiny satellites that.
[9:16] 00:09:16.313" data-end="00:09:22.164">They're amazing satellites and they're mainly used for communications, these big communications 9:21">networks.
00:09:26.101">So like Elon Musk's Starlink, brilliant service that it can provide.
00:09:30.981">It communicates basically anywhere on the planet with a fairly inexpensive handset.
00:09:34.821">9:31">But the problem for astronomers here is that these things do catch the light.
00:09:38.701">9:35">So as you say, if you're taking a picture of a distant quasar or something and all of 00:09:41.781">9:39">a sudden the satellite goes right through the middle of it with this shining light, 00:09:44.781">9:42">reflecting this light down into your telescope, it's ruined it.
00:09:48.421">9:45">There are plans to have tens of thousands of these things up there.
00:09:52.941">Well Starlink's now got what, 3,666 as of last count.
00:09:56.061">9:53">Yeah, well I think he's got approval of what, 44,000 or something.
00:09:57.621">So something like that and look at that.
00:10:01.621">9:58">And he's not the only one. 9:59">There are plenty of others who want to do it as well and there's an estimated, you know, 00:10:08.821">10:02">perhaps 100,000 of these things will be up there soon. 10:04">So it will mean that the one we're talking about in the magazine is called Blue Walker 00:10:11.407">10:09">and these are small satellites.
00:10:15.341">10:12">Main guts of the satellite is small but it's got a large solar panel array which is...
00:10:20.075">10:16">Fantastic for reflecting sunlight because it's designed to look at the sun. The panels are 00:10:24.075">designed to point at the sun. If you get the right angles, of course, then this causes a big flash in 00:10:29.357">the night sky or a big moving dot of light in the night sky. With potentially 100,000 of these things.
[10:30] 00:10:34.848">Up there, it's going to ruin or at least affect every single picture that you would take of, 00:10:35.115" data-end="00:10:41.115">anything in the night sky, essentially. There'd be no way around it. The only way to, if these 00:10:45.315">satellite operator can't figure out a way to change their satellites to make them less 00:10:50.715">reflective or something or tangle them in a different way, then astronomers are going to be out of a job.
00:10:50.715" data-end="00:10:55.230">10:51">They'll have to rely on just space observatories up there and some people suggest that, well, 00:10:58.083">10:56">this might be the reason why we have to move observatories to the moon.
00:11:03.235">The idea of building originally radio telescopes, but well, why not optical telescopes on the 00:11:04.355">far side of the moon?
00:11:07.555">Radio telescopes on the far side of the moon would be brilliant because the bulk of the 00:11:15.206">11:08">moon would block any interference in the earth. 11:11">you could stick an optical telescope anywhere really, fireside would be fantastic.
[11:16] 00:11:19.235">The thing is, pretty much like telescopes these days, it would be automated.
00:11:20.940">You wouldn't have astronauts up there running them.
00:11:21.115" data-end="00:11:24.847">You just get them set up and then just let them do their thing. That may happen.
00:11:24.892" data-end="00:11:27.715">11:25">The other big problem with the proliferation of all these little satellites is a thing 00:11:29.515">11:28">called the Kessler syndrome.
00:11:34.075">11:30">Now this was named after a person called Kessler, of course, who raised the prospect of a potential, 00:11:37.171">11:35">big problem, which is where if you've got hundreds of thousands of satellites up there, 00:11:40.075">even with the best of intentions, some of them are going to run into each other.
00:11:43.075">When you get two satellites smashing into each other at high velocity, it's going to 00:11:45.595">cause a huge debris field.
00:11:50.155">11:46">Every little bit of those debris can race off in different directions and then smash 00:11:53.655">into other satellites, which then break up and then smash into other satellites.
00:11:57.835">11:54">Before you know it, you've got a chain reaction happening where all these satellites are obliterating 00:11:58.984">each other up there in space.
00:11:59.275" data-end="00:12:03.755">You end up with a huge swarm of space jump floating around the planet.
00:12:08.652">12:04">So bad that it would be perilous to launch anything through that swarm.
[12:09] 00:12:09.282" data-end="00:12:15.452">Right, to get to other orbits, whether it's unmanned or manned craft. It is a real potentiality.
00:12:20.332">That would just basically stop spaceflight or any sort of space exploration or the launching of new.
[12:21] 00:12:21.132" data-end="00:12:25.052">Replacement communication satellites and Earth observation satellites, all these things we rely 00:12:29.492">upon, GPS satellites, would basically mean that we would be stopped from launching them for decades.
00:12:34.092">12:30">This would want to throw in the risk of every third one getting destroyed or two out of three 00:12:37.932">being destroyed on their way up. We'd have to send up lots of them and hope some get through.
00:12:40.610">12:38">That's another big problem or potential problem as well.
00:12:45.412">12:41">It's provided a great opportunity for a company called Leo Labs to develop their own satellite 00:12:48.217">control system, a traffic control system for satellites.
00:12:52.892">So you know where your satellites are and where potential dangers threaten so you can 00:12:57.492">12:53">avoid them. 12:54">So you can avoid them, yeah, but it's all very well with what if one malfunctions and 00:12:58.354">if you lose control of it.
00:13:05.732">So, um, 13:00">Well, then you get a Hollywood movie made. 13:01">The one good thing the movie Gravity did was it showed us what the Kessler syndrome was 00:13:06.732">like.
00:13:06.816" data-end="00:13:10.516">13:07">Well, correct. 13:08">That was brilliantly portrayed in that movie.
00:13:14.549">13:11">I mean the idea of jumping from one spacecraft to another, that's not going to happen but...
00:13:22.972">13:15">Oh look, there's the space station just over there. 13:17">It took some understandable license I guess with the laws of physics to make the story work.
00:13:26.684">13:23">That's Jonathan Nally, the editor of Australian Sky and Telescope magazine.
00:13:27.188" data-end="00:13:34.750">And this is space time. 13:29">Still to come, China launching more and more spy satellites and now spy balloons.
00:13:35.047" data-end="00:13:39.890">And later in the science report, researchers suggest that it only took 10,000 years, 00:13:42.942">13:40">to populate all of Australia and Papua New Guinea.
00:13:43.320" data-end="00:14:08.072">All that and more still to come on Space Time. 13:46">It's been a busy start to 2023 for China, with multiple rocket launches, many carrying.
[13:47] 14:02" data-start="00:13:47.120" data-end="00:14:01.680">Music.
[14:08] 00:14:08.072" data-end="00:14:09.760">Military spy satellites.
00:14:15.323">14:10">As Beijing continues what Chinese President Xi Jinping and his communist government describe, 00:14:17.357">as preparations for war.
00:14:18.032" data-end="00:14:25.441">On January 13, a Long March 2D rocket carrying the Yaogang 37 and Xi'an 22A and B satellites, 00:14:28.745">14:26">launched from the Xukuan Satellite Launch Center in the Gobi Desert.
00:14:29.392" data-end="00:14:34.252">The United States Space Force's 18th Space Defense Squadron says the three spacecraft 00:14:37.829">were placed into a 515-kilometer-high circular orbit.
00:14:38.423" data-end="00:14:43.972">China's state-run media claims the three satellites will be mainly used for in-orbit verification 00:14:48.379">14:44">of new technologies such as space environment monitoring and remote sensing.
00:14:49.012" data-end="00:14:53.132">The Cheyenne designation is used for experimental spacecraft programs.
00:14:59.101">14:54">However, the Yalgang 37 is nothing more than a classified military surveillance satellite, 00:15:02.783">operated by the People's Liberation Army to spy on other nations.
[15:04] 00:15:03.836" data-end="00:15:09.846">Meanwhile, a week earlier, back on January 8, China's first launch for 2023 was a Longmar 7A 00:15:14.886">15:10">rocket from the Wing Chang Space Launch Center in Henan province carrying three satellites into 00:15:21.046">15:15">orbit. And this is where the story gets rather confusing. The official Chinese news agency, 00:15:27.926">claims the mission carried the Shenzhen-23 and Xi'an-22A and-22B experimental satellites.
[15:29] 00:15:28.637" data-end="00:15:33.446">Now the thing is they're the same Cheyenne 22A and B satellites that were supposed to 00:15:35.920">have launched five days later from Zhukuan.
00:15:36.326" data-end="00:15:40.169">So that means there's obviously something else being launched that they don't want you 15:39">to know about.
[15:41] 00:15:45.328">And the third spacecraft to board the flight, the Shizhan 23 is also interesting.
00:15:48.965">15:46">It was observed deploying a smaller satellite once in orbit.
00:15:49.514" data-end="00:15:54.686">15:50">The US Space Force thinks the smaller satellite may have been a payload attached to an AKM, 00:15:56.238">15:55">that is Apogee Kick Motor.
00:15:58.975">15:57">Determining any more than that would be guesswork.
00:15:59.526" data-end="00:16:06.375">16:00">The orbital deployment occurred in geostationary space at an altitude of 35,786 km.
00:16:11.218">16:07">A similar operation occurred two years ago with the Shenzhen-21 spacecraft.
00:16:14.333">It deployed a smaller satellite which was then used for testing.
00:16:20.436">16:15">The Shenzhen-21 then docked with a disused Beidao 2G2 Chinese navigation satellite and, 00:16:26.046">16:21">physically moved it into a new, different orbit, proving that China now has the technology 00:16:29.196">to grab and manipulate the spacecraft of other nations.
00:16:33.598">16:30">That means you could either knock it out of orbit or add something else to it.
[16:35] 00:16:34.806" data-end="00:16:40.266">Just 13 hours before the Zhiquan launch, Beijing launched a Long March 2C rocket from the Zhaichang 00:16:46.166">Satellite Launch Center in southwestern China's Sichuan province carrying the AppStar 6E telecommunications 00:16:48.433">satellite into geostationary orbit.
00:16:49.006" data-end="00:16:55.149">The 4.3-ton satellite carries 25 Ku-band and 3 Ka-band Gateway transponders.
00:17:01.847">16:56">The satellite used to provide high-throughput broadband telecommunication services on a footprint covering Southeast Asia.
[17:03] 00:17:02.873" data-end="00:17:08.766">Then on January 15, China launched a Long March 2D rocket from the Taiyuan satellite launched 00:17:13.766">17:09">sent to a northern China's Yangtze province carrying 14 satellites into orbit.
00:17:19.050">17:14">The payloads included a mixture of remote sensing and optical high-resolution surveillance satellites.
[17:20] 00:17:20.049" data-end="00:17:25.226">A week earlier, Galactic Energy launched its fifth Series 1 rocket from Xi'an, 00:17:27.539">carrying five small satellites into orbit.
00:17:28.025" data-end="00:17:33.166">The successful mission brings to 19 the number of satellites placed into orbit by Galactic Energy.
00:17:39.107">17:34">The 20-meter-tall Series 1 launch vehicle can place payloads of up to 300 kilograms, 00:17:42.204">into 500-kilometer-high sun-synchronous orbits.
[17:43] 00:17:43.185" data-end="00:17:47.362">China now has an estimated 611 satellites orbiting the Earth, 00:17:52.686">17:48">including more than 259 Earth observation, surveillance and reconnaissance satellites, 00:17:58.206">17:53">and they include at least 47 GaoFeng and 112 Yaogang spy satellites.
[17:59] 00:18:03.197">China has announced plans to carry out at least 60 orbital missions this year.
[18:04] 00:18:04.179" data-end="00:18:13.209">And of course it's not just satellites. 18:07">On February 4, a US Air Force F-22 Raptor shot down a high-altitude Chinese spy balloon 00:18:18.060">which had been flying over at least half a dozen classified American nuclear facilities.
00:18:22.444">18:19">Beijing claimed it was just a rogue weather balloon that had veered off course.
00:18:27.809">18:23">Yet its flight path just coincidentally happened to take it over several intercontinental ballistic 00:18:32.309">18:28">missile launch silos and a number of US Air Force bases.
00:18:37.169">Former US Joint Chiefs of Staff Chairman Mike Mullen rejected China's claims that it was 00:18:41.929">simply blown off course, saying the balloon had propellers and was maneuverable, able 00:18:44.320">18:42">to change its course and altitude at will.
00:18:51.269">18:45">The Pentagon says this 60-meter-tall balloon flew at an altitude of 55,000 feet or 17 kilometers, 00:18:55.870">at an average speed of 25 knots or 46 kilometers per hour.
00:18:56.449" data-end="00:19:01.369">It was carrying an extensive solar array and several tons of surveillance and reconnaissance 00:19:05.989">equipment designed to intercept signals and communications and then beam that data by 00:19:07.852">19:06">satellite back to Beijing.
00:19:08.369" data-end="00:19:12.089">The Pentagon says steps were taken to prevent the balloon's instruments from collecting 00:19:14.504">confidential information during its flight.
00:19:15.049" data-end="00:19:19.309">It says it monitored the balloon being launched from China's Henan Island, flying towards 00:19:24.669">the US military base on Guam, but then suddenly veering northeast and entering US airspace 00:19:27.954">19:25">over Alaska's Aleutian Islands on January 28.
[19:29] 00:19:28.549" data-end="00:19:33.329">It then flew over mainland Alaska and Canada before suddenly heading south and re-entering 00:19:38.603">the continental United States airspace over northern Idaho on January 31.
00:19:39.069" data-end="00:19:43.669">The next day it was spotted over Montana's Minuteman III missile silos before heading 00:19:49.109">19:44">towards the Ellsworth Air Force Base in South Dakota where the US Air Force's new B-21, 00:19:50.567">stealth bombers are being based.
[19:51] 00:19:51.229" data-end="00:19:55.829">The bloon was finally ordered shot down above the Atlantic Ocean off the coast of South 00:20:00.669">19:56">Carolina falling into relatively shallow waters just 14 meters deep where it was 00:20:03.143">20:01">retrieved by the US Coast Guard and Navy.
00:20:07.935">20:04">Beijing later acknowledged a second balloon, another weather balloon, had run off course.
00:20:08.086" data-end="00:20:12.596">This one was spotted by US and Colombian officials as it drifted over Latin America.
00:20:13.145" data-end="00:20:17.935">And that's raising questions as to how many of these balloons are being launched by China, 00:20:18.042" data-end="00:20:23.775">and over which countries. Throughout this saga, US President Joe Biden has been heavily criticized 00:20:28.255">20:24">over his failure to act earlier when the balloon first appeared in US airspace.
00:20:34.055">He was then criticised for his overcompensation by ordering the military to shoot down three 00:20:37.568">further smaller balloons without identifying what they were.
00:20:38.135" data-end="00:20:43.295">We know one was the size of a car that was shot down over Alaska, a second one sort of 00:20:48.095">lozenge-shaped was shot down over Canada's Yukon territory by US fighters, not by the 00:20:54.988">Royal Canadian Air Force, and a third hexagonal object took two missiles to shoot down over late Huron.
[20:56] 00:20:55.615" data-end="00:20:59.895">After initially trying to avoid the issue, Biden was later forced to confirm that none 00:21:05.925">21:00">of these three objects were spy balloons, but rather legitimate civilian weather and scientific balloons.
00:21:06.415" data-end="00:21:10.595">In an attempt to deflect criticism from Biden's failure to act earlier, the White House claimed 00:21:13.487">21:11">three similar events had occurred during the Trump presidency.
00:21:18.355">21:14">However, that was quickly rejected by General Glenn Van Hecke, the commander of the North 00:21:23.642">American Aerospace Defense Command NORAD, who said no such events had ever been detected.
00:21:24.175" data-end="00:21:28.080">The White House was then asked if aliens from outer space could have been involved, 00:21:31.753">from which point the whole thing's degraded into a bit of a farce. This is space time.
[21:32] 21:51" data-start="00:21:31.760" data-end="00:21:51.120">Music.
[21:51] 00:21:56.055">And time now to take another brief look at some of the other stories making news in science 00:21:58.012">this week with the Science Report.
[21:59] 00:21:59.057" data-end="00:22:04.975">A new study has found that around 1 in 6 Australians over the age of 14 are still using tobacco 00:22:10.517">22:05">on cannabis or both despite their known carcinogenic and mental health effects respectively.
00:22:11.155" data-end="00:22:17.178">The findings reported in the Australian Drug and Alcohol Review are based on a study of 22:16">over 20,000 people.
00:22:22.067">22:18">It shows that one in ten smoked tobacco while nearly one in twelve used cannabis.
00:22:27.295">22:23">The authors looked at the rates of cannabis and tobacco use over the past 12 months and 00:22:30.394">they searched for patterns to the type of people who used them.
00:22:37.835">22:31">They say 2.4% of respondents use birth tobacco and cannabis, 5.5% use cannabis alone, 8% 00:22:41.675">22:38">tobacco alone and 84% of people use neither.
[22:43] 00:22:43.231" data-end="00:22:47.761">A small Australian trial has shown that adding a type of high-fibre supplement to people's 00:22:52.044">22:48">diets helped reduce their blood pressure by changing their gut bacteria.
00:22:57.161">22:53">The findings reported in the journal Nature Cardiovascular Research included 20 people 00:23:02.021">who were given food for three weeks that either contained a high-fibre supplement, a resistant 00:23:04.485">starch called hamshab, or a placebo.
00:23:05.101" data-end="00:23:08.961">The group who ate the diet with the resistant starch had a clinically significant drop in 00:23:10.589">23:09">their systolic blood pressure.
00:23:11.141" data-end="00:23:15.721">The ham-shab diet also changed people's gut bacteria, and these changes are likely to 00:23:18.079">23:16">be what's helped to lower their blood pressure.
00:23:22.541">23:19">The authors say the drop in blood pressure is equivalent to taking blood pressure-lowering 00:23:28.035">23:23">drugs and could reduce coronary death by 9% and stroke death by 14%.
[23:30] 00:23:29.501" data-end="00:23:34.381">New researchers revealed that it took about 10,000 years to fully populate the entire 00:23:40.301">continent of Sol. 23:36">Sol is the name of the combined megacontinent that joined Australia with New Guinea when 00:23:42.385">sea levels were much lower than today.
00:23:47.121">23:43">The findings, reported in the journal Quarterly Science Reviews, are based on sophisticated 00:23:52.421">new computer simulations combining improvements in demography and models showing geographic 00:23:57.968">influences in order to show the scale of challenges faced by the ancestors of indigenous people, 00:23:58.013" data-end="00:24:03.576">as they made their mass migration across the supercontinent more than 60,000 years ago.
00:24:04.201" data-end="00:24:08.721">The pattern led to a rapid expansion both southward towards the Great Australian Bight 00:24:15.927">24:09">and northward from the Kimberley region to settle all parts of New Guinea 24:13">and later the southwest and southeast of Australia.
[24:17] 00:24:17.449" data-end="00:24:22.238">As the world transitions away from fossil fuels such as coal-fired power stations, 00:24:29.611">the so-called greener alternatives of renewable energy from solar and wind 24:27">are showing that they have their own serious problems.
00:24:30.088" data-end="00:24:34.724">Renewables mean blackouts when the sun doesn't shine and the wind doesn't blow.
00:24:35.264" data-end="00:24:42.682">It also means bird populations being slaughtered by wind turbines 24:39">and mining pollution poisoning vast areas of land, 00:24:46.364">24:43">in order to obtain the rare earths needed for solar panels and batteries.
00:24:53.638">24:47">The CSIRO says the cost of new poles and wires in eastern Australia alone 24:52">will be more than a trillion dollars.
00:24:54.160" data-end="00:24:58.941">Guess who's paying for that? 24:56">Building gas turbines or modular nuclear power plants 00:25:02.568">24:59">next to existing power stations would be an economical solution, 00:25:04.576">25:03">but politically undesirable.
00:25:05.107" data-end="00:25:09.701">So, the recent breakthrough in laser nuclear fusion research by the Lawrence Livermore 00:25:14.381">25:10">National Laboratories has been widely welcomed and celebrated.
00:25:20.852">Scientists fired an array of ultra-high-powered lasers at a tiny Tritium-Duterium pellet triggering nuclear fusion.
00:25:21.501" data-end="00:25:25.501">25:22">What made this event different is that they generated more power than what it took to 00:25:31.150">25:26">trigger the event in the first place, in the process replicating the forces that power 25:30">the sun.
00:25:37.074">25:32">It's a small but highly significant step on the ladder to produce pollution-free limitless energy, 00:25:42.808">25:38">and without all the radioactive waste associated with today's nuclear fusion power stations.
[25:44] 00:25:43.753" data-end="00:25:47.443">But there's a big difference between doing it for a split second in the lab and being 00:25:53.386">able to replicate that on an industrial scale, generating enough reliable electricity to 25:52">power a city.
00:25:54.063" data-end="00:25:59.948">And so that's triggered a good degree of scepticism, despite the important proof of concept advances that it's achieved.
00:26:00.483" data-end="00:26:05.283">Tim Mendham from Australian Skeptic says there have been lots of promises before about nuclear 00:26:09.243">fusion and a commercial supply is still decades away.
00:26:14.283">The trouble is with the history of nuclear fusion energy has been full of ups and downs 00:26:19.603">and missteps and hoaxes and misunderstandings and all sorts of things which make people 00:26:21.083">26:20">wonder will we ever get there.
00:26:28.123">Obviously the idea is that to get there is the power. 26:24">If the activity that powers the sun and if we can have it, we do without waste.
00:26:31.563">It's an easily accessible source. 26:30">Well global warming would end.
00:26:34.526">26:32">Global warming would end. 26:33">Reliance on fossil fuels would end.
00:26:35.723">I don't know if global warming would...
00:26:35.877" data-end="00:26:39.967">26:36">Completely end. It certainly ends a lot. The idea is that therefore you can get unlimited energy 00:26:45.327">26:40">from a source that is really basically water and you use that for fusing hydrogen. But there's been, 00:26:48.927">people have been trying to do this for a hundred years. Ever since sort of people started looking, 00:26:49.191" data-end="00:26:53.807">at the makeup of atoms, et cetera, play with atomic physics and that sort of thing. And they've had 00:26:57.567">26:54">various, well they've had very poor success actually, obviously along the road here. Some 00:27:02.207">26:58">good ideas, some bad ideas has been tried out by Europeans, Americans, Russians, all sorts of 00:27:05.967">different people. There were some very badly designed experiments as well like cold fusion.
00:27:10.859">27:06">Yeah, cold fusion with the Ponson-Fleischman, the two American researchers who had this great claim.
[27:11] 00:27:11.167" data-end="00:27:16.127">It was totally over hyped. It was picked up by a lot of magazines, science, probably sober science 00:27:19.487">publications and that sort of thing. It has an amazing breakthrough and it turned out that it was 00:27:24.607">totally, I wouldn't say a hoax. It was just an error, a mistake, just an over enthusiastic response.
00:27:30.047">27:25">A badly designed experiment. Yeah, but there are others. There's a fellow in Italy who has supposedly 00:27:34.544">developed a desktop fusion reactor which would be interesting. Seeing as fusion reactors tend to be.
[27:35] 00:27:40.287">Rather large, this is basically you plug it in and you can create fusion energy. He's been touting 00:27:44.447">this around all over the place trying to get people to buy licenses, to get investors, to get all 00:27:49.487">sorts of things and there really is no evidence. We're skeptics here, we investigated it and had 00:27:53.967">a look at it, have a look at the wiring etc. We found there's probably sort of a rather hidden 00:27:58.847">27:54">wiring involving power in, power out using the earth connection or whatever that it's not quite 00:28:03.487">27:59">what it appears to be and it sort of 28:00">fooled a lot of people. The followers of the 00:28:02.047" data-end="00:28:07.007">history of nuclear fusion probably following it very closely and they have 00:28:05.167" data-end="00:28:08.847">very jaundiced view about a lot of these 00:28:14.287">people. So it's not skepticism of nuclear 28:09">fusion per se but it's skepticism and 00:28:11.207" data-end="00:28:18.767">cynicism of the history of it so far. Well the thing is even with this Lawrence 00:28:16.127" data-end="00:28:23.167">Livermore experiment which was a success 28:19">it was a once-off thing. They needed so 00:28:21.007" data-end="00:28:26.527">much energy to carry out this fusion event. It's not something they can do 00:28:30.367">28:27">You couldn't have tapped your power system into it because it lasted how long?
00:28:34.367">A gazillionth of a second I think. 28:32">That's a scientific term.
00:28:40.407">Yes, a gazillionth of a second and it's not something you can actually practically apply 28:39">at this stage.
00:28:41.989">They're just showing that it works.
[28:42] 00:28:42.287" data-end="00:28:49.767">It's not something you can actually use at this stage. 28:44">So the theory is they want to get the practical proof of it and they're heading that way.
00:28:54.287">28:50">You probably eventually would think they would but how far down the track that is.
00:28:59.847">Well, I've been reporting on this for the last 30 years of my time as a reporter and 00:29:04.767">29:00">a journalist and a broadcaster and I can tell you that it's always been about 20 years away.
00:29:11.751">29:05">It was that 30 years ago and it's 20 years away, 10 years ago and it's 20 years away 29:10">now. Yeah, yeah.
00:29:11.847" data-end="00:29:15.577">29:12">And it's the improvements are tiny incremental improvements, right?
00:29:19.567">29:16">But this one is interesting because they are getting more energy out than put in but you've 00:29:24.287">29:20">got to continue with the right technology. 29:21">It has to be repeatable and that's the hard thing.
00:29:28.727">So maybe they've cracked it, but it's going to be a long time before it becomes anything usable.
00:29:29.116" data-end="00:29:30.340">Them. Australian skeptics.
[29:32] 29:46" data-start="00:29:31.760" data-end="00:29:46.160">Music.
[29:46] 00:29:53.773">And that's the show for now. 29:49">Spacetime is available every Monday, Wednesday and Friday through Apple Podcasts iTunes, 00:29:54.007" data-end="00:30:01.677">Stitcher, Google Podcasts, Pocket Casts, Spotify, Acast, Amazon Music, Bytes.com, SoundCloud, 00:30:02.007" data-end="00:30:07.601">YouTube, your favorite podcast download provider and from spacetimewithstuartgarry.com.
[30:08] 00:30:08.222" data-end="00:30:12.759">Spacetime's also broadcast through the National Science Foundation on ScienceZone Radio and, 00:30:13.007" data-end="00:30:15.901">and on both iHeartRadio and TuneIn Radio.
00:30:16.447" data-end="00:30:19.847">And you can help to support our show 30:18">by visiting the Spacetime store 00:30:22.365">30:20">for a range of promotional merchandising goodies, 00:30:26.967">30:23">or by becoming a Spacetime patron, 30:25">which gives you access to triple episode 00:30:30.927">30:27">commercial-free versions of the show, 30:29">as well as lots of Burness audio content, 00:30:31.079" data-end="00:30:35.661">which doesn't go to air, 30:32">access to our exclusive Facebook group and other rewards.
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00:30:40.367" data-end="00:30:45.347">And if you want more Spacetime, 30:42">Please check out our blog where you'll find all the stuff we couldn't fit in the show, 00:30:50.647">30:46">as well as heaps of images, news stories, loads of videos and things on the web I find 00:30:51.793">interesting or amusing.
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00:31:27.327">31:21">You've been listening to Space Time with Stuart Gary. 31:24">This has been another quality podcast production from Bitesz.com.