S27E136: Magnetars' Mysterious Birth, Voyager's Light Day Journey, and Australia's Satellite Setback

[00:00:00] This is SpaceTime Series 27 Episode 136 for broadcast on Remembrance Day the 11th of November 2024.

[00:00:08] Coming up on SpaceTime, discovering the origins of Magnetars, NASA's Voyager 1 spacecraft about to reach one light day away from Earth, and Australia acts as a vital military satellite defence system. All that and more coming up on SpaceTime.

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

[00:00:46] A new study suggests that highly magnetic neutron stars known as Magnetars are actually born out of stellar mergers rather than single star supernova events.

[00:00:57] The findings reported in the journal Nature follows new research into the origins of fast radio bursts.

[00:01:03] Fast radio bursts, or FRBs, are sudden high-energy flashes at very specific wavelengths, lasting just nanoseconds and usually originating at cosmic distances.

[00:01:14] But in that time, they can release more energy than half a billion suns.

[00:01:19] The first fast radio burst was discovered back in 2007, that was in data from the Parkes Radio Telescope in New South Wales.

[00:01:26] Most are singular events, occurring just once at a specific location and then never again.

[00:01:33] And that suggests they're caused by some sort of cataclysmic event such as a supernova, the destructive explosion of a star.

[00:01:40] But astronomers are now detecting more and more fast radio bursts that have repeated from the same location.

[00:01:45] And that suggests a different cause.

[00:01:47] Feeding black holes, glitching neutron stars and highly magnetised neutron stars called Magnetars are all suspected.

[00:01:55] Or on the other hand, it could simply be that all fast radio bursts are repeaters, with some just a lot more active than others.

[00:02:02] Currently, confirmed fast radio bursts number in the hundreds, and scientists are assembling mounting evidence that they are triggered by Magnetars.

[00:02:10] And that's where this latest research comes in.

[00:02:13] It's found that fast radio bursts are more likely to occur in massive star-forming galaxies rather than low-mass ones.

[00:02:20] And this finding has in turn led to new ideas about how the Magnetars themselves are being created.

[00:02:27] Specifically, the new work suggests that these exotic dead stars, whose magnetic fields are a hundred trillion times stronger than the Earth's,

[00:02:34] often form when two stars merge and then explode as a supernova.

[00:02:39] Previously, it was unclear whether Magnetars were formed from the explosion of two merged stars,

[00:02:44] or whether they might form when a single star explodes.

[00:02:47] The study's lead author, Kriti Sharma from Caltech, says the immense power output of Magnetars makes them some of the most fascinating and extreme objects in the universe.

[00:02:56] But very little is known about what causes their formation upon the death of massive stars.

[00:03:02] And that's where this new work comes in to try and help answer that question.

[00:03:06] Sharma and colleagues used Caltech's Deep Synoptic Array 110 in the Owens Valley Radio Observatory near Bishop, California.

[00:03:14] That array's already detected and localized some 70 fast radio bursts pinning them down to a specific galaxy of origin.

[00:03:22] Although fast radio bursts are now known to occur in galaxies that are actively forming stars,

[00:03:27] Sharma and colleagues found that they tend to occur more often in massive star-forming galaxies rather than low-mass star-forming ones.

[00:03:34] And that's important, because massive galaxies tend to be more metal-rich.

[00:03:38] That's because the metals in our universe, that is the elements manufactured by stars,

[00:03:43] take time to build up over the course of cosmic history.

[00:03:47] Now of course when astronomers speak of metals, they're speaking of all elements on the periodic table other than hydrogen and helium,

[00:03:53] the elements created in the Big Bang itself.

[00:03:55] The fact that fast radio bursts are more common in these metal-rich galaxies implies that their source magnetars are also more common in these types of galaxies.

[00:04:05] And the simple fact is, stars that are rich in metals tend to grow larger than other stars.

[00:04:11] Over time, as galaxies grow, successive generations of stars enrich those galaxies with more and more metals as those stars evolve and die.

[00:04:20] Also, massive stars that explode in supernovae, and can become magnetars, are more commonly found in pairs.

[00:04:27] In fact, some 84% of all known massive stars are in binary systems.

[00:04:33] So, when one star in a binary system is puffed up due to extra metal content,

[00:04:37] the excess material gets drawn over to the binary partner, which facilitates the ultimate merger of the two stars.

[00:04:44] These now-merged stars would therefore have a far greater combined magnetic field than that of a single star.

[00:04:50] And, a star with more metal content expands and drives more mass transfer, culminating in a merger and thus forming an even more massive star,

[00:04:59] with a total magnetic field greater than what the individual star would have had.

[00:05:03] It's nice when the pieces all fit together.

[00:05:06] This is space-time.

[00:05:08] Still to come, Voyager 1 about to reach a distance of one light day from Earth,

[00:05:13] and a vital military satellite defence system axed by the Albanese government.

[00:05:17] All that and more still to come on Space Time.

[00:05:36] NASA's Voyager 1 spacecraft is about to become the first man-made object to travel more than a light day's distance from Earth.

[00:05:44] Now, to put that in perspective, a light day is a distance of 26 billion kilometres.

[00:05:50] Now, the historic achievement won't happen for a while yet.

[00:05:53] It'll be January 2027, but it's worth mentioning it.

[00:05:56] Voyager 1, together with its twin Voyager 2 spacecraft, are continuing their journey through unexplored interstellar space.

[00:06:03] And it's been a drama-filled mission, with tensions again set soaring recently,

[00:06:08] when Voyager 1 suddenly lost contact with mission managers.

[00:06:12] Scientists were concerned that the unexpected loss signal might have meant the end of the historic 47-year-long interstellar mission.

[00:06:19] Turns out the loss of contact was triggered by a glitch in Voyager 4 protection system,

[00:06:25] that caused its primary radio transmitter to suddenly switch off.

[00:06:29] Eventually, engineers were able to re-establish contact and identify the source of the problem.

[00:06:34] Now, this system usually autonomously manages onboard functions,

[00:06:38] reducing power use by deactivating non-essential equipment in order to safeguard the spacecraft's core operations.

[00:06:44] The incident unfolded when the flight team, based at NASA's Jet Propulsion Laboratory in Pasadena, California,

[00:06:51] commanded Voyager 1 to power on a heater on October 16.

[00:06:55] Now, although the spacecraft seemed to have enough power,

[00:06:58] the command unexpectedly triggered a fault protection system.

[00:07:01] And on October 18, NASA's Deep Space Communications Network was no longer able to detect its signal.

[00:07:08] Initially, engineers hypothesized the fault protection system had reduced the data transmission rate

[00:07:13] on the X-band radio transmitter, requiring less power but complicating signal detection.

[00:07:19] Eventually, they were able to detect a weak signal coming from the spacecraft,

[00:07:23] indicating that Voyager 1 remained operational and was in a stable condition.

[00:07:28] However, the following day, October 19, communications appeared to cease entirely,

[00:07:33] leading the team to suspect that Voyager's fault protection system activated again,

[00:07:37] switching from the primary X-band transmitter to a much weaker S-band transmitter.

[00:07:42] Now, this S-band transmitter has not been used since 1981.

[00:07:46] It emits a weaker signal and therefore presents a far greater chance for detection over Voyager 1's

[00:07:51] nearly 25,879,000,000 km distance.

[00:07:56] Glenn Nagel from NASA's Deep Space Communications Network complex near Canberra says

[00:08:01] engineers managed to pick up the S-band signal and confirm that Voyager 1 remains operational,

[00:08:06] although full functionality has not yet been restored.

[00:08:10] Yes, just in recent times, a standard command set sent to the spacecraft

[00:08:14] commanded it to turn one of its onboard heaters on,

[00:08:17] and that seems to have tripped a fault inside the computer on the Voyager spacecraft.

[00:08:22] And it did something that wasn't expected.

[00:08:24] Normally, the spacecraft transmits to us on its X-band transmitter,

[00:08:28] which is a good, strong frequency that we can get back data from the spacecraft

[00:08:32] and understand about the health of the spacecraft, but this fault turned off the X-band

[00:08:36] and turned on the S-band communication.

[00:08:39] Now, the S-band transmitter hasn't been operated in over 30 years,

[00:08:44] but this S-band switched on and worked.

[00:08:47] The problem with S-band is it's a much wider band,

[00:08:49] much wider frequency and much lower signal coming back to the Earth.

[00:08:53] So, unfortunately, the spacecraft, while we could hear it barely above the background noise of the rest of the universe,

[00:09:00] we could not get science data from it.

[00:09:02] But what we discovered is the spacecraft was still commandable,

[00:09:05] and that was really great news.

[00:09:07] We could uplink commands to the spacecraft.

[00:09:09] We had to wait for nearly 46 hours at round-trip time at the speed of light

[00:09:13] to get the signal to Voyager 1 and back again

[00:09:15] and be able to determine that the spacecraft was responding to the commands that we gave it,

[00:09:20] to some little offsets in the frequency that it was transmitting at.

[00:09:23] So, that was good news.

[00:09:24] So, we're in lock with the spacecraft.

[00:09:26] In fact, as we're speaking right now,

[00:09:28] we're actually talking with Voyager 1 through our big dish here in Canberra.

[00:09:31] And so, the spacecraft seems to be good, in good health.

[00:09:33] And now it's just up to the science team to try to figure out what was the fault,

[00:09:37] how can they rectify it, how can we switch back to the X-band transmitter

[00:09:41] and get back in full science mode with Voyager.

[00:09:43] Well, of course, the two Voyager twins are getting on in use, aren't we all?

[00:09:47] And there have been a couple of incidents of late.

[00:09:49] Yeah, so they've been both out there for over 47 years now.

[00:09:52] And just like a lot of us, we might get a little bit forgetful from time to time,

[00:09:55] have a few aches and pains as we wake up in the morning.

[00:09:58] Last year, Voyager 2, we lost contact with it for a few weeks

[00:10:01] when an incorrect command set to the spacecraft

[00:10:04] recalibrated its antenna to actually point away from the Earth.

[00:10:07] And again, it was sort of camberl to the rescue,

[00:10:10] transmitting at high power to the spacecraft to re-lock in and up to computers,

[00:10:13] even though the antenna was pointed away from us,

[00:10:15] and to be able to get it back to science again.

[00:10:18] And it's been quite in good health over the last year and a half or so.

[00:10:22] But Voyager 1, earlier this year, also had a problem on board.

[00:10:26] It's an onboard computer, which we're talking about computers that were built in the 1970s.

[00:10:31] Some very, very basic chips on that spacecraft.

[00:10:34] And when I talk about a chip, not like the little tiny ones you might have in your car fob,

[00:10:37] these are ones that are 10,000 times less powerful than what's in the car fob to open the car door.

[00:10:44] And these one of the little chips out of a set of eight must have been hit by a cosmic ray strike.

[00:10:50] And that flipped a bit on that and made that particular chip unusable.

[00:10:55] And so it took a while to determine what was the problem.

[00:10:58] The spacecraft was sending back gibberish to us, basically.

[00:11:01] A spacecraft is talking in binary code, ones and zeros.

[00:11:04] And we're either just getting ones or just getting zeros.

[00:11:06] And that doesn't tell us anything about the spacecraft.

[00:11:09] It's just nonsense.

[00:11:10] But some great engineers within the science team and within the Deep Space Network that we're a part of

[00:11:15] actually noticed that there was some information there buried quite deep into the data.

[00:11:21] And that helped us understand what the problem with the spacecraft was,

[00:11:24] to identify the problem with the chip onboard,

[00:11:26] and then to write a program which we were then able to uplink through our antennas

[00:11:31] and transmit to the spacecraft to ensure that it could then go,

[00:11:35] don't look at that chip anymore.

[00:11:36] Let's distribute the program across the other chips which we still know are working.

[00:11:41] And as soon as that was done, we waited an anxious 46 hours for the transmission time there and back.

[00:11:47] And we received the data and Voyager 1 was back in full communication.

[00:11:51] So this is just another one, this current pause is just another one of a series of issues with an aging spacecraft.

[00:11:57] But you've got to remember, nobody ever expected Voyager to last this long.

[00:12:01] They were a 12-year mission.

[00:12:03] Go and explore the giant planets of our solar system.

[00:12:05] They finished that journey in 1989.

[00:12:08] But they've kept going.

[00:12:09] They've now left behind the solar system.

[00:12:11] They're both in interstellar space.

[00:12:12] They're still telling us new and unique things about a region of space

[00:12:16] that nobody ever thought we'd be having a spacecraft operate and to explore that region so soon.

[00:12:22] So they've got a remarkable legacy behind them.

[00:12:24] They have a remarkable journey ahead of them.

[00:12:26] Scientists are still using the data they gathered back in the 1980s to carry out new studies of bodies within the solar system.

[00:12:34] Some Voyager 2 data just the other day was used to confirm that the Uranian moon,

[00:12:39] if that's the correct term, Miranda, possibly has a liquid water ocean under its surface.

[00:12:44] Yeah, it is remarkable.

[00:12:45] We're still mining that data, both for scientists all over the world and even some amateurs,

[00:12:50] using some of the available Voyager data to actually make new discoveries,

[00:12:55] even find a once-thought-of moon that was sort of lost out at Neptune and rediscover that in some of the images,

[00:13:02] just through amateurs working on the data.

[00:13:04] So it's amazing that after 47 years, these two spacecraft are still telling us new things about our own solar system

[00:13:09] and are now telling us about the rest of the universe.

[00:13:12] That's Glenn Nagel from NASA's Deep Space Communications Network near Canberra.

[00:13:16] The incident is the latest example of the mission's complex engineering demands,

[00:13:21] especially as the twin Voyager spacecraft, which were launched back in 1977,

[00:13:25] are raging ever closer to the half-century mark.

[00:13:28] Voyager 1 entered interstellar space, that's the region of the galaxy beyond the heliosphere,

[00:13:33] a bubble created by the solar wind and magnetic field emanating from the Sun,

[00:13:37] back in 2012 when it was some 123 astronomical units from the Sun.

[00:13:43] An astronomical unit is the average distance between the Earth and the Sun,

[00:13:47] about 150 million kilometres or 8.3 light minutes.

[00:13:51] Voyager 2 followed its twin into interstellar space in 2018,

[00:13:55] although travelling in a different direction.

[00:13:57] In the decades following their launch, on August 20 and September 5, 1977 respectively,

[00:14:04] the Voyager twins have undertaken a grand tour of the outer solar system,

[00:14:08] studying Jupiter, Saturn, Uranus and Neptune.

[00:14:11] Now if nothing else goes wrong,

[00:14:13] the Voyager probes could continue to operate using their existing power reserves until the late 2020s.

[00:14:19] But as time goes by, continued operations are becoming more and more challenging,

[00:14:23] with mission power diminishing by 4 watts every year,

[00:14:27] and the two spacecraft will continue to cool down as this power decreases.

[00:14:32] This is space-time.

[00:14:35] Still to come, the Australian government acts as a crucial $7 billion satellite defence project,

[00:14:41] and later in the science report,

[00:14:43] it turns out people using private jets generate 500 times more carbon dioxide in a year than the average person.

[00:14:51] All that and more still to come on Space Time.

[00:15:10] The Australian government has just axed a crucial $7 billion satellite defence project.

[00:15:15] The move is a significant blow to Australia's defence capabilities,

[00:15:19] and it comes at a time of growing regional tensions between China and Taiwan, China and India,

[00:15:25] and Beijing's ever-expanding interests in controlling the South China Sea.

[00:15:29] The ambitious JP9102 military satellite communications system was awarded just 18 months ago

[00:15:36] to US defence contractor Lockheed Martin.

[00:15:38] Its sudden cancellation marks a dramatic reversal for what was a key project

[00:15:43] designed to make Australia's military communications safer

[00:15:46] at a time when the cyber attack and electronic warfare landscape has been dramatically evolving.

[00:15:51] As well as launching numerous large military-grade satellites,

[00:15:55] the program would have also included satellite communication ground stations

[00:15:59] and a central mission control system.

[00:16:01] The planned satellite network would have provided advanced encryption and anti-jamming capabilities,

[00:16:07] creating what experts call an uncrackable data network across the Australian Defence Force.

[00:16:12] It would have provided secure communications for military aircraft,

[00:16:16] naval vessels and ground forces over the vast Indo-Pacific region.

[00:16:20] Without it, Australia's military lacks the comprehensive coverage

[00:16:24] and secure communications network that JP9102 would have delivered.

[00:16:29] The decision comes at a time when Australia's Foreign Minister Penny Wong

[00:16:33] has given more than $32.2 million of taxpayer money to groups like UNRWA,

[00:16:38] the controversial United Nations organisation with close ties to Hamas

[00:16:42] and other Palestinian terrorist organisations.

[00:16:44] The news of the satellite contract cancellation also comes in the wake of a promised cut of $16 billion

[00:16:51] by the Albanese government in future HECS debt repayments by university students

[00:16:56] if it wins the next federal election, slated for sometime around May next year.

[00:17:01] China, Iran, North Korea and Russia are all widely recognised as having advanced capabilities

[00:17:07] to jam satellite signals, intercept communications, undertake cyber warfare and take control of satellite systems.

[00:17:14] This is Space Time.

[00:17:32] And time now to take a brief look at some of the other stories making news in science this week with a science report.

[00:17:38] The next time politicians and celebrities bleed out about their green credentials,

[00:17:42] it might be worth reminding them of a new study which has found that people using private jets

[00:17:47] to get themselves around the globe generate some 500 times more carbon dioxide every year than the average person.

[00:17:54] The findings reported in the journal Communications Earth and Environment also showed that the annual carbon dioxide emissions from private planes

[00:18:02] has increased by 46% between 2019 and 2023.

[00:18:06] The study also found significant emission peaks around certain international events,

[00:18:12] including the 2022 FIFA World Cup, Cannes Film Festival and ironically the COP28 United Nations Climate Challenge Conference.

[00:18:20] The data shows Australia currently has 317 private jets, which accounts for 1.2% of the global total.

[00:18:28] But it ranks 6 highest globally for the number of planes per 100,000 residents.

[00:18:34] A new study has identified 22 pesticides consistently linked to the incidence of prostate cancer.

[00:18:41] The findings reported in the journal Cancer assess links between 295 different pesticides and prostate cancer

[00:18:47] using a lag period between exposure and cancer incidence of 10 to 18 years.

[00:18:53] The time lag was needed because most prostate cancers grow slowly.

[00:18:57] The years 1997 to 2001 were assessed for pesticide use and the years 2011 to 2015 for prostate cancer outcomes.

[00:19:06] Similarly, 2002 to 2006 were assessed for pesticide use and 2016 to 2020 for outcomes.

[00:19:13] Among the 22 pesticides showing consistent direct links with prostate cancer incidence across both analyses

[00:19:20] were three that had previously been linked to prostate cancer, including 2,4-D,

[00:19:25] which had been used for weed control in Australia since the 1960s.

[00:19:29] The other 19 pesticides had not been linked to prostate cancer before

[00:19:33] and included 10 herbicides, several fungicides and insecticides and one soil fumigant.

[00:19:39] Four pesticides linked to prostate cancer incidence were also linked with an increased risk of death from prostate cancer.

[00:19:46] Three herbicides, Trifluraline, which is approved for use in Australia,

[00:19:51] Coloransulomethanol, which is not approved in Australia,

[00:19:53] and Difluflenzopree, for which there's no Australian information,

[00:19:57] and also one insecticide, Thiomethoxam, which is also approved in Australia.

[00:20:03] A new study has found that humans aren't the only species that deliberately consume alcohol.

[00:20:09] The findings, reported in the journal Trends in Ecology and Evolution,

[00:20:13] looked at growing evidence of how commonly ethanol naturally occurs in fruits and nectar

[00:20:17] that are commonly food for wild animals.

[00:20:20] The researchers say most animals that eat sugary fruits are likely to be exposed to at least some ethanol.

[00:20:25] And while most naturally fermented fruits only reach about 1-2%,

[00:20:29] concentrations as high as 10.2% have been found.

[00:20:33] The authors admit there's not much we know about why animals might choose to consume ethanol.

[00:20:38] That's because being drunk is generally a bad idea when you're living in the wild.

[00:20:42] However, it's possible that while humans like the effects of alcohol but not the calories,

[00:20:47] other animals may be risking the effects specifically to consume the calories.

[00:20:52] A new systematic review covering thousands of studies has confirmed yet again

[00:20:58] that there's no scientific evidence that cell phones can cause brain cancer.

[00:21:03] This latest review was commissioned by the World Health Organization

[00:21:06] and published in the journal Environment International.

[00:21:09] It's the most comprehensive review so far and included more than 5,000 studies,

[00:21:14] of which 63 published between 1994 and 2022 were included in the final analysis.

[00:21:21] Tim Mendham from Australian Skeptic says,

[00:21:23] while there are a few isolated studies that have raised concerns,

[00:21:26] a more complete examination of the data has negated those results.

[00:21:30] You sort of wonder how much proof do you need?

[00:21:32] But obviously in certain circumstances people just don't believe the proof.

[00:21:35] So you've got to say it again and again and again.

[00:21:37] People looked at individual studies and done their meta-studies

[00:21:40] of thousands in some cases of other studies and looking at those that are good

[00:21:44] and those that are bad studies, etc. and they come to the conclusion,

[00:21:47] no, there ain't no problem.

[00:21:49] It's not going to cause brain cancer.

[00:21:50] You might spend too much time on the phone, but that's a different issue.

[00:21:53] But yeah, this theory that it was causing brain cancer,

[00:21:55] the radiation from mobile phones you hold to your ear when you're listening to them

[00:21:59] is going to sort of give you cancer is not true.

[00:22:01] Over hundreds and thousands of studies, over millions of people,

[00:22:05] over a long time that mobile phones have been available,

[00:22:07] there is no evidence that that is causing brain cancer.

[00:22:10] There's just been no correlation between the increase in cell phone usage.

[00:22:14] Brain cancer rates have not increased.

[00:22:15] Brain cancer rates have not increased,

[00:22:17] but the usage of the technology has dramatically increased.

[00:22:19] That's Tim Mendham from Australian Skeptics.

[00:22:37] And that's the show for now.

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