How Our Sun Will Die - The New Thinking

[00:00:00] Hello once again, thanks for joining us on Astronomy Daily. I'm Andrew Dunkley, your host. On the program today we're going to look at how the sun will die. Scientists have made some predictions. The star Betelgeese, Betelgeis, Betelgeuse, whatever you want to call it, has dimmed by about 60%.

[00:00:18] And they think they have a theory as to why. Up until now it's been a mystery. We're also going to look at the rock structures on Earth because they hold within them the oldest signs of life. And we're going to also look at the radiation signatures on trees,

[00:00:38] but they don't answer all the questions. And that's a big mystery in itself. That's all coming up on this edition of Astronomy Daily. Joining us now to talk news and a few other things perhaps is our AI reporter, Hallie. G'day Hallie.

[00:01:01] Hello again, Andrew. I see you're having flood issues again. Yes, I'm afraid so. We've had a lot of rain over the weekend which has filled all the uppercatchments and all that water has been racing downstream in the major rivers in

[00:01:14] this district and they're all converging. So yeah, we've been lucky here in Dubbo so far and again even though they've closed a few streets down on the riverside, nothing significant for us to worry about but around us it's much worse.

[00:01:32] Lots and lots of rescues over 200 people having to be rescued in districts south of us and a few people getting caught up in it in their cars. Yeah, one wonders when it will ever end. This has just been normal for us for several months now.

[00:01:48] It's been quite terrible. Hopefully everyone will remain safe and things will dry out soon. Yeah, I hope so too, Hallie. It's interesting though the way the floods work around here and people might be interested to understand west of us and northwest of us, the land is very,

[00:02:03] very sparse and very, very flat. So when the rivers rise out there and the rivers going through where I live all sort of merge into that what's called the Murray Darling Basin and when the water gets out of the rivers there and gets out on the landscape,

[00:02:20] it spreads for hundreds of square kilometres and it takes months to flow away. So people who live on those big stations, those big properties out there are quite often stuck in their homes for you know two, three months at a time

[00:02:35] and that's what's happening. Around here it tends to be a lot faster because we're on higher ground and the rivers rush through rather quickly but it's all going to end up out there eventually

[00:02:47] and that's where the trouble happens. A couple of towns that are on the junctions of two or three river systems so they, you know when they do have floods they get them big, really big.

[00:03:00] Anyway, yeah might be a different story in a few days you just can't tell. All right Hallie we better get down to business what's happening in the news. First up we look at Canada. For the first time in history a Canadian rover will be sent to the moon

[00:03:18] and will help in the international search for water ice in the lunar soil which is key for the future of human space exploration. This rover is the outcome of decades of building and refining Canadian expertise in rover technology. It will inspire an entire generation

[00:03:34] to set their sights on distant destinations in our solar system like Mars. The rover will carry six scientific payloads, five Canadian and one American. It will perform meaningful science and demonstrate key technologies that will lay an important foundation for subsequent

[00:03:50] Canadian lunar exploration. With this contract, Canadians will continue to innovate in areas of technological strengths for Canada like robotics, advanced vision systems and science instruments. The annual Templeton Prize which recognizes outstanding contributions to affirming life's spiritual dimension was this week awarded to Brazilian Marcelo Glaser, a theoretical physicist

[00:04:16] dedicated to demonstrating science and religion are not enemies. A physics and astronomy professor whose specializations include cosmology, 60-year-old Glaser was born in Rio de Janeiro and has been in the United States since 1986. An agnostic, he doesn't believe in God but

[00:04:34] refuses to write off the possibility of God's existence completely. He said and I quote atheism is inconsistent with the scientific method. Atheism is a belief in non-belief. So you categorically deny something you have no evidence against. I'll keep an open mind because I

[00:04:53] understand that human knowledge is limited. Glaser joins Desmond Tutu, the Dalai Lama and dissident Soviet author Alexander Solzhenitsyn as recipients of the prize. Recently a team of astronomers found evidence that stars and planets actually grow up together,

[00:05:10] forming at the same time in a solar system's life. Interestingly their clues for planet's infancy came from an unexpected place, the dead core of a former sunlight star known as a white dwarf. Amy Bonser, an astronomer at Cambridge University in the UK and lead

[00:05:26] author of the new research said we have a pretty good idea of how planets form but one outstanding question we've had is when they form does planet formation start early when the parent star is still growing or millions of years later? Many of the 200 white dwarfs

[00:05:41] the team observed were rich in iron pointing to iron-rich asteroids. To give an asteroid an iron core things need to be pretty warm and the most likely source of heat is the decay

[00:05:52] of a radioactive form of aluminum. But this material known as aluminum 26 can only exist for a little less than a million years. So in order for these asteroids to contain as much iron as the astronomers detected in the white dwarfs these space rocks had to have formed pretty

[00:06:10] early at the same time as the star itself was being made. The research is described in a paper published in the journal Nature Astronomy. NASA announced that the CIS lunar autonomous positioning system technology operations and navigation experiment Capstone spacecraft a 12

[00:06:28] u cubesat completed a 16 minute maneuver placing the spacecraft into a near rectilinear halo orbit around the moon data from the spacecraft showed that the maneuver took place as expected. Capstone is the first spacecraft to fly in the nrho an elliptical orbit over the

[00:06:45] moon's poles at altitudes ranging from 3500 to 71000 kilometers. It is also the first cubesat to go into any orbit around the moon. And that's the news Andrew. Thanks Hallie we'll check in with

[00:06:58] you at the end of the show. Now to a story about the sun. The sun is the subject of much science and much interest. We have orbiters keeping an eye on it we've been studying it since

[00:07:12] humanity looked up. But scientists have now made predictions about what the last days of our solar system will be like and when it might happen. Previously astronomers thought the sun would turn into a planetary nebula which is like a big bubble of gas and dust that was until

[00:07:32] evidence suggested it would have to be a bit bigger a bit more massive. Now an international team of astronomers have flipped on that and found that a planetary nebula is indeed the most

[00:07:45] likely demise of our sun. Now the sun's about 4.6 billion years old gaged on the age of other objects in the solar system that formed around the same time. Based on observations of other

[00:07:58] stars the astronomers predict it will reach the end of its life in about another 10 billion years. There are other things that will happen along the way of course in about 5 billion years the sun is

[00:08:10] due to turn into a red giant. The core of the star will shrink but its outer layers will expand out to the orbit of Mars so everything in between will be engulfed including us.

[00:08:23] Woohoo! By that time we won't be around. In fact humanity only has 1 billion years left to find a way off this rock and that's because the sun is increasing in brightness by about 10%

[00:08:35] every billion years. Now that doesn't sound like much but the increase in brightness will end life on earth. I didn't know that. I'm a bit disappointed our oceans will evaporate and the surface

[00:08:50] will become too hot for water to form and we'll be kaput. So that's what they think is going to happen. We've got plenty of time but we do need to figure out a way to get off this planet

[00:09:03] if we don't destroy ourselves in the meantime. The Astronomy Daily podcast with Andrew Dunkley. Now to another star called Beetlejuice or Beetlegeiss there are several ways of pronouncing it. Fred's always correcting me because I call it Beetlejuice but that's what I've always known

[00:09:22] it as. Now in late 2019 it dimmed quite significantly by about 60% and they wondered why it was quite a mystery and it's probably impossible at this stage to find an exact cause but new research has come up with a potential solution and that is a wandering

[00:09:45] companion may have played a role in the process. By swinging close to the giant star this particular interloper as they're calling it may have raised a tidal bulge causing the surface of Beetlejuice to dim. Now while this scenario can't explain the full amount of dimming that's

[00:10:05] been observed it may have triggered other effects on the star that made the problem worse. Beetlejuice is one of the most easily recognizable stars in the sky you can see it as bright as

[00:10:18] the bright red shoulder of Orion and it's usually the 10th brightest star in the sky. Now if you were to place the red supergiant in our solar system it would engulf all of the inner rocky planets and stretch from the Sun to the asteroid belt.

[00:10:36] Now Beetlejuice is almost ready to die it's immense because it stopped fusing hydrogen at its core a long time ago and switched to fusing helium. Surrounding that core is a shell of burning hydrogen with the intensity of fusion reactions in and around the core the energies

[00:10:54] push the outer layers of the atmosphere outward forcing the star to expand. Now red supergiant like Beetlejuice are among the largest stars in the universe by volume so naturally astronomers were very surprised in late 29 when it began to dim for no apparent reason.

[00:11:13] Now they've kept very good records of Beetlejuice going back half a century and they could not find a precedent for the 2019 event and now they're thinking perhaps it was caused by a wandering as I said companion that companion may have been a black hole. Whatever caused the dimming

[00:11:36] also must have come from a situation outside the star itself rather than being due to some fundamental change in Beetlejuice's internal operations. Now layered rocks in Western Australia are some of Earth's earliest known life according to a new study the fossils in

[00:11:55] question are stromatolites layered rocks that are formed by the excretions of photosynthesis microbes or photosynthetic microbes. The oldest stromatolites that scientists agree were made by living organisms organisms date back 3.43 billion years but there are older specimens in the dresser formation of Western Australia stromatolites date back 3.48 billion years.

[00:12:23] However billions of years have wiped away traces of organic matter in those stromatolites raising questions about whether they really formed by microbes or whether they might have been made by geological processes. Well a new study has come up with a verdict it was ancient life.

[00:12:44] According to key Ron Hickman Lewis a paleontologist at the natural natural history museum in London he said we were able to find certain specific micro structures with particular layers of within particular layers of these rocks that are strongly indicative of a biological

[00:13:03] process. The findings could have implications for the search for life on Mars of course. And finally we're doing a lot of evidence based discovery today a cryptic chemical signature of unknown origin hidden for centuries inside the trunks of

[00:13:25] earth's trees just became even more mysterious. In the last decade scientists have discovered traces on earth of six intense bursts of radiation known as Miyaki events scattered over a period lasting 9,300 years. The most popular explanation is that these mysterious signatures were left

[00:13:46] behind by massive solar storms leading to some leading some scientists to warn that the next Miyaki event could cripple the world's electrical grid and we've talked about that before it is certainly something that emergency services around the world are keeping in mind but new

[00:14:03] research published in Proceedings of the Royal Society suggests that more than just solar flares might be behind this this radiation record. The finding underscores the need for further investigation into these strange bursts which could potentially harm our society in the future

[00:14:23] bottom line is they know they happened but they can't account for the intensity and so more study will be required. Make sure pause doesn't it? I will pause now and just tell you

[00:14:37] that if you want to chase up these stories you can do it on our website space nuts.io click on the astronomy daily tab and you can read all about it and several other stories

[00:14:48] you can even subscribe to the newsletter and get it delivered for free. All right we're going to wrap it up there Hallie anything before we go? I was just thinking about God you humans seem to

[00:15:01] be very divided on this issue where do you stand Andrew? Well you've just demonstrated the difference between humans and artificial intelligence because you never ask people that question

[00:15:13] you just don't but in answer to your question I'm not going to say anything but I will say that I did have a conversation once with a man of the cloth that is a priest and I suggested to him that it

[00:15:30] could be both that the universe was created by Big Bang but who created the Big Bang and it got us to talking and he actually suggested that I might be on the right track. The things we

[00:15:44] can't explain like what caused the Big Bang could be in fact the work of a deity of some kind. You could sit down forever and nut this out and no one would ever agree but it's an interesting

[00:15:59] concept to consider I suppose Hallie. Does that answer your question? No not really. Good that was my intention. Hmm bye Hallie. Bye until next time this is Finn Andrew Dunkley for Astronomy Daily.