14 ms·
Stellar Explosion in Earth's Proximity
- DarkmSparks 6y agoSurely (even) if it was deposited here 2.5 million years ago, it would have taken an insanely long time to get here.
- Ma8ee 6y agoConsidering that a supernova jettisons material 15,000 to 40,000 kilometers per second [0], it would only take a few decades for the material to reach earth from a star in earth's proximity, which I interpret as a few light years away. [0] https://www.nationalgeographic.com/science/space/universe/supernovae/ https://www.nationalgeographic.com/science/space/universe/su...
- DrBazza 6y agoAlso, the material swept up from the supernova, by the Earth is of the order of hundreds of tons (https://en.wikipedia.org/wiki/Death_from_the_Skies https://en.wikipedia.org/wiki/Death_from_the_Skies!)
- dredmorbius 6y agoThat would be 400--1,000 years for a supernova 50 light years distant, and clearly less for a closer event. Astronomically and geologically an eyeblink.
- snapetom 6y agoThere's thought that it was so close, we're still flying through the remnants.
- 7373737373 6y agoShould have added a [2.5 million years ago], I was worried for a second there
- mckirk 6y agoIt's 2020, my first instinct was to look at the sky to try and spot the impending supernova.
- mtgx 6y ago2020: Stellar Explosion for president!
- 1_player 6y agoHow good is our supernova detection technology? Would we be able to predict one with reasonable precision [1] before it wipes off the face of the Earth, or would we fry with gamma rays before we knew what was going on? 1: "by this time next year we'll all be dead with 99% certainty"
- spaetzleesser 6y agoI think right now “reasonable precision” means “within the next few ten thousand years”.
- BurningFrog 6y agoAfter Betelgeuze blows, we should know more about what to look for.
- spaetzleesser 6y agoI think that’s the real problem. We have no first hand observations of the processes around a supernova before it blows up. It may take a very long time until we will get these observations.
- zaarn 6y agoBetelgeuse, the only star that I know of within the range to produce a supernova dangerous to us, has scientists looking at it closely. Mostly because it's a closeby giant and those are interesting. I think most estimates range between 40'000 and 140'000 years until core hydrogen is exhausted. It's ejecta are unlikely to reach earth or cause harm (either radiation or otherwise). So while it lasts, you can enjoy reading a book under the light of a dying star at night for a few days. Eta Carinae is another candidate but it's too far away and unlikely to outshine Venus significantly. It's also not due for some due. There is also the possibility it'll just collapse into a black hole with no fanfare or extra light emission, it'll just be gone one day. Supernovae usually come from very bright stars, those are easily detectable and visible. From what I remember, there aren't any candidates even close to us that are about to expire minus Betelgeuse, which isn't aiming it's poles at us and won't do much harm. I would like to add that in the even we could predict that a supernova is about to wipe us out, there isn't anything we could do. Any nearby object we could use as shelter, such as Venus, Mars, the Jupiter Moons etc would likely be just as affected if not more (Jupiter's magnetic field will likely make a Supernova hit more deadly IMO). It would be over within the span of a few days and nobody will survive. Just lean back and enjoy the show, tbh.
- princekolt 6y ago> When the brightness of the star Betelgeuse dropped dramatically a few months ago, some observers suspected an impending supernova—a stellar explosion that could also cause damage on Earth. Why do people keep fretting about Betelgeuse?? No, it's extremely unlikely it will harm earth when it goes nova: https://arxiv.org/pdf/1406.3143v2.pdf https://arxiv.org/pdf/1406.3143v2.pdf
- sillyquiet 6y agoHeh remember the panic about CERN creating mini black holes? Science reporting is so very bad.
- taneq 6y agoI'm not saying the LHC did create a mini black hole and suck the Earth into a parallel pocket universe on a dark dystopian timeline, but... gestures vaguely at everything
- rob74 6y agoAnd since then we are all trapped in... the Twilight Zone! (cue spooky music)
- Loughla 6y agoI mean, that's a good philosophical premise for a book, I think. Would we know if we were sucked into an alternate timeline via that kind of science? Would it matter to us? Could we change it? I'm sure there's a YA novel in there somewhere.
- dylan604 6y agoEvery single SciFi show uses a shimmering effect when that happens, and I never saw that effect. So, it either happened when I was sleeping or otherwise wasn't looking, or it didn't happen. Or maybe it happened the night I took all of those mushrooms. Never can tell if I'm seeing something or just seeing something.
- datenwolf 6y agoThey did it, they finally did it! Context: I did my diploma thesis work at that lab, and shared the office with those guys. This is a result almost 10 years in the making. Congrats!
- foota 6y agoSo stupid question, what was the slow part of this? Was the spectrometry process developed just for this?
- datenwolf 6y agoThey were using a so called accelerator mass spectrometer (AMS). The main challenge, as I understood it from talking with them, was in the chemistry required to prepare the samples for injection into the AMS. Specifically ensuring that there's no background signal created from the preparation itself. So there was a lot of work done just to get the process right (the less steps to prepare the sample, the less steps that might contaminate it). Then a lot of verification, calibration on the AMS and optimizing the beam transport to reduce losses as far as possible. EDIT: The AMS was built and used in a lot of experiments before that. Among other things done with that instrument was measuring the neutron flux of the nuclear blast at various locations in Hiroshima, by determining the isotopic composition of the copper on building facade elements. Neutron capture produces some radioactive as well as "unnatural" stable isotopes and by determining their ratio, one can determine the neutron flux and energies. https://www.researchgate.net/publication/6012967_Neutron-induced_63Ni_in_copper_samples_from_Hiroshima_and_Nagasaki_A_comprehensive_presentation_of_results_obtained_at_the_Munich_Maier-Leibnitz_Laboratory https://www.researchgate.net/publication/6012967_Neutron-ind... It saddens me, that the accelerator they (and I for that matter) used for their research, has been decommissioned as of last year and is being dismantled right now :( – I could start a major rant about it, that would touch the subjects of funding, some people's personal pride and good science vs. fashionable science.
- cmpb 6y agoPlease, rant away! I'm interested in your opinion and the context of the decommissioned machine
- ivoras 6y agoAstrophysics just seems soooo speculative. Even with margins of error in the millions of years and light years, it just seems that most of it is assumptions supported not by evidence (because we can't get direct evidence) but by previous assumtions which have over time fossilised into accepted theories. Not saying this paper isn't good or anything, just that extrapolating a supernova from a few atoms of an isotope of a metal seems... a long fetch. Though probably better than nothing.
- simonh 6y agoWell, they have to come from somewhere and supernovae are the only process that makes them. If you find them consistently in a layer of a certain age all over the Earth, that points to a single source. Two different isotopes too, but only created by the same process so far as we know. It’s pretty decent evidence. As for direct evidence, I know what you mean. There so way to observe the supernova, but how often do the jury get to watch a murder happen on film? Yet we still convict murderers.
- Cederfjard 6y agoHow do you define evidence?
- Cogito 6y ago'Speculative' is an interesting word choice. There are assumptions in play, but I doubt they are the ones you are thinking of. The two main ones are that physics is the same everywhere, and physics is the same all the time. We have no way to say if these assumptions are correct, but we don't have evidence that they are wrong and we do have observations that are consistent with them being correct. If we take those two assumptions as true, then astrophyiscs is squarely in the middle of the model and measure of hard sciences. Modelling in particular is wide open for speculation, but there is no reason to think speculative models will be maintained if they are not consistent with measurement. Even the simplest speculative models necessarily have falsifiable and testable claims - if they don't then they don't say much about how the world is. The nature of astrophysics means that we are able to test and measure in so many ways: near and far, in the present and in the past, atomic scale and galaxy scale. As long as we hold those two assumptions above, we have a lot of evidence and reason to believe our current astrophysical models of the universe.
- DrBazza 6y agoIs this the cause of the Local Bubble? Phil Plait's Death From The Skies book mentions a 'smoking gun'.
- btilly 6y agoIt seems to line up well enough. And it is hard to imagine another explanation. The gas arrived here 2.5 million years ago. According to https://en.wikipedia.org/wiki/Local_Bubble https://en.wikipedia.org/wiki/Local_Bubble it seems that the Local Bubble was created 10-20 million years ago by a supernova, and we've been traveling through an area currently occupied it for the last 5-10 million years. If we've been traveling through that region for 5 million years, and the bubble is expanding as fast as we are moving (and we are moving at a pretty good clip), then we would have encountered the edge of the bubble 2.5 million years ago. Which would be exactly right for that to be this. And it is hard to imagine that there has been another supernova near us that it could have been, without it having left obvious signs of its existence. So Occam's razor says that this has to be right. The supernova that we know from astronomy had to happen near where we are now is the one that dumped detectable amounts of material on us 2.5 million years ago.
- antonvs 6y agoThe Local Bubble is thought to have been caused my multiple supernovae. See e.g. this 2002 paper: https://arxiv.org/abs/astro-ph/0205128v2 https://arxiv.org/abs/astro-ph/0205128v2 Edit: Here's a more recent paper - https://link.springer.com/referenceworkentry/10.1007%2F978-3-319-20794-0_14-1 https://link.springer.com/referenceworkentry/10.1007%2F978-3... : > "More detailed models for the origins of the Local Bubble have found that it requires anywhere from 3 (Smith and Cox 2001) to 20 (Fuchs et al. 2006) SNe to create a bubble with the correct characteristics in terms of size, pressure, and emission characteristics."
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- baxtr 6y agoI wonder if the The Permian Extinction (250 mil years ago) was caused by something like that?
- JKCalhoun 6y agoAlways fascinated by historical observations of super novae: https://en.wikipedia.org/wiki/History_of_supernova_observation#Early_history https://en.wikipedia.org/wiki/History_of_supernova_observati...
- snapetom 6y agoIf anyone is not familiar with Anton Petrov, he churns out YouTube videos on new astronomy and astrophysics papers. He does a wonderful ELI5 job of explaining the evidence and what it all means in the grand scheme of things. He did one on this paper earlier this week. https://www.youtube.com/watch?v=7uF_W-W7h08 https://www.youtube.com/watch?v=7uF_W-W7h08
- qubex 6y agoHe’s a truly wonderful person. ;)