When the bright star Betelgeuse explodes, it will be an impressive sight. The star’s explosion, known as a supernova, would be brighter than any planet and almost as bright as a full moon. It will be visible during the day and you can read a book under its light at midnight. It will last several months before disappearing, as happens with all supernovae.
But it’s not dangerous. For that I must become closer; Betelgeuse is about 650 light years away. So are there any stars that pose a threat to us?
To estimate how close a supernova is to causing serious damage Landwe have to observe the destructive capabilities of supernovae.
First, the shock wave from the explosion itself. But trust me: If you’re close enough to a supernova to not have to worry about the shockwave, then you’re close enough to a pre-supernova star that you’ve already received a lethal dose of radiation, and you should stay away. A long time ago.
Then, there was visible light. Even though it has a big impact and causes blindness, this will not be a factor that destroys our planet.
Speaking of energy production, most of the energy emitted by supernovae is in the form of neutrinos, ghost particles that almost never interact with matter. In fact, there are trillions of neutrinos passing through your body right now and I bet you don’t even realize it. So even if you had a supernova-sized neutrino in your face, it wouldn’t bother you.
But what about other wavelengths of light, such as X-rays and gamma rays? The good news is that supernovae don’t usually produce large amounts of high-energy radiation. But the bad news is that this is only relative. On any reasonable absolute scale (such as the number of gamma rays that will pass through the atmosphere), this amount is still high-energy radiation.
And finally, there are cosmic rays, particles that are accelerated almost to the limit speed of light. Supernovae are capable of producing large amounts of cosmic rays, which can cause serious damage.
Related: An extremely rare ‘failed supernova’ may have wiped a star from the night sky without a trace
An animation shows a core collapse supernova creating a neutron star or black hole. (Image credit: INAF/Maurice HPM van Putten et al., ApJL, 2024)
blast radius
So what makes X-rays, gamma rays, and cosmic rays so dangerous to Earth? This form of radiation has enough energy to destroy nitrogen and oxygen molecules. The elements are in earth’s atmosphere They prefer to float like molecules. But once they separate, they recombine in interesting and surprising ways (for example, they produce various nitrogen oxides, including nitrous oxide, also known as laughing gas), which causes ozone depletion.
Without the ozone layer, the earth is vulnerable to ultraviolet radiation from sun. This not only means skin browns more quickly, skin burns more quickly, and skin cancer rates are higher. Photosynthetic microorganisms, such as algae, become vulnerable. In essence, they cook and die. And because they form the base layer of the food chain, the entire ecosystem collapses and there is a mass extinction.
For supernovae to be likely to occur in our galaxy, the dying star would have to be about 25 to 30 light years from Earth to remove at least half the ozone layer, which is enough to trigger all the previously mentioned negative effects. things.
And here’s some good news to help you sleep at night: There are no known supernova candidates within 30 light years of Earth. The closest candidate, Spica, is about 250 light years away, and no star has been a supernova candidate within 30 light years of Earth during its lifetime. So we’re safe on that, at least for now.
However, on longer time scales, things get more interesting because they tend to deal with entities that pose existential risks to the entire biosphere.
One of the fun things is ours solar system now enters Orion’s spiral arm Milky Wayand spiral arms are known for their high star formation rates (which is why they tend to stand out in images). But a higher rate of star formation means a higher rate of stellar death, which means a higher-than-average chance of getting too close for comfort in the 10 million years it takes us to cross.
Once all these factors are taken into account, you are left with an estimate of potentially deadly supernova encounters a few times every billion years.
In fact, some astronomers believe that there is a short distance a supernova caused a mass extinction 360 million years agowhich killed 75% of all species.
A gravitationally lensed view of a supernova seen by the James Webb Space Telescope. (Image credits: NASA, ESA, CSA, STScI, B. Frye (University of Arizona), R. Windhorst (Arizona State University), S. Cohen (Arizona State University), J. D’Silva (University of Western Australia, Perth ), A. Koekemoer (Space Telescope Science Institute), J. Summers (Arizona State University))
Don’t sleep on it
There is a slight caveat, however: this analysis only applies to ordinary, typical supernovae. There are also special cases where a dying star is enveloped in a thick layer of dust. When the supernova’s shock wave hit the dust, it released an avalanche of X-rays, which was followed by a burst of cosmic rays centuries later. This is a nasty double whammy: X-rays can travel more than 150 light years, weakening the planet’s atmosphereand then, several hundred years later, cosmic rays finished their job.
Then there are type Ia supernovae, which are activated when extremely dense white dwarfs (the remains of low- or intermediate-mass stars like the Sun) collect material from their orbiting companion stars. But white dwarfs are generally small and dark, making them harder to detect, and their evolution into supernovae is much more random. One day they just hang out and the next day they turn into a nuclear inferno.
Fortunately, the closest candidate is the binary white dwarf IK Pegasi, located about 150 light years away.
However, before you get too complacent, you should know about gamma-ray bursts, which result from neutron star mergers and hypernovae. They are much more dangerous because they are very powerful and the energy of the explosion is concentrated in a narrow beam that can pass through galaxies more than 10,000 light years away. Because gamma-ray bursts are much farther away than supernovae, they are more difficult to predict and plan for.
Sleep soundly!
Originally published in outerspace.com.
Ah, Betelgeuse! The star that promises a spectacular show, like the universe’s plan for an intergalactic fireworks display. When this cosmic giant goes kaboom, we’re talking brighter than all the planets combined. You could read a book at midnight under its light—provided, of course, you can tear yourself away from scrolling through TikTok. Imagine trying to explain that to your friends at the pub: “Oh, you see that bright thing? That’s just Betelgeuse having an existential crisis.”
But let’s address the elephant in the galaxy. While it sounds like a spectacle, fear not! Betelgeuse is a whopping 650 light-years away. So, if you’re worried, relax—you’re more likely to get struck by lightning while binge-watching your favorite series than face a supernova explosion. Although, given how streaming services are going, that’s still a possibility!
Now let’s dive into some science! We’ve all seen those disaster flicks where the hero has to save the world from a threatening explosion—and thank goodness, we’re quite safe for now. Studies have warned of the dangers of the shockwave from a supernova, but if you were to be close enough to experience it, you’d have already toasted your marshmallows in the lethal radiation beforehand. Fun fact: not the kind of camping trip anyone is signing up for!
Visible light from a supernova might be blinding enough to make you squint—the kind of brightness that’d put your ex’s Instagram filter to shame—but it’s not going to wipe out the planet. All those epic explosions tend to release a lot of neutrinos, those feisty particles that seem to have a massive aversion to interacting with anything. Imagine neutrinos as those distant relatives at the family reunion: they’re there, you can feel their presence, but good luck getting them to join the conversation! You’re practically swimming in them right now, and I bet you didn’t even notice.
The more troubling issues come with high-energy radiation such as X-rays and gamma rays. And no, sadly, not the ones you find at the cinema. While supernovae don’t typically produce massive amounts of this radiation, when they do, it’s enough to pull off a stellar performance of the “bad news bears” variety. We’re not talking “slightly annoying.” We’re talking the kind of UV rays that make the sun look as threatening as a gentle summer breeze.
And cosmic rays—the real troublemakers! These particles are like the Nespresso machine of the universe, sending enough energy rushing in to possibly wreak havoc on your day. If you thought the lockdown caused chaos to the ecosystem, supernova-produced cosmic rays are like the world’s worst party guests that just keep showing up uninvited.
So, just how safe are we? Fortunately, any supernova capable of causing significant damage would need to be about 25-30 light-years away—a comforting thought when you consider that Spica, our closest stellar culprits, are chilling at a cool 250 light-years. So, it’s a long commute, and I’m sure the traffic is awful anyway!
But wait, there’s an exhilarating twist! We drift through the Milky Way and are entering Orion’s spiral arm, where the stellar drama unfolds. While the thrill of star formation is high, so is the risk of stellar tomb raiders—the supernovae drifting a tad too close for comfort. If you take into account all the endless cosmic shenanigans, we might see a few potentially murderous star explosions every billion years. That’s the galactic equivalent of waiting for the bus and missing it by a decade!
Here’s an interesting tidbit: some astronomers suspect a supernova might have caused a mass extinction 360 million years ago. You heard that right—75% of all species out of commission. Much like any self-respecting 80s movie, but with a much quieter ending. “Sorry, T-Rex—no big dinner plans tonight.”
However, just like bad relationships, there are “special” supernovae that can ruin your cosmic picnic. Imagine a dying star in a thick layer of dust—when they explode, it’s an avalanche of X-rays followed by a nasty wave of cosmic rays, all while you’re toasting marshmallows under the stars. Romantic, right? Just remember—the universe really does have a sense of humor!
And then we have gamma-ray bursts, the dramatic shows of the stellar world. Picture a neutron star merger that releases more energy than your average Netflix binge—suddenly, instead of watching on your couch, you’re sent straight into the cosmic drama with no remote in sight. The problem with gamma-ray bursts is they can annihilate across galaxies. They’re sneaky! You won’t even see them coming! It’s like waiting for the kettle to boil and it suddenly explodes in your face when you were just trying to make a nice cup of tea.
So the good news? You can sleep soundly for now, but keep in mind that the universe loves to keep things unpredictable. It’s a cosmic circus out there—so whether you’re dealing with star explosions or your flatmate’s questionable cooking, buckle up for the ride!
Originally published in outerspace.com.
When the radiant star Betelgeuse finally undergoes its catastrophic explosion, it promises to be an extraordinary spectacle. This cosmic event, known as a supernova, will radiate energy that outshines any planet and will come close to matching the luminosity of a full moon. Remarkably, it will be visible even in daylight, allowing observers to read a book under its illumination during the darkness of midnight. The brilliance of this stellar explosion will endure for several months before it fades from view, a phenomenon typical of all supernovae.
However, there’s no reason to fear such an event. For any potential devastation to be a concern, we would need to be significantly closer; Betelgeuse resides approximately 650 light years away from Earth. This leads to a compelling question: are there any stars in our vicinity that could pose a threat to our planet?
Understanding the proximity needed for a supernova to inflict serious harm on Earth requires careful examination of the destructive forces unleashed by these cosmic phenomena. A supernova creates a shock wave that travels outward with incredible force. Yet, if you find yourself close enough to be concerned about the shockwave, you are far too close to a pre-supernova star and would have already absorbed a fatal dose of radiation—an imperative to avoid such proximity altogether.
Even the visible light emitted by a supernova, while intense enough to cause temporary blindness, does not literally represent an existential threat to our planet. However, the primary energy output during a supernova event is in the form of neutrinos, elusive subatomic particles that very rarely interact with normal matter. Trillions of neutrinos are currently traversing through your body without you being aware of their presence. Consequently, a supernova neutrino bombarding you would go unnoticed.
Looking beyond neutrinos, what about other forms of high-energy radiation like X-rays and gamma rays? Thankfully, supernovae typically do not emit substantial quantities of these dangerous high-energy photons. Nevertheless, the relative nature of this ‘good news’ should not be overlooked; on any reasonable scale of measuring the number of gamma rays that might filter through our atmosphere, the quantities still qualify as significant high-energy radiation.
Addressing another potential hazard, cosmic rays emitted by supernovae represent high-energy particles accelerated to nearly the speed of light. These cosmic rays can pose serious threats, as they have sufficient energy to fragment and break apart nitrogen and oxygen molecules within our atmosphere.
In an alarming chain reaction, the dismantling of these essential atmospheric elements leads to the creation of compounds that can deplete the ozone layer. Without this protective layer, the Earth becomes increasingly vulnerable to ultraviolet radiation from the sun, resulting in a higher incidence of skin burns and an increase in skin cancer cases. The repercussions extend further, compromising photosynthetic microorganisms like algae, which forms the fundamental base of the food chain, thereby instigating a potential ecosystem collapse culminating in a mass extinction event.
For a supernova to pose a genuine threat to Earth, it would need to be situated approximately 25 to 30 light years away to fully eradicate at least half of the ozone layer, triggering all the aforementioned detrimental effects. Thankfully, astronomers have identified no known supernova candidates within this potentially hazardous distance from Earth. The nearest candidate, the star Spica, is a safe 250 light years away, and throughout its lifetime, no star has posed the risk of becoming a supernova within 30 light years of our planet.
However, on more extended timelines, the situation becomes more engrossing, particularly as our solar system traverses Orion’s spiral arm, a region recognized for a heightened rate of star formation. Consequently, an increased frequency of stellar births correlates directly with a greater likelihood of stellar deaths, thus raising the probability that we might be uncomfortably close to a supernova as we make this journey over the next 10 million years.
When these factors are taken into account, estimates suggest that potentially lethal supernova encounters could occur just a few times every billion years. Interestingly, some astronomers speculate that a supernova may have contributed to a mass extinction event around 360 million years ago, decimating approximately 75% of all species on Earth.
There is, however, a caveat regarding supernova analysis; this information predominantly relates to conventional supernovae. Special scenarios exist, such as a dying star encased in a thick layer of cosmic dust. In such a case, when the shockwave from the supernova collides with the dust, it generates a surge of X-rays, followed by a cascade of cosmic rays potentially centuries later. This phenomenon represents a dangerous double jeopardy, as X-rays are capable of moving over long distances, compromising planetary atmospheres, and then, years later, cosmic rays may deliver the final blow.
Additionally, there are type Ia supernovae which form when dense white dwarf stars gather material from companion stars. These stars, remnants of low to mid-mass stars such as the Sun, are often elusive and unpredictable in their transition to supernovae, making them challenging to detect until they erupt into nuclear chaos.
The nearest such candidate, IK Pegasi, remains safely about 150 light years away from Earth—a relief, especially considering the dangers posed to life on our planet. However, gamma-ray bursts, resulting from neutron star collisions or hypernovae, could warrant a greater level of concern due to their potency. Concentrated in a narrow beam, these bursts possess the capacity to impact areas across vast distances exceeding 10,000 light years. Given their distances from Earth, forecasting these events presents considerable difficulties.
With that said, rest easy! There’s currently no imminent threat from the cosmos.
Originally published in outerspace.com.
How do current astronomical models account for the uncertainties associated with cosmic events like supernovae, and what implications does this have for future observations?
Rrelated occurrences and probabilities rather than certainties. The universe is full of uncertainties, and while we can make educated guesses based on current astronomical observations and models, the chaotic nature of space means that surprises are always possible.
So, as we contemplate the vastness of the galaxy and the potential hazards of supernovae, it’s crucial to closely monitor our cosmic neighborhood while also appreciating the beauty of the stars above. After all, while it’s vital to stay informed about the perils of the universe, we also want to take a moment to enjoy that twinkling light—side note: it’s much less about impending doom and more about the awe-inspiring wonders that the cosmos has to offer!
while supernovae can pose serious threats under certain circumstances, the reality is that Earth currently enjoys a safe distance from potential destruction. As we look forward to celestial events and potential new discoveries in our galactic backyard, let’s hold onto that sense of wonder and curiosity, ensuring we’re always ready to marvel at the spectacular universe we call home while remaining aware of its unpredictable and often humorous nature. So grab your marshmallows, keep your binoculars handy, and prepare for a cosmic show—because who knows what might come next?
