Latest news with #AstrophysicalJournal
The Independent
3 hours ago
- General
- The Independent
How a planetarium show led to a cosmic breakthrough
Scientists at the American Museum of Natural History discovered the true shape of the Oort Cloud, a region far beyond Pluto, while preparing a planetarium show called 'Encounters in the Milky Way '. The inner section of the Oort Cloud, which is made of billions of comets, was found to resemble a bar with two waving arms, similar to the Milky Way galaxy. The spiral shape was identified by experts when fine-tuning a scene featuring the Oort Cloud, which is filled with icy relics. This discovery challenges the long-held belief that the Oort Cloud was shaped like a sphere or flattened shell. Researchers published their findings in The Astrophysical Journal, noting that this discovery marks a significant shift in understanding the outer solar system.
The Independent
4 hours ago
- Entertainment
- The Independent
Scientists solve solar system mystery after freak accident at planetarium show
Scientists have solved one of the solar system's enduring mysteries with the help of an unexpected source: a planetarium show. Last year, experts at the American Museum of Natural History were preparing 'Encounters in the Milky Way," a deep dive into our home galaxy shaped by the movements of stars and other celestial objects. While fine-tuning a scene featuring what's known as the Oort Cloud, a region far beyond Pluto filled with icy relics from the solar system's formation, scientists noticed something unusual projected onto the planetarium's dome. The Oort Cloud is known to send comets hurtling towards Earth, but its true shape has remained elusive to scientists until now. 'Why is there a spiral there?' said the museum's Jackie Faherty. The inner section of the Oort Cloud, made of billions of comets, resembled a bar with two waving arms, similar to the shape of our Milky Way galaxy. Scientists had long thought the Oort Cloud was shaped like a sphere or flattened shell, warped by the push and pull of other planets and the Milky Way itself. The planetarium show hinted that a more complex shape could lie inside. The museum contacted the researcher who provided the Oort Cloud data for the show, who was also surprised to see the spiral. 'It's kind of a freak accident that it actually happened,' said David Nesvorny with the Southwest Research Institute. Realising they'd stumbled on something new, the researchers published their findings earlier this year in The Astrophysical Journal. The spiral is "a striking shift in our understanding of the outer solar system,' planetary scientist Andre Izidoro with Rice University, who was not involved with the study, said. The discovery, relying on data on how celestial objects move and using simulations, will be difficult to confirm with observations. But knowing more about the orbits of distant comets could give scientists some clues, Izidoro said. While putting together the planetarium show, the museum's experts weren't expecting a window into the universe's inner workings. The show, narrated by actor Pedro Pascal, features many vivid scenes that may capture audiences more than the Oort Cloud, said the museum's Jon Parker — including an ongoing merge of the Sagittarius mini galaxy with the Milky Way. No matter how striking and beautiful the visuals of the show, the museum was committed to making it scientifically accurate. That's what created the perfect conditions to stumble upon something new, said the museum's Carter Emmart. 'You just never know what you're going to find,' Emmart said.
Yahoo
3 days ago
- General
- Yahoo
Does extraterrestrial life smell like the sea?
Dimethyl sulfide, also known as DMS, sounds like it could be a chemical compound you'd try to avoid on an ingredient label, or the poisonous ingredient in a murder mystery. But some scientists view this simple compound as a biosignature — a key indicator of life. So there was great excitement when DMS was discovered on a "sub-Neptune planet" far from our solar system – 124 light years away, or about 17 trillion miles, in the constellation Leo. 'We want to be a bit careful in claiming any evidence of life at this stage,' cautioned lead author Nikku Madhusudhan, of Cambridge University, about the findings he published last month in The Astrophysical Journal Letters, a publication of the American Astronomical Society, with other researchers from two American space institutes and two British physics and astronomy departments. 'We have to look at a lot more molecules, and we have, and we couldn't come up with a much better explanation,' Madhusudhan told Salon in a video interview. He admits he can't be 100% certain that dimethyl sulfide, or (CH3)2S, exists on the planet called K2-18 b. But it looks very likely, as last month's research built on a paper published in 2023 that also found suggestions of DMS on the same planet but relied on different evidence. But why would a random compound detected on a planet so far beyond our reach be a strong indicator of life? Well, let's consider the story of DMS on Earth, a story of the strange and poetic ways life appears and reappears in different guises — and with different scents. Dimethyl sulfide is the largest natural source of atmospheric sulfur on Earth, which means that it gets into the atmosphere and cycles around. But it starts its journey in the ocean. You're absolutely familiar with DMS, even if you've never heard of it before. It's the source of the smell of the sea, that sort of fishy, sort of eggy aroma that evokes deeply nostalgic reactions in, well, almost everyone. Interesting pushback came from Christophe Laudamiel, a master perfumer at Generation by Osmo. 'I have personally never used that ingredient for the smell of the sea,' he told Salon by email. 'It would be rather used for 'hot' smells and for ripe to overripe smells." He compared the odor of DMS to "fish that stayed too long in the sun," adding, quite understandably, that "we usually avoid" such associations "when we recreate the smell of the sea in perfumery." Rather than relying on those fish-rotting-in-sun odors to get ocean-smelling perfume, suggested Generation by Osmo founder and CEO Alex Wiltschow (also by email), "We combine aquatic notes with mineral wet stone notes, salty notes and clean air notes," along with, perhaps, "a touch of seaweed absolute as well or mossy top notes." Similarly environment-evoking are the substances geosmin and petrichor. Petrichor is the pleasant, earthy aroma of rain falling on dry soil, sometimes described more simply as the smell of rain. That word has almost become trendy. In fact its use appears to have skyrocketed in the past quarter-century, though it was coined in the journal Nature in 1964. Like geosmin, the substance that gives earth its characteristic "earthy" odor, petrichor remains close to the ground. Dimethyl sulfide, however, gets around. The DMS that cycles around our world is produced, for the most part, by marine organisms, most notably the microscopic plants known as phytoplankton that live in the nutrient-rich upper layer of the ocean. These tiny organism exist in abundance, which is why DMS is responsible for most of that smell we associate with the seaside. From the surface layer of the Earth's oceans, DMS, which is a volatile chemical, escapes into the air, joining the atmospheric cycling of sulfur. As one researcher describes this process, once in the atmosphere DMS "has other major effects, being the 'seed' that sets off cloud formation over the oceans. Indeed, the production of this molecule is on such a scale that it has major effects on the world's climate, thanks to its effect on the cloud cover over the oceans.' That quotation is nearly 20 years old, but scientists still don't know exactly to what extent DMS is responsible for seeding clouds, just that it's a significant factor. The tiny aerosol particles formed when DMS molecules are zapped by sunlight and other molecules in the atmosphere, which become the 'seeds' for clouds, also exert meaningful effects on our climate by reflecting sunlight back into space. In 2007, scientists at the University of East Anglia discovered that a single gene could produce dimethyl sulfide from dimethylsulfoniopropionate, or DMSP, the food that phytoplankton eat. As described in a paper in Science, you can take that gene, which has the catchy name dddD, from bacteria that live in the sea, or find it in other species of bacteria that hang out with plants instead but also produce DMS. Once you've found a bacterium with the dddD gene, you can clone it and stick it into an bacterium, which will then happily produce dimethyl sulfide. The aforementioned predecessor chemical DMSP is found, by the billions of tons, all over the world's oceans, seas and seashores. Marine plants and phytoplankton use it to protect themselves from the saltiness of seawater, literally as a buffer against stress. When these tiny plants die, some of their DMSP becomes available, as food for other bacteria. Terrestrial plants may also have symbiotic bacteria living in their root systems, which produce dimethyl sulfide from the DMSP released when their hosts die. This process — one kind of organism dies, offering sustenance to others — is how this cycle begins, at least on Earth. (If you can actually say that a cycle has a beginning or an end.) As one of the East Anglia scientists, Andrew Johnston, wrote in a 2007 project funding proposal, describing the role of DMS in seeding clouds, its importance has been known since 1971, "with some 30 million tons of it being liberated into the air, worldwide, every year.' Aquatic bird species such as sea petrels and shearwaters are attracted to the ripe-fish aroma, while Johnston later discovered that the Atlantic herring has strains of bacteria in its gut microbiome called Pseudomonas and Psychrobacter, which digest DMSP and break it down into, yes, dimethyl sulfide. How did those bacteria get inside a fish? Herring eat small plants known as mesozooplankton, which themselves eat the much smaller phytoplankton. This familiar ecological pattern — bigger creatures eating smaller creature — has internalized the production of this evocative and volatile to the food chain, it seems, the creation dimethyl sulfide can take place not just in the surface layer of the ocean, but inside herring guts as well. Herrings are vertebrates, in the greater evolutionary scheme not all that different from us. Does this mean that humans also have the potential to create sulfurous stinks from our own insides? Well, there's no evidence at this point that our microbiomes contain DMS-producing bacteria. But that's ok. As you may be aware, our species can produce our own glorious forms of stink. Dimethyl sulfide is an essential element in the characteristic odors of blood, serum, tissues, urine and breath in people (and rats). Not to mention the distinctive smell of feces and flatus, i.e., farts. Let's mention here that dimethyl sulfide is emitted during wildfires, and so contributes to a scent that has grown chillingly familiar in many parts of North America in recent years. It's also largely responsible for the smell of the delicately-named dead horse arum, a relative of the so-called corpse flower, or titan arum. Other flowers with unappetizing odors use different chemicals as their top notes, all with the purpose of attracting pollinators drawn to the aroma of their preferred type of rotting meat. Here for example is Wikipedia's almost lyrical rundown of the various sources of the corpse flower's scent: 'Analyses of chemicals released by the spadix show the stench includes dimethyl trisulfide (like limburger cheese), dimethyl disulfide (garlic), trimethylamine (rotting fish), isovaleric acid (sweaty socks), benzyl alcohol (sweet floral scent), phenol (like Chloraseptic), and indole (like feces).' Scientists comparing the molecules involved in producing the stench of dead horse arum with those produced by a rotting corpse found that dimethyl sulfide was associated with the middle stage of decomposition in actual corpses (to be clear, this involved dead mice, not dead horses or human cadavers). All this odoriferous research has convinced some scientists that DMS is intimately associated with life, making it an ideal biosignature if found hundreds of light years away on some lonely planet. Critics of Madhusudhan's findings point out, however, that dimethyl sulfide can exist without demonstrating life at all. For one thing, you can make it in a lab. As the perfumer Laudamiel told Salon, DMS is "often used in perfumery, but not for its low-tide, rotten egg facet.' The human nose can detect one part per million of DMS, as an unpleasant, cabbage-like smell used, for example, to add a warning signal to the poisonous gas carbon monoxide, which is otherwise odorless natural gas. DMS also results from kraft pulping, producing a ghastly, retch-inducing smell you'll have noticed if you've ever driven by a paper processing plant. It's produced naturally as bacteria do their work on dimethyl sulfoxide waste in sewers. When it's not saving us from asphyxiation or carrying out useful industrial processes, dimethyl sulfide also lends its "low-tide, rotten egg facet" as a nearly subconscious flavor in food and drinks, measured in a few parts per million. In brewing certain lagers, though, breweries may want that slightly funky flavor, and add enough DMS to cross the flavor threshold as a hint of the ocean (or of distant rotten eggs, or cabbage). The natural production of DMS is also medically useful. It turns out that as a kind of bacteria turns from existing peacefully in our mouths to causing colon cancer in our nether regions, it produces dimethyl sulfide. Worsening osteoporosis in older women may lead to exhaling DMS, as can the positive effects of a medication cocktail for children with cystic fibrosis. But how is it that the compound that gives us the glorious smell of the sea — and just perhaps, our first evidence of life on a distant planet — also provides the generally disagreeable fragrance of flatus, feces and flowers that smell like rotting meat? 'It works just like salt in a cake," explained Laudamiel. "In combination with other molecules, at low, unrecognizable dosages, it brings out the flavors of other facets." Unpleasant-sounding flavor notes such as "the overripe 'vomity' note found naturally in papaya ... the 'feet' note found in Parmigiano or the 'sweaty' note found naturally in dark chocolate" produce magical effects in combination with others and in just the right amount. Remove those notes, he concluded, and your papaya, cheese or chocolate will "taste much less yummy." Indeed, DMS, provided by nature at just the right dosage, is a component in the much coveted scent of truffles. Turning away from our planet with its stinky-feet cheese, vomity papayas and sweaty chocolate, and turning to the stars, DMS is used as an additive in rocket fuel, added to ethylene oxide to prevent exhaust nozzles getting dirty and stop carbon building up on firing-chamber surfaces. But no existing or planned spacecraft can get us anywhere near the next possible known source of dimethyl sulfide on K2-18 b, the planet where Madhusudhan and colleagues have found, thanks to the James Webb Space Telescope, what they think could well be this signature of life. Astronomers these days are really interested in sub-Neptune planets, meaning those with diameters larger than Earth but smaller than Neptune. It's an exotic niche that doesn't exist in our solar system, and could offer new possibilities for finding life. They're particularly interested in a newly-defined type of planet that could exist within that range: Hycean worlds, which would possess water-rich interiors, planet-spanning oceans and atmospheres rich in hydrogen gas. The Madhusudhan team's detection of methane and carbon dioxide gases on K2-18 b supports his argument that the planet might have surface water, as does the fact that they did not find ammonia, which is soluble in water — if that's detected in the atmosphere, there probably isn't an ocean. But while DMS is a biosignature here on Earth, other scientists point out that it could be cooked up by some other process elsewhere, just as it can be produced in a laboratory for industrial purposes. Some scientists have suggested other possible explanations for the signals found by Madhusudhan's team, including statistical noise. Two findings within the past year bolster these criticisms. One, described last October, is the presence of dimethyl sulfide in a comet named 67P/Churyumov-Gerasimenko, which no one would argue suggests biological activity. Madhusudhan says that does nothing to disprove his hypothesis; comets are known to be little laboratories that can cook up all sorts of unlikely things. 'The same comet also has molecular oxygen in it, right?' he countered. 'It also has methane and other molecules, including amino acids." Finding something in a comet, he said, "doesn't mean that it can't be a biosignature in a planetary atmosphere, because those are two very different environments." Another finding that may cast doubt on the idea that DMS equates to the presence of life is the discovery of dimethyl sulfide, which here on Earth makes the sea smell like the sea, drifting around in deep space between the stars. Reporting on the open science platform Arxiv in February, an international group of astronomers said they found DMS during an ultra-deep molecular line survey, which uses fancy telescopes to look at a spectrum of wavelengths in one particular stretch of outer space and then catalog its chemical composition and physical properties, such as temperature and density. In this case, they pointed their telescopes toward a Galactic Center molecular cloud named G+0.693-0.027. And there they found dimethyl sulfide, just vibing in the void.
Yahoo
23-05-2025
- Science
- Yahoo
Hypervelocity Stars Hint at a Nearby Supermassive Black Hole
An astonishing fact only known for the past few decades is that every big galaxy in the universe has a supermassive black hole at its heart. This was suspected in the 1980s, and observations from the Hubble Space Telescope, which has peered deep into the cores of galaxies all across the sky, confirmed it. The 'normal' kinds of black holes made when stars explode range from five to about 100 times the mass of the sun, more or less. But these central galactic monsters are millions of times more massive, and some have grown to the Brobdingnagian heft of billions of solar masses. A lot of mysteries still remain, of course, such as how they formed early in the history of the universe, how they grew so humongous so fast and what role they played in their host galaxy's formation. But one odd question still nagging at astronomers is: What's the galaxy size cutoff where this trend stops? In other words, is there some lower limit to how massive a galaxy can be and still harbor one of these beasts? The inklings of an answer are emerging from a surprising place: studies of rare stars moving through our own galaxy at truly ludicrous speeds. [Sign up for Today in Science, a free daily newsletter] Orbiting our Milky Way galaxy is a menagerie of smaller 'dwarf' galaxies, some so tiny and faint you need huge telescopes to see them at all. But two are so large and close that they're visible to the unaided eye from the Southern Hemisphere: the Large and Small Magellanic Clouds. The Large Magellanic Cloud (LMC) is the bigger and closer of the two, and it's not clear if it harbors a supermassive black hole (SMBH). If such an SMBH exists there, it must be quiescent, meaning it's not actively feeding on matter. As material falls toward such a black hole, it forms a swirling disk of superheated plasma that can glow so brightly it outshines all the stars in the galaxy combined. No such fierce luminescence is seen in the LMC, so we don't know if an SMBH is there and not actively feeding or if the LMC is simply SMBH-free. But a recent study published in the Astrophysical Journal offers strong evidence that an SMBH does lie at the center of the LMC—based on measurements of stellar motions in our own Milky Way! The study looked at hypervelocity stars, ones that are screaming through space at speeds far higher than stars around them. Some of these stars are moving so rapidly that they have reached galactic escape velocity; the Milky Way's gravity can't hold them. In the coming eons, they'll flee the galaxy entirely. And we have good reason to believe these runaway stars were launched by SMBHs—but how? Such a situation starts with a binary system, two stars orbiting each other. These systems contain a substantial amount of orbital energy, the sum of the kinetic energy of the two stars—their energy of motion—and their gravitational potential energy, the amount of energy released if they were to move closer together. If the binary star approaches a third object, some of that energy can be swapped around. One star can become bound to the third object, for example, while the other star can get a kick in its kinetic energy, flinging it away. The amount of the kick depends in part on the gravity of the third object. A massive black hole, of course, has an incredibly strong gravitational field that can fling the star away at high speed. And I do mean high speed; such a star can be flung away from the black hole at a velocity greater than 1,000 kilometers per second. S5-HVS1, for example, was the first confirmed such hypervelocity star, and it's moving at more than 1,700 kilometers per second. Feel free to take a moment to absorb that fact: an entire star has been ejected away from a black hole at more than six million kilometers per hour. The energies involved are terrifying. We have seen a few of these stars in our galaxy, and careful measurements suggest they're moving away from the center of the Milky Way, which is pretty convincing evidence that Sagittarius A*, our own Milky Way's SMBH, is to blame. But not all of the high-velocity stars that have been detected appear to come from our galactic center. Fortunately, Gaia, the sadly now decommissioned European Space Agency astronomical observatory, was designed to obtain extremely accurate measurements of the positions, distances, colors and other characteristics of well more than a billion stars—including their velocity. There are 21 known hypervelocity stars at the outskirts of the Milky Way. Using the phenomenally high-precision Gaia measurements, the astronomers behind the new research examined the stars' 3D velocities through space. They found that five of them have ambiguous origins, while two definitely come from the Milky Way center. Of the 14 still left, three clearly come from the direction of the LMC. The trajectories of these stars effectively point back to their origin, and based on our current knowledge, that origin must be a supermassive black hole. Even better, although the remaining 11 stars have trajectories that are consistent with both Milky Way and LMC origins, the researchers found that five are more likely to have come from our home galaxy and the other six are more likely to have come from the LMC. So there could be nine known hypervelocity stars plunging through our galaxy that were ejected by a supermassive black hole in another galaxy. Using some sophisticated math, the team found that the most likely mass of the black hole is 600,000 or so times the mass of the sun. This isn't huge for an SMBH—it's very much on the low end of the scale, in fact—but then, the LMC is a small galaxy, only 1 percent or so the mass of the Milky Way. We know that the mass of a black hole tends to scale with its host galaxy's mass (because they form together and affect each other's growth), so this lower mass is consistent with that. If this is true, then our satellite galaxy is shooting stars at us! And there may be more of them yet to be found, hurtling through space unseen on the other side of our galaxy, or so far out that they're difficult to spot and even harder to study. And all this helps us get a clearer—but still quite hazy!—sense of just how far down the galactic scale we can expect to find big black holes. Black holes are funny. Most people would worry about falling into one, as well as a host of other terrors, but now you can add 'having to dodge intergalactic stellar bullets' to that list.
Scientific American
23-05-2025
- Science
- Scientific American
Hypervelocity Stars Hint at a Supermassive Black Hole Right Next Door
An astonishing fact only known for the past few decades is that every big galaxy in the universe has a supermassive black hole at its heart. This was suspected in the 1980s, and observations from the Hubble Space Telescope, which has peered deep into the cores of galaxies all across the sky, confirmed it. The 'normal' kinds of black holes made when stars explode range from five to about 100 times the mass of the sun, more or less. But these central galactic monsters are millions of times more massive, and some have grown to the Brobdingnagian heft of billions of solar masses. A lot of mysteries still remain, of course, such as how they formed early in the history of the universe, how they grew so humongous so fast and what role they played in their host galaxy's formation. But one odd question still nagging at astronomers is: What's the galaxy size cutoff where this trend stops? In other words, is there some lower limit to how massive a galaxy can be and still harbor one of these beasts? The inklings of an answer are emerging from a surprising place: studies of rare stars moving through our own galaxy at truly ludicrous speeds. On supporting science journalism If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today. Orbiting our Milky Way galaxy is a menagerie of smaller 'dwarf' galaxies, some so tiny and faint you need huge telescopes to see them at all. But two are so large and close that they're visible to the unaided eye from the Southern Hemisphere: the Large and Small Magellanic Clouds. The Large Magellanic Cloud (LMC) is the bigger and closer of the two, and it's not clear if it harbors a supermassive black hole (SMBH). If such an SMBH exists there, it must be quiescent, meaning it's not actively feeding on matter. As material falls toward such a black hole, it forms a swirling disk of superheated plasma that can glow so brightly it outshines all the stars in the galaxy combined. No such fierce luminescence is seen in the LMC, so we don't know if an SMBH is there and not actively feeding or if the LMC is simply SMBH-free. But a recent study published in the Astrophysical Journal offers strong evidence that an SMBH does lie at the center of the LMC—based on measurements of stellar motions in our own Milky Way! The study looked at hypervelocity stars, ones that are screaming through space at speeds far higher than stars around them. Some of these stars are moving so rapidly that they have reached galactic escape velocity; the Milky Way's gravity can't hold them. In the coming eons, they'll flee the galaxy entirely. And we have good reason to believe these runaway stars were launched by SMBHs—but how? Such a situation starts with a binary system, two stars orbiting each other. These systems contain a substantial amount of orbital energy, the sum of the kinetic energy of the two stars—their energy of motion—and their gravitational potential energy, the amount of energy released if they were to move closer together. If the binary star approaches a third object, some of that energy can be swapped around. One star can become bound to the third object, for example, while the other star can get a kick in its kinetic energy, flinging it away. The amount of the kick depends in part on the gravity of the third object. A massive black hole, of course, has an incredibly strong gravitational field that can fling the star away at high speed. And I do mean high speed; such a star can be flung away from the black hole at a velocity greater than 1,000 kilometers per second. S5-HVS1, for example, was the first confirmed such hypervelocity star, and it's moving at more than 1,700 kilometers per second. Feel free to take a moment to absorb that fact: an entire star has been ejected away from a black hole at more than six million kilometers per hour. The energies involved are terrifying. We have seen a few of these stars in our galaxy, and careful measurements suggest they're moving away from the center of the Milky Way, which is pretty convincing evidence that Sagittarius A*, our own Milky Way's SMBH, is to blame. But not all of the high-velocity stars that have been detected appear to come from our galactic center. Fortunately, Gaia, the sadly now decommissioned European Space Agency astronomical observatory, was designed to obtain extremely accurate measurements of the positions, distances, colors and other characteristics of well more than a billion stars—including their velocity. There are 21 known hypervelocity stars at the outskirts of the Milky Way. Using the phenomenally high-precision Gaia measurements, the astronomers behind the new research examined the stars' 3D velocities through space. They found that five of them have ambiguous origins, while two definitely come from the Milky Way center. Of the 14 still left, three clearly come from the direction of the LMC. The trajectories of these stars effectively point back to their origin, and based on our current knowledge, that origin must be a supermassive black hole. Even better, although the remaining 11 stars have trajectories that are consistent with both Milky Way and LMC origins, the researchers found that five are more likely to have come from our home galaxy and the other six are more likely to have come from the LMC. So there could be nine known hypervelocity stars plunging through our galaxy that were ejected by a supermassive black hole in another galaxy. Using some sophisticated math, the team found that the most likely mass of the black hole is 600,000 or so times the mass of the sun. This isn't huge for an SMBH—it's very much on the low end of the scale, in fact—but then, the LMC is a small galaxy, only 1 percent or so the mass of the Milky Way. We know that the mass of a black hole tends to scale with its host galaxy's mass (because they form together and affect each other's growth), so this lower mass is consistent with that. If this is true, then our satellite galaxy is shooting stars at us! And there may be more of them yet to be found, hurtling through space unseen on the other side of our galaxy, or so far out that they're difficult to spot and even harder to study. And all this helps us get a clearer—but still quite hazy!—sense of just how far down the galactic scale we can expect to find big black holes. Black holes are funny. Most people would worry about falling into one, as well as a host of other terrors, but now you can add 'having to dodge intergalactic stellar bullets' to that list.
