Galactic ‘Wind’ Stifling Star Formation Is Most Distant Yet Seen

For the first time, a powerful “wind” of molecules has been detected in a galaxy located 12 billion light-years away. Probing a time when the universe was less than 10 percent of its current age, University of Texas at Austin astronomer Justin Spilker’s research sheds light on how the earliest galaxies regulated the birth of stars to keep from blowing themselves apart. The research will appear in the Sept. 7 issue of the journal Science.

“Galaxies are complicated, messy beasts, and we think outflows and winds are critical pieces to how they form and evolve, regulating their ability to grow,” Spilker said.

Some galaxies such as the Milky Way and Andromeda have relatively slow and measured rates of starbirth, with about one new star igniting each year. Other galaxies, known as starburst galaxies, forge hundreds or even thousands of stars each year. This furious pace, however, cannot be maintained indefinitely.

To avoid burning out in a short-lived blaze of glory, some galaxies throttle back their runaway starbirth by ejecting — at least temporarily — vast stores of gas into their expansive halos, where the gas either escapes entirely or slowly rains back in on the galaxy, triggering future bursts of star formation.

Until now, however, astronomers have been unable to directly observe these powerful outflows in the very early universe, where such mechanisms are essential to prevent galaxies from growing too big, too fast.

Spilker’s observations with the Atacama Large Millimeter/submillimeter Array (ALMA), show — for the first time — a powerful galactic wind of molecules in a galaxy seen when the universe was only 1 billion years old. This result provides insights into how certain galaxies in the early universe were able to self-regulate their growth so they could continue forming stars across cosmic time.

Astronomers have observed winds with the same size, speed and mass in nearby starbursting galaxies, but the new ALMA observation is the most distant unambiguous outflow ever seen in the early universe.

The galaxy, known as SPT2319-55, is more than 12 billion light-years away. It was discovered by the National Science Foundation’s South Pole Telescope.

ALMA was able to observe this object at such tremendous distance with the aid of a gravitational lens provided by a different galaxy that sits almost exactly along the line of sight between Earth and SPT2319-55. Gravitational lensing — the bending of light due to gravity — magnifies the background galaxy to make it appear brighter, which allows the astronomers to observe it in more detail than they would otherwise be able to. Astronomers use specialized computer programs to unscramble the effects of gravitational lensing to reconstruct an accurate image of the more-distant object.

This lens-aided view revealed a powerful wind of star-forming gas exiting the galaxy at nearly 800 kilometers per second. Rather than a constant, gentle breeze, the wind is hurtling away in discrete clumps, removing the star-forming gas just as quickly as the galaxy can turn that gas into new stars.

The outflow was detected by the millimeter-wavelength signature of a molecule called hydroxyl (OH), which appeared as an absorption line: essentially, the shadow of an OH fingerprint in the galaxy’s bright infrared light.

Molecular winds are an efficient way for galaxies to self-regulate their growth, the researchers note. These winds are probably triggered by either the combined effects of all the supernova explosions that go along with rapid, massive star formation, or by a powerful release of energy as some of the gas in the galaxy falls down onto the supermassive black hole at its center.

“So far, we have only observed one galaxy at such a remarkable cosmic distance, but we’d like to know if winds like these are also present in other galaxies to see just how common they are,” Spilker concluded. “If they occur in basically every galaxy, we know that molecular winds are both ubiquitous and also a really common way for galaxies to self-regulate their growth.”

Study Reveals Secret Origins Of Asteroids And Meteorites

Most asteroids and meteorites originate from the splintering of a handful of minor planets formed during the infancy of our solar system, a new study shows.

A study appearing online today in Nature Astronomy found at least 85 percent of 200,000 asteroids in the inner asteroid belt—the main source of Earth’s meteorites—originate from five or six ancient minor planets. The other 15 percent may also trace their origins to the same group of primordial bodies, said Stanley Dermott, lead author and a theoretical astronomer at the University of Florida.

The discovery is important for understanding the materials that shaped our own rocky planet, Dermott said.

The finding provides a more robust understanding of the evolutionary history of asteroids and the materials that form them—information Dermott says could prove essential to protecting the Earth and ourselves from meteorites the size of the Statue of Liberty and asteroids more powerful than atomic bombs.

“These large bodies whiz by the Earth, so of course we’re very concerned about how many of these there are and what types of material are in them,” said Dermott, professor emeritus in UF’s College of Liberal Arts and Sciences. “If ever one of these comes towards the earth, and we want to deflect it, we need to know what its nature is.”

Dermott’s team demonstrated that the type of orbit an asteroid has depends on the size of the asteroid. This finding suggests that differences in meteorites found on Earth appear because of the evolutionary changes that occurred inside a few large, precursor bodies that existed more than four billion years ago, Dermott said.

“I wouldn’t be surprised if we eventually trace the origins of all asteroids in the main asteroid belt, not just those in the inner belt, to a small number of known parent bodies,” Dermott said.

Building knowledge of the evolutionary history of bodies that formed our early solar system helps theoretical astronomers answer questions related to where planets like our own might exist in the universe, Dermott said. But, first, he said we have to understand the processes that produced the planet we live on.

Researchers See Beam Of Light From First Confirmed Neutron Star Merger Emerge From Behind Sun

A research team led by astronomers at the University of Warwick had to wait over 100 days for the sight of the first of confirmed neutron star merger to remerge from behind the glare of the Sun.

They were rewarded with the first confirmed visual sighting of a jet of material that was still streaming out from merged star exactly 110 days after that initial cataclysmic merger event was first observed. Their observations confirm a key prediction about the aftermath of neutron star mergers.

The binary neutron star merger GW170817 occurred 130 million light years away in a galaxy named NGC 4993. It was detected in August 2017 by the Advanced Laser Interferometer Gravitational-Wave Observatory (Adv-LIGO), and by Gamma Ray Burst (GRB) observations, and then became the first ever neutron star merger to be observed and confirmed by visual astronomy.

After a few weeks the merged star then passed behind the glare of our sun leaving it effectively hidden from astronomers until it remerged from that glare 100 days after the merger event. It was at that point that the University of Warwick research team were able to use the Hubble Space Telescope to see the star was still generating a powerful beam of light in a direction that, while off centre to the Earth, was starting to spread out in our direction.

Their research has just been published in a paper entitled: “The optical afterglow of the short gamma-ray burst associated with GW170817” in Nature Astronomy’s website at 4pm UK time on Monday 02 July 2018.

The lead author of the paper, Dr. Joe Lyman from the University of Warwick’s Department of Physics, said:

“Early on, we saw visible light powered by radioactive decay of heavy elements, over a hundred days later and this has gone, but now we see a jet of material, ejected at an angle to us, but at almost of the speed of light. This is quite different than some people have suggested, that the material wouldn’t come out in a jet, but in all directions.”

Professor Andrew Levan from the University of Warwick’s Department of Physics, another of the papers leading authors added:

“If we’d looked straight down this beam we’d have seen a really powerful burst of gamma-ray. This means that it is quite likely that every neutron star that mergers actually creates a gamma-ray burst, but we only see a small fraction of them because the jet doesn’t line up all that often. Gravitational waves are a whole new way to find this kind of event, and they might be more common than we think.”

These observations confirm the prediction made by the second author of the paper, Dr. Gavin Lamb from the University of Leicester’s Department of Physics and Astronomy, said that these types of events will reveal the structure of these jets of material travelling close to the speed of light:

“The behaviour of the light from these jets, how it brightens and fades, can be used to determine the velocity of the material throughout the jet. As the afterglow brightens we are seeing deeper into the jet structure and probing the fastest components. This will help us understand how these jets of material, travelling close to the speed of light, are formed and how they are accelerated to these phenomenal velocities.”

Best Evidence Of Rare Black Hole Captured

Scientists have been able to prove the existence of small black holes and those that are super-massive but the existence of an elusive type of black hole, known as intermediate-mass black holes (IMBHs) is hotly debated. New research coming out of the Space Science Center at the University of New Hampshire shows the strongest evidence to date that this middle-of-the-road black hole exists, by serendipitously capturing one in action devouring an encountering star.

“We feel very lucky to have spotted this object with a significant amount of high quality data, which helps pinpoint the mass of the black hole and understand the nature of this spectacular event,” says Dacheng Lin, a research assistant professor at UNH’s Space Science Center and the study’s lead author. “Earlier research, including our own work, saw similar events, but they were either caught too late or were too far away.”

In their study, published in Nature Astronomy, researchers used satellite imaging to detect for the first time this significant telltale sign of activity. They found an enormous multiwavelength radiation flare from the outskirts of a distant galaxy. The brightness of the flare decayed over time exactly as expected by a star disrupting, or being devoured, by the black hole. In this case, the star was disrupted in October 2003 and the radiation it created decayed over the next decade. The distribution of emitted photons over the energy depends on the size of the black hole. This data provides one of the very few robust ways to weight, or determine the size of, the black hole.

Researchers used data from a trio of orbiting X-ray telescopes, NASA’s Chandra X-ray Observatory and Swift Satellite as well as ESA’s XMM-Newton, to find the multiwavelength radiation flares that helped identify the otherwise uncommon IMBHs. The characteristic of a long flare offers evidence of a star being torn apart and is known as a tidal disruption event (TDE). Tidal forces, due to the intense gravity from the black hole, can destroy an object — such as a star — that wanders too close. During a TDE, some of the stellar debris is flung outward at high speeds, while the rest falls toward the black hole. As it travels inward, and is ingested by the black hole, the material heats up to millions of degrees and generates a distinct X-ray flare. According to the researchers, these types of flares, can easily reach the maximum luminosity and are one of the most effective way to detect IMBHs.

“From the theory of galaxy formation, we expect a lot of wandering intermediate-mass black holes in star clusters,” said Lin. “But there are very, very few that we know of, because they are normally unbelievably quiet and very hard to detect and energy bursts from encountering stars being shredded happen so rarely.”

Because of the very low occurrence rate of such star-triggered outbursts for an IMBH, the scientists believe that their discovery implies that there could be many IMBHs lurking in a dormant state in galaxy peripheries across the local universe.

Astronomers See Distant Eruption As Black Hole Destroys Star

For the first time, astronomers have directly imaged the formation and expansion of a fast-moving jet of material ejected when the powerful gravity of a supermassive black hole ripped apart a star that wandered too close to the cosmic monster.

The scientists tracked the event with radio and infrared telescopes, including the National Science Foundation’s Very Long Baseline Array (VLBA), in a pair of colliding galaxies called Arp 299, nearly 150 million light-years from Earth. At the core of one of the galaxies, a black hole 20 million times more massive than the Sun shredded a star more than twice the Sun’s mass, setting off a chain of events that revealed important details of the violent encounter.

Only a small number of such stellar deaths, called tidal disruption events, or TDEs, have been detected, although scientists have hypothesized that they may be a more common occurrence. Theorists suggested that material pulled from the doomed star forms a rotating disk around the black hole, emitting intense X-rays and visible light, and also launches jets of material outward from the poles of the disk at nearly the speed of light.

“Never before have we been able to directly observe the formation and evolution of a jet from one of these events,” said Miguel Perez-Torres, of the Astrophysical Institute of Andalusia in Granada, Spain.

The first indication came on January 30, 2005, when astronomers using the William Herschel Telescope in the Canary Islands discovered a bright burst of infrared emission coming from the nucleus of one of the colliding galaxies in Arp 299. On July 17, 2005, the VLBA revealed a new, distinct source of radio emission from the same location.

“As time passed, the new object stayed bright at infrared and radio wavelengths, but not in visible light and X-rays,” said Seppo Mattila, of the University of Turku in Finland. “The most likely explanation is that thick interstellar gas and dust near the galaxy’s center absorbed the X-rays and visible light, then re-radiated it as infrared,” he added. The researchers used the Nordic Optical Telescope on the Canary Islands and NASA’s Spitzer space telescope to follow the object’s infrared emission.

Continued observations with the VLBA, the European VLBI Network (EVN), and other radio telescopes, carried out over nearly a decade, showed the source of radio emission expanding in one direction, just as expected for a jet. The measured expansion indicated that the material in the jet moved at an average of one-fourth the speed of light. Fortunately, the radio waves are not absorbed in the core of the galaxy, but find their way through it to reach the Earth.

These observations used multiple radio-telescope antennas, separated by thousands of miles, to gain the resolving power, or ability to see fine detail, required to detect the expansion of an object so distant. The patient, years-long data collection rewarded the scientists with the evidence of a jet.

Most galaxies have supermassive black holes, containing millions to billions of times the mass of the Sun, at their cores. In a black hole, the mass is so concentrated that its gravitational pull is so strong that not even light can escape. When those supermassive black holes are actively drawing in material from their surroundings, that material forms a rotating disk around the black hole, and superfast jets of particles are launched outward. This is the phenomenon seen in radio galaxies and quasars.

“Much of the time, however, supermassive black holes are not actively devouring anything, so they are in a quiet state,” Perez-Torres explained. “Tidal disruption events can provide us with a unique opportunity to advance our understanding of the formation and evolution of jets in the vicinities of these powerful objects,” he added.

“Because of the dust that absorbed any visible light, this particular tidal disruption event may be just the tip of the iceberg of what until now has been a hidden population,” Mattila said. “By looking for these events with infrared and radio telescopes, we may be able to discover many more, and learn from them,” he said.

Such events may have been more common in the distant Universe, so studying them may help scientists understand the environment in which galaxies developed billions of years ago.

The discovery, the scientists said, came as a surprise. The initial infrared burst was discovered as part of a project that sought to detect supernova explosions in such colliding pairs of galaxies. Arp 299 has seen numerous stellar explosions, and has been dubbed a “supernova factory.” This new object originally was considered to be a supernova explosion. Only in 2011, six years after discovery, the radio-emitting portion began to show an elongation. Subsequent monitoring showed the expansion growing, confirming that what the scientists are seeing is a jet, not a supernova.

Mattila and Perez-Torres led a team of 36 scientists from 26 institutions around the world in the observations of Arp 299. They published their findings in the 14 June online issue of the journal Science.

The Long Baseline Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Astronomers See Distant Eruption as Black Hole Destroys Star

For the first time, astronomers have directly imaged the formation and expansion of a fast-moving jet of material ejected when the powerful gravity of a supermassive black hole ripped apart a star that wandered too close to the cosmic monster.

The scientists tracked the event with radio and infrared telescopes, including the National Science Foundation’s Very Long Baseline Array (VLBA), in a pair of colliding galaxies called Arp 299, nearly 150 million light-years from Earth. At the core of one of the galaxies, a black hole 20 million times more massive than the Sun shredded a star more than twice the Sun’s mass, setting off a chain of events that revealed important details of the violent encounter.

Only a small number of such stellar deaths, called tidal disruption events, or TDEs, have been detected, although scientists have hypothesized that they may be a more common occurrence. Theorists suggested that material pulled from the doomed star forms a rotating disk around the black hole, emitting intense X-rays and visible light, and also launches jets of material outward from the poles of the disk at nearly the speed of light.

“Never before have we been able to directly observe the formation and evolution of a jet from one of these events,” said Miguel Perez-Torres, of the Astrophysical Institute of Andalusia in Granada, Spain.

The first indication came on January 30, 2005, when astronomers using the William Herschel Telescope in the Canary Islands discovered a bright burst of infrared emission coming from the nucleus of one of the colliding galaxies in Arp 299. On July 17, 2005, the VLBA revealed a new, distinct source of radio emission from the same location.

“As time passed, the new object stayed bright at infrared and radio wavelengths, but not in visible light and X-rays,” said Seppo Mattila, of the University of Turku in Finland. “The most likely explanation is that thick interstellar gas and dust near the galaxy’s center absorbed the X-rays and visible light, then re-radiated it as infrared,” he added. The researchers used the Nordic Optical Telescope on the Canary Islands and NASA’s Spitzer space telescope to follow the object’s infrared emission.

Continued observations with the VLBA, the European VLBI Network (EVN), and other radio telescopes, carried out over nearly a decade, showed the source of radio emission expanding in one direction, just as expected for a jet. The measured expansion indicated that the material in the jet moved at an average of one-fourth the speed of light. Fortunately, the radio waves are not absorbed in the core of the galaxy, but find their way through it to reach the Earth.

These observations used multiple radio-telescope antennas, separated by thousands of miles, to gain the resolving power, or ability to see fine detail, required to detect the expansion of an object so distant. The patient, years-long data collection rewarded the scientists with the evidence of a jet.

Most galaxies have supermassive black holes, containing millions to billions of times the mass of the Sun, at their cores. In a black hole, the mass is so concentrated that its gravitational pull is so strong that not even light can escape. When those supermassive black holes are actively drawing in material from their surroundings, that material forms a rotating disk around the black hole, and superfast jets of particles are launched outward. This is the phenomenon seen in radio galaxies and quasars.

Such events may have been more common in the distant Universe, so studying them may help scientists understand the environment in which galaxies developed billions of years ago.

Mattila and Perez-Torres led a team of 36 scientists from 26 institutions around the world in the observations of Arp 299. They published their findings in the 14 June online issue of the journal Science. Data from the NSF’s Very Large Array (VLA) and Green Bank Telescope (GBT) were used for some of this work.

1 Million Habitable Planets Could (Theoretically) Orbit a Black Hole

A black hole could have 1 million planets orbiting near it that are potentially capable of supporting life as we know it, an astrophysicist suggests.

Since there is life virtually everywhere liquid water exists on Earth, astronomers often judge a world as potentially habitable if it orbits within a zone where liquid water could survive on its surface. Our sun’s “habitable zone” hosts just one planet (Earth), but the story could be different for other stars. For example, the TRAPPIST-1 system has three Earth-size planets within its habitable zone.

Sean Raymond, an astrophysicist at the Observatory of Bordeaux in France, researches how planetary systems form and evolve. As part of a column Raymond writes called “Building the Ultimate Solar System,” he set out to see how many planets could orbit a black hole.

“I think we can learn from the extremes … they are basically the boundaries of the box in which we are searching,” Raymond told Space.com. “This system is one extreme — the most packed imaginable. It’s a fun blend of imagination and science.”

There are currently two kinds of black holes that scientists know best, Raymond said. Stellar-mass black holes are equal in mass to a few suns, and form when giant stars die and collapse in on themselves. Supermassive black holes are millions to billions of times the mass of the sun, and are thought to exist in the hearts of most, if not all, large galaxies. (A third class, intermediate-mass black holes, is poorly understood.)

Black holes are extremely compact. A black hole with the mass of the sun would be about only 3.7 miles (6 kilometers) wide. In comparison, Sagittarius A*, the supermassive black hole thought to lurk at the heart of the Milky Way, has a mass of about 4 million suns and a diameter of about 14.7 million miles (23.6 million km), or a little more than 40 percent the size of Mercury’s orbit around the sun.

What if the sun had a black hole companion?
A common question in physics classes is to imagine what would change if the sun were replaced with a black hole of the same mass, Raymond said. The answer is that nothing would change regarding the planets’ orbits — if the black hole had the same mass as the sun, the orbits would remain the same. (Life on Earth would obviously suffer from the lack of light and heat in such a scenario, Raymond added.)

If the sun had an equal-mass black hole companion orbiting near it — at, say, one-tenth of an astronomical unit (AU) — the orbits of the solar system’s planets would not change much, Raymond noted. (One AU is the Earth-sun distance — about 93 million miles, or 150 million km.)

Still, assuming these planets kept the same distance from the sun as they do now, the gravitational pull of the sun and its black hole partner would lead these worlds to complete their orbits a bit more quickly, with Earth’s year decreasing from 365 days to 258 days, he said.

In the above scenario, the sun and the black hole would complete an orbit with one another every 2.9 days. This means the amount of energy that Earth would receive from the sun would fluctuate between 90 percent and 110 percent of its average as the sun moved farther from or closer to Earth.

What if a supermassive black hole had a ring of planets?
In addition to imagining life around a stellar-mass black hole, Raymond also calculated how many potentially habitable planets might fit around a supermassive black hole 1 million times the mass of the sun. “That’s almost as massive as the one in the center of the Milky Way,” he said. It would only be about the diameter of the sun, he added.

Around the sun, the orbits that planets travel can come only so close together before the effects of their gravitational pulls overwhelm those of the sun, leading to unstable orbits. Raymond noted that about six Earth-mass planets can fit in stable concentric orbits within the sun’s habitable zone.

In contrast, a supermassive black hole’s gravitational pull is extraordinarily strong, enough to easily overwhelm those of planets. If the sun were replaced with a million-solar-mass black hole, 550 Earth-mass planets could fit in stable concentric orbits in the habitable zone, Raymond calculated.

The supermassive black hole’s gravity would pull more strongly on the side of each planet closer to the black hole. This would stretch the habitable-zone planets out, although they would not be close enough to get ripped apart, Raymond said.

One way to create a habitable zone around this supermassive black hole is to place stars between it and the planets. A ring of nine sun-like stars 0.5 AU from a million-sun black hole would make each of the 550 Earth-mass planets in the above scenario potentially habitable, Raymond said.

“It would be pretty interesting to live on a planet in this system,” Raymond noted. “It would take just a few days to complete an orbit around the black hole — about 1.6 days at the inner edge of the habitable zone and 4.6 days at the outer edge.”

At the closest approach, or conjunction, between two such planets, the distance between these worlds would be “about twice the Earth-moon distance,” Raymond noted. “At conjunction, each planet’s closest neighbor appears about twice the size of the full moon in the sky.”

In addition, the next-nearest neighbors would be only twice as far away, and so would appear as big as the full moon during conjunction, Raymond said. Four more planets would be at least half the size of the full moon during conjunction, he added. “Conjunctions happen a little less than once per orbit, so every few days there is a gaggle of giant objects passing across the sky,” he said.

The nine suns “would also be a sight to behold,” Raymond said. Each would complete its orbit around the black hole every 3 hours.

“That means that every 20 minutes, one of the suns would pass behind the black hole,” Raymond said. “When a sun passes behind the black hole, the black hole’s gravity bends its light and can act like a lens. It focuses the sun’s light toward the planet. This distorts the shape of the sun into a ring … a pretty sweet light show.”

Furthermore, starlight would be stretched by the black hole’s gravity. “Stars closer to the black hole would appear redder, and those farther from the black hole would appear bluer,” Raymond said.

A million planets around a black hole
In the prior scenario, each planet was alone in its orbit around the supermassive black hole. Raymond also modeled what would happen if multiple planets shared an orbit around a million-sun black hole. Previously, Raymond calculated that 42 Earth-mass planets could orbit in a ring 1 AU from the sun.

To have a stable ring of planets, Raymond noted that planets in that ring must all have roughly the same mass. There must also be at least seven planets in such a ring, and they must be evenly spaced along a circular orbit.

Given a million-sun black hole with an orbiting ring of nine sun-like stars, Raymond calculated that a million Earth-mass planets could orbit within the habitable zone in 400 rings, each holding 2,500 planets spaced apart by about the same distance as that between Earth and the moon. In this scenario, planets would again take anywhere from 1.6 to 4.6 days to complete an orbit.

Instead of placing nine sun-like stars between the black hole and the planets, Raymond also suggested one could place 36 sun-like stars in a ring 6 AU wide. In this scenario, “each planet is bathed in sunlight from all sides — the planets have no night side,” Raymond said. “It’s like Asimov’s permanent-daytime planet Kalgash.”

“You would never feel alone in these systems — the other planets would loom huge in the sky,” Raymond added. Neighboring planets would be about 10 times closer than the moon is to Earth, meaning they would appear “about 40 times larger in the sky than the full moon,” Raymond said. “That’s about the size of a laptop computer held at arm’s reach, only up in the sky.”

In this latter scenario, the planets would be much closer to the black hole, each completing an orbit in just about 9 hours. This means they would orbit at extraordinary speeds — about 10 percent of the speed of light. According to Einstein’s theory of special relativity, time would appear to move noticeably more slowly the closer one gets to the speed of light, so “two babies born at the same instant on different rings would age at slightly different rates,” Raymond said. “The baby on the inner ring would age slightly more slowly.”

The differences in speed between the rings would be great enough to likely make it impossible for a spaceship to travel from one ring to another with any current technology, Raymond said. However, each world would share its ring with thousands of others, and the relative speed between neighboring planets would be almost zero. “A space elevator could connect planets,” Raymond said.

If each pair of neighboring planets along a given ring were connected, it would resemble a “Ringworld,” a gigantic alien megastructure in Larry Niven’s science-fiction epic of the same name. “The difference between this setup and the ‘Ringworld’ from Larry Niven’s book is that, in this case, there is no livable surface area in between the planets,” Raymond said.

Where might such million-planet systems come from? “I can imagine super-advanced aliens creating a system like the million-Earth solar system as a cosmic work of art, kind of like the art of skyscrapers or painted icebergs,” Raymond said. “A way to say, ‘Look how fancy we are,’ on the grandest scale.”

“Or maybe aliens would create this kind of system as a zoo,” Raymond said. “They could have a gradient in climates from the hottest to coldest, and stock the planets with all sorts of creatures they collect across the universe. Of course, they’d have to be careful not to put the wrong combinations of space creatures on the same ring of planets, because that wouldn’t end well.”

All in all, “it’s helpful to try to come up with all the possible planetary systems that might be out there,” Raymond said. “Some discoveries could have been anticipated by ‘going there’ and imagining possibilities that are far outside the norm. These systems are a combination of science fiction and ‘going there’ in that sense.”

“The main thing I go for is simply to try to push the limits of what we think is possible,” Raymond concluded.