- Tiny Fragments of Interstellar Meteor May Have Been Found in Pacific Ocean Sci.News
- Harvard professor believes he may have found alien technology CBS News
- Harvard scientist claims ‘anomalous’ metal spheres pulled from the ocean could be alien technology. Others are not convinced. Livescience.com
- Physicist who found spherical meteor fragments claims they may come from an alien spaceship: Here’s what to make of it Phys.org
- Harvard professor Avi Loeb believes he may have found fragments of alien technology #shorts CBS News
- View Full Coverage on Google News
Tag Archives: interstellar
Tiny interstellar probes could carry engineered microbes to other stars
Microbes carried by laser-propelled sails could serve as interstellar probes that can build communications stations to phone home from Alpha Centauri, suggests a scientist known for wanting to resurrect extinct woolly mammoths and use DNA to detect dark matter.
This concept from George Church, a geneticist at Harvard University, builds upon efforts to greatly speed up spaceflight. Current spacecraft usually take years to make trips within the solar system; for example, NASA’s New Horizons probe took nearly 10 years to reach Pluto.
In theory, spacecraft using conventional rockets would require thousands of years to complete an interstellar voyage. For instance, Alpha Centauri, the nearest star system to Earth, is located about 4.37 light-years away — more than 25.6 trillion miles (41.2 trillion kilometers), or more than 276,000 times the distance from Earth to the sun. NASA’s Voyager 1 spacecraft, which launched in 1977 and reached interstellar space in 2012, would take about 75,000 years to reach Alpha Centauri even if the probe were headed in the right direction, which it’s not.
The interstellar challenge
The problem that all rocket thrusters face is that the propellant they carry with them has mass. Long trips need a lot of propellant, which makes spacecraft heavy. This, in turn, requires more propellant, making them heavier, and so on.
Previous research has suggested that “light sailing” might be one of the only feasible ways to get a spacecraft to another star within a human lifetime. Although light does not exert much pressure, scientists have long suggested that what little pressure it does apply could have a major effect. Indeed, many experiments have shown that “solar sails” can rely on sunlight for propulsion if the spacecraft is light enough and has a big enough sail.
Indeed, the $100 million Breakthrough Starshot initiative, announced in 2016, plans to launch swarms of microchip-size spacecraft to Alpha Centauri, each of them equipped with extraordinarily thin, incredibly reflective sails propelled by the most powerful lasers ever built. The plan has them flying at up to 20% the speed of light, reaching Alpha Centauri in about 20 years.
However, Starshot faces many technical challenges. These include building lasers powerful enough for propulsion and creating sails that can withstand extraordinary forces and stay on track to their targets.
George Church, Ph.D., is a genetics professor at Harvard Medical School and the Founding Core Faculty and Lead for Synthetic Biology at the Wyss Institute of Harvard University. He is also a Professor of Health Sciences and Technology at Harvard and the Massachusetts Insitute of Technology and serves as Director for both the U.S. Department of Energy Technology Center and National Institutes of Health Center of Excellence in Genomic Science.
In addition, even if Starshot successfully launches “space-chips” at Alpha Centauri, without another laser at that destination, there is no way for them to slow down. This likely limits Starshot missions to flybys instead of landings.
Any Starshot probe attempt to land would likely prove catastrophic. Although the spacecraft are designed to be extraordinarily lightweight — each just 0.035 ounces (1 gram) or so — when traveling at 20% the speed of light, they would each pack as much energy as one-eight the atom bomb dropped on Hiroshima in World War II, Church noted.
Instead, Church suggested using probes a billion times lighter. If they did make impact, it would only pack as much energy as half a food calorie, he noted.
“A probe that lands is tremendously more valuable than one that flies by at great distance and for a very brief time,” Church told Space.com.
Picogram interstellar probes
How might such an incredibly light probe prove useful? If they carried genetically modified microbes, they could build themselves equipment upon landing, Church suggested.
Previously, Church has made a number of radical proposals that sound like science fiction. For example, he suggested DNA could help detect dark matter, the invisible and largely intangible substance that researchers suggest makes up about five-sixths of all matter in the universe. He also wants to resurrect extinct beasts such as the woolly mammoth.
However, Church is also a pioneering biologist. In 1984, he developed the first direct genomic sequencing method, which resulted in the first genome sequence, that of Helicobacter pylori, a bacterium normally found in the human stomach. He also helped initiate the Human Genome Project in 1984 to completely map the roughly 3 billion letters contained in human DNA.
Church noted that he became interested in this new idea because of how he grew up in Florida in the shadow of Cape Canaveral rocket launches, and because he teaches a course at MIT called “How To Grow Almost Anything.” As such, he was “looking for projects that push that envelope,” he said.
Previously, scientists have suggested creating interstellar “von Neumann” probes that can replicate themselves and equipment. The concept is named after mathematician John von Neumann, who proposed the idea of self-replicating machines in 1948, Church noted.
Church based his new proposal both on his experience in biology and the pioneering research conducted for Starshot. Since his probes are only about one-billionth the mass of Starshot craft, he suggested that a billion of his probes could be launched for a similar cost to a single Starshot mission.
Starshot also calls for a 100-gigawatt laser array, which would be by far be the most powerful laser humanity has ever constructed. Since Church suggested extraordinarily tiny probes, a relatively modest laser might suffice, he said. For example, a mothership about 0.0014 ounces (40 mg) in mass with a 1.3-foot-diameter (0.4 meter) sail that carries many tiny probes might only require a 2-gigawatt laser array.
Starshot’s probes often call for a sail about 108 square feet (10 square meters) in size with a mass of less than 0.035 ounces (1 gram). In comparison, given how a typical bacterium has a mass of about 1 picogram, or one-trillionth of a gram, it would only require a sail about 15 millionths of a square inch (0.0001 square centimeters) in size with a mass of about 7.6 picograms, Church said. He added that light sails about 8.8 millionths of an ounce (0.25 milligrams) in mass have already been tested in vacuum and in microgravity.
“Deceleration is hard even for picogram scale, but not even under consideration for gram scale,” Church said.
Interstellar probes would likely experience impacts that could cripple or destroy them — from dust grains, or even hydrogen atoms. However, the fact that one could launch a billion or so microbial probes for the cost of one Starshot craft means that losing probes might not prove a major setback.
A living probe with ‘biolaser’
A probe that lands is tremendously more valuable than one that flies by at great distance and for a very brief time.
George Church, Ph.D.
After the probes reached their destination, Church suggested that genetically modified microbes could build themselves communications modules. One strategy to communicate might be bioluminescence, with which microbes could emit light using the kinds of molecules found in fireflies or other naturally bioluminescent organisms. Although this light might be relatively dim, Church noted that given no predators and ideal growing conditions, microbes could cover an entirely planetary surface in just 124 hours.
For a more compact approach, Church suggested a living probe might create a “biolaser” capable of converting starlight into a communication beam. He noted that the gold beetle (Aspidimorpha tecta) can build reflective surfaces potentially useful for creating such an organic device, although Church conceded that building it “would be an interesting laboratory challenge.”
Church suggested the communications array these probes build could transmit flashes back at Earth. These beams could encode data about the destination site such as temperatures, pressure and pH.
Related: A Wild ‘Interstellar Probe’ Mission Idea Is Gaining Momentum
It might prove difficult to find places for these interstellar seeds to grow. “This is why we want millions of shots on millions of target sites,” Church said. Scientists could also rely on so-called “extremophile” microbes known to survive extremes of temperature, pH, pressure and other conditions on Earth, Church said.
Church noted that one potential target might be the closest known exoplanet—Proxima Centauri b, a rocky world in the Alpha Centauri system. However, it receives only 3% of the kind of light useful for photosynthesis, which could make it difficult for any microbial probes to thrive there. It could also potentially experience 10,000 more flares from its star capable of stripping off any atmosphere, making it a hostile place to try and live.
Other potential targets include worlds that may exist around the sun-like stars Alpha Centauri A and B in the Alpha Centauri system. These may not be rocky planets—instead, they may be more similar to Uranus and Neptune, and covered in water and ammonia. However, there are microbes on Earth that could survive in such locales, such as bacteria found in deep-ocean hydrothermal vents.
One major concern would be planetary protection issues — in this case, making sure that Earth microbes do not inflict damage on any alien life that might exist at destinations. Probes can be designed to “aim for strictly limited amount of growth,” Church suggested. An “absolutely high priority” would be testing any potential interstellar probes at targets within the solar system first to see how well they perform, he added.
Church detailed his idea (opens in new tab) Dec. 6 in the journal Astrobiology.
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James Webb Space Telescope sees ‘ghostly’ interstellar light
The first deep field image of the cosmos taken by the James Webb Space Telescope (JWST) has allowed scientists to study the faint almost ghostly light from orphan stars that exist between galaxies in galactic clusters.
Not gravitationally bound to galaxies, these stars are pulled free of their homes and drift into intergalactic space by the massive tidal forces generated between galaxies in clusters. The light emitted by these stellar orphans is called intracluster light and it is so dim that it possesses just one percent of the brightness of the darkest sky it is possible to see over Earth.
Not only could the study of this ghostly light from orphan stars reveal how galactic clusters form, but it could give scientists hints at the properties of dark matter, the mysterious substance that accounts for around 85% of the universe’s mass.
Related: The James Webb Space Telescope is revealing the earliest galaxies of the universe like never before, scientists say
Dark matter doesn’t interact with light meaning scientists know it isn’t the same as everyday matter made up of protons and neutrons. Its presence can currently only be inferred by its gravitational interactions which literally prevent the stars and planets of galaxies from flying apart.
The JWST sees the universe in infrared light, frequencies of electromagnetic radiation that let astronomers see galactic clusters differently from the picture painted in visible light.
The sharpness of the JWST infrared images allowed Instituto de Astrofísica de Canarias (IAC) researchers Mireia Montes and Ignacio Trujillo to study the intracluster light from the galactic cluster SMACS-J0723.3–7327 in an unprecedented level of detail.
This sharpness arises from the fact that JWST images of SMACS-J0723.3–7327, which is located around 4 billion light-years from Earth in the constellation of Volans, are twice as deep as observations of the same cluster taken previously by the Hubble Space Telescope.
“In this study, we show the great potential of JWST for observing an object which is so faint,” research first author Montes, said in a statement (opens in new tab). “This will let us study galaxy clusters which are much further away, and in much greater detail.”
Studying this faint intracluster light required more than the sheer observing power of the JWST, however, meaning the team also needed to develop new image analysis techniques. “In this work, we needed to do some extra processing to the JWST images to be able to study the intracluster light, as it is a faint and extended structure,” Montes explained in the statement. “That was key to avoid biases in our measurements.”
The data obtained by the scientists is a striking demonstration of the potential of intracluster light to reveal the processes behind the formation of structure in galactic clusters.
“Analyzing this diffuse light, we find that the inner parts of the cluster are being formed by a merger of massive galaxies, while the outer parts are due to the accretion of galaxies similar to our Milky Way,” Montes said.
In addition to this, because the intracluster stars follow the gravitational influence of the cluster as a whole rather than that of individual galaxies, the light from these stellar orphans presents an excellent way of studying the distribution of dark matter in these clusters.
“The JWST will let us characterize the distribution of the dark matter in these enormous structures with unprecedented precision, and throw light on its basic nature,” study second-author Trujillo added.
The duo’s research was published on Dec. 1 in the Astrophysical Journal Letters (opens in new tab).
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‘Dynamic Soaring’ Trick Could Speed Spacecraft Across Interstellar Space : ScienceAlert
Sailing to the stars on the scale of human lifetimes could be a matter of choosing the right kind of wind.
Researchers from McGill University in Canada and the Tau Zero Foundation in the US have proposed a new way to cross the extraordinary distances of interstellar space, using a whole lot of nothing and a touch of inspiration from seabirds.
Until now, one of the most promising solutions to space travel makes use of the spectrum of starlight streaming from the Sun. Though small in impact, sheer numbers and high speeds make photons an intriguing source of power for building up the high velocity needed to cross light-years of emptiness in a short time.
Innovations in solar sail technology have progressed considerably over the years, with models going as far as being tested in the hostile environments of our inner Solar System.
Though functional, solar sails all have one downside in common: the sail itself. Solar sails must stretch meters across to catch the photons needed to propel a craft.
They also need the right shape and material to turn every photon’s tiny bit of momentum into movement. And they need to shed heat well enough not to distort and break.
This isn’t just a headache in materials science; all of these requirements add mass. Even using the lightest materials known, the fastest speeds we might achieve using our Sun’s radiation would be just over 2 percent the speed of light, meaning a trip to the nearest star would still take a few centuries.
Needless to say, sailing to the stars would be a lot easier if we could ditch the sails part.
Fortunately, another kind of gale blows from the solar surface, one made not of photons but a plasma of ions whipped into a frenzy by the snap and crackle of the Sun’s magnetic fields.
Though there are far fewer high-speed electrons and protons blasting from the Sun than photons, their charged masses pack a greater punch.
Such particles would usually be a problem for typical sails, imparting their charges on the material’s surface like static on a woolen jumper in winter, creating drag and changing the sail’s shape.
Yet as anybody who has ever tried pushing the poles of magnets together knows all too well, an electromagnetic field can provide resistance without requiring a large, solid surface.
And so it’s goodbye shiny material, and hello superconductor. A cable just a few meters long could, in theory, produce a field wide enough to deflect the Sun’s charged wind on the scale of tens to hundreds of kilometers.
The system would act more like a magnetic parachute, one that is being dragged by a flow of particles moving at speeds of close to 700 kilometers (about 430 miles) a second, or just under a quarter of a percent of the speed of light.
This isn’t bad, but as birds like the albatross know, the winds don’t set the speed limits when it comes to flying high.
By looping in and out of air masses moving at different velocities, seabirds can pick up the energy of a headwind, using what’s known as dynamic soaring to gain speed before returning to their original trajectory.
Using a similar trick in the ‘headwind’ of the termination shock – a turbulent zone of contrasting stellar winds used by astronomers to define the edge of our Solar System – a magnetic sail could exceed the solar wind’s speeds, potentially bringing it within reach of solar sails based on radiation alone.
Though the technology might not initially seem much faster than the ‘traditional’ solar sails method, other forms of turbulence at the fringes of interstellar space might provide a bigger boost.
Even without a gentle nudge from dynamic soaring, feasible plasma-based technology could put cube-sat satellites around Jupiter within months rather than years.
Like the age of sail of yore, there are plenty of ways we might be able to take advantage of the currents that wash through the vastness of space.
And still, the seabirds show us the way.
This research was published in Frontiers in Space Technologies.
Scientists want to build an ‘interstellar interceptor’ to play hide-and-seek with the next ’Oumuamua
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A team of scientists has proposed building an “interstellar interceptor,” a spacecraft capable of getting up-close and personal with the next asteroid or comet to enter the solar system.
So far, astronomers have spotted two such objects whizzing through our star system: The cigar-shaped interstellar visitor ‘Oumuamua, which was first spotted in October 2017 and made headlines as a suspected alien probe, and the comet 2I/Borisov, which astronomers first spotted in August 2019.
Sending a probe to investigate interstellar objects would allow astronomers to photograph the space rocks’ surfaces more accurately and potentially even take samples of gases that seep out from comet interlopers like 2I/Borisov. However, by the time telescopes detect such interstellar objects, it is too late to design, build and launch a spacecraft to chase after them, so these travellers end up sailing through our star system and taking most of their secrets with them when they leave.
To get around this problem, researchers drafted and submitted a proposal to the arXiv preprint database (opens in new tab) on Nov. 3. Their study, which has not yet been peer-reviewed, suggests that a space agency, such as NASA, should build and launch an interstellar interceptor that can wait patiently in far-Earth orbit. Then, once astronomers detect an incoming interstellar object,the probe can rapidly fly off to intercept the invader on its path through the solar system.
Related: Could there be a link between interstellar visitor ‘Oumuamua and unidentified aerial phenomena?
The best place to store an interstellar interceptor in space will be one of Earth’s Lagrange points, the researchers proposed. At these points in space, the gravitational pull of two large masses, in this case the Earth and sun, roughly cancel each other out, allowing small objects like satellites or asteroids to stay relatively fixed in one position, according to NASA (opens in new tab).
The team have identified the L2 Lagrange point, which is also home to NASA’s James Webb Space Telescope, as the best place to park the spacecraft because it will allow the probe to intercept a wide range of potential trajectories that alien space rocks may take through our cosmic neighborhood.
The proposed interstellar interceptor would wait in low-power mode — possibly for decades — until a suitable candidate is detected, at which point scientists could send the probe to the best possible location to cut off the interloper.
But we may not need to wait that long for the next visitor to come calling.
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Astronomers already suspect that multiple interstellar objects pass through the solar system unnoticed every year. The construction of new state of the art telescopes, such as the Vera C. Rubin Observatory (opens in new tab) in Chile, which is expected to be fully operational in early 2024, will allow scientists to spot more of these objects than ever before.
The authors of the new study predicted that when Chile’s new observatory is fully operational, it will detect between one and 10 interstellar objects every year. The researchers therefore concluded there is a 95% chance that an ‘Oumuamua-like interloper can be detected and surveyed by a potential interstellar interceptor within the next decade.
Related: Interstellar interloper 2I/Borisov may be the most pristine comet ever observed
Now is the perfect time to build an interstellar interceptor, the researchers argued, because it could be launched and installed in orbit by the time we have the capacity to spot more interstellar objects.
This is not the first time that researchers have drawn up plans to track down such solar system visitors.
In February, a separate group of researchers proposed that by slingshotting a spacecraft around, Earth, Venus and then Jupiter, scientists could launch a probe to catch up to and intercept ‘Oumuamua in the outer reaches of the solar system, known as the Oort cloud, which extends up to 100,000 times farther out from the sun than Earth, according to NASA (opens in new tab). However, in order for this to work, the proposed mission would have to be launched by 2028, or else the mysterious object will be out of our reach forever.
Scientists Are Drawing Up Plans to Intercept an Interstellar Object : ScienceAlert
We finally have the technological means to detect interstellar objects. We’ve detected two in the last few years, ‘Oumuamua and 2I/Borisov, and there are undoubtedly more out there.
As such, there’s been a lot of interest in developing a mission that could visit one once we detect it. But what would such a mission look like?
Now, a draft paper from a team of primarily American scientists has taken a stab at answering that question and moved us one step closer to launching such a mission.
Part of what makes an interstellar visitor mission interesting is that interstellar visitors are so weird. Borisov acted like a typical comet once it entered the Solar System, but ‘Oumuamua was a different beast entirely.
It never developed a cometary tail, as many scientists expected it to. It also exhibited acceleration that didn’t seem to be accounted for by radiative or other means, leading some prominent scientists to claim it might have even been an alien probe.
The best way to combat such fanciful claims is to closely examine them. And to do that, we have to have a mission that can catch it. But first, we would have to see it, and astronomers are already working on that.
The Vera C Rubin Observatory Legacy Survey of Space and Time (LSST) will be able to detect somewhere between 1-10 interstellar objects about the same size as ‘Oumuamua every year, according to the authors’ calculations.
That’s plenty of opportunity to find the right candidate. But what criteria should that candidate meet?
Most importantly would be, “Where is it coming from?” While there isn’t a “best” angle for an interstellar object (ISO) to approach from, it does make a difference based on where we store the “interstellar interceptor” (ISI).
According to the paper, the best place for that is most likely the Earth-Sun L2 Lagrange point. It has more than one advantage – first, there’s very little fuel needed to stay on station, and any ISI might need to stay waiting in storage mode for years.
Once it is called into action, it has to react quickly, and another resident of L2 could help it do so.
NASA’s Time-domain Spectroscopic Observatory (TSO) is a 1.5-m telescope planned to locate at the L2 Lagrange point, along with more famous telescopes like the JWST.
For all its amazing ability to capture spectacular images, JWST has a significant weakness – it is slow. It can take 2-5 days to focus on a specific object, making it useless when tracking ISOs. TSO, on the other hand, only takes a few minutes.
It could be supplemented by another telescope, the planned Near Earth Object Surveyor, which is intended to reside at the L1 Lagrange point of the Earth-Moon system.
When combined with the TSO, these two quick-reacting telescopes should be able to capture images of any ISO that enters the inner Solar System that isn’t directly on a trajectory along the L1-L2 baseline.
Once detected, getting to the ISO is the next task. Some will, unfortunately, just be out of reach from an orbital mechanics standpoint.
But the authors calculate that there is an 85 percent chance that an ISI stored at L2 will be able to find a suitable object of interest that is the size of ‘Oumuamua within 10 years.
So, in essence, once we’re able to detect ISOs, it is just a matter of patiently waiting for the right opportunity.
Once the ISI reaches the ISO, it can then begin close-quarters observation, including a full spectroscopic map of both natural and artificial materials, which might help settle the debate about whether such objects are alien-made probes.
It could also monitor for any outgassing that could explain the mysterious forces acting on ‘Oumuamua.
There are undoubtedly plenty more exciting things that scientists would like to understand about the first interstellar object we visit.
But from the calculations in this paper, there will be plenty of opportunities to do so and plenty of data to collect when we do. Time to get on to the planning stages, then!
This article was originally published by Universe Today. Read the original article.
Confirmed! A 2014 meteor is Earth’s 1st known interstellar visitor
Astronomers have confirmed that a suspicious space rock that hit Earth in 2014 came from another star system, predating the famous interstellar visitor ‘Oumuamua by three years.
Researchers found the meteor in the catalog of NASA’s Center for Near Earth Object Studies (CNEOS) in 2019. At that time, however, some of the data about the rock’s trajectory were kept secret by the U.S. Department of Defence (DoD), whose sensors collected them.
But in March this year, the DoD released a statement confirming the measurements, allowing scientists to complete their calculation of the mysterious rock’s origin.
The 3-foot-wide (0.9 meters) mini-asteroid, which entered Earth’s atmosphere on Jan. 8, 2014, arrived at a very fast speed of 134,200 mph (216,000 km/h). It also followed an odd trajectory, which suggested it may have come from outside the solar system. By modeling the rock’s path into the past and assessing its gravitational interactions with planets in the solar system, the authors of the new paper confirmed the tiny asteroid was, indeed, a newcomer into the sun‘s corner of the Milky Way galaxy.
Related: Interstellar objects might have crashed onto the moon
The confirmation makes the rock, named CNEOS 2014-01-08, the first known visitor from interstellar space, predating the famous 650-foot-wide (200 m) asteroid ‘Oumuamua that zipped past Earth in 2017. Only one year later, astronomers discovered the second interstellar object, the 1,650-foot-wide (0.5 km) comet Borisov. The short interval between those discoveries led astronomers to believe that smaller interstellar rocks, only feet or tens of feet wide, must be much more common in the solar system and even regularly cross paths with our planet.
That’s why the authors of the new paper, famed Harvard astronomer Avi Loeb and his colleague Amir Siraj, set out to scour the CNEOS catalog. In addition to CNEOS 2014-01-08, they found another promising meteor, for which the necessary data is still classified, however. That space rock sliced Earth’s atmosphere in March 2017.
The researchers believe that interstellar space rocks might hit Earth’s atmosphere about once per decade. Analyzing those meteors, the researchers suggest in the paper, could provide new insights into the chemistry of distant star systems.
“By extrapolating the trajectory of each meteor backward in time and analyzing the relative abundances of each meteor’s chemical isotopes, one can match meteors to their parent stars and reveal insights into planetary system formation,” the authors said in the paper (opens in new tab). “[Some chemical] elements can be detected in the atmospheres of stars, so their abundances in meteor spectra can serve as important links to parent stars.”
Because most meteoroids burn up in the atmosphere before making it to Earth’s surface, and because retrieving those that do is extremely time-consuming and challenging on a technical level, the researchers propose creating a worldwide camera network capable of making spectroscopic measurements, analyses of the light-absorption fingerprints of arriving space rocks that could reveal their chemical composition.
CNEOS 2014-01-08 exploded above the ocean near Papua New Guinea, Siraj told Space.com in an email, and the scientists believe that some pieces of the rock may have survived the journey through Earth’s atmosphere and fallen into the sea. Siraj and Loeb plan an expedition to attempt to retrieve some of the fragments next year.
The researchers also suggest that such a high frequency of interstellar visitors throughout Earth’s history could mean that the seeds of life that had sprouted on our planet in the past 3.5 billion years may have come from another star system.
The study (opens in new tab) was published on Nov. 2 in the Astrophysical Journal.
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Webb, Hubble Team Up To Trace Interstellar Dust – “We Got More Than We Bargained For”
By combining data from NASA’s James Webb Space Telescope and NASA’s Hubble Space Telescope, researchers were able to trace light that was emitted by the large white elliptical galaxy at left through the spiral galaxy at right. As a result, they were able to identify the effects of interstellar dust in the spiral galaxy. Webb’s near-infrared data also show us the galaxy’s longer, extremely dusty spiral arms in far more detail, giving them an appearance of overlapping with the central bulge of the bright white elliptical galaxy on the left, though the pair are not interacting. In this image, green, yellow, and red were assigned to Webb’s near-infrared data taken in 0.9, 1.5, and 3.56 microns (F090W, F150W, and F356W respectively). Blue was assigned to two Hubble filters, ultraviolet data taken in 0.34 microns (F336W) and visible light in 0.61 microns (F606W).
Credit: Science: NASA, ESA, CSA, Rogier Windhorst (ASU), William Keel (University of Alabama), Stuart Wyithe (University of Melbourne), JWST PEARLS Team, Image Processing: Alyssa Pagan (STScI)
“We got more than we bargained for by combining data from
VV 191 is the latest addition to a small number of galaxies that helps researchers directly compare the properties of galactic dust. This target was selected from nearly 2,000 superimposed galaxy pairs identified by Galaxy Zoo citizen science volunteers.
Because dust changes the brightness and colors that appear in images of the galaxies, it is important to understand where dust is present in them. Since dust grains are partially responsible for the formation of new stars and planets, astronomers are always striving to identify their presence for further investigations.
Researchers identified a previously unknown lensed galaxy for the first time in new near-infrared data from NASA’s James Webb Space Telescope. Above the white elliptical galaxy at left, a faint red arc appears in the inset at 10 o’clock. This is a very distant galaxy whose appearance is warped. Its light is bent by the gravity of the elliptical foreground galaxy. Plus, its appearance is duplicated. The stretched red arc is warped where it reappears – as a dot – at 4 o’clock. In this image, green, yellow, and red were assigned to Webb’s near-infrared data taken in 0.9, 1.5, and 3.56 microns (F090W, F150W, and F356W respectively). Blue was assigned to two Hubble filters, ultraviolet data taken in 0.34 microns (F336W) and visible light in 0.61 microns (F606W).
Credit: Science: NASA, ESA, CSA, Rogier Windhorst (ASU), William Keel (University of Alabama), Stuart Wyithe JWST PEARLS Team, Image Processing: Alyssa Pagan (STScI)
The image also holds a second discovery that’s easier to overlook. Carefully examine the white elliptical galaxy at left. A faint red arc appears in the inset at 10 o’clock. This arc is a very distant galaxy whose light is bent by the gravity of the elliptical foreground galaxy – and its appearance is duplicated. The stretched red arc is warped where it reappears – as a dot – at 4 o’clock. Because these images of the lensed galaxy are so faint and so red that they went unrecognized in Hubble data. However, they are unmistakable in Webb’s near-infrared image. Simulations of gravitationally lensed galaxies like this help astronomers reconstruct how much mass is in individual stars, as well as how much dark matter is in the core of this galaxy.
As with many images from the James Webb Space Telescope, this image of VV 191 shows additional galaxies deeper and deeper in the background. Two patchy spirals to the upper left of the elliptical galaxy have similar apparent sizes, but show up in very different colors. One is likely very dusty and the other very far away, but astronomers will need to obtain data known as spectra to determine which is which.
References:
“Webb’s PEARLS: dust attenuation and gravitational lensing in the backlit-galaxy system VV 191” by William C. Keel, Rogier A. Windhorst, Rolf A. Jansen, Seth H. Cohen, Benne Holwerda, Sarah T. Bradford, Clayton D. Robertson, Giovanni Ferrami, Stuart Wyithe, Haojing Yan, Christopher J. Conselice, Simon P. Driver, Norman A. Grogin, Christopher N.A. Willmer, Anton M. Koekemoer, Brenda L. Frye, Nimish P. Hathi, Russell E. Ryan Jr., Nor Pirzkal, Madeline A. Marshall, Dan Coe, Jose M. Diego, Thomas J. Broadhurst, Michael J. Rutkowski, Lifan Wang, S.P. Willner, Andreea Petric, Cheng Cheng and Adi Zitrin, 30 August 2022, Astrophysics > Astrophysics of Galaxies.
arXiv:2208.14475
“Webb’s PEARLS: Prime Extragalactic Areas for Reionization and Lensing Science: Project Overview and First Results” by Rogier A. Windhorst, Seth H. Cohen, Rolf A. Jansen, Jake Summers, Scott Tompkins, Christopher J. Conselice, Simon P. Driver, Haojing Yan, Dan Coe, Brenda Frye, Norman Grogin, Anton Koekemoer, Madeline A. Marshall, Nor Pirzkal, Aaron Robotham, Russell E. Ryan Jr., Christopher N. A. Willmer, Timothy Carleton, Jose M. Diego, William C. Keel, Rosalia O’Brien, Paolo Porto, Caleb Redshaw, Sydney Scheller, Andi Swirbul, Stephen M. Wilkins, S. P. Willner, Adi Zitrin, Nathan J. Adams, Duncan Austin, Richard G. Arendt, John F. Beacom, Rachana A. Bhatawdekar, Larry D. Bradley, Thomas J. Broadhurst, Cheng Cheng, Francesca Civano, Liang Dai, Herve Dole, Jordan C. J. D’Silva, Kenneth J. Duncan, Giovanni G. Fazio, Giovanni Ferrami, Leonardo Ferreira, Steven L. Finkelstein, Lukas J. Furtak, Alex Griffiths, Heidi B. Hammel, Kevin C. Harrington, Nimish P. Hathi, Benne W. Holwerda, Jia-Sheng Huang, Minhee Hyun, Myungshin Im, Bhavin A. Joshi, Patrick S. Kamieneski, Patrick Kelly, Rebecca L. Larson, Juno Li, Jeremy Lim, Zhiyuan Ma, Peter Maksym, Giorgio Manzoni, Ashish Kumar Meena, Stefanie N. Milam, Mario Nonino, Massimo Pascale, Justin D. R. Pierel, Andreea Petric, Maria del Carmen Polletta, Huub J. A. Rottgering, Michael J. Rutkowski, Ian Smail, Amber N. Straughn, Louis-Gregory Strolger, James A. A. Trussler, Lifan Wang, Brian Welch, J. Stuart B. Wyithe, Min Yun, Erik Zackrisson, Jiashuo Zhang and Xiurui Zhao, 9 September 2022, Astrophysics > Cosmology and Nongalactic Astrophysics.
arXiv:2209.04119
Webb interdisciplinary scientist Rogier Windhorst of Arizona State University and his team obtained the data used in this image from early results of the Prime Extragalactic Areas for Reionization and Lensing Science (PEARLS) JWST Guaranteed Time Observation (GTO) programs, GTO 1176 and 2738. Additional data from Hubble’s STARSMOG snapshot program (SNAP 13695) and GO 15106, were added. Jake Summers, also of Arizona State, performed the pipeline data reduction. The dust analysis was led by William Keel of the University of Alabama, while the Hubble data acquisition was led by Benne Holwerda of the University of Louisville in Kentucky. The detailed gravitational-lensing analysis was conducted by Giovanni Ferrami and Stuart Wyithe, both of the University of Melbourne, Australia and ASTRO 3D, Australia.
Hubble Captures 2 Galaxies Overlapping to Form a Stunning Interstellar ‘Snail’ : ScienceAlert
A new image from the Hubble Space Telescope beautifully illustrates why astronomers need to be so careful about distance in space.
Over 1 billion light-years away, two galaxies float in the darkness, beautiful golden snail-like spirals seemingly caught in the act of colliding. They’re named SDSS J115331 and LEDA 2073461, and in spite of appearances, they’re not interacting at all.
Instead, they’re separated by quite some distance. Their alignment is an absolutely beautiful line-of-sight coincidence.
Galaxies do collide in space, quite frequently, drawn together along dark matter superhighways to galaxy cluster nodes, where they stream towards a mutual galactic center.
This process is thought to be one way the supermassive black holes at their centers grow to masses billions of times that of the Sun: When galaxies merge, their central black holes do too.
But space is large, and there are a lot of things in it, so scientists must be careful when interpreting two objects that appear to be in the same place. Are they interacting, or are they overlapping with a vast distance in between?
Distance is one of the most important tools we have for interpreting the Universe around us. Many objects’ size, mass, and brightness can’t be accurately gauged without an accurate distance measurement.
But distances in space can also be tricky to gauge. You can’t tell how far away something is just by looking at it unless you know how much light it emits.
That’s why things like Type Ia supernovae, which have a known intrinsic brightness, are a useful tool for gauging distance in space.
For relatively close objects, we can use parallax – the way objects move across the sky in relation to each other.
However, beyond a certain distance, individual objects become harder and harder to see. So scientists rely on other tools, such as the way the expansion of the Universe stretches out light from distant objects.
That’s how we know SDSS J115331 and LEDA 2073461 are not in the midst of a giant collision, although there are other clues, too: The two galaxies are far too neat; a collision would mess them up.
Even in the vicinity of the Milky Way, distances can be hard to gauge. Recently, scientists found that a source of gamma radiation was more distant than they had thought. In that case, the shared shape and alignment of the radiation and its source allowed scientists to make the connection.
Although overlapping galaxies may not help scientists better understand galactic collisions and mergers, they can be used to understand spiral galaxies.
When backlit by a more distant galaxy, the interstellar dust in a foreground galaxy can be easier to view. Scientists have used this quirk of alignment to map the distribution of interstellar dust in multiple galaxies.
It’s unclear whether Hubble’s image of SDSS J115331 and LEDA 2073461 will be used for this purpose. But it’s incredibly pretty to look at.
You can download wallpaper-sized versions of this image from the Hubble website.
Interstellar objects might have crashed onto the moon
At least one interstellar object (ISO) has likely crashed into Earth’s moon over the eons, a new paper suggests.
The moon, which is filled with thousands of craters, is thus a good hunting ground for objects originating in interstellar space, the authors suggest through statistics and simulation.
“Given the number of ISOs that we expect to encounter in the solar system, there are probably a few craters that were formed by very high-speed ISOs throughout the solar system, and there are probably one or two on the moon,” lead author Sam Cabot, a Ph.D. candidate at Yale University, told Space.com.
That said, the challenge is finding such a crater in the first place.
Related: Interstellar Comet Borisov shines in incredible new Hubble photos
ISOs are comets or asteroids that originated beyond the borders of our solar system. Only two have been confirmed so far: ‘Oumuamua and Borisov. The new study suggests that we may find out more about the composition of these enigmatic objects if we can track down a crater on the moon formed by an interstellar impact.
Decades of observations of our closest large neighbor, most especially with NASA’s Lunar Reconnaissance Orbiter, have provided high-definition maps that will be used for NASA’s Artemis program. The Artemis program seeks to land humans on the moon later in the 2020s, if all goes to plan.
That said, maps can only provide so much information about the craters that are imaged, the authors say. The challenge is that maps provide little spectroscopic information about the composition of the craters. While some analysis can be done from orbit, the authors say it will likely require “ground truth” to determine if a crater indeed was formed from an ISO, Cabot said.
Related: Amazing moon photos from NASA’s Lunar Reconnaissance Orbiter
Predicting what astronauts may find will be difficult, Cabot added, as the two ISOs already spotted are quite different from each other. Borisov is the most similar to other solar system objects that we know about; however, astronomers were surprised by just how much carbon monoxide was present in its composition, he said. ‘Oumuamua is even more enigmatic, he said, because there is no “satisfactory theory” that fully explains its composition.
Something was outgassing from the surface of ‘Oumuamua and causing it to accelerate as it was leaving our solar system for interstellar space, Cabot explained.
“The quandary,” he continued, “is that we in the community observed with space telescopes, looking for the typical gases you’d expect to be vaporized off the surface that are in astronomical objects. None of them were detected confidently.”
Since astronomers were unable to find typical products of outgassing such as water, instead they are thinking that the object has unique kinds of volatiles on its surface, Cabot said. (Volatiles are chemical elements and compounds that vaporize relatively easily.) To better figure out what ISOs are made of more generally, the moon may present one location to gather concrete evidence, he added.
Related: Photographers capture ‘ridiculously detailed image’ of the moon for NASA’s Artemis 1 launch
Better yet, there may be boots on the lunar surface relatively soon. Providing that funding and technological development on the Artemis program goes to plan, humans can seek out the sources of craters within their landing area.
The challenge, however, is there is no way of predicting exactly where an ISO may have landed. Moreover, human excursions will be confined, for the time being, to the south pole of the moon; that’s where NASA and other space agencies hope to put their astronauts in the near future.
Nevertheless, Cabot said, human missions “give us a lot of opportunities for regolith characterization, [meaning] figuring out the composition of the lunar soil, and trying to answer questions about the early solar system.”
Related: How did the solar system form?
The little we know about ISOs suggests one strong hypothesis for how those craters may be different, he said. ISOs tend to travel at higher speeds compared to other objects within our solar system. That’s because objects that are bound to the sun have a sort of “speed limit” due to being confined by the sun’s gravity.
“ISOs, which flow freely throughout the galaxy, can enter the solar system at much higher speeds,” Cabot said. “So that was the premise of our paper: to investigate telltale signatures of extremely high speed impacts.”
The astronomers picked the cutoff speed of 225,000 mph (360,000 km/h) because it is extremely rare for solar system objects to achieve anything near that speed. The authors suggest that signs of melting at the impact site may be higher at that increased speed, although the composition of the melt would depend on the rock composition in the area.
What is needed next, Cabot said, is “widespread characterization of lunar regolith, which is something that we are hopefully going to see with Artemis.” The challenge, he continued, is that astronauts and their equipment will need to figure out how to process large volumes of regolith from the moon to make a meaningful comparison to what an ISO may contain.
Related: NASA’s Artemis 1 moon mission explained in photos
Some of NASA’s future robotic landing missions may serve as test drives for large-scale regolith processing. NASA has a program called Commercial Lunar Payload Services (CLPS), which seeks to put private landers and payloads on the moon in support of the Artemis missions. A selection of these payloads may be able to process regolith as a secondary objective to other scientific explorations, Cabot said.
In the meantime, the authors, along with the rest of the astronomical community, are still on the hunt for other ISOs through powerful wide-field telescopes. And that search will get in a boost in the near future when instruments such as the Vera C. Rubin Observatory come online.
A paper based on the research was published in the Planetary Science Journal (opens in new tab). A preprint version is available on Arxiv. (opens in new tab)
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