This Week in Astronomy: The Fate of Milky Way, The Biggest Map of The Universe and A New Eye on the Universe

<v Speaker 1>Welcome to Bedtime Astronomy. Explore the wonders of the cosmos
<v Speaker 1>with our soothing Bedtime Astronomy podcast. Each episode offers a
<v Speaker 1>gentle journey through the stars, planets, and beyond, perfect for
<v Speaker 1>unwinding after a long day. Let's travel through the mysteries
<v Speaker 1>of the universe as you drift off into a peaceful
<v Speaker 1>slumber under the night sky. This week in Astronomy, Rethinking
<v Speaker 1>the Fate of Milky Way, the biggest map of the
<v Speaker 1>Universe in a new Eye on the Universe, Rethinking the
<v Speaker 1>Fate of the Milky Way. For many years, astronomers have
<v Speaker 1>believed that the Milky Way was destined for a dramatic fate,
<v Speaker 1>a direct collision with the Andromeda Galaxy, our nearest large
<v Speaker 1>galactic neighbor. This idea has been deeply ingrained in scientific literature, documentaries,
<v Speaker 1>and public imagination, often presented as a near certain event
<v Speaker 1>that would occur in roughly five billion years. The belief
<v Speaker 1>in this inevitable galactic crash has been based on observations
<v Speaker 1>of Andromeda's motion toward the Milky Way, detected through changes
<v Speaker 1>in the color of its light known as the Doppler shift,
<v Speaker 1>which reveals how objects move along our line of sight. However,
<v Speaker 1>galaxies also move sideways across the sky in what's called
<v Speaker 1>proper motion or transverse velocity, and this type of motion
<v Speaker 1>is notoriously hard to measure accurately, especially for objects millions
<v Speaker 1>of light years away. Previous studies typically assume that Andromeda's
<v Speaker 1>transverse motion was minimal, which made a head on collision
<v Speaker 1>between the two galaxies seem almost guaranteed. In a new
<v Speaker 1>study published in Nature Astronomy and led by til Soola
<v Speaker 1>from the University of Helsinki, researchers have now challenged this
<v Speaker 1>long standing assumption by closely examining the uncertainties in current
<v Speaker 1>astronomical data and by incorporating the gravitational influences of other
<v Speaker 1>nearby galaxies. The study didn't rely on new observational data,
<v Speaker 1>but instead re analyzed existing data from major space missions
<v Speaker 1>like the Hubble Space Telescope and the European Space Agency's
<v Speaker 1>Guy emission. Unlike earlier work, this research emphasized the importance
<v Speaker 1>of including the full range of uncertainties in the measurements,
<v Speaker 1>rather than treating the most likely values as fixed. By
<v Speaker 1>running thousands of simulations and slightly altering the initial conditions
<v Speaker 1>such as the relative speeds and positions of the Milky
<v Speaker 1>Way and Andromeda. In each one, the team was able
<v Speaker 1>to explore a broader set of possible futures. When they
<v Speaker 1>repeated the assumptions used in earlier studies, they obtained the
<v Speaker 1>same results a future merger, but by expanding the range
<v Speaker 1>of possible initial conditions, they uncovered a more nuanced picture.
<v Speaker 1>They also factored in the influence of two additional galaxies,
<v Speaker 1>the Large Magellanic Cloud, a massive satellite galaxy currently falling
<v Speaker 1>into the Milky Way, in the Triangulum Galaxy also known
<v Speaker 1>as M thirty three, which orbits Andromeda. These galaxies exert
<v Speaker 1>significant gravitational effects that subtly alter the motions of the
<v Speaker 1>Milky Way in Andromeda. The Triangulum galaxy pulls Andromeda slightly
<v Speaker 1>closer to the Milky Way, increasing the chances of a
<v Speaker 1>future merger, while the Large Magellanic Cloud exerts a force
<v Speaker 1>that shifts the Milky Way's path away from Andromeda, making
<v Speaker 1>a collision less likely. With these complexities in mind, the
<v Speaker 1>study found that there is only about a fifty percent
<v Speaker 1>chance the Milky Way and Andromeda will merge within the
<v Speaker 1>next ten billion years. In other words, it's just as
<v Speaker 1>likely that the two galaxies will never collide at all
<v Speaker 1>in that timeframe. Depending on how the various gravitational influences
<v Speaker 1>play out, The galaxies might instead swing past each other
<v Speaker 1>in a close encounter, or settle into a prolonged orbital
<v Speaker 1>dance without ever merging. Adds a new layer of uncertainty
<v Speaker 1>an intrigue to our understanding of the Milky Way's distant future.
<v Speaker 1>Even if a merger does eventually occur, it wouldn't be
<v Speaker 1>catastrophic in the way Hollywood might imagine. Stars within galaxies
<v Speaker 1>are separated by such fast distances that direct collisions between
<v Speaker 1>them are extremely rare. Instead, the gravitational forces would gradually
<v Speaker 1>draw the two galaxies together, reshaping them into a single,
<v Speaker 1>larger elliptical galaxy over time. If the galaxies do not merge,
<v Speaker 1>they may remain near each other in a sore of
<v Speaker 1>cosmic waltz, orbiting gently for Ian's without ever quite coming together.
<v Speaker 1>Both outcomes would reshape our view of the universe and
<v Speaker 1>our place in it, albeit in very different ways. The
<v Speaker 1>biggest remaining variable in this celestial forecast is Andromeda's transverse velocity.
<v Speaker 1>Even small adjustments in this sideways motion can determine whether
<v Speaker 1>the galaxies eventually merge or just brush past each other.
<v Speaker 1>Future measurements, especially as observational technology improves, will help to
<v Speaker 1>refine our estimates and clarify the Milky Way's fate. For now,
<v Speaker 1>the future remains uncertain, but that uncertainty underscores the dynamic
<v Speaker 1>and evolving nature of our understanding of the cosmos. Even
<v Speaker 1>when examining something as seemingly familiar as our own galaxy,
<v Speaker 1>there is still so much to discover. The biggest map
<v Speaker 1>of the universe a major scientific breakthrough has just unfolded
<v Speaker 1>with the release of a massive new data set, the
<v Speaker 1>largest map of the universe ever created, built using data
<v Speaker 1>from the James Web Space telescope. This monumental project, called
<v Speaker 1>cosmos Web, is the work of a vast international collaboration
<v Speaker 1>of scientists who have now made their findings publicly available
<v Speaker 1>in the name of open science. The cosmos Web field
<v Speaker 1>includes stunningly detailed images and a catalog of nearly eight
<v Speaker 1>hundred thousand galaxies, stretching across almost the entire history of
<v Speaker 1>the universe, from the present day back to just a
<v Speaker 1>few hundred million years after the Big Bang. In terms
<v Speaker 1>of cosmic time, that's about ninety eight percent of everything
<v Speaker 1>that has happened since the beginning of the universe. One
<v Speaker 1>of the leaders of this effort, a physicist from u
<v Speaker 1>SEE Santa Barbara named Caitlin Casey, explained that their goal
<v Speaker 1>was to create a view of deep space on a
<v Speaker 1>scale far beyond anything previously attempted. To understand the scale,
<v Speaker 1>she compared it to a famous image called the Hubble
<v Speaker 1>Ultra Deep Field, which shows nearly ten thousand galaxies. If
<v Speaker 1>that image fit on a normal sheet of paper, the
<v Speaker 1>new JWST based Cosmos image would be like a mural
<v Speaker 1>over thirteen feet wide and equally tall, revealing far more
<v Speaker 1>detail and cosmic diversity. The motivation behind this enormous undertaking
<v Speaker 1>wasn't just to identify the earliest galaxies that formed after
<v Speaker 1>the Big Bang, but to better understand the environments in
<v Speaker 1>which they lived. The vast cosmic structures made up of
<v Speaker 1>dense regions and empty voids where stars, galaxies, and black
<v Speaker 1>holes first took shape. Scientists expected to see a few
<v Speaker 1>rare early galaxies. Because the universe needed time to evolve
<v Speaker 1>after the Big Bang, matter had to collapse under gravity
<v Speaker 1>stars had to ignite and galaxies had to gradually take form,
<v Speaker 1>but the James Web Space telescopes surprised them. It revealed
<v Speaker 1>around ten times more galaxies from this early period than
<v Speaker 1>anyone had predicted. It also uncovered previously unseen supermassive black holes,
<v Speaker 1>enormous regions of gravity so strong that not even light
<v Speaker 1>can escape, that were invisible to earlier telescopes like Hubble.
<v Speaker 1>In other words, it wasn't just more galaxies than expected,
<v Speaker 1>it was a new view of what those galaxies were like,
<v Speaker 1>how massive they were, and where they lived in the
<v Speaker 1>early universe. As Offen happens in science, answering one big
<v Speaker 1>question leads to a dozen more. The discoveries from the
<v Speaker 1>Cosmos web field have started to challenge the very model
<v Speaker 1>scientists used to understand the Cosmos. One puzzling issue is
<v Speaker 1>that galaxies in the early universe appear to have formed
<v Speaker 1>far too quickly. Based on our current understanding of cosmology,
<v Speaker 1>It simply shouldn't be possible for them to accumulate so
<v Speaker 1>much mass up to a billion times the mass of
<v Speaker 1>our Sun, in only a few hundred million years after
<v Speaker 1>the Big Bang. There are ideas to explain this, but
<v Speaker 1>no clear answers yet. This mystery is one of the
<v Speaker 1>most exciting parts of the new data. Scientists around the
<v Speaker 1>world are being invited to explore it further, and that's
<v Speaker 1>exactly what the Cosmos collaboration intended. A major aim of
<v Speaker 1>the project is to make cutting edge astronomy more accessible.
<v Speaker 1>Although the telescope data was available immediately after collection, it
<v Speaker 1>was innittionally raw and difficult to work with. Only experts
<v Speaker 1>with powerful computers and technical know how could really make
<v Speaker 1>use of it. For the past two years, the Cosmos
<v Speaker 1>team has been working to turn all that raw material
<v Speaker 1>into organized, easy to use images in catalogs, so that
<v Speaker 1>scientists everywhere, including students and young researchers, can dive in
<v Speaker 1>and make discoveries of their own. They believe the best
<v Speaker 1>science happens when many different minds look at the same
<v Speaker 1>data in their own way. That's why the Cosmos team
<v Speaker 1>has made the full data set available to the public,
<v Speaker 1>along with the scientific papers that explain it, and they're
<v Speaker 1>not stopping here. More observations are planned and the team
<v Speaker 1>is going back to the Cosmos web field to learn
<v Speaker 1>even more. They believe they may have already spotted the
<v Speaker 1>earliest galaxies ever seen, but now they need to confirm
<v Speaker 1>that by using a method called spectroscopy. This technique spreads
<v Speaker 1>the galaxies light into its d different wavelengths like a rainbow,
<v Speaker 1>revealing its chemical composition and allowing astronomers to calculate its
<v Speaker 1>true distance, which also tells them how old it is.
<v Speaker 1>In the process, scientists will also gain new insights into
<v Speaker 1>the chemical makeup of those ancient galaxies, studying key elements
<v Speaker 1>like carbon, nitrogen, and oxygen. This will help unlock the
<v Speaker 1>secrets of interstellar chemistry and offer clues to how stars, planets,
<v Speaker 1>and even life itself might have begun. Although these findings
<v Speaker 1>already pushed the boundaries of what we thought we knew
<v Speaker 1>about the universe, this is only the beginning. The universe
<v Speaker 1>is still full of mysteries, and thanks to this collaborative
<v Speaker 1>effort and the incredible power of the James Webspace Telescope,
<v Speaker 1>humanity is now better equipped than ever to explore them.
<v Speaker 1>A new eye on the universe. On June twenty third,
<v Speaker 1>twenty twenty five, the world will witness the unveiling of
<v Speaker 1>the first images captured by one of the most advanced
<v Speaker 1>asc stronomical instruments ever created. The Veriice Reuben Observatory situated
<v Speaker 1>high in the Chilean Andes. This observatory is set to
<v Speaker 1>revolutionize our understanding of the cosmos. For the next ten years,
<v Speaker 1>it will capture hundreds of images of the Southern Hemisphere's
<v Speaker 1>sky every single night, creating the most detailed and comprehensive
<v Speaker 1>time lapse record of the universe humanity has ever seen.
<v Speaker 1>This ambitious project is known as the Legacy Survey of
<v Speaker 1>Space and Time or LSST. Unlike traditional telescopes that focus
<v Speaker 1>on narrow sections of the sky, the Ruben Observatory will
<v Speaker 1>scan the entire visible southern sky repeatedly, creating an ever
<v Speaker 1>evolving portrait of the universe. Scientists will use this dynamic
<v Speaker 1>wide angle view to track cosmic phenomena such as supernova asteroids,
<v Speaker 1>black holes, and distant galaxies as they change in unfold
<v Speaker 1>in real time. Rather than presenting space as a series
<v Speaker 1>of still snapshots, the observatory will deliver an ongoing cosmic
<v Speaker 1>narrative night after night. At the center of this endeavoral Eyes,
<v Speaker 1>a technological marvel, a digital camera of extraordinary scale and power,
<v Speaker 1>roughly the size of a compact car and weighing over
<v Speaker 1>three tons. This camera boasts a staggering three thousand, two
<v Speaker 1>hundred megapixels, an image resolution so high that a single
<v Speaker 1>photo could reveal a golf ball from twenty five kilometers away.
<v Speaker 1>The level of detail is immense. To view a full
<v Speaker 1>image in its entirety, one would need hundreds of ultra
<v Speaker 1>high definition television screens to record the universe in full color.
<v Speaker 1>The camera employs massive filters, each as wide as a
<v Speaker 1>dust been lid, that isolates specific wavelengths of light from
<v Speaker 1>ultraviolet to near infrared. The observatory itself has been more
<v Speaker 1>than two decades in the making. First proposed in two
<v Speaker 1>thousand and one, construction began in April two, twenty fifteen
<v Speaker 1>on Sero Poshon, a mountain ridge in northern Chile. By
<v Speaker 1>October twenty twenty four, initial testing began with a low
<v Speaker 1>resolution camera, paving the way of the main camera's first
<v Speaker 1>official images, which are now ready to be shared. The
<v Speaker 1>Reuben Observatory is not just a feat of engineering. It
<v Speaker 1>is a scientific mission designed to tackle some of the
<v Speaker 1>most profound mysteries in astronomy. One of its primary goals
<v Speaker 1>is to investigate the nature of dark energy, the enigmatic
<v Speaker 1>force behind the accelerating expansion of the universe. By measuring
<v Speaker 1>how galaxies cluster and move, the observatory will provide vital
<v Speaker 1>data for exploring this cosmic puzzle. Equally important is its
<v Speaker 1>role in mapping the large scale structure of the universe
<v Speaker 1>in investigating dark matter, an invisible substance that makes up
<v Speaker 1>twenty seven percent of the cosmos. Dark matter acts as
<v Speaker 1>a kind of scaffolding for the universe, an unseen web
<v Speaker 1>that guides the form and evolution of galaxies. The observatory
<v Speaker 1>is named in honor of doctor VERA. Rubin, a pioneering
<v Speaker 1>American astronomer whose groundbreaking research offered the first compelling evidence
<v Speaker 1>for dark matter. As a woman in a predominantly male field,
<v Speaker 1>Reuben faced numerous challenges, yet remained a tireless advocate for
<v Speaker 1>scientific integrity and gender equality. She passed away in twenty
<v Speaker 1>sixteen at the age of eighty eight, and the observatory
<v Speaker 1>bearing her name stands as a tribute not only to
<v Speaker 1>her scientific achievements, but also to her resilience and legacy
<v Speaker 1>of inclusion. Beyond its contributions to understanding dark matter and
<v Speaker 1>dark energy, the Ruben Observatory will also keep watch over
<v Speaker 1>our cosmic neighborhood. It will discover and track millions of
<v Speaker 1>asteroids and nearer Earth objects, playing a crucial role in
<v Speaker 1>planetary defense by helping detect potential threats long before they
<v Speaker 1>come close. Additionally, it will monitor stars whose brightness changes,
<v Speaker 1>which can indicate the presence of orbiting planets, further expanding
<v Speaker 1>our understanding of exoplanetary systems. The observatory will be poised
<v Speaker 1>to capture rare and dramatic cosmic events, such as neutron
<v Speaker 1>star collisions, which produce bursts of light and gravitational waves
<v Speaker 1>that ripple across the fabric of space. What sets Reuben apart, however,
<v Speaker 1>is not only what it is designed to discover, but
<v Speaker 1>what it might reveal unexpectedly. Some of the greatest astronomical
<v Speaker 1>breakthroughs have come from the unanticipated, mysterious flashes, strange motions,
<v Speaker 1>and phenomena never before observed. Because of the observatori's vast
<v Speaker 1>and continuous data collection, it may uncover new classes of
<v Speaker 1>celestial objects, or even reveal unknown laws of physics. But
<v Speaker 1>this immense undertaking depends on one key element. The darkness
<v Speaker 1>of the night sky. Light pollution, particularly from satellite Mega
<v Speaker 1>constellations come post of hundreds or thousands of orbiting satellites
<v Speaker 1>poses a serious threat. These satellites can reflect sunlight and
<v Speaker 1>create bright streaks and telescope images, disrupting the data and
<v Speaker 1>making analysis more difficult. While software tools can remove some
<v Speaker 1>of these marks, doing so adds to the workload, increases cost,
<v Speaker 1>and can reduce data quality. To address these challenges, Ruben
<v Speaker 1>observatory scientists are already developing simulations to predict and reduce
<v Speaker 1>satellite interference. They are also collaborating with satellite operators to
<v Speaker 1>dim spacecraft or adjust their paths, ensuring clearer skies not
<v Speaker 1>only for Reuben, but for future generations of telescopes and astronomers.
<v Speaker 1>The Rubin Project is a global collaboration led by the
<v Speaker 1>US National Science Foundation and the Department of Energy, with
<v Speaker 1>partners around the world contributing to data processing and scientific interpretation.
<v Speaker 1>A significant portion of the data will be made publicly available,
<v Speaker 1>opening the door for researchers, students, and even amateur astronomers
<v Speaker 1>to engage with the findings and possibly make discoveries of
<v Speaker 1>their own. The unveiling of Reuben's first images will be
<v Speaker 1>marked by a global celebration with events streamed live in
<v Speaker 1>both English and Spanish, allowing people everywhere to participate in
<v Speaker 1>this historic moment. For the scientific community, this is a
<v Speaker 1>rare and transformative milestone, an observatory poise to reshape our
<v Speaker 1>understanding of the universe, ignite public curiosity, and spark discoveries
<v Speaker 1>that will resonate through the decades to come.
<v Speaker 2>To do at the names