This Week in Astronomy: Bennu - A Time Capsule, Hunting Cosmic Rays with Neutrinos and Before the Big Bang

<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, Benu
<v Speaker 1>a time capsule hunting cosmic rays with neutrinos and before
<v Speaker 1>the Big Bang. Benu a time capsule from the early
<v Speaker 1>Solar System asteroid. Benu is an object made of many
<v Speaker 1>different kinds of material, some of which come from very
<v Speaker 1>far parts of the Solar System and even from outside it.
<v Speaker 1>Over billions of years, these materials were changed by water
<v Speaker 1>and by the tough conditions of space. We now know
<v Speaker 1>this because NASA's Osyrus RX mission brought pieces of venue
<v Speaker 1>back to Earth in twenty twenty. Scientists from all over
<v Speaker 1>the world are studying them with leadership from the University
<v Speaker 1>of Arizona. Benu itself is not one solid rock, but
<v Speaker 1>a collection of fragments that once belonged to a larger asteroid.
<v Speaker 1>That asteroid was shattered by a collision, probably in the
<v Speaker 1>asteroid belt between Mars and Jupiter. The parent asteroid contained
<v Speaker 1>materials from close to the Sun, from far away in
<v Speaker 1>the Solar System, and even from other stars. This means
<v Speaker 1>Benu preserves a record of the early days of our
<v Speaker 1>Solar system more than four billion years ago. By analyzing
<v Speaker 1>the samples, scientists discovered grains of stardust, tiny particles that
<v Speaker 1>were formed in other stars long before our Solar system
<v Speaker 1>was born. These grains can be recognized because their atomic
<v Speaker 1>fingerprints are different from anything made inside our Solar system.
<v Speaker 1>Researchers also found unusual organic material that likely came from
<v Speaker 1>interstellar snea, along with solid matter formed near the Sun.
<v Speaker 1>This shows that Benue holds a mixture of ingredients from
<v Speaker 1>many different regions. The studies also revealed that Benu's parent
<v Speaker 1>body contained a lot of ice. Over time, this ice melted,
<v Speaker 1>creating liquid water that reacted with minerals at temperatures similar
<v Speaker 1>to room temperature. These chemical reactions changed much of the
<v Speaker 1>material inside the asteroid, forming new minerals that still hold
<v Speaker 1>water within them today. In fact, around eighty percent of
<v Speaker 1>the minerals in Benue samples carry evidence of water. This
<v Speaker 1>means that the asteroid's interior once went through long lasting
<v Speaker 1>water driven processes similar to very slow chemical cooking. But
<v Speaker 1>water was not the only factor. Benue has also been
<v Speaker 1>hit by tiny meteorites and exposed directly to the solar
<v Speaker 1>wind because it has no atmosphere. These conditions left microscopic
<v Speaker 1>craters and melted its spots on its surface, proving that
<v Speaker 1>Benu has been constantly reshaped by what scientists call space weathering.
<v Speaker 1>This process seems to happen more quickly than researchers expected.
<v Speaker 1>All of these results show that Benu is like a
<v Speaker 1>time capsule. It contains pieces of ancient stars, organic molecules,
<v Speaker 1>minerals that reacted with water billions of years ago, and
<v Speaker 1>signs of constant bombardment in space. This makes it one
<v Speaker 1>of the best records we have of what the early
<v Speaker 1>Solar System was made of and how it evolved. Unlike
<v Speaker 1>meteorites that fall to Earth, Benu' samples were collected directly
<v Speaker 1>in space without being contaminated by our atmosphere, which is
<v Speaker 1>why missions like osiris RIX are so important for understanding
<v Speaker 1>our cosmic history. Hunting cosmic rays with neutrinos, scientists are
<v Speaker 1>trying to figure out where cosmic radiation comes from, and
<v Speaker 1>they are using a special kind of particle called neutrinos
<v Speaker 1>to help them in this search. Neutrinos are useful because
<v Speaker 1>they can travel across the universe without being stopped or
<v Speaker 1>changed much by matter, which means they carry information straight
<v Speaker 1>from their source to Earth. To detect them, researchers use
<v Speaker 1>a huge observatory called ice Cube, buried deep in the
<v Speaker 1>ice at the South Pole. Since two thousand and nine,
<v Speaker 1>an international team has been running ice Cube, and recently
<v Speaker 1>a group led by Professor Anafronskaliak in Bochum developed new
<v Speaker 1>computer methods that make it much easier to analyze the data.
<v Speaker 1>These methods can calculate the energy and direction of a
<v Speaker 1>neutrino in about thirty seconds, and the result is shared
<v Speaker 1>immediately with telescopes all over the world. That way, astronomers
<v Speaker 1>can quickly point their instruments at the right spot in
<v Speaker 1>the sky to look for possible sources such as galaxies,
<v Speaker 1>black holes, or other powerful cosmic events. The system is
<v Speaker 1>also refined later with slower but more accurate calculations, which
<v Speaker 1>are now force of five times better than before. This
<v Speaker 1>speed matters because some of These cosmic events are very
<v Speaker 1>short lived and can be missed if telescopes are not
<v Speaker 1>directed in time. The researchers also used their algorithms to
<v Speaker 1>go back and recheck older data collected by ice Cube.
<v Speaker 1>In doing so, they had to rule out some previously
<v Speaker 1>suspected sources. For example, they had thought that tidal disruption
<v Speaker 1>events might produce neutrinos. These events happen when a star
<v Speaker 1>passes too close to a quiet black hole and the
<v Speaker 1>black hole's gravity stretches and rips the star apart. In
<v Speaker 1>earlier data, three neutrino detections seemed linked to such events,
<v Speaker 1>but when the team reanalyzed the trajectories with the improved method,
<v Speaker 1>they found the neutrinos did not actually come from the
<v Speaker 1>same places as the tidal disruption events. So far, no
<v Speaker 1>definite source of cosmic radiation has been identified, but the
<v Speaker 1>improved tools give researchers a much better chance of subt
<v Speaker 1>solving this mystery in the future. Their work has already
<v Speaker 1>produced three scientific publications, including one in a major astronomy
<v Speaker 1>journal and two shared online for the scientific community. Before
<v Speaker 1>the Big Bang, simulating the unknown, scientists have long debated what,
<v Speaker 1>if anything happened before the Big Bang. Some say the
<v Speaker 1>question makes no sense because the laws of physics break
<v Speaker 1>down when we try to trace the universe back that far.
<v Speaker 1>But a new study by researchers in London and Oxford
<v Speaker 1>suggests a way forward, using advanced computer simulations to explore
<v Speaker 1>extreme cosmic conditions where pen and paper calculations fail. Einstein's
<v Speaker 1>theory of general relativity describes how gravity works and how
<v Speaker 1>matter and energy move through space time. Normally, cosmologists simplify
<v Speaker 1>these equations by assuming the universe looks the same in
<v Speaker 1>all directions and is evenly spread out. This is a
<v Speaker 1>good description of the universe we see today, but when
<v Speaker 1>you rewind the clock to the Big Bang, those assumptions
<v Speaker 1>may no longer hold. Pushing the equations to that limit
<v Speaker 1>usually leads to a singularity, a point of infinite density
<v Speaker 1>where the theory stops working. That's the same problem physicists
<v Speaker 1>face when trying to describe what happens inside black holes.
<v Speaker 1>The new idea is to rely on a branch of
<v Speaker 1>physics called numerical relativity. Instead of solving Einstein's equations exactly,
<v Speaker 1>which is impossible in extreme situations, Scientists program computers to
<v Speaker 1>approximate the solutions step by step. This method was originally
<v Speaker 1>developed decades ago to predict what would happen if two
<v Speaker 1>black holes crashed together. It became especially important after the
<v Speaker 1>Ligo experiment was proposed to detect gravitational waves, and in
<v Speaker 1>two thousand and five researchers finally managed to model such
<v Speaker 1>collisions successfully. That breakthrough showed that numerical relativity can solve
<v Speaker 1>problems too complex for traditional methods. Now, scientists hope to
<v Speaker 1>use it to investigate early universe mysteries. One of these
<v Speaker 1>is cosmic inflation, the rapid expansion that supposedly happened just
<v Speaker 1>after the Big Bang. Inflation explains why the universe today
<v Speaker 1>looks smooth and uniform across vast distances, but physicists still
<v Speaker 1>don't know what caused inflation or how it started. The
<v Speaker 1>trouble is that when they try to study it with
<v Speaker 1>Einstein's equations, they must already assume the universe was uniform
<v Speaker 1>in the beginning, which inflation was meant to explain in
<v Speaker 1>the first place. Numerical relativity could let them test more complicated,
<v Speaker 1>less tidy starting points, perhaps even predictions from string theory
<v Speaker 1>Beyond inflation, The technique could also help explore other fascinating possibilities.
<v Speaker 1>It might show what kind of gravitational waves would be
<v Speaker 1>produced by cosmic strings, hypothetical defects in space time left
<v Speaker 1>over from the early universe. It could also help look
<v Speaker 1>for traces of our universe bumping into another one, which
<v Speaker 1>would support the idea of a multiverse. And, perhaps most strikingly,
<v Speaker 1>it could test scenarios in which the universe did not
<v Speaker 1>begin with a single big bang, but instead goes through
<v Speaker 1>endless cycles of collapse and rebirth, so that something existed
<v Speaker 1>before our cosmos began. Running these simulations is extremely demanding,
<v Speaker 1>requiring supercomputers and sophisticated programming, but as computing power grows,
<v Speaker 1>researchers expect major progress. The team behind the new paper
<v Speaker 1>hopes their work will bring together two communities cosmologists who
<v Speaker 1>have big questions but often lack the tools to solve them,
<v Speaker 1>and numerical relativists, who have powerful techniques but usually focus
<v Speaker 1>on black holes rather than the universe as a whole.
<v Speaker 1>By combining forces, they believe science might finally move closer
<v Speaker 1>to understanding what really happened before the big band name
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