This Week in Astronomy: Echoes from the Cosmic Dawn, The Hidden Life of Red Galaxies, Perseverance Uncovers Mars History

<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, Echoes
<v Speaker 1>from the Cosmic Dawn, the Hidden life of red galaxies,
<v Speaker 1>and Perseverance uncovers Martian history Echoes from the Cosmic Dawn.
<v Speaker 1>Mapping the early universe has long been a central pursuit
<v Speaker 1>in cosmology, aiming to unravel the mysteries of the universe's infancy.
<v Speaker 1>The period known as the Dark Ages, occurring after the
<v Speaker 1>emission of the cosmic microwave background CMB and before the
<v Speaker 1>formation of the first stars, remains one of the least
<v Speaker 1>understood epics. This as era holds crucial information about the
<v Speaker 1>formation of the first structures in the universe and the
<v Speaker 1>nature of dark matter and dark energy. However, observing this
<v Speaker 1>period is exceptionally challenging due to the faintness of the
<v Speaker 1>signals in interference from Earth's atmosphere and human made radio frequencies.
<v Speaker 1>To overcome these obstacles, scientists are turning their attention to
<v Speaker 1>the Moon, specifically its far side as an ideal location
<v Speaker 1>for radio astronomy. The Moon's far side is shielded from
<v Speaker 1>Earth's radio frequency interference, providing a pristine environment for detecting
<v Speaker 1>the faint signals from the early universe. Several projects are
<v Speaker 1>underway to deploy lunar orbiting satellites equipped with radio antennas
<v Speaker 1>to map these ancient signals. One such initiative is the
<v Speaker 1>collaboration between the British company Blue Sky Space and the
<v Speaker 1>Italian Space Agency. They are designing a fleet of cube
<v Speaker 1>SATs intended to orbit the Moon and detect faint radio
<v Speaker 1>signals from the Union versus early periods. These satellites aim
<v Speaker 1>to capture signals from the dark ages before the formation
<v Speaker 1>of the first stars, offering insights into the universe's infancy.
<v Speaker 1>The project builds on previous efforts such as NASA's rolls
<v Speaker 1>as one and the upcoming LUCNIT project. Blue Skies also
<v Speaker 1>proposes integrating their satellites into ESA's Moonlight program, which envisions
<v Speaker 1>a constellation of satellites for lunar communication and navigation, thereby
<v Speaker 1>enabling accurate positioning in data transmission for the observation satellites. Similarly,
<v Speaker 1>China's HONGMNG project, also known as the Discovering Sky at
<v Speaker 1>the Longest Wavelengths DSL project, plans to launch an array
<v Speaker 1>of satellites into lunar orbit to observe the sky at
<v Speaker 1>ultralong wavelengths. This mission aims to probe the early history
<v Speaker 1>of the universe by detecting signals from the zero point
<v Speaker 1>one to thirty megahertz frequency range, which are inaccessible from
<v Speaker 1>Earth due to them the ionosphere and radiofrequency interference. The
<v Speaker 1>project envisions a mother satellite and several daughter satellites forming
<v Speaker 1>a linear array, with the daughter satellites conducting observations and
<v Speaker 1>transmitting data to the mother satellite for processing in communication
<v Speaker 1>with Earth. These lunar based observations focus on detecting the
<v Speaker 1>hydrogen twenty one centimeters line, a spectral line emitted by
<v Speaker 1>neutral hydrogen atoms. This line serves as a powerful probe
<v Speaker 1>of the early universe, providing information about the distribution and
<v Speaker 1>state of matter during the dark ages. By measuring the
<v Speaker 1>twenty one centimeters signal, scientists can gain insights into the
<v Speaker 1>formation of the first stars and galaxies, the nature of
<v Speaker 1>dark matter, and the processes that led to the reionization
<v Speaker 1>of the universe. The deployment of lunar orbiting satellites for
<v Speaker 1>mapping the early universe represents a significant advancement in our
<v Speaker 1>ability to study the cosmos By utilizing them the Moon's
<v Speaker 1>unique environment, these missions aim to overcome the limitations of
<v Speaker 1>Earth based observations and open a new window into the
<v Speaker 1>universe's formative epics. The data collected from these missions will
<v Speaker 1>not only enhance our understanding of the universe's origins, but
<v Speaker 1>also inform models of cosmic evolution and the fundamental physics
<v Speaker 1>governing the cosmos. The hidden life of red galaxies. The
<v Speaker 1>universe doesn't come with an instruction manual, but if it did,
<v Speaker 1>Charles Steinhardt, assistant professor at the University of Missouri, suspects
<v Speaker 1>there would be entire sections missing. Either the cosmos has
<v Speaker 1>always been governed by rules we don't fully understand, or
<v Speaker 1>we've misread the script from the start. For decades, astronomers
<v Speaker 1>have comfortably placed galaxies into two broad categories, blue ones
<v Speaker 1>teeming with young stars and actively forming new ones. And
<v Speaker 1>red ones characterized as older, quieter systems that have ceased
<v Speaker 1>star production. This classification, long considered foundational, is now being reconsidered.
<v Speaker 1>Steinhardt proposes that there is a third, overlooked type of galaxy,
<v Speaker 1>one that complicates the binary and challenges how we interpret
<v Speaker 1>cosmic history. These are red star forming galaxies. Unlike the
<v Speaker 1>blue galaxies bursting with high mass luminous stars, red star
<v Speaker 1>forming galaxies give birth to mostly low mass stars. Their
<v Speaker 1>appearance remains red not because they are old and inert,
<v Speaker 1>but because the kinds of stars they form don't shine
<v Speaker 1>as brightly or as blue as their massive counterparts. According
<v Speaker 1>to Steinhardt, this distinction isn't just cosmetic. It solves a
<v Speaker 1>couple of deep, unresolved problems in astrophysics. One of them
<v Speaker 1>concerns the long standing discrepancies between black hole mass and
<v Speaker 1>stellar mass. Another issue lies in the differing initial mass
<v Speaker 1>functions observed in blue and red galaxies, distributions that determine
<v Speaker 1>the variety of stars formed at birth. These differences couldn't
<v Speaker 1>be adequately explained by aging or by the usual suspects
<v Speaker 1>like galactic mergers. What Steinhardt and his team are proposing
<v Speaker 1>is more than a new label. It's a revised narrative
<v Speaker 1>of the cosmos itself. If red star forming galaxies were
<v Speaker 1>more prevalent or influential than previously understood, our estimates of
<v Speaker 1>total star formation across the universe's history might be far
<v Speaker 1>too low. In other words, the universe might be significantly
<v Speaker 1>more productive than we've assumed. The consequences of this are broad.
<v Speaker 1>It would alter the way astronomers interpret the timeline of
<v Speaker 1>galaxy evolution, forcing a revision of models that once followed
<v Speaker 1>a clear linear path from youthful blue spirals to dormant
<v Speaker 1>red ellipticals. This idea spills over into how we think
<v Speaker 1>about other odd types of galaxies as well, such as
<v Speaker 1>post starburst galaxies. These have traditionally been explosed as the
<v Speaker 1>aftermath of violent mergers, where two galaxies collide, leading to
<v Speaker 1>a quick burst of star formation that exhausts available gas
<v Speaker 1>and leaves the system in a quiet red state. But
<v Speaker 1>what if that's not always the case. Steinhardt proposes that
<v Speaker 1>some post starburst galaxies may never have gone through such
<v Speaker 1>an intense phase. Instead, they might have slowly and steadily
<v Speaker 1>produced low mass stars enough to classify them as still
<v Speaker 1>forming stars, just not in the way astronomers have been
<v Speaker 1>trained to look for. If this is true, the very
<v Speaker 1>definition of what counts as a post starburst galaxy may
<v Speaker 1>need rethinking. Some of these systems may be quietly thriving
<v Speaker 1>in their own red hued way. The implications are enormous.
<v Speaker 1>If this third category exists in meaningful numbers, it opens
<v Speaker 1>the door to a new interpretation of how galaxies live
<v Speaker 1>and die. It challenges long held beliefs about stellar populations
<v Speaker 1>and the mechanics of galactic evolution. It reframes what we
<v Speaker 1>thought we understood about the color and life cycle of
<v Speaker 1>the cosmos itself. Steinhardt isn't working alone in this endeavor.
<v Speaker 1>At the University of Missouri's Department of Physics, undergraduate students
<v Speaker 1>are already preparing to expand the investigation. Matthius Harper and
<v Speaker 1>his team will delve deeper into the evidence, trying to
<v Speaker 1>identify more galaxies that might fit the red star forming profile. Simultaneously,
<v Speaker 1>Carter Meierhoff and Zach Barowiak are leading a separate effort
<v Speaker 1>using data from the European Space Agency's GAIA satellite, which
<v Speaker 1>tracks the positions and properties of over two billion stars
<v Speaker 1>within the Milky Way. By analyzing this vast trove of data,
<v Speaker 1>the team hopes to shed new light on stellar populations
<v Speaker 1>and the kinds of stars that dominate different galactic environments.
<v Speaker 1>If these efforts bear fruit, it could mark a turning point.
<v Speaker 1>The story of galaxy may no longer be a simple
<v Speaker 1>to act play with blue beginnings and red endings. There
<v Speaker 1>may be a whole middle chapter written in shades of red,
<v Speaker 1>waiting to be fully understood. Perseverance uncovers Martian history. NASA's
<v Speaker 1>Perseverance rover has been exploring the rim of Jazaro Crater,
<v Speaker 1>uncovering a remarkable variety of rocks that provide a unique
<v Speaker 1>window into the geological history of Mars. This area has
<v Speaker 1>turned out to be a treasure trove of intriguing rocky outcrops,
<v Speaker 1>offering valuable insights into the planet's past and its potential
<v Speaker 1>to support life. Since January twenty twenty five, Perseverance has
<v Speaker 1>made significant progress in its mission, with the rover extracting
<v Speaker 1>core samples from five different rocks along the crater's rim.
<v Speaker 1>These samples are then sealed in tubes for future analysis
<v Speaker 1>and return to Earth. The rover has also conducted in
<v Speaker 1>death investigations on numerous other rocks, employing tools like a
<v Speaker 1>laser to set study eighty three additional rocks from a distance.
<v Speaker 1>This marks the fastest pace of scientific data collection since
<v Speaker 1>the rover landed on Mars more than four years ago.
<v Speaker 1>The rovers climb up the western side of Jazaro Crater
<v Speaker 1>took about three and a half months with perseverance, reaching
<v Speaker 1>the rim on December twelfth, twenty twenty four. The science
<v Speaker 1>team now finds itself exploring a four hundred and forty
<v Speaker 1>five foot tall slope known as which Hazel Hill, where
<v Speaker 1>they have been discovering a stunning diversity of rocks. This
<v Speaker 1>abundance of very geological features was more than the scientists
<v Speaker 1>had hoped for in earlier missions. Finding unique rocks for
<v Speaker 1>study could take months, but here on the rim of Jazero,
<v Speaker 1>new and fascinating rocks are found everywhere. The area around
<v Speaker 1>Jazaro Crater's western rim is particularly interesting because it contains
<v Speaker 1>rocks that were once deep underground, ejected by meteor impacts
<v Speaker 1>that occurred billions of years ago. These rocks, many of
<v Speaker 1>which have been fragmented by violent impacts, sit next to
<v Speaker 1>well preserved layered rocks that formed at the surface in
<v Speaker 1>mars early geologic past. Some of these rocks show signs
<v Speaker 1>of past water activity, while others have remained relatively untouched
<v Speaker 1>by water over the ends. The variety in age of
<v Speaker 1>these rocks allows scientists to trace the planet's geological evolution
<v Speaker 1>over a vast timespan. One of the earliest rock samples
<v Speaker 1>taken from this area was named Silver Mountain, which Perseverance
<v Speaker 1>collected on January twenty eighth, twenty twenty five. This sample
<v Speaker 1>came from a rock known as Shallow Bay, believed to
<v Speaker 1>have formed at least three point nine billion years ago
<v Speaker 1>during Mars Noekian period, which marks the planet's earliest geologic era.
<v Speaker 1>The rock may have been altered by an ancient meteor impact,
<v Speaker 1>which is common in this region. Another intreating discovery was
<v Speaker 1>made a short distance away, where a different outcrop contained
<v Speaker 1>igneous minerals that crystallized from magma deep within the Martian crust.
<v Speaker 1>These minerals are particularly valuable because they preserve information about
<v Speaker 1>the conditions that existed when the rock formed. However, not
<v Speaker 1>all attempts to sample these rocks were successful. Perseverance tried
<v Speaker 1>to core a rock containing igneous minerals, but two attempts failed.
<v Speaker 1>Due to the rock's crumbly texture. The rover then moved
<v Speaker 1>to another site five hundred and twenty feet away, where
<v Speaker 1>it successfully collected a sample from a rock called Tablelands.
<v Speaker 1>This rock is composed largely of serpentine minerals, which form
<v Speaker 1>when water interacts with iron and magnesium rich rocks, a
<v Speaker 1>process that often causes the rocks to expand in fracture.
<v Speaker 1>The serpentinization process can also produce hydrogen gas, which may
<v Speaker 1>play a role in the creation of methane in the
<v Speaker 1>presence of carbon dioxide on Earth. Such rocks are known
<v Speaker 1>to support microbial life, making them particularly intriguing in the
<v Speaker 1>search for signs of past or present life on Mars.
<v Speaker 1>One of the challenge's perseverance faced in collecting the Tableland
<v Speaker 1>sample was sealing the sample tube. The powdered rock at
<v Speaker 1>the top of the tube made it difficult to achieve
<v Speaker 1>a proper seal. To solve this problem, the rover's team
<v Speaker 1>employed a technique known as a flick maneuver. This technique
<v Speaker 1>involved using the rover's robotic arm to vibrate the tube,
<v Speaker 1>clearing any obstruction at the top. After several attempts, the
<v Speaker 1>team was able to successfully seal the sample on March second,
<v Speaker 1>twenty twenty five, ensuring that it could be stored for
<v Speaker 1>later return to Earth. After sealing the tableland sample, Perseverance
<v Speaker 1>collected another sample from a rock called Maine River, which
<v Speaker 1>was notable for its alternating bands of bright and dark minerals.
<v Speaker 1>These bands were unlike anything the science team had seen before,
<v Speaker 1>suggesting that the rock had undergone a unique geological history.
<v Speaker 1>The rover has continued to explore which Hazel Hill, analyzing
<v Speaker 1>additional rocky outcrops such as Sally's Cove, Dennis Pond, and
<v Speaker 1>Mount Pearl. The team is eager to continue their investigations,
<v Speaker 1>confident that more exciting discoveries await. The exploration of Jazaro
<v Speaker 1>Crater's rim has proven to be a whirlwind of scientific activity,
<v Speaker 1>with each new rock sample providing valuable data that will
<v Speaker 1>help researchers piece together the story of Mars past. Perseverance's
<v Speaker 1>mission continues with the science team using the data they
<v Speaker 1>have gathered to plan their next steps in this exciting
<v Speaker 1>chapter of Martian exploration. As they continue to study the
<v Speaker 1>crater rim, they remain hopeful that more groundbreaking discoveries are
<v Speaker 1>just around the corner.
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