Unveiling the Unseen: Neutrinos Illuminate a New Image of the Milky Way

The Milky Way galaxy has always been studied using different types of light, from visible starlight to radio waves. However, scientists have now taken a unique approach by using invisible particles called neutrinos to create a new image of our galaxy. Neutrinos are ghost-like particles that usually pass through Earth without being noticed. By determining the origin of thousands of neutrinos, researchers have produced the first-ever galactic portrait using particles instead of light.

This breakthrough was made possible by a collaboration of scientists using the IceCube Neutrino Observatory, located at the Amundsen-Scott South Pole Station in Antarctica and supported by the U.S. National Science Foundation. The observatory consists of thousands of sensors buried deep within a cubic kilometer of pristine ice. It detects high-energy neutrinos from space and provides valuable data. The results of this research were presented at an event at Drexel University and will be published in the journal Science.

The moment Naoko Kurahashi Neilson, a physicist from Drexel University, and her two doctoral students examined the neutrino-based image, they realized its significance. This innovative computational analysis was made possible by funding from the NSF's Faculty Early Career Development program. Denise Caldwell, the director of NSF's Physics Division, emphasizes that breakthroughs in science often rely on technological advancements. The IceCube detector's sensitivity, combined with new data analysis tools, has given scientists a fresh perspective on our galaxy. As these capabilities continue to improve, we can anticipate a clearer and more detailed image of our galaxy, potentially uncovering hidden features that have never been seen before.

Francis Halzen, a physicist at the University of Wisconsin-Madison and the principal investigator at IceCube, highlights the intriguing fact that the universe shines brighter in neutrinos compared to any other form of light. However, detecting and distinguishing neutrinos from other interstellar particles is a challenging task. Determining the source of neutrinos is an even more ambitious goal. When neutrinos interact with the ice beneath IceCube, they produce faint patterns of light, which can be detected. Some patterns point to specific areas of the sky, enabling researchers to identify the sources of neutrinos. These interactions were crucial in the IceCube Collaboration's previous discovery of neutrinos originating from a galaxy 47 million light-years away.

However, some interactions produce less directional patterns, resulting in cascades of diffuse light in the ice. Kurahashi Neilson explains that her colleagues, Sclafani and Hünnefeld, developed a machine-learning algorithm to analyze more than 60,000 neutrino-generated light cascades recorded by IceCube over a decade. After meticulous testing and verification using simulated data, they applied the algorithm to the real data provided by IceCube. The result was an image showing bright spots corresponding to suspected neutrino-emitting locations in the Milky Way. These locations align with areas where gamma rays are observed, which are believed to be produced by collisions between cosmic rays and interstellar gas, a process that should also generate neutrinos.

Sclafani remarks that the measurement of a neutrino counterpart confirms our understanding of the galaxy and the sources of cosmic rays. Over the years, scientists have made numerous astronomical discoveries by expanding their observation methods. They have utilized radio waves, infrared light, gravitational waves, and now neutrinos. Kurahashi Neilson sees the neutrino-based image of the Milky Way as another significant step in this lineage of discovery. She predicts that neutrino astronomy will be refined, just like the methods that came before it, eventually unveiling previously unknown aspects of the universe. For scientists like her, the excitement lies in witnessing something never seen before and gaining a deeper understanding of the universe.

Space Debris: The Threat of Orbital Junk to Astronauts and Satellites

What is a space debris?

Space debris, also known as space junk, refers to any human-made object in orbit around the Earth that no longer serves a useful function. This includes nonfunctional spacecraft, abandoned launch vehicle stages, mission-related debris and fragmentation debris. Space debris can be as large as an inactive satellite or as small as a flake of paint. The real danger of space debris is the speed at which these objects move - more than 28,000 kilometers per hour - which makes even small pieces of debris potentially lethal to spacecraft and satellites.

Space debris is a significant problem for space exploration and poses a threat to both crewed and uncrewed spaceflight. The risk of catastrophic collision between space shuttles and pieces of space debris was estimated to be 1 in 300. In the first collision between an operational satellite and a piece of space debris in July 1996, a fragment from the upper stage of a European Ariane rocket collided with Cerise, a French microsatellite. Cerise was damaged but continued to function[4].

Since the beginning of the space era in 1957, tons of rockets, spaceships, and satellites have been launched into space. At least initially, no one foresaw what to do with them at the end of their useful life. The European Space Agency (ESA) estimates that there are some 900,000 objects over one centimeter in size orbiting Earth today.

Size and types of space junk

Space debris, also known as space junk, is any piece of machinery or debris left by humans in space. It can refer to big objects such as dead satellites that have failed or abandoned launch vehicle stages. It can also be as small as a microscopic chip of paint. The amount of space debris in orbit increases with the growth of the space industry on Earth.

Space debris poses a significant threat to the astronauts and spacecraft that work in Earth's orbit, according to NASA. Even tiny pieces of space junk can cause incredible damage because objects in orbit move at high speeds. For example, during an STS-120 EVA to reinforce a torn solar panel, a pair of pliers was lost, and in an STS-126 EVA, Heidemarie Stefanyshyn-Piper lost a briefcase-sized tool bag.

Rocket upper stages which end up in orbit are a significant source of space debris. In characterizing the problem of space debris, it was learned that much debris was due to rocket upper stages (e.g. the Inertial Upper Stage) which end up in orbit and break up due to decomposition of unvented propellants or residual pressure within fuel tanks. By one estimate, there are a hundred million bits of debris that are a millimeter in size and a hundred million as small as a micron.

Threat to astronauts and spacecraft

Space debris poses a significant threat to astronauts and spacecraft. Space debris can damage spacecraft or space stations due to the high speed at which it travels. The rising population of space debris increases the potential danger to all space vehicles, including the International Space Station. Fortunately, at the moment, space junk doesn't pose a huge risk to our exploration efforts. The biggest danger it poses is to other satellites in orbit.

NASA recognizes the dangers of space debris and has an Orbital Debris Program Office that tracks more than 8,000 orbiting objects larger than 4 inches (10 cm), of which only 7% are operational. The rest are debris - dead satellites, parts of exploded rockets, nuts, bolts, other lost hardware, etc. NASA is also working on ways to mitigate the risks posed by space debris. For example, NASA's Restore-L project aims to refuel and service a satellite in low Earth orbit that was not designed for servicing.

Solutions and Future Challenges

Space debris is a growing problem that poses a significant threat to current and future space missions. It is essential to address this issue to ensure the sustainability of space exploration. There are several solutions for managing space debris, including prevention, removal, and mitigation. Prevention involves designing spacecraft with end-of-life disposal in mind and avoiding in-orbit explosions. Removal involves capturing debris or deorbiting old satellites. Mitigation involves reducing the creation of debris from collisions by employing collision avoidance techniques or removing large objects from orbit.

Several organizations are working on addressing the issue of space debris. The World Economic Forum has launched the world's first Space Sustainability Rating, which aims to reduce space debris and ensure that rapidly increasing space exploration missions are "managed safely". Aerospace's Center for Orbital and Reentry Debris Studies (CORDS) is developing tools and techniques that will analyze potential collision scenarios, study reentry breakups of upper stages and spacecraft, and model debris objects in orbit. ESA is working on mitigating space debris generation by preventing in-orbit explosions and applying both prevention and removal measures broadly and in a timely manner.

In conclusion, addressing the issue of space debris is crucial for ensuring the sustainability of current and future space missions. Several solutions exist for managing space debris, including prevention, removal, and mitigation. Organizations such as the World Economic Forum, Aerospace's CORDS, and ESA are working on developing tools and techniques to address this issue.

Borisov Comet May Be A Common One

Interstellar comets like Borisov may not be all that rare

Borisov Comets (NASA, ESA and D. Jewitt (UCLA))

It is surprising that certain comets such as Halley comets are not very rare. Well, we don't know it yet. Comet is composed of ice with small solar system body, that, when passing close to the Sun, it releases gases which is called outgassing.

In 2019, astronomers spotted something incredible, a rogue comet from another star system. They named it as Borisov, and this icy snowball traveled over a hundred thousand miles per hour, and became the first and only interstellar comet ever detected by humans.

But what if these interstellar visitors - comets, meteors, asteroids, and other debris from beyond our solar system - are more common than we think?

In a new study published Monday in the Monthly Notices of the Royal Astronomical Society, astronomers Amir Siraj and Avi Loeb at the Center for Astrophysics | Harvard & Smithsonian (CfA) present new calculations showing that in the Oort Cloud - a shell of debris in the farthest reaches of our solar system - interstellar objects outnumber objects belonging to our solar system. The calculations, made using conclusions drawn from Borisov, include significant uncertainties, Siraj points out. But even after taking these into consideration, interstellar visitors prevail over objects that are native to the solar system.

Although interstellar objects in the planetary region of the solar system would be rare, but our results clearly show that they are more common than solar system material in the dark reaches of the Oort cloud. Thus, observations with next-generation technology may help confirm the team's results. The Transneptunian Automated Occultation Survey (TAOS II), which is specifically designed to detect comets in the far reaches of our solar system, may also be able to detect one of these passersby. TAOS II may come online as early as this year.

Source: Eurekalert

The origin of magnetic fields in the universe

The galaxy's magnetic field (image source form ETH Zurich)

Astronomers are on the hunt for magnetic fields in our galaxy that were born in the very early universe since they could provide a new way to study the big bang. Magnetic fields are thought to play an important role in star formation within galaxies, and the Milky Way is home to various types of field. Some come from stellar explosions, others from black holes, while some, known as primordial magnetic fields, are believed to come from rapid inflation thought to have occurred fractions of a second after the big bang.

As we know that the magnetic field in the Earth is coming from two poles, indeed, the north and south pole. With that field, our earth including the living thing (well, the human itself) is protected by the solar or any radiation that comes from the outer space. On the other hand, the Earth itself rotates while at the same time orbits to the Sun, which eventually the Sun orbits to the center of the Galaxy. Thus, what makes these planetary movements? Is it a force which is perhaps the magnetic force?

Then, a team of scientist from the University of Cambridge runs a model of simulation about the origin of the magnetic field.

We have never been able to tease these ancient fields apart from the others. We found a way to do so, and I was so surprised that they survived, - says Martin-Alvarez from the University of Cambridge

The team modelled the evolution of recent and primordial magnetic fields in the Milky Way. The group found that primordial magnetic fields always seemed to survive throughout time and could stay far stronger than previously thought, which is based on a previous study. The primordial magnetic fields seem to be distributed more towards the centre of the galaxy, while those that come from stars and black holes are more evenly distributed. The team hopes soon to calculate what astronomers will need to look out for to distinguish these ancient fields.

That could have big implications. If you can measure primordial magnetic fields in one galaxy, you could potentially measure the primordial magnetic field of the universe.

What Is Comet? And Why It Is So Important to be Researched

Regarding to comet, it is a very interesting discussion which is not only to be talked, but also to be researched. Comets are space matters that are known to be the Rosetta Stone, and they are decided to be considered as the origin of the solar system. The chemical composition of comets has been known to be volatile ice, with several mineralogical substances including abundant isotopic matters of dust grains. As a result, understanding comets may have led us to fundamental information related to condensation and agglomeration of space matters as they also travel around the space.

To these days, several information related to comets have been reported by many civilizations. One of the earliest systematic records of comets were reported by the Chinese civilization in 467 BC, where the Kou Kin-ting informed that the comet tails always pointed away from the Sun. In Europe, many philosophers including Aristotle to postulate the association of comets with transient phenomena in the atmosphere of Earth. Ever since those ancient knowledge, middle-ages astronomers such as Tycho Brahe, Newton as well as Kepler put their interests in studying, observing and even recording the comets. However, the most important breakthrough about comet was reported by Edmund Halley.

English astronomer Edmund Halley compared the observed positions of bight stars on the celestial sphere with those found in Ptolemy’s Almagest. Ptolemy’s conclusion stated that three stars had changed position and were not in position of fixed in firmament. Therefore, he deduced the elliptic orbit of cometary movements around the sun, and he found that this is the same comet that orbits around the sun within a period of 75.5 years in 1682. Later, this comet is very popular with the name of Comet Halley. In 1758, his prediction became true as the comet appeared in that year, as well as in 1986. This also showed the world at that time that space objects have regular movements. Thus, comets become invaluable data revealing the true nature of the most primitive bodies in the solar system.

Due to his forecasting, modern astronomical team from former Soviet Union, Japan, Europe and the United States have been starting their interests to comets. In addition, an extensive network for ground-based comet observations was organized by NASA to coordinate the study of comet Halley. This program is called as International Halle Watch (IHW), proved to be successful in maintaining a high level of cometary research in all areas. The latest observation about comet was done to investigate the Rosetta Comet.

The Development of Clocks in Human History

Quantum Clocks

What if you were in an era that there is no such digital technology? You may have found difficulties in finding what time it is now. With today’s standard, successful people are those who are able to organize their activities, and to do that they need to manage their time in daily basis. However, our global population is not distributed in central area, but it is the opposite, which spread all over the world. Thus, the need of standardized time is required to balance the activities, including in stock market and transportation.

One of the international organisations that are responsible in keeping the correct time is the National Institute of Standards and Technology throughout its atomic clock. However, atomic is thought to be having a drawback due to the precision level. In a study published in Nature, current atomic clock cannot be linked throughout global network, so that they proposed the idea of a global network of atomic clocks linked by the strange science of quantum entanglement. This proposal is still theoretical; however it could have given relatively high impacts to the global clocks. Surprisingly, how we could be in Quantum Clocks? Here the previous clocks

Sundial

Sundial. The sundial, which uses a vertical object like a pillar or cross that casts a shadow to indicate the time of day, is the earliest known timekeeping device, appearing around 3500 BC. The device ultimately proved unreliable since, in addition to inference from pesky clouds and storms, the key component was in the sky only half the day.

Pendulum Clocks

Pendulum Clock. The beginning of pendulum clock was pioneered by Dutch mathematician who is Christiaan Huygens in 1656 throughout his invention, the pendulum clock. This type of clock measured time more reliably than the sundial because it can be used to measure time at the night, but it still had its limitations. The clock’s mechanical parts left its accuracy at the mercy of shifting temperatures, pressures and even Earth’s gravitational pull, since pendulums swing faster at lower altitudes and at Earth’s poles.

Chronometer

Chronometer. In a voyage, time is very important to determine the condition of the sea. As the pendulum cannot be used on the sea due to the altitudes, sailors needed reliable clocks. In particular, a clock that could tell the local land time so they could calculate longitude. Enter English carpenter, John Harrison, whose timepiece could determine longitude within half a degree. His clock, called a chronometer later in the 18th century, which is basically a proto-pocket watch, improved accuracy through balance and spring combinations and kept time within 0.8 seconds per day.

Atomic Clock

Atomic Clock. In 1949, the National Institute of Standards and Technology created the first atomic clock, which determined time by measuring how long certain atomic processes last. In 1967, the second itself was officially defined as 9.2 billion oscillations of microwave radiation emanating from a system of cesium atoms. Today’s updated NIST-F2 model boasts an accuracy of one second across 300 million years.

Quantum Clock

Quantum Clock. The proposed quantum clock network could operate by mounting entangled atomic clocks on global satellites or stationing them at various labs located around Earth. As the clocks are quantum linked, each could almost instantly relay its time to one central node, which would average the times and relay them back. Each clock could thus adjust its accuracy, creating what it is called as superclock. With a clock this accurate, scientists could gather more precise real-time measurements of continental shifts, potentially detecting natural disasters like earthquakes, storm, weather forecasting, and many more.

The Surface of Mars Shaped by Rainfall, not Volcanoes

The Surface of Mars (Image credit to NASA)

Research says the fall of rain helped to carve the valley network on the surface of Mars. Consequently, this latest finding also suggests that the Martian atmosphere at the time was considerably colder than first thought, implying to the vital source of life (water).

For decades, scientists have operated under the assumption that the intricate lithosphere of the Red Planet was shaped by the ancient activity of Tharsis plateau, home to the largest volcano in our Solar System – however, new research says the deep and winding valleys on Mars’ surface were actually created by rain and snowfall in the planet’s youth.

Tharsis was formed around 3.7 billion years ago in a period of Martian history known as the Noachian Era and it has long been thought as the cause of these lithosphere alterations, with its massive tonnes causing the mantle to tear and shift as it began to form. Since these valleys are oriented in the same direction, parallel to the equator of the planet, the Tharsis theory has remained the most plausible scientific argument.

A team lead by Sylvain BOuley, a planetary scientist at the University of Paris-Sud, France, theorises that these valleys are instead the networked remains of a complex system of rivers that ran around the surface in a thick, criss-crossed band. More so, these valleys were created during the same period as Tharsis’ formation, rather than as a direct by-product of its rise.

The researchers ran 3D simulations that showed the river network grew during the theorised heavy rainfall of the Noachian Period as the Tharsis bulge continued to rise, with the band shifting over the Martian equator as the period drew a close.