The Most Distant Twin of the Milky Way Ever Observed: Unlocking the Secrets of Galaxy Formation in the Early Universe

In a groundbreaking discovery, an international team led by the University of Geneva has identified the most distant spiral galaxy candidate known to date. This remarkable find, named Zhúlóng, existed just one billion years after the Big Bang and showcases a surprisingly mature structure, with a central old bulge, a large star-forming disk, and well-defined spiral arms.

The discovery was made using data from the James Webb Space Telescope (JWST) and offers crucial insights into how galaxies can form and evolve so rapidly in the early Universe. This finding challenges our previous understanding of galaxy formation, which suggested that massive spiral galaxies like the Milky Way take billions of years to develop.

Zhúlóng’s disk spans over 60,000 light-years, comparable to our own galaxy, and contains more than 100 billion solar masses in stars. This makes it one of the most compelling Milky Way analogues ever found at such an early time, raising new questions about how massive, well-ordered spiral galaxies could form so soon after the Big Bang.

The discovery was made possible by JWST’s deep infrared imaging and its unique “pure parallel” mode, which allows for high-quality images to be collected while the main instrument is taking data on another target. This strategy has proven essential for discovering massive galaxies, as they are incredibly rare.

“This discovery shows how JWST is fundamentally changing our view of the early Universe,” says Prof. Pascal Oesch, associate professor in the Department of Astronomy at the Faculty of Science of UNIGE and co-principal investigator of the PANORAMIC program.

Future observations with JWST and the Atacama Large Millimeter Array (ALMA) will help confirm Zhúlóng’s properties and reveal more about its formation history. As new wide-area JWST surveys continue, astronomers expect to find more such galaxies – offering fresh insights into the complex processes shaping galaxies in the early Universe.

The discovery of Zhúlóng has far-reaching implications for our understanding of galaxy evolution, and it is a testament to the power of modern astronomy’s ability to unlock the secrets of the cosmos.

The long-standing debate over the origin of water on Earth has finally been put to rest by a team of researchers at the University of Oxford. Using a rare type of meteorite known as an enstatite chondrite, which has a composition analogous to that of the early Earth (4.55 billion years ago), they have uncovered crucial evidence for the origin of water on our planet.

The research team analyzed the elemental composition of a meteorite known as LAR 12252, originally collected from Antarctica. They used an elemental analysis technique called X-Ray Absorption Near Edge Structure (XANES) spectroscopy at the Diamond Light Source synchrotron at Harwell, Oxfordshire. This powerful tool allowed them to search for sulphur-bearing compounds in the meteorite’s structure.

When scanning the sample, the team focussed their efforts on the non-crystalline parts of the chondrules, where hydrogen had been found before. However, serendipitously, they discovered that the matrix itself was incredibly rich in hydrogen sulphide. In fact, their analysis found that the amount of hydrogen in the matrix was five times higher than that of the non-crystalline sections.

This finding suggests that the material which our planet was built from was far richer in hydrogen than previously thought. Without hydrogen, a fundamental elemental building-block of water, it would have been impossible for our planet to develop the conditions to support life.

The research team’s discovery contradicts the popular theory that water on Earth originated from asteroids bombarding its surface. Instead, their findings suggest that Earth had the hydrogen it needed to create water from when it first formed. This supports the idea that the formation of water on Earth was a natural process, rather than a fluke of hydrated asteroids bombarding our planet after it formed.

Tom Barrett, DPhil student in the Department of Earth Sciences at the University of Oxford, who led the study, said: “We were incredibly excited when the analysis told us the sample contained hydrogen sulphide — just not where we expected! Because the likelihood of this hydrogen sulphide originating from terrestrial contamination is very low, this research provides vital evidence to support the theory that water on Earth is native — that it is a natural outcome of what our planet is made of.”

Co-author Associate Professor James Bryson (Department of Earth Sciences, University of Oxford) added: “A fundamental question for planetary scientists is how Earth came to look like it does today. We now think that the material that built our planet — which we can study using these rare meteorites — was far richer in hydrogen than we thought previously. This finding supports the idea that the formation of water on Earth was a natural process, rather than a fluke of hydrated asteroids bombarding our planet after it formed.”

The discovery of this hidden secret to Earth’s water origin has significant implications for our understanding of the planet’s history and evolution. It suggests that the conditions necessary for life to arise were present from the very beginning, and that the formation of water was an integral part of the process.

The discovery of 2M1510 (AB) b has sent shockwaves through the astronomical community, as it marks the first-ever confirmed instance of a planet orbiting a pair of stars in a perpendicular configuration.

While several planets have been found to orbit binary star systems before, these exoplanets typically follow orbits that align with the plane in which their host stars rotate around each other. However, the unprecedented discovery of 2M1510 (AB) b has shed new light on the possibility of polar planets existing in our universe.

A team of astronomers led by Thomas Baycroft from the University of Birmingham used the European Southern Observatory’s Very Large Telescope (VLT) to make this groundbreaking find. By refining the orbital and physical parameters of the two brown dwarfs in 2M1510, they were able to infer the existence of an exoplanet on a polar orbit around them.

“We reviewed all possible scenarios, and the only one consistent with the data is if a planet is on a polar orbit about this binary,” says Baycroft. “I am particularly excited to be involved in detecting credible evidence that this configuration exists.”

The 2M1510 system consists of a pair of young brown dwarfs, which are objects larger than gas-giant planets but too small to be considered proper stars. These two brown dwarfs produce eclipses as seen from Earth, making them part of an eclipsing binary. This particular system is incredibly rare, with only the second pair of eclipsing brown dwarfs known to date and containing the first exoplanet ever found on a path at right angles to the orbit of its host stars.

“A planet orbiting not just a binary, but a binary brown dwarf, as well as being on a polar orbit is rather incredible and exciting,” says co-author Amaury Triaud. “The discovery was serendipitous, in the sense that our observations were not collected to seek such a planet, or orbital configuration. As such, it is a big surprise.”

Overall, this groundbreaking discovery has opened up new avenues for research into polar planets and their potential existence in our universe.