Astronomers Release a Cosmic Atlas of 380,000 Galaxies in our Neighborhood

Optical mosaics of 42 galaxies from the SGA-2020 sorted by increasing angular diameter from the top-left to the bottom-right. This figure illustrates the tremendous range of types, sizes, colors and surface brightness profiles, internal structure, and environments of the galaxies in the SGA. Credit: CTIO/NOIRLab/DOE/NSF/AURA/J. Moustakas.

The Milky Way is just one galaxy in a vast cosmic web that makes up the Universe’s large-scale structure. While ESA’s Gaia spacecraft is building a map of our stellar neighborhood, a team of astronomers with the Dark Energy Spectroscopic Instrument (DESI) Legacy Survey have released a comprehensive galactic map that includes all the data from three wide-ranging surveys completed between 2014 and 2017. Called the Siena Galaxy Atlas (SGA), it contains the distance, location, and chemical profile of 380,000 galaxies across half of the night sky.

“Previous galaxy compilations have been plagued by incorrect positions, sizes and shapes of galaxies, and also contained entries which were not galaxies but stars or artifacts,” explained Arjun Dey, an astronomer with NOIRLab, who was involved in the project. “The SGA cleans all this up for a large part of the sky. It also provides the best brightness measurements for galaxies, something we have not reliably had before for a sample of this size.”

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Juno Completes its Closest Flyby of Io Yet

Not since the Galileo mission ended 20 years ago have we seen such great images of Io. NASA's Juno spacecraft captured this image with its JunoCam instrument on October 15th from less than 12,000 km altitude. Ted Stryk processed the image. Image Credit: Ted Stryk/NASA/JPL-Caltech/SwRI/MSSS/

Jupiter’s ocean moons capture most of our attention because of their potential habitability. But Io, Jupiter’s bad-boy volcanic moon, is in a class of its own. There’s nothing else like it in the Solar System, and NASA’s Juno spacecraft captured new images of the volcanic satellite during its closest approach yet.

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Thinking About Time Travel Helps Solve Problems in Physics

Physicists have shown that simulating models of hypothetical time travel can solve experimental problems that appear impossible to solve using standard physics. Credit: Yaroslav Kushta via Getty Images

Time travel. We’ve all thought about it at one time or another, and the subject has been explored extensively in science fiction. Once in a while, it is even the subject of scientific research, typically involving quantum mechanics and how the Universe’s four fundamental forces (electromagnetism, weak and strong nuclear forces, and gravity) fit together. In a recent experiment, researchers at the University of Cambridge showed that by manipulating quantum entanglements, they could simulate what could happen if the flow of time were reversed.

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Blue Origin Reveals its Orbital Maneuvering Vehicle: Blue Ring

Artist rendering of Blue Origin’s spacecraft platform, Blue Ring, which is seen featuring a multitude of payloads and accessories. (Credit: Blue Origin)

The Jeff Bezos-founded aerospace company, Blue Origin, recently announced its new and upcoming Swiss army knife-style spacecraft platform, Blue Ring, which comes after very little public discussion by Blue Origin regarding this project. For example, a January 2023 story broke when Blue Origin briefly announced a job posting for “Blue Ring Senior Program Manager” on its “Careers” page, but the job was pulled less than 24 hours later. Overall, Blue Origin has been quite mum about Blue Ring.

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If There Was Ever Life on Mars, this Ancient Mud Lake is the Perfect Place to Look

This image of Mars shows a region dominated by massive outflows from the planet's Southern Highlands to its Northern Lowlands. All that sediment could hold evidence for ancient life, if scientists look in the right place. Image Credit: NASA / JPL-Caltech / MOLA Science Team

When it comes to Mars and our ongoing efforts to understand that planet’s ancient habitability, evidence is so far elusive. But scientists have an idea where the evidence is likely hiding: in sediments.

New research shows that an ancient mud lake is a good place to explore.

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NASA Mission Had the Perfect View for the Recent Solar Eclipse

As the Moon crossed between the Sun and Earth during the 2023 annular eclipse, its shadow darkened skies across the United States. NASA image courtesy of the DSCOVR EPIC team.
As the Moon crossed between the Sun and Earth during the October 14, 2023 annular eclipse, its shadow darkened skies across the United States. NASA image courtesy of the DSCOVR EPIC team.

Eclipse-gazers across the United States got a chance last weekend to watch as the Moon aligned with the Sun to create an annular eclipse. They watched from the ground for a short experience of not-quite-darkness. NASA’s Deep Space Climate Observatory (DSCVR) caught the action from Earth orbit for a different view of the event.

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This Dark Nebula Hides an Enormous Star

Stars forming in this dark nebula, named G35.2-0.7N, are particularly massive and many of them will explode as supernovae. Image Credit: ESA/Hubble & NASA, R. Fedriani, J. Tan

The birth of a star is a spectacular event that plays out behind a veil of gas and dust. It’s a detailed process that takes millions of years to play out. Once a star leaves its protostar stage behind and begins its life of fusion, the star’s powerful radiative output blows the veil away.

But before then, astrophysicists are at a disadvantage.

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Air Showers Ruin Astrophotos, but They Could be a New Method for Studying the Universe

An example of a cosmic-ray extensive air shower recorded by the Subaru Telescope. The highlighted tracks, which are mostly aligned in similar directions, show the shower particles induced from a high-energy cosmic ray. Credit: NAOJ/Hyper Suprime-Cam (HSC) Collaboration

Cosmic rays are a fascinating and potentially hazardous phenomenon. These high-energy particles typically consist of protons that have been stripped of their electrons and accelerated to nearly the speed of light. When these rays collide with Earth’s atmosphere, an enormous amount of secondary particles known as an “air shower” results. Ordinarily, these showers are a source of frustration for astronomers since they leave “tracks” on telescope images that obscure the celestial objects (asteroids, stars, galaxies, exoplanets, etc.) being observed.

However, a research team from the National Astronomical Observatory of Japan (NAOJ) and Osaka Metropolitan University has found a new application for these energetic particles. Using a novel method, they could observe these extensive cosmic-ray air showers with unprecedented precision. The key to their method is the Subaru Prime Focus Camera (Suprime-Cam) mounted on the Subaru Telescope atop the Mauna Kea volcano in Hawaii. This method and the team’s findings could provide a new method for studying the Universe’s most energetic particles.

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The Combination of Oxygen and Methane Could Reveal the Presence of Life on Another World

Artist’s impression of a Super-Earth orbiting a Sun-like star. Credit: ESO

In searching for life in the Universe, a field known as astrobiology, scientists rely on Earth as a template for biological and evolutionary processes. This includes searching for Earth analogs, rocky planets that orbit within their parent star’s habitable zone (HZ) and have atmospheres composed of nitrogen, oxygen, and carbon dioxide. However, Earth’s atmosphere has evolved considerably over time from a toxic plume of nitrogen, carbon dioxide, and traces of volcanic gas. Over time, the emergence of photosynthetic organisms caused a transition, leading to the atmosphere we see today.

The last 500 million years, known as the Phanerozoic Eon, have been particularly significant for the evolution of Earth’s atmosphere and terrestrial species. This period saw a significant rise in oxygen content and the emergence of animals, dinosaurs, and embryophyta (land plants). Unfortunately, the resulting transmission spectra are missing in our search for signs of life in exoplanet atmospheres. To address this gap, a team of Cornell researchers created a simulation of the atmosphere during the Phanerozoic Eon, which could have significant implications in the search for life on extrasolar planets.

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