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What Ancient Stars Say About the Milky Way’s History

When you look at models of galaxy formation to try and understand how the Milky Way came about, there’s a common theme: material comes together. It does it over and over again, from the protogalaxy to galaxy collisions to star formation, to planetary formation. This is what astronomers term a ” “hierarchical model.” According to a hierarchical model of galaxy formation, small galactic building blocks formed first, only to coalesce into ever larger galaxies over the lifetime of the Universe. Stars formed early in the process. In one, baby galaxies collide with each other to form larger galaxies. This is what astronomers call the “top-down” theory of formation. In the other, the protogalaxies merge to form larger ones that eventually begin to spin and produce disk-like structures. This is often referred to as the “bottom-up” theory of formation. Both models imply that the very oldest stars in a galaxy should be present in the dense, inner regions. This certainly seems to be true for the Milky Way. And, using spectroscopy, astronomers found that the chemical properties of those ancient stars match those of the earliest stars in the Universe.

Astronomers see time moving in slow motion in early universe

A recent study published in Nature Astronomy has provided evidence for cosmic time dilation, confirming Einstein’s prediction that the expansion of space influences the flow of time. By analyzing the flickering of nearly 200 quasars over two decades, researchers found that the universe appeared to be ticking five times slower when it was only a billion years old. This discovery demonstrates that quasars conform to the rules of cosmology, dispelling the notion that they posed a challenge to our understanding of the universe.

Link: https://youtu.be/3prF2V_a2gY

The Human Body in Space

In the space, the human body undergoes several changes and faces various risks in space. These risks are categorized into the acronym “RIDGE”: Space Radiation: Astronauts are exposed to higher levels of radiation, which can increase the risk of cancer and other health issues. Isolation and Confinement: Long-duration space missions involve isolation and confinement, which can lead to psychological and emotional challenges such as loneliness and depression. Distance from Earth: Astronauts on missions to distant locations like Mars will face communication delays and limited real-time support, requiring them to handle emergencies and make critical decisions independently. Gravity Fields: Living in microgravity causes muscle and bone loss, cardiovascular deconditioning, changes in vision, fluid shifts, and immune system alterations. Hostile/Closed Environments: NASA’s the design of spacecraft ecosystems aims to ensure the health and well-being of astronauts during extended missions to the Moon, Mars, and beyond. Addressing these risks is crucial for the health and safety of astronauts, especially for longer missions beyond the International Space Station. NASA’s research aims to understand these effects and develop countermeasures to ensure astronauts’ well-being during extended space exploration.

Radio noise from satellite constellations could interfere with astronomers

Astronomers have detected electromagnetic interference emissions from SpaceX Starlink satellites during their passage over a Dutch radio observatory, highlighting the unintended interference caused by satellite constellations and the lack of international regulations regarding such emissions; while the impact on radio astronomy is still uncertain, the findings emphasize the need for mitigation measures and clear regulations to protect radio astronomy bands from unintended radiation as more satellite constellations are planned.

‘Like a mirror’: Astronomers identify most reflective exoplanet

Astronomers have discovered a scorching hot exoplanet, named LTT9779b, that reflects 80 percent of the light from its host star, making it as shiny as Venus. This Neptune-sized planet is located over 260 light years away from Earth and orbits its star in just 19 hours. Despite its extreme temperatures, metallic clouds have formed in its atmosphere, acting as a mirror to reflect light and prevent the planet’s atmosphere from being blown away. This finding challenges previous assumptions about planets in the “Neptune desert” and sheds light on the survival mechanisms of such planets. The observations were made using Europe’s Cheops space telescope.

This Week in Our Art Corner

This week, we have chosen an immersive content from the dusty shelves of the series sea. “Cosmic Journeys” is a science fiction series set in the near future. The story tells the adventures of the space exploration ship Horizon, led by a brave team with a spirit of exploration. The Horizon crew embarks on dangerous and exciting missions to explore unknown galaxies, star systems and the depths of space.

In each episode, the team reaches a new planet or galaxy and tries to unravel the mysteries they encounter in those places. At the same time, the personal journeys, pasts and futures of team members become part of the story. Internal conflicts, friendships, loves and losses also increase the emotional depth of the series. “Cosmic Journeys” presents an unforgettable series of experiences that invite viewers to pursue the unknown and explore the depths of the universe.