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Milky Way

The Milky Way is a barred spiral galaxy which forms part of the Local Group. Although the Milky Way is but one of billions of galaxies in the universe, the Galaxy has special significance to humanity as it is the home of the solar system. The term "milky" originates from the hazy band of white light appearing across the celestial sphere visible from Earth, which comprises stars and other material lying within the galactic plane. The galaxy appears brightest in the direction of Sagittarius, towards the galactic center. Relative to the celestial equator, the Milky Way passes as far north as the constellation of Cassiopeia and as far south as the constellation of Crux, indicating the high inclination of Earth's equatorial plane and the plane of the ecliptic relative to the galactic plane. The fact that the Milky Way divides the night sky into two roughly equal hemispheres indicates that the solar system lies close to the galactic plane. The main disk of the Milky Way Galaxy is about 80,000 to 100,000 light-years in diameter, about 250,000 to 300,000 light-years in circumference, and outside the Galactic core, about 1,000 light-years in thickness. It is composed of 200 to 400 billion stars.

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Space & Time News

September 12, 2025

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Scientists using Google’s quantum processor have taken a major step toward unraveling the deepest mysteries of the universe. By simulating fundamental interactions described by gauge theories, the ...
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NASA and ISRO s NISAR satellite has just reached a major milestone: the successful deployment of its enormous 39-foot antenna reflector in orbit. Folded up like an umbrella during launch, the reflector is now fully extended and ready to support ...
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Thirteen years after landing on Mars, NASA’s Curiosity rover is running smarter and more efficiently than ever. With new autonomy and multitasking capabilities, it’s maximizing the output from its long-lasting nuclear power source while ...
Engineers at the University of Wisconsin-Madison uncovered a critical flaw in how lunar and Martian rovers are tested on Earth. Simulations revealed that test results have been misleading for decades because researchers only adjusted rover weight to ...
UF engineers, backed by DARPA and NASA, are perfecting laser-forming techniques that let metal sheets fold themselves into giant solar arrays, antennas, and even space-station parts right in ...
The LSST camera at the Vera C. Rubin Observatory has released its jaw-dropping first images, each capturing 45 times the area of the full moon in one shot. Over the next ten years, this cosmic giant will scan the southern sky in ultra-HD, helping ...

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