This NASA/ESA Hubble Space Telescope image features the spiral galaxy IC 4709 located around 240 million light-years away in the southern constellation Telescopium. Hubble beautifully captures its faint halo and swirling ...
Astronomy
Sep 6, 2024
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It's not easy making green. For years, scientists have fabricated small, high-quality lasers that generate red and blue light. However, the method they typically employ—injecting electric current into semiconductors—hasn't ...
Optics & Photonics
Aug 28, 2024
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Launched in 2011, NASA's NEOWISE mission operated in Earth's orbit until late last week. It detected more than 3,000 near-Earth objects or NEOs—asteroids or comets whose orbits can bring them close to Earth, even with the ...
Astronomy
Aug 13, 2024
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The primary instrument for NASA's Nancy Grace Roman Space Telescope is a sophisticated camera that will survey the cosmos from the outskirts of our solar system all the way out to the edge of the observable universe. Called ...
Astronomy
Aug 13, 2024
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Infrared (IR) radiation is electromagnetic radiation whose wavelength is longer than that of visible light (400-700 nm), but shorter than that of terahertz radiation (100 µm - 1 mm) and microwaves (~30,000 µm). Infrared radiation spans roughly three orders of magnitude (750 nm and 100 µm).
Direct sunlight has a luminous efficacy of about 93 lumens per watt of radiant flux, which includes infrared (47% share of the spectrum), visible (46%), and ultra-violet (only 6%) light. Bright sunlight provides luminance of approximately 100,000 candela per square meter at the Earth's surface.
This text uses material from Wikipedia, licensed under CC BY-SA
