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Mercury (planet)
Mercury is the innermost and smallest planet in the solar system, orbiting the Sun once every 88 days. It ranges in brightness from about −2.0 to 5.5 in apparent magnitude, but is not easily seen; its greatest angular separation from the Sun (greatest elongation) is only 28.3° (it can only be seen in twilight). Comparatively little is known about the planet: the only spacecraft to approach Mercury was Mariner 10 from 1974 to 1975, which mapped only 40 to 45 percent of the planet's surface.
Physically, Mercury is similar in appearance to the Moon as it is heavily cratered. It has no natural satellites and no substantial atmosphere. The planet has a large iron core which generates a magnetic field about 1 percent as strong as that of the Earth. Surface temperatures on Mercury range from about 90 to 700 K (-180 to 430°C) , with the subsolar point being the hottest and the bottoms of craters near the poles being the coldest.
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Space & Time News
May 20, 2026
May 18, 2026 NASA’s Nancy Grace Roman Space Telescope is now aiming for an earlier launch in September 2026. Designed to explore dark matter, dark energy, and distant exoplanets, the telescope will capture massive, ultra-detailed surveys of the cosmos using ...
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May 15, 2026 NASA’s Roman Space Telescope could expose a vast hidden population of neutron stars lurking unseen across the Milky Way. By detecting subtle shifts in starlight caused by gravity, the mission may ...
May 12, 2026 Astronomers using NASA’s James Webb Space Telescope have created the clearest map yet of the universe’s “cosmic web” — the enormous hidden structure that connects galaxies across space. By ...
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May 11, 2026 NASA’s Curiosity rover had an unexpectedly stubborn Mars souvenir after drilling into a rock nicknamed “Atacama” — the entire chunk ripped loose from the ground and stayed stuck to the rover’s drill. Engineers watched as Curiosity shook, ...
May 6, 2026 A bold step toward returning humans to the Moon is underway with Blue Origin’s uncrewed MK1 “Endurance” lander, designed to test the technologies that future astronauts will rely on. Built in ...
May 6, 2026 A powerful new electromagnetic thruster has taken a major step forward after a successful high-energy test at NASA’s Jet Propulsion Laboratory. Fueled by lithium vapor and driven by intense magnetic forces, the experimental engine reached ...
May 4, 2026 Artemis II proved NASA’s deep space systems are ready for the next leap. Orion survived its high-speed return with improved heat shield performance and pinpoint landing accuracy, while the SLS rocket nailed its trajectory. Even the launch pad ...
May 4, 2026 Voyager 1 just powered down a nearly 50-year-old instrument to stay alive in deep space. The spacecraft is running critically low on energy, forcing NASA to make careful sacrifices to keep its mission going. Despite the shutdown, it continues to ...
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Apr. 27, 2026 A group of undergraduate students pulled off something remarkable: they built their own dark matter detector and used it to probe one of physics’ biggest mysteries. Working with limited resources but plenty of creativity, they designed a ...
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May 20, 2026 Astronomers have uncovered a strange magnetic “flip” hidden inside the Milky Way. Using a new radio telescope, researchers mapped the galaxy’s magnetic field in unprecedented detail and ...
May 19, 2026 Black holes crashing together may be revealing clues about dark matter hidden across the universe. Physicists created a new model predicting how dark matter could subtly distort gravitational waves ...
May 18, 2026 For more than 200 years, scientists have struggled to pin down the exact strength of gravity — and one physicist spent a decade chasing the answer ...
May 18, 2026 Time might be even stranger than Einstein imagined. Physicists are now exploring the possibility that a single clock could exist in a quantum superposition, ticking both faster and slower at the same ...
May 16, 2026 Astronomers have revealed the sharpest image ever captured of a filament in the cosmic web — the enormous hidden structure connecting galaxies ...
May 15, 2026 A colossal valley near Mars’s equator is revealing dramatic clues about the Red Planet’s watery and volcanic past. Stretching roughly 1,300 kilometers, Shalbatana Vallis was carved billions of ...
May 14, 2026 A newly discovered meteor stream may be the smoking gun of an asteroid slowly disintegrating under the Sun’s intense heat. Scientists say these fiery streaks across the night sky could reveal ...
May 14, 2026 Scientists studying mysterious ultra-powerful cosmic rays have uncovered a surprising hidden pattern that could finally help explain where these particles come from. Using the DAMPE space telescope, ...
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