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Definition of planet
The definition of "planet" has for some time been the subject of intense debate. Although the word dates back thousands of years, no officially decreed scientific definition of "planet" existed before the early 21st century. Until the beginning of the 1990s, there was little need for one, as astronomers had only a single sample of planets in solar system to study, and one small enough for its many irregularities to be dealt with individually.
However, after 1992 and the discovery of the myriad tiny worlds beyond the orbit of Neptune, the size of the sample rose from nine to at least several dozen. Following the discovery of the first extrasolar planet beyond our solar system in 1992, the number of samples has now reached hundreds. These revelations not only increased the number of potential planets, but, in their variety and peculiarity (some nearly large enough to be stars, others smaller than our Moon) challenged long perceived notions of what a planet could be.
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August 1, 2025
July 27, 2025 — 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 ...
July 2, 2025 — 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 ...
June 27, 2025 — 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 ...
June 25, 2025 — Imagine printing your Martian home from dust, sunlight, and a bit of biology. A new synthetic lichen system uses fungi and bacteria to grow building materials directly from Martian soil, completely autonomously and without human ...
June 24, 2025 — Lichen from the Mojave Desert has stunned scientists by surviving months of lethal UVC radiation, suggesting life could exist on distant planets orbiting volatile stars. The secret? A microscopic “sunscreen” layer that protects their vital ...
June 15, 2025 — AI has helped astronomers crack open some of the universe s best-kept secrets by analyzing massive datasets about black holes. Using over 12 million simulations powered by high-throughput computing, scientists discovered that the Milky Way's central ...
June 11, 2025 — By using a clever quantum approach that involves two "hands" on a clock one moving quickly and invisibly in the quantum world, the other more traditionally scientists have found a way to boost timekeeping precision dramatically. Even better, this ...
June 5, 2025 — Supermassive black holes might naturally replicate the colossal energies of man-made particle colliders possibly even revealing dark matter offering a cosmic shortcut to discoveries that would ...
June 3, 2025 — Astronomers have revealed new research showing that millions of new solar system objects are likely to be detected by a brand-new facility, which is expected to come online later this ...
June 3, 2025 — Scientists have identified a new source of energetic particles near the Sun. These definitive observations were made by instruments aboard NASA's Parker Solar Probe, which detected the powerful phenomena as the spacecraft dipped in and out of the ...
June 2, 2025 — WASP-121b may have been born in a frozen zone and later migrated into its current inferno-like orbit. A surprise discovery of methane in the wrong place suggests intense vertical winds are reshaping how we understand planetary ...
June 2, 2025 — Researchers have engineered a laser device smaller than a penny that they say could power everything from the LiDAR systems used in self-driving vehicles to gravitational wave detection, one of the most delicate experiments in existence to observe ...
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Aug. 1, 2025 — Using a powerful mathematical tool, scientists have unveiled the intricate "ringing" of black holes, unlocking patterns missed for decades and laying ...
July 31, 2025 — A team of scientists has proposed a groundbreaking new theory on the Universe's origins, offering a fresh, radical take on the Big Bang's early ...
July 29, 2025 — Scientists at UC Merced have engineered artificial cells that can keep perfect time—mimicking the 24-hour biological clocks found in living organisms. By reconstructing circadian machinery inside ...
July 28, 2025 — Neutrinos, ghostly particles barely interacting with matter, may secretly be reshaping the fates of massive stars. New research suggests that as stars collapse, they form natural "neutrino ...
July 25, 2025 — In the sprawling Hydra constellation, 137 million light-years away, lies NGC 3285B—a dazzling spiral galaxy recently spotlighted by NASA’s Hubble Space Telescope. This cosmic beauty orbits the ...
July 23, 2025 — Astronomers have likely witnessed a planet forming in real time, seen inside a spiral arm of the HD 135344B protoplanetary disc—exactly where theory predicted. The direct light detection is what ...
July 22, 2025 — NASA’s Roman Space Telescope is set to embark on a deep-sky survey that could capture nearly 100,000 cosmic explosions, shedding light on ...
July 20, 2025 — A tiny object far beyond Pluto, newly discovered by the Subaru Telescope, could reshape our understanding of the early Solar System. Named 2023 KQ14, ...
July 20, 2025 — Astronomers have discovered a bizarre object in the outer solar system, 2020 VN40, that dances to Neptune’s gravitational beat in a never-before-seen rhythm. It’s the first of its kind, orbiting ...
July 20, 2025 — Astronomers studying a rare neutron star system have uncovered a surprising source of powerful X-rays. Using NASA s IXPE telescope and data from other observatories, an international team found that ...