Reference Terms
from Wikipedia, the free encyclopedia
Planet
The International Astronomical Union defines "planet" as a celestial body that, within the Solar System that is in orbit around the Sun; has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape; and has cleared the neighbourhood around its orbit; or within another system, it is in orbit around a star or stellar remnants; has a mass below the limiting mass for thermonuclear fusion of deuterium; and is above the minimum mass/size requirement for planetary status in the Solar System.
Note: The above text is excerpted from the Wikipedia article "Planet", which has been released under the GNU Free Documentation License.
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Space & Time News
April 18, 2024
Apr. 16, 2024 — Astronomers have identified the most massive stellar black hole yet discovered in the Milky Way galaxy. This black hole was spotted in data from the European Space Agency's Gaia mission because it imposes an odd 'wobbling' motion on the companion ...
Apr. 15, 2024 — The mystery of how Pluto got a giant heart-shaped feature on its surface has finally been solved by an international team of astrophysicists. The team is the first to successfully reproduce the unusual shape with numerical simulations, attributing ...
Apr. 12, 2024 — An international research team has for the first time directly detected stellar winds from three Sun-like stars by recording the X-ray emission from their astrospheres, and placed constraints on the mass loss rate of the stars via their stellar ...
Apr. 8, 2024 — Linking analyses of the moon's gravity field with models of its earliest evolution, scientists tell a story of the moon turning itself inside out after it solidified from a primordial magma ocean. The process left behind a vestige of dense, ...
Latest Headlines
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Apr. 17, 2024 — Astronomers have discovered methane emission on a brown dwarf, an unexpected finding for such a cold and isolated world. The findings suggest that this brown dwarf might generate aurorae similar to ...
Apr. 17, 2024 — Scientists have developed a new method using knot theory to find the optimal routes for future space missions without the need to waste ...
Apr. 16, 2024 — In an approach they call 'nanostitching,' engineers used carbon nanotubes to prevent cracking in multilayered composites. The advance could lead to next-generation airplanes and ...
Apr. 16, 2024 — A nearby supernova in 2023 offered astrophysicists an excellent opportunity to test ideas about how these types of explosions boost particles, called cosmic rays, to near light-speed. But ...
Apr. 15, 2024 — Physicists solve a puzzle linked to JWST-ER1g, a massive ancient galaxy that formed when the universe was just a quarter of its current ...
Apr. 12, 2024 — In 2022, astronomers discovered the brightest gamma-ray burst (GRB) of all time. Now, astronomers confirm that a 'normal' supernova, the telltale ...
Apr. 12, 2024 — A star's magnetic field must be considered in order to correctly determine the characteristics of exoplanets from observations by space telescopes such as Kepler, James Webb, or PLATO. Researchers ...
Apr. 11, 2024 — When astronomers looked at a stellar pair at the heart of a stunning cloud of gas and dust, they were in for a surprise. Star pairs are typically very similar, like twins, but in HD 148937, one star ...
Apr. 11, 2024 — Researchers have found that baby stars discharge plumes of gas, dust, and magnetic flux from their protostellar disk. The protostellar disk that surrounds developing stars are constantly penetrated ...
Apr. 10, 2024 — Astrophysicists shed light on the relationship between the Milky Way and the Egyptian sky-goddess Nut. The paper draws on ancient Egyptian texts and simulations to argue that the Milky Way might have ...