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
March 24, 2025
Mar. 20, 2025 — The Dark Energy Spectroscopic Instrument used millions of galaxies and quasars to build the largest 3D map of our universe to date. Combining their data with other experiments shows signs that the impact of dark energy may be weakening over time -- ...
Mar. 19, 2025 — On 19 March 2025, the European Space Agency's Euclid mission releases its first batch of survey data, including a preview of its deep fields. Here, hundreds of thousands of galaxies in different shapes and sizes take center stage and show a glimpse ...
Mar. 13, 2025 — At least two mass extinction events in Earth's history were likely caused by the 'devastating' effects of nearby supernova explosions, a new study suggests. Researchers say these super-powerful blasts -- caused by the death of a massive star -- may ...
Mar. 20, 2025 — Astronomers have detected oxygen in the most distant known galaxy, JADES-GS-z14-0. This record-breaking detection is making astronomers rethink how quickly galaxies formed in the early ...
Latest Headlines
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Mar. 24, 2025 — To mitigate global climate change, emissions of the primary culprit, carbon dioxide, must be drastically reduced. A newly developed process helps solve this problem: CO2 is directly split ...
Mar. 5, 2025 — Satellite images from space are allowing scientists to delve deeper into the individual functions of different tropical forest canopies with new and ...
Mar. 18, 2025 — Physicists have measured a nuclear reaction that can occur in neutron star collisions, providing direct experimental data for a process that had ...
Mar. 18, 2025 — Where do meteorites of different type come from? In a review paper, astronomers trace the impact orbit of observed meteorite falls to several previously unidentified source regions in the asteroid ...
Mar. 17, 2025 — The James Webb Space Telescope has captured its first direct images of carbon dioxide in a planet outside the solar system in HR 8799, a multiplanet ...
Mar. 17, 2025 — A combination of cosmic processes shapes the formation of one of the most common types of planets outside of our solar system, according to a new ...
Mar. 17, 2025 — New modeling indicates the main belt asteroid (52246) Donaldjohanson may have formed about 150 million years ago when a larger parent asteroid broke apart; its orbit and spin properties have ...
Mar. 13, 2025 — Water once existed in abundance of at the surface of Mars. How much of that water has been stored in the planet's crust is still unclear, according to a new ...
Mar. 13, 2025 — Astronomers have constructed the first detailed 3D map of the properties of cosmic dust in our home galaxy. For their map, the astronomers used 130 million spectra from ESA's Gaia mission, results ...
Mar. 14, 2025 — Astronomers have discovered two exoplanets around TOI-1453, a star about 250 light years away. These two exoplanets, a super-Earth and a sub-Neptune, are common in the galaxy, yet are absent from our ...