Reference Terms
from Wikipedia, the free encyclopedia
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.
Related Stories
1
2
Space & Time News
October 5, 2025
Oct. 3, 2025 — Researchers have designed a new type of gravitational wave detector that operates in the milli-Hertz range, a region untouched by current observatories. Built with optical resonators and atomic clocks, the compact detectors can fit on a lab table ...
Sep. 30, 2025 — A new boron-rich compound, manganese diboride, delivers much higher energy density than current solid-rocket materials while remaining stable until intentionally ignited. Its power comes from an unusual, strained atomic structure formed during ...
Sep. 18, 2025 — Astronomers have long relied on supercomputers to simulate the immense structure of the Universe, but a new tool called Effort.jl is changing that. By mimicking the behavior of complex cosmological models, this emulator delivers results with the ...
Sep. 18, 2025 — Faint hydrogen signals from the cosmic Dark Ages may soon help determine the mass of dark matter particles. Simulations suggest future Moon-based observatories could distinguish between warm and cold dark matter, providing long-sought answers about ...
Sep. 17, 2025 — A new AI model from NYU Abu Dhabi predicts solar wind days in advance with far greater accuracy than existing methods. By analyzing ultraviolet solar images, it could help protect satellites, navigation systems, and power grids from disruptive space ...
Sep. 15, 2025 — The booming space industry has filled the skies with rockets and satellites, but this rapid expansion comes with a hidden danger: slowing the recovery of the ozone layer. Rocket launches and burning space debris release chlorine, soot, and metals ...
Sep. 11, 2025 — NASA’s Magnetospheric Multiscale Mission has uncovered surprising behavior of pickup ions drifting through the solar wind near Earth. These particles, once thought to be minor players, appear capable of generating waves and influencing how the ...
Sep. 10, 2025 — Physicists have unveiled a new superconducting detector sensitive enough to hunt dark matter particles smaller than electrons. By capturing faint photon signals, the device pushes the search into uncharted ...
Sep. 9, 2025 — Scientists caution that asteroid deflection must be precise, as striking the wrong spot risks sending it through a gravitational keyhole that sets up a future collision with Earth. Using lessons from NASA’s DART mission, researchers are developing ...
Aug. 25, 2025 — Scientists using Google’s quantum processor have taken a major step toward unraveling the deepest mysteries of the universe. By simulating fundamental interactions described by gauge theories, the ...
Aug. 22, 2025 — Astronomers using AI have captured a once-in-a-lifetime cosmic event: a massive star’s violent death triggered by its black hole companion. The explosion, known as SN 2023zkd, not only produced a brilliant supernova but also shocked scientists by ...
Aug. 18, 2025 — NASA and ISRO s NISAR satellite has just reached a major milestone: the successful deployment of its enormous 39-foot antenna reflector in orbit. Folded up like an umbrella during launch, the reflector is now fully extended and ready to support ...
Latest Headlines
updated 12:56 pm ET
Oct. 3, 2025 — Astronomers have uncovered a runaway feeding frenzy in a rogue planet drifting freely through space, devouring six billion tonnes of gas and dust every second. Located 620 light-years away in the ...
Oct. 3, 2025 — New lunar samples from the far side reveal it formed from cooler magma than the near side, confirming the Moon’s interior is not uniform. Researchers suggest fewer heat-producing elements on the ...
Oct. 2, 2025 — Fresh analysis of Cassini data has revealed new complex organic molecules inside ice grains spewing from Enceladus. These discoveries strengthen the case that the moon’s underground ocean hosts ...
Oct. 1, 2025 — The LUX-ZEPLIN detector is breaking new ground in the hunt for dark matter, setting unprecedented limits on WIMP particles. Its results not only narrow the possibilities for dark matter but also open ...
Oct. 1, 2025 — For decades, Uranus baffled scientists because it seemed to have no internal heat. Now, new computer modeling shows the planet actually emits more energy than it receives from the Sun. This subtle ...
Oct. 1, 2025 — Perseverance rover data shows Jezero Crater once held a calm lake, leaving behind mudstones rich in organic-linked minerals. The presence of iron-phosphate and iron-sulfide nodules suggests processes ...
Oct. 1, 2025 — Astronomers using the James Webb Space Telescope are unraveling the mysteries of TRAPPIST-1e, an Earth-sized exoplanet 40 light years away that could harbor liquid water. Early data suggests hints of ...
Sep. 29, 2025 — The James Webb Telescope has revealed fierce auroras, storms, and unchanging sand-like clouds on the rogue planet SIMP-0136. These insights are pushing the boundaries of our understanding of alien ...
Sep. 29, 2025 — Hubble has captured a striking new image of NGC 2775, a galaxy that defies easy classification. Blending features of spirals, ellipticals, and lenticulars, its puzzling structure may be the result of ...
Sep. 29, 2025 — Scientists have shown that Earth’s basic chemistry solidified within just three million years of the Solar System’s formation. Initially, the planet was barren and inhospitable, missing water and ...