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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
October 22, 2025
Oct. 15, 2025 — 3I/ATLAS, a mysterious interstellar object racing toward the Sun, is baffling scientists with its speed and origin. Some researchers suggest it could even be alien-made, drawing comparisons to probes ...
Oct. 14, 2025 — High above the Sun’s blazing equator lie its mysterious poles, the birthplace of fast solar winds and the heart of its magnetic heartbeat. For decades, scientists have struggled to see these regions, hidden from Earth’s orbit. With the upcoming ...
Oct. 12, 2025 — A colossal northern asteroid impact billions of years ago likely shaped the Moon’s south polar region and explains its uneven terrain. Researchers found that the South Pole-Aitken Basin formed from a glancing northern strike, revealing deep ...
Oct. 12, 2025 — ESA’s Mars orbiters have observed comet 3I/ATLAS, only the third interstellar comet ever discovered. The faint, distant object revealed a glowing coma as it was heated by the Sun. Researchers are still studying the data to understand its makeup ...
Oct. 9, 2025 — Mars may look calm, but new research reveals it’s a world of fierce winds and swirling dust devils racing at hurricane-like speeds. Using deep learning on thousands of satellite images from European orbiters, scientists have discovered that ...
Oct. 6, 2025 — ESA has inaugurated a powerful new 35-meter deep space antenna at its New Norcia site in Western Australia, marking a major boost to Europe’s ability to communicate with spacecraft exploring the ...
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 ...
Latest Headlines
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Oct. 22, 2025 — Our Milky Way is far from calm — it ripples with a colossal wave spanning tens of thousands of light-years, revealed by ESA’s Gaia telescope. ...
Oct. 19, 2025 — Researchers from The University of Western Australia node at the International Centre for Radio Astronomy Research (ICRAR) have uncovered a colossal bridge of neutral hydrogen gas linking two dwarf ...
Oct. 19, 2025 — Mars’ north polar vortex locks its atmosphere in extreme cold and darkness, freezing out water vapor and triggering a dramatic rise in ozone. Scientists found that the lack of sunlight and moisture ...
Oct. 18, 2025 — Scientists at Johns Hopkins may be closing in on dark matter’s elusive trail, uncovering a mysterious gamma ray glow at the heart of our galaxy that could signal unseen matter colliding — or ...
Oct. 18, 2025 — Researchers have unveiled a new model for the universe’s birth that replaces cosmic inflation with gravitational waves as the driving force behind creation. Their simulations show that gravity and ...
Oct. 17, 2025 — Researchers have discovered chemical fingerprints of Earth's earliest incarnation, preserved in ancient mantle rocks. A unique imbalance in potassium isotopes points to remnants of “proto Earth” ...
Oct. 17, 2025 — Scientists from NASA and Chalmers University have discovered that incompatible substances can mix on Titan’s icy surface, breaking the “like dissolves like” rule of chemistry. Under ultra-cold ...
Oct. 16, 2025 — For the first time, scientists observed a black hole tearing apart a star far from its galaxy’s center, producing the fastest-changing radio signals ever recorded. The event, AT 2024tvd, revealed ...
Oct. 16, 2025 — Ryugu’s samples reveal that water activity on asteroids lasted far longer than scientists thought, possibly reshaping theories of how Earth gained its oceans. A billion-year-old impact may have ...
Oct. 16, 2025 — Researchers discovered a new field of ancient tektites in South Australia, revealing a long-forgotten asteroid impact. These 11-million-year-old glass fragments differ chemically and geographically ...