New! Sign up for our free email newsletter.
Reference Terms
from Wikipedia, the free encyclopedia

Andromeda Galaxy

TThe Andromeda Galaxy (also known as Messier 31, M31, or NGC 224; older texts often called it the Andromeda Nebula) is a spiral galaxy approximately 2.5 million light-years away in the constellation Andromeda. The Andromeda Galaxy is easily visible to the naked eye in a moderately dark sky, though such a sky is available only in smaller towns and isolated areas reasonably far from population centers and sources of light pollution. It appears quite small without a telescope because only the central part is bright enough to be visible, but the full angular diameter of the galaxy is seven times that of the full moon.

Related Stories
 


Space & Time News

October 29, 2026

NASA’s Artemis I mission has revealed that cosmic radiation near the Moon is higher than in Earth orbit, but not by as much as scientists might expect. Tiny experimental detectors also uncovered ...
Scientists have cracked a 178-year-old mystery surrounding a train delayed by a solar storm, revealing that the famous incident happened in 1848 rather than 1841. The discovery rewrites the early history of space weather and highlights a threat that ...
A new study tracking 13 astronauts suggests that the human heart may be surprisingly well equipped for a journey to Mars, especially with regular exercise during spaceflight. Researchers found that astronauts' hearts adapted to months of ...
NASA’s Perseverance rover has shattered a historic space exploration record, traveling farther across another world than any vehicle before it. Its advanced self-driving system helped it surpass ...
NASA’s Nancy Grace Roman Space Telescope has exceeded expectations after engineers made incredibly tiny adjustments to sharpen its view of the universe. By moving a mirror just one-sixteenth the width of a human hair, the team helped bring its ...
SpaceX just delivered some surprisingly strange cargo to the International Space Station, including tiny brain models, 3D heart tissue, and technology for making artificial retinas in space. ...
Europe's Sentinel-3C satellite has returned breathtaking images of Earth just two weeks after launch, revealing the snowy Alps, frozen Arctic islands, and brilliant turquoise Caribbean waters. Its ...
Scientists in Vienna have achieved a major breakthrough in timekeeping by creating the world’s first self-stabilizing nuclear clock, a technology that could eventually surpass even the most precise atomic clocks. Instead of relying on electrons in ...
NASA is preparing for humanity’s first Moon base with three investigations that will hunt for underground shelters, uncover hidden ice, and track dangerous conditions on the lunar surface. The findings could reveal how astronauts can survive and ...
Earth’s center of mass is constantly on the move, shifting by a few millimeters as enormous amounts of water, ice, and even air migrate around the planet with the seasons. NASA scientists have developed a more precise way to track these tiny ...
NASA has selected the GIMLI project to investigate whether the Marius Hill Pit opens into a vast underground cave or lava tube. Using radar, seismic sensors, gravity measurements, and cameras, researchers will search beneath the lunar surface and ...
A meteor crater buried beneath Oklahoma has turned out to be nearly 100 million years younger than scientists thought. Zircon crystals show the Ames impact occurred about 370 million years ago, meaning it was not part of the mysterious Ordovician ...

Latest Headlines

updated 12:56 pm ET