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This category presents the reader with astronomical events that can be seen each week, and month.
Dark energy is one of the least satisfying names in astronomy because it sounds more specific than it is. Scientists did not discover a glowing substance called dark energy. They…
In empty space, light travels at exactly 299,792,458 meters per second. That is about 300,000 kilometers per second, or 186,282 miles per second. It is the fastest speed at which…
Satellite constellations can leave bright trails across telescope images. Here is what that means for astronomy and the night sky.
A neutron star is what remains after the core of a massive star collapses. It is not a small ordinary star. It is the crushed core of a dead one,…
When people picture a galaxy, they often imagine a bright spiral like the Milky Way or Andromeda. The shape is memorable, but it is only the visible part of the…
Popular images of the asteroid belt usually show a spacecraft weaving through a crowded field of tumbling rocks. The real region between Mars and Jupiter is far less dramatic—and more…
A parsec is a distance defined by parallax. Here is how astronomers use the unit to measure the space between stars and galaxies.
From the ground, the daytime sky seems to be a blue dome wrapped around Earth. Astronauts looking through a spacecraft window see something very different: a thin blue line at…
Space is often described as freezing, while the Sun is described as a furnace. Both descriptions can be true at the same time, but not in the simple way they…
Astronomers have catalogued more than 120 molecular species in a cloud near the centre of the Milky Way. The finding matters because the cloud contains several compounds associated with the…
Astronomers have directly measured an extremely faint radio signal from neutral hydrogen billions of light-years away. The detection, made with South Africa’s MeerKAT array, gives researchers a new way to…
Einstein’s theory of general relativity has survived another demanding test. Researchers used clouds of ultracold atoms aboard China’s space station to compare how two forms of rubidium respond to gravity,…
The universe is forming stars at less than half the rate it did roughly 4.5 billion years ago. A new survey now shows that this decline cannot be explained simply…
A telescope is often described as a device that makes distant objects look closer. That is true, but it leaves out the part that matters most to astronomers. The main…
Astronomers using the James Webb Space Telescope have identified a likely Type II supernova that exploded when the universe was only about two billion years old. The event, called SN…
NASA’s Nancy Grace Roman Space Telescope has successfully deployed its high-gain antenna and its visor-like sunshade, completing two of the observatory’s first major tests in space. The work is part…
The Moon has no wind, rain or active plate tectonics to erase its surface history. That makes its soil a possible archive of events that happened far beyond Earth. A…
Large carbon-based molecules are common in space, turning up around dying stars, inside interstellar clouds, and in material returned from carbon-rich asteroids. The problem has been explaining how they form…
Researchers have completed one of the largest computer simulations of cosmic history yet assembled. Called ASTRID, it follows the growth of galaxies and black holes from the universe’s early days…
Venus looks pale yellow in ordinary photographs, but ultraviolet images reveal dark and bright bands moving through its upper clouds. Scientists have known about those markings for about a century.…
Astronomers often treat the thin streams of stars around the Milky Way as sensitive tracers of dark matter. A new University of Washington simulation shows why that evidence needs to…
Two stars once considered promising Dyson sphere candidates have now been removed from the list. Follow-up observations with NASA’s James Webb Space Telescope showed that the infrared glow did not…
A quasar is a distant galaxy with a brilliant active centre. Here is how a feeding supermassive black hole can outshine every star around it.
A light-year sounds as if it should measure time. It does not. A light-year is a unit of distance: the distance light travels through empty space in one year. Astronomers…