dark interstellar cloud

The cloud L1688 in the constellation Ophiuchus resembles a dance floor where partners don't always hold hands. Astronomers have long assumed that gas in molecular clouds moves together with the young stars born within them.

In the coldest, darkest corners of space, dust grains get covered in ice, like a window on a frosty day. This ice isn't just frozen water: it also contains carbon monoxide and carbon dioxide. From such ice, comets and planets may eventually assemble. But until now, it was unclear how the dust grain itself affects the ice that forms on it.

The night sky looks black, but if you remove the stars and accumulate light for a long time, a faint glow emerges — the summed light of all galaxies born over 13.8 billion years. Astronomers call it the extragalactic background light.

In the dark outskirts of our Galaxy, far from bright star clusters, millions of black holes lurk. They are invisible: they don't shine and don't noticeably accrete matter. Conventional search methods, designed for dense stellar fields, are useless here. A different approach is needed. Astronomers have proposed using the very fabric of space as a detector.

Two cities endure a series of fires. In one, the wind carries ash far beyond the outskirts, leaving the sky clear. In the other, ash settles as a dense veil, painting sunsets crimson. Roughly the same thing, just on a galactic scale, happens with supernova explosions, the final flares of massive stars.

Around some young stars where star formation has recently ended, there swirl not just dust rings but actual planetary battlefields — extreme debris disks.

The invisible hand of dark matter squeezes galaxies in gravity's embrace, yet its nature has remained elusive for nearly a century.

In the boundless night of space, galaxies come together in a slow gravitational dance, merging into one. Such collisions are not head-on impacts but rather like fingers moving slowly through water, leaving swirls and tails behind.

Moments before totality, swift shadow bands glide across the ground, like ripples from pebbles tossed into water. For centuries, this phenomenon baffled scientists. It turns out the key is that light is a wave. The Sun isn't a pinpoint lamp but a vast disk. When the Moon nearly covers it, a thin glowing crescent remains.

Civilizations in the Universe are separated not just by distance, but by the vast gulf of time. Hunting for their traces is like archaeology: instead of palace ruins, we find clouds of cosmic dust.

Using the James Webb telescope, astronomers peered into an ancient quasar — the dazzling heart of a galaxy where a giant black hole sucks in matter. It turns out it doesn't just destroy, but also creates: its powerful outflows and shock waves act like a true cosmic mill.

A bonfire that no one sees, but everyone feels the warmth: that's how astronomers found a flare in a distant galaxy. Not by its light, but by the infrared radiation of heated dust. The galaxy SDSS J010320.39+140152.5 caught attention when its center suddenly blazed in the infrared, as if someone had thrown logs onto an invisible fire.

In the heart of the Eagle Nebula, about 7000 light-years away, three giant pillars of gas and dust rise — the Pillars of Creation. Their shape is familiar to many from Hubble Space Telescope images. Now, Webb's infrared camera has allowed us to peer inside these dense cocoons where stars are born.

Black holes come in two types: tiny ones — the remnants of supernova explosions, and giants in the cores of galaxies. But where are the intermediate ones, with hundreds and thousands of solar masses? The answer may lie in star swarms, where black holes collide like balls on a billiard table and, merging, bulk up.

The JWST telescope has spotted a multitude of bright galaxies in the young universe. Their ultraviolet light was barely absorbed by cosmic dust — defying previous expectations.

A glowing cloud in a telescope looks like a wisp of fog about to dissipate. Planetary nebulae are gas shells cast off by dying stars. Young nebulae are bright and compact, but as they age, they expand, cool, and become increasingly transparent until they vanish into the interstellar medium.

A young star is surrounded by a flat, rotating disk of gas and dust, like pizza dough that's been spun out. Planets are born inside such a disk. But around three stars (Elias 2-24, IM Lup, and DM Tau) astronomers noticed something odd: far beyond the edge of the bright disk stretches a barely visible but enormous dust halo.

The FAST radio telescope in China is a giant dish half a kilometer in diameter, nestled in a natural sinkhole among mountains.

In a disk of gas and dust around a young star, dust particles behave like sand grains in a stream of water: the gas flows faster, the dust lags behind, and friction arises between them. This friction can rock the magnetic waves that run through the disk. The galaxy is full of such disks: it is precisely in them that planets are born.

On the outskirts of our Galaxy, far beyond the familiar stellar disk, the Subaru Telescope has spotted something unexpected: a scattered cloud of stars spanning an area of one hundred square degrees across the sky.

Around young stars, disks of gas and dust swirl — the building blocks for future planets. Inside these disks, dust grains don't just fly randomly: they align along invisible lines of gas flow. Recently, astronomers noticed that dust grains in such disks behave like badminton shuttlecocks — always turning their long side into the wind.

In a dark cloud where no star has yet ignited, gas begins to pull together toward a common center. This is how the most massive stars in the Galaxy are born: those tens of times heavier than the Sun. Astronomers pointed radio telescopes at the cloud SDC335.579-0.292 and saw gas molecules lining up into streams falling inward.

A gas cloud the size of a small galaxy is falling into the Milky Way at hundreds of kilometers per second. Such clouds are called high-velocity clouds, and until now no stars had been found in them — only gas. Now, in one of them, named Complex H, astronomers have spotted a pair of young star clusters.

In a constellation where new stars are born, one of them behaves like a faulty lightbulb: sometimes shining steadily, sometimes dimming by a factor of several. Astronomers have been monitoring the star Gaia-GIC-1 for several years and now understand that its blinking is the shadow of a huge dust cloud that periodically passes in front of it.

When a massive star runs out of fuel, its core collapses and a shock wave races outward. But even before the star tears apart, particles that barely interact with ordinary matter may be born in its depths. If they decay into light, that energy leaks into the dense gas around the star. This gas, like a blanket, wraps the star.

A distant galaxy birthing hundreds of stars should glow in oxygen. That's what astronomers thought: hot young stars heat the gas, which then emits a characteristic infrared glow at a wavelength of 63 microns. It's like steam rising from a boiling pot — a sure sign of vigorous activity.

In the dark cloud L43, where stars are born, dust grains twirl like tiny compasses. Light from a young star pushes them, while the magnetic field lines them up in a specific direction. When a grain is turned sideways to us, its heat reaches us polarized, like light passing through a narrow slit.

In the Antennae Galaxies, which are crashing into each other, giant gas clouds collided at a speed of 50 kilometers per second. It's like two trains hurtling toward each other — the impact compressed the gas, and it ignited with new stars.

In the cold clouds of gas and dust where stars will one day ignite, some atoms have lost electrons and become charged. Charged particles feel the magnetic field, while neutral ones do not, so the charged ones slip through the neutral ones like water through a sieve. Astronomers have measured this drift speed: about a hundred meters per second.

In the dense Virgo galaxy cluster, astronomers have spotted six strange clouds of neutral hydrogen — gas that emits no light and is therefore invisible to ordinary telescopes. Radio telescopes can pick it up, but where it came from was unclear.

A spinning black hole acts like a cosmic generator: its rotation pumps energy into an invisible scalar cloud — a prime candidate for dark matter. A scalar field is like temperature: at every point in space it's just a single number, with no arrows or vectors. The cloud grows until it overflows.

Astronomers pointed the James Webb at three galaxies whose light traveled 12 billion years. Early data pointed to incredibly fast growth — like an infant reaching adult height in just a year, clashing with the expansion of the Universe.

In 2014, astronomers spotted a massive yellow star in the Andromeda galaxy. By 2022, it had vanished without a trace — without the usual blinding explosion of a supernova. It was as if someone simply switched off the light.

Some stars fizzle out like a dud firework: instead of a bright blast, just a cloud of smoke. Usually, a massive star ends with a supernova explosion, leaving a black hole. But sometimes there's no bang: the star collapses straight into a black hole, almost unnoticed.