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Galaxy NGC 5584 is a vast stellar city, where some neighborhoods are just being built while others are already marked by aging giants. To see both, astronomers used two very different flashlights. The ultraviolet telescope Swift lit up hot blue patches — stellar nurseries where massive stars have recently ignited.

A lamp is hidden behind a large aquarium filled with water. You see not one light source but several reflections and refractions — the water bends the path of the rays.

Somewhere in the depths of the Milky Way, radio pulses flare up from time to time — rare, steady, like the ticks of a distant metronome. These long-period radio transients were discovered only recently, and they immediately puzzled astronomers.

When an orchestra of thousands of musicians plays in harmony, the credit goes not only to each player's talent but also to the invisible work of the conductor.

At the heart of our Galaxy lives the supermassive black hole Sagittarius A*. If an invisible companion orbits nearby, their dance can be spotted through the light of other stars. The pair's gravity works like a lens: as the black holes pass in front of a background star, its light briefly brightens and splits into two.

At the very heart of the Milky Way, stars whirl around an invisible supermassive black hole. One of them, S301, completes an orbit in just 8.7 years. Its path is a highly squashed ellipse: sometimes it grazes the black hole, sometimes it shoots far away. At closest approach, the distance to the black hole is tiny by cosmic standards.

Two hundred forty-two thousand three hundred twenty-seven galaxies — like grains of sand on a beach. But astronomers turned this chaos into a map: the UMAP algorithm (a machine learning method) took from each galaxy eleven parameters — seven colors from optical to mid-infrared (that's photometry), magnitude…

In 2034, a rocket leaves a spaceport with an unusual payload: two spheres the size of a large globe, each weighing nearly a ton. No engines, no electronics. Just a mirrored surface of hundreds of corner-cube reflectors — tiny prisms that return light exactly to where it came from. This is the future space tuning fork.

Predicted by Albert Einstein, gravitational waves are like beacons in the dark ocean of space. They flare up when black holes collide, sending ripples through the fabric of the Universe.

The optical sky background is a cosmic palimpsest, where light from billions of unresolved galaxies is layered, each layer corresponding to a different epoch. Until now we could only distinguish the brightest "letters"—individual stars and nearby galaxies.

Modern cosmology has hit a dissonant chord. Local measurements of the Hubble constant from supernovae and Cepheids give around 73 km/s/Mpc, while global constraints from the cosmic microwave background within the standard ΛCDM model point to 67 km/s/Mpc.

In the Galactic bulge, where the light of billions of stars merges into a continuous glow, four cold giants passed unnoticed. You can't see them through a telescope — too far, too dim.

The Universe is a giant labyrinth of curved mirrors. The mass of galaxies and clusters distorts the light of distant quasars, as if toying with our perception of the cosmos. Hidden in this hall of mirrors is the key to the greatest mystery: dark energy, which is pushing space apart ever faster.

Every night the sky above the Vera Rubin Observatory flares with ten million transient lights — astronomical transients.

The birth of planets resembles the workings of a cosmic forge. Rocky blocks collide and fuse together. A powerful impact strikes a spark — material heats to white-hot and glows like cooling metal. Computer simulations show: the flash is visible from days to years, peaking at a tenth of the sun's light.

The cosmological constant is causing the universe to expand at an accelerating rate. In the far future, when all matter has dispersed, only empty de Sitter space will remain — an ideal cosmic backdrop.

Throughout the last century, cosmology measured the universe's expansion rate using supernovae, redshifts, and the cosmic microwave background.

In the lab, there's a trap, an invisible 'pit' made of electric fields, where a charged dust grain about a hundred nanometers across levitates. It oscillates back and forth like a pendulum in a clock.

In the 1930s, Fritz Zwicky first noticed that galaxies in clusters were moving too fast — something invisible was holding them. Later, Vera Rubin measured the rotation of spiral galaxies, confirming that space is permeated by dark matter.

When the James Webb Space Telescope turned its gaze deep into time, astronomers expected to see familiar galaxies. Instead, the images were dotted with a scattering of bright, incredibly compact red dots.

The first two billion years after the Big Bang were an era when the universe resembled a boiling construction pit. Dark matter clumped the gas together, igniting the first stars. It seemed there simply wasn't enough time to assemble massive elliptical galaxies—'dormant' stellar metropolises — from this raw material.

A vast hall where hundreds of orchestras play at once. Amid this din, you need to pick out one specific duet — two supermassive black holes circling each other in a distant galaxy. That's how pulsar timing arrays work: they listen to the "hum" of the entire sky, created by gravitational waves from many such pairs.

On a dark night over the Uruguayan pampa, a dazzling fireball silently flares up. It streaks for a few seconds, scattering sparks, and fades beyond the horizon. This is a bolide — a large asteroid fragment slamming into the atmosphere. If it survives the fall, a meteorite will land on the ground.

A stone falls into a well, and the splash reaches your ears with a delay. Something similar happens to light as it leaves Earth: its oscillations become less frequent, the beam seems to 'tire.' This is gravitational redshift — a phenomenon Einstein spoke of a century ago.

Searching for extraterrestrial signals is like trying to hear a whisper at a roaring stadium. The Green Bank Telescope listened to 70,000 stars, but 100 million bursts turned out to be earthly noise — from phones, satellites, microwave ovens.

Edwin Hubble and Georges Lemaître discovered the expansion of the Universe nearly a century ago. One way to test it is the surface brightness test: in an expanding cosmos, the light of a distant galaxy should fade like a pattern on a stretching film.

At the edge of the solar system, far beyond Neptune, hundreds of icy chunks circle the Sun. Some of them move as if an invisible hand had aligned their orbits like compass needles. Ten years ago, this led astronomers to suspect that a massive planet, about ten times heavier than Earth, is hiding there.

Light from the distant Dragon Galaxy has been traveling toward us for more than seven billion years. On its way, it passes by a huge galaxy cluster whose gravity bends the path of light like a lens. As a result, the galaxy appears brighter and larger than it really is, just as a magnifying glass enlarges fine print.

A handful of coins accelerates to one-fifth the speed of light. That's what Coracle interstellar probes will be like — tiny spacecraft weighing just a few grams, each with an ultrathin sail film. A powerful laser beam pushes them forward: light presses on the sail like wind fills a yacht's sails, except instead of air, it's a stream of photons.

In the vast cosmic web, the James Webb Space Telescope spotted something unusual — tiny but bright red sparks that astronomers have nicknamed 'little red dots.' They shine as if an invisible fire is raging inside: their spectrum looks like a letter V, and the hydrogen lines are broadened, as if someone smeared paint across a canvas.

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

By day in Chile's Atacama Desert, the air shimmers with heat like the haze above a hot skillet. Sunlight passing through this shimmer begins to dance and flicker. Astronomers call this airy trembling "seeing" — and it keeps telescopes from getting a sharp view of the stars. To fight this nuisance, engineers have built a special instrument — a solar seeing monitor.

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.

A lighthouse blinks every few seconds, but then begins to slowly brighten and dim over the course of a year. That is exactly what about a third of red giants do — huge stars in the late stages of life. Their normal pulsations take days or weeks, but on top of that, long secondary periods are visible: months and years.

A massive star's explosion is bright but brief. The flash itself lasts weeks, but the dust it heats around it glows in infrared for years. It's like a camera flash illuminating a room, then hot dust particles lingering in the air — only on a cosmic scale.

Imagine you and your friends are in a dark room. You agree that after a common flash, each of you will turn on a flashlight ten seconds later, but with a correction for the light delay — since the light from the flash reaches each of you with a slight lag.

On old photographic plates from the 1950s, astronomers found hundreds of thousands of brief flashes. Brightness measurements confirmed they weren't defects but real events linked to solar activity.

The night sky looks still, but many stars tremble like a drum after a strike. For seven straight years, the TESS satellite stared at the same patches of sky and caught this trembling in 19,151 red giants — old, bloated stars. Previously, far fewer of these 'singing' giants were known, and now the list has grown by 80%.

Light from distant stars, as it travels through cosmic dust, loses some of its energy. Dust grains absorb and scatter light, and the way they do so at different wavelengths reveals their composition and size. Astronomers call this the dust extinction curve.

Astronomers have tested the new Vera C. Rubin telescope in Chile, much like adjusting the focus and aperture on a brand-new camera. The first images covered a patch of sky the size of 60 full Moons, and immediately revealed millions of galaxies and stars. The imaging was done in various colors, from invisible ultraviolet to thermal infrared.