Four Indian Air Force pilots are preparing to fly aboard Gaganyaan, India's first crewed spacecraft. Their training splits between ISRO's facility in Bengaluru and the Yuri Gagarin Cosmonaut Training Centre in Russia, where they are learning everything from orbital mechanics to abort procedures. Here is what that preparation actually looks like, and why the programme is harder than most people assume.

India's Mangalyaan spent years watching Mars from an orbit no other active mission shared, swinging close enough to sample the exosphere and far enough to photograph the entire planet at once. What ISRO's MOM sent back rewrote parts of the story about Mars losing its water, its atmosphere, and its past.

Every lunar night lasts roughly 14 Earth days, and the darkness brings temperatures that plunge to -173°C. For a rover on the moon's surface, that is not just cold, it is a shutdown. Chandrayaan-3's Pragyan rover went silent in September 2023 and never woke up. Here is what ISRO's engineers knew would happen, and why survival was always the harder problem.

Something is pushing the universe apart faster every second, and no one has ever touched it, trapped it, or directly measured it. Dark energy makes up roughly 68 percent of everything that exists, yet it remains invisible to every instrument humanity has built. This is what science knows, what it admits it doesn't, and why the mystery keeps getting stranger.

The universe is not a random scatter of galaxies. It is a cosmic web of filaments, voids, and nodes so vast that our entire Milky Way is a speck on one thread. Scientists have been mapping this structure for decades, and what they keep finding reshapes every assumption about how matter moves, clusters, and disappears into the dark.

Stephen Hawking proposed that black holes aren't truly black, they leak energy through a process now called Hawking radiation. This happens because of quantum effects at the event horizon, where virtual particle pairs split, sending one particle escaping as heat. Over vast timescales, this radiation causes black holes to lose mass and eventually evaporate completely, rewriting what we thought we knew about entropy and physics.

India's astronomers have been mapping black hole behaviour, measuring X-ray jets, and building instruments that feed data to the world's biggest observatories, mostly without credit. From TIFR in Mumbai to IUCAA in Pune, the scientists and institutions doing this research have changed what gravity means at its most extreme. Here is the work they have actually done.

The Event Horizon Telescope didn't build one giant dish. It linked radio observatories across six continents into a single imaging instrument with a resolution no single telescope could achieve. The EHT used a technique called interferometry to synchronise signals from Chile to the South Pole, and in 2019, it showed the world its first photograph of a black hole.

Stand close enough to a black hole and time itself slows to a crawl. The event horizon is the point of no return: not a wall, not a surface, just the last place where light can still escape gravity's pull. What happens to matter, spacetime, and any unfortunate traveller beyond that line is stranger than most science fiction has managed.

A teaspoon of neutron star material weighs roughly a billion tonnes. These stellar corpses are what the universe makes when a massive star collapses but gravity hasn't quite won. They spin, pulse, and occasionally flip magnetic poles with enough force to strip satellites from orbit. Understanding neutron stars means understanding the exact line where matter ends and a black hole begins.