In addition to being a staple of science fiction, the concept of megastructures has long been the subject of serious scientific studies. As famed physicist Freeman Dyson originally proposed in 1960, "Malthusian pressures will ultimately drive an intelligent species" to occupy an "artificial biosphere which completely surrounds its parent star." In short, he theorized that advanced civilizations would disassemble their planet (or planets) to create a structure (which has since come to be called a "Dyson Sphere" that would harness all the energy from their star and provide immense living space.

Our first satellites were little more than repeater stations that propagated our radio and tv signals around the world. But now we live in an age where a fleet of orbiting space telescopes and satellites seeks out and examines light from across the cosmos. When a powerful burst of energy flashes elsewhere in the Universe, satellites detect it, record it, and then scientists analyze it in excruciating detail.

This is Part 2 of a series on interstellar comets. Read Part 1.

Most galaxies have a supermassive black hole at their center, but some galaxies have two. These supermassive binaries form when two galaxies collide and merge. We can detect some of these binaries, such as by observing the periodic changes of a quasar or by observing the binary directly, such as in the case of NGC 7727. But most supermassive binaries remain hidden. They are too far away to be observed directly or too inactive to be observed by jets. And while gravitational wave observatories can detect the mergers of stellar-mass black holes, we can't yet detect the mergers of supermassive black holes. But a new study shows how we might detect some of them.

Traditional chemical rockets, though they are the most commonly used propulsion method for space exploration today, are beholden to the tyranny of the rocket equation. Every ounce of thrust they use must also start out as fuel, which means the rocket itself will have to weigh more, and weight is one of the limiting factors in how fast a propulsion system can go. So, scientists have been searching for, and actively testing, alternatives for decades. One of the most promising is the solar sail - a huge reflective sheet that uses sunlight, or in some cases a “pushing laser” to maneuver about the solar system without any onboard propellant necessary. A recent paper published in the Journal of Nanophotonics by Dimitar Dimitrov and Elijah Taylor Harris of Tuskegee University describes a new type of light sail that solves some of the major problems of existing designs.

The Chinese didn't invent the rocket but they came remarkably close. More than a thousand years ago, during the Song Dynasty, Chinese engineers were packing black powder into bamboo tubes and launching fire arrows that hissed across battlefields on jets of smoke and flame. Those crude devices were the distant ancestors of every launch vehicle that has ever punched through Earth's atmosphere and there's a pleasing symmetry in the fact that, today, China operates one of the most capable and ambitious space programmes on the planet. From its first satellite in 1970 to a fully operational crewed space station orbiting overhead right now, the journey has been extraordinary. And in 2026, it's about to get even more interesting.