Our Solar System

For most of the twentieth century, the planets were taught as static objects with fixed properties. They were not. Voyager 2's 1986 flyby of Uranus — the only time a spacecraft has ever visited the planet — happened during a freak solar wind compression that distorted the magnetosphere by a factor of twenty. A 2024 reanalysis of the archived magnetometer data showed that nearly everything we have believed about Uranus for forty years was a measurement of the wrong moment. Mars, similarly, was thought to be a dead, dust-blown world without electrical phenomena. In November 2025, Perseverance's microphone — listening for unrelated reasons — caught 55 faint pops in 45 months of audio. They were lightning.

The Moon is the most studied object in space, and we are still rewriting where it came from. The current best model is that a Mars-sized object named Theia struck the proto-Earth roughly 4.5 billion years ago, vaporized most of its own mantle, and reassembled into the Moon we see today. The same collision is increasingly suspected to have given Earth its tilted axis, its plate tectonics, and the deep-mantle anomalies recently mapped seismically — the buried remains of Theia herself. The Moon was not an accident. It was, possibly, the event that made Earth habitable.

The outer solar system is wilder. Jupiter's moon Io has more active volcanoes than every other body in the system combined; Juno's close flybys are mapping their distribution and revealing a tidal-heating mechanism that turns gravity itself into magma. Saturn's rings are younger than the dinosaurs. The dwarf planet Haumea, out past Neptune, spins so fast it has deformed into an egg and is the only trans-Neptunian object with confirmed rings. And the Sun, the star at the center of all of it, has just hit the peak of Cycle 25 — a peak that, statistically, brings the risk of a repeat of the 1859 Carrington Event, an electromagnetic storm that today would cost over a trillion dollars and take a decade to recover from.

The articles below cover the solar system one body at a time, with a final section on the missions — Juno, Artemis, Europa Clipper — that are doing the looking.