The inner solar system is home to four rocky worlds that formed under the intense heat of the young Sun. This video explores Mercury, the scarred planet that is slowly shrinking; Venus, where a ...

In the crowded early Solar System, young planets frequently collided and reshaped each other. But Mercury stood out. It formed unusually close to the Sun. Mercury’s days are longer than its years. It ...

The workings of our solar system are roughly the same now as they have been for millions of years. Moons circle their planets, the planets circle the sun, the sun’s magnetic fields and sunspots wax ...