Discovered by amateur astronomers, a mysterious arc of gas might be the ghostly remains of a star shedding its outer layers. However, astronomers haven’t reached a consensus yet.
Our middle-aged Solar System is mostly calm and stable, with fully-formed planets staying in their lanes while placidly orbiting the Sun. But it wasn't always this way. The Solar System had a tempestuous youth, full of collisions that shattered many bodies into tiny pieces. The debris-strewn main asteroid belt is evidence of this.

