Star system with right-angled planets surprises astronomers

Two planets orbit the poles while another revolves around the star's equator, suggesting a mysterious force

Star systems come in all shapes and sizes. Some have lots of planets, some have larger planets and others have no planets at all. But a particularly unusual system about 150 light-years from our own has scientists scratching their heads.

In 2016, astronomers discovered two planets orbiting the star HD 3167. They were thought to be super-Earths — between Earth and Neptune in size — and circled the star every one and 30 days. A third planet was found in the system in 2017, orbiting in about eight days. What’s unusual is the inclinations of the outer two planets, HD 3167