David Nesvorný

350 light-years away, four planets orbit the star V1298 Tau. They are 5–10 times larger than Earth but lighter than they appear. For nine years, astronomers tracked their motion to understand what they are made of and how they lived in the past. The planets are lined up in a chain: their orbital periods are nearly in 3:2, 2:1, and 3:1 ratios.

At the outskirts of the Solar System, beyond Neptune's orbit, millions of icy chunks circle the Sun — leftover building material from the era of planet formation. Astronomers call them trans-Neptunian objects, and they have a peculiarity: their surfaces are painted in various shades of red. Some are merely reddish, like rust, while others are very red, like dried blood.