K2-33 b, shown in this illustration, is one of the youngest exoplanets detected to date and makes a complete orbit around its star in about five days. These two characteristics combined provide new constraints for planet formation theories. K2-33 b could have formed farther out and quickly migrated inward. Alternatively, it could have formed in situ, or in place.
Image credit: NASA/JPL-Caltech/R. Hurt