Moon or Planet? The Awkward Case of CD-35 2722B

Problems of definition will long be with us as we take ever closer looks at exoplanets. But they’re suddenly on everyone’s mind because of the detection of what some are calling an ‘exomoon’ in the system CD-35 2722, found in the constellation Columba. The primary in this system is an M-dwarf thought to be 50–200 […]