Interestingly, that was not the first article where science journalist Martha G. Morrow mentioned the public's idea of a "planet". In 1943, there was a claimed discovery of an exoplanet (later proven a spurious measurement). Martha wrote the following about peoples' reactions:

That now seems kind of hilarious! Planets can exist only in our solar system! That was not the view of scientists. As early as the 1600s, Copernican astronomers all (or nearly all?) believed that all the stars have planets. They called them planets, and they called the worlds.

From the 1600s to mid-1800s, astronomers believed *ALL* the planets had life and civilizations, including every exoplanet at every star. But from the 1850s to early 1900s, "science had driven these beings from every planet in our system except the Earth."

But still, scientists assumed there would be "planets" at other stars. On the other hand, Morrow reported in this 1943 article that there was skepticism among "some astronomers" that exoplanets exist. Note the quotes on "planets", questioning if they can even be called planets.

From the earliest times (at least from Galileo), one of the working definitions of "planet" was "opaque" bodies, as opposed to "luminous" bodies (the stars). Planets give light by reflection, whereas stars create light. This is found in the literature from 1600s though 1800s.

We see this idea hinted in this 1943 article by Morrow. The implication is: they really are planets, because they're too small to make their own light. (Eddington in 1920 who proposed that stars make light by fusion.) Since some bodies *are* too small, they must be planets!

We also see in 1943 the inevitable question about life on the exoplanet. Find a planet, and this question is asked! Why? Because of what planets are and what they do. Astrobiology was inseparable from planetary science even at the time of Galileo & Kepler.

Morrow then reminded her readers that the original Greek meaning of "planet" was "wanderer". So even back in 1943, science reporters were talking about the definition of "planet" in a confusing milieu of ideas between the scientists and the public. /END