Why do we need to spend any more effort on extra-solar planets?
We found some, they’re there. Lumps of rocks, gasballs. We’re done, right?
This, loosely paraphrased, was a serious question I got last week.
The context was a question of why I was spending serious effort on exoplanet research, rather than focusing exclusively on other subfields.
I’ve heard similar comments from physicists, some particle physicists are notoriously focused in their consideration of what counts as “real physics”, but this came from an astronomer; and one that I know does stars, inside the galaxy, sometimes, not just extragalactic.
Well, why indeed?
In 1922, Edwin Hubble, using a new state of the art observing facility, discovered that the “nebulae” were galaxies, like the Milky Way, but of various types, and external to The Galaxy.
By 1929 he had shown they were distant, receding from us, in general and that they showed some interesting unexplained correlations.
Then he stopped and astronomy shrugged.
Astronomers have spent 80+ years doing quantitative statistical analysis of galactic populations; classifying them into different types, getting their luminosity functions, by type, age and environment; looking at their internal structure, individually and as a class; looked for anomalies, peculiar galaxies, colliding galaxies, groups of galaxies, clusters of galaxies, ultra-luminous galaxies, low surface brightness galaxies, dwarf galaxies, young galaxies, star forming galaxies and active galaxies.
Study of galaxies has revealed their formation process, formation of structure in the universe, the origin of the universe, the presence of dark matter and the existence of dark energy.
The details are the interesting part, that is where we learn science.
It boggles the mind that there are scientists who can seriously hear of a major set of discoveries, shrug and be, like, whatever.
Existence of extrasolar planets does not make galaxies less interesting, it does not lead us to abandon the study of stars, it means we need to do even more studying of all of it to understand the universe.
We live on a planet.
We are surrounded by planets.
It behooves us to understand them in some detail,
and as with so many other phenomena, more data is really helpful.