One of the reasons science loves raw numbers is because numbers can reveal things that aren't immediately obvious to our pattern recognition-dependent brains. That's why a new study that attempts to pin a number on the amount of planets in a normal galaxy offers so much promise for the future of interplanetary exploration.
In a new study conducted by the California Institute of Technology (Caltech), astronomers have concluded that, based on estimates of the number of planets in our own galaxy, the universe contains more planets than we could ever visit, even if we had something like the fictional warp drive-capable starship Enterprise. The study's author, John Johnson, assistant professor of planetary astronomy at Caltech, said, "There's at least 100 billion planets in the galaxy — just our galaxy. That's mind-boggling."
The estimates are based on the analysis of the planets surrounding the star known as Kepler-32. Kepler-32 makes for a good candidate in that it's an M-dwarf star system, the most common kind of star in our Milky Way galaxy. From NASA's Jet Propulsion Laboratory:
"M-dwarf systems like Kepler-32's are quite different from our own solar system. For one, M dwarfs are cooler and much smaller than the sun. Kepler-32, for example, has half the mass of the sun and half its radius. The radii of its five planets range from 0.8 to 2.7 times that of Earth, and those planets orbit extremely close to their star. The whole Kepler-32 system fits within just over a tenth of an astronomical unit (the average distance between Earth and the sun) — a distance that is about a third of the radius of Mercury's orbit around the sun."
Extrapolating forward, the researchers determined that there is at least one planet for every one of the roughly 100 billion stars in our galaxy. This probably means that those exciting announcements about finding distant Earth-like planets are likely to increase in coming years. Though, none that we've spotted to date are quite what we're looking for in an exoplanet.
Even still, such prospects could help to further spur the development of commercial space ventures, as the riches of space beckon. But the other, unmentioned aspect of this finding will be obvious to most: If planets are that ubiquitous, how can we continue to even question that, statistically, there is likely another form of intelligent life somewhere out there amongst the billions and billions of planets?
You can read more about the research team's findings at the Caltech website.