First, a quiz question. Who wrote this?
In space there are countless constellations, suns and planets; we see only the suns because they give light; the planets remain invisible, for they are small and dark. There are also numberless earths circling around their suns, no worse and no less than this globe of ours.”
A. Carl Sagan in 1977
B. NASA Kepler Principle Investigator William Borucki, 2013
C. Giordano Bruno, De l'Infinito, Universo, e Mondi. 1584.
D. Captain Kirk, Star Trek episode 52, 1969
The answer, which I’ll reveal further down in this post, illustrates the notion that this week’s NASA announcement on the abundance of habitable planets confirms rather than contradicts intuition.
Sometimes, science writers attempt to pump up a new finding by exaggerating how much it contrasts with what had been thought before. That only works well if you really know what was thought before and there really is a contrast.
There was no need to exaggerate anything to capture the excitement surrounding this week’s announcement that NASA’s Kepler satellite has observed a representative sample of the Milky Way and concluded that about a fifth of all stars in our galaxy have planets that could possibly support life.
Some stories tried to use the contrast approach, suggesting that planets were not, in fact, rare or the space was not lonely. But who ever said it was? I just talked to an astronomer who said the latest findings add certainty to previous estimates. And that gets back to the quiz quote – attributed to Bruno (C) some time before he was burned at the stake. He’s actually a bit cocky, in retrospect, since there were no data to back his insight. But Bruno’s statement boldly goes where reason takes the human mind once untethered from the human-centric religious cosmology of his time.
And so NASA’s latest feat doesn’t defy reason or previous observations, but it still can inspire a sense of wonder. This is a tricky story to pull off since there’s a list of caveats required for responsible coverage, and it takes a certain finesse to generate excitement in the lede without having to undermine it with all those qualifications.
One story that really nailed it was Joel Achenbach’s take in the Washington Post. The lede is more precise, factual and qualified than most others and the story is by far the most readable I’ve seen:
Roughly one in every five sunlike stars is orbited by a potentially habitable, Earth-size planet, meaning that the universe has abundant real estate that could be congenial to life, according to an analysis of observations by NASA’s Kepler space telescope.
Our Milky Way galaxy alone could harbor billions of rocky worlds where water might be liquid at the surface, according to the report, which was published Monday in the Proceedings of the National Academy of Sciences and discussed at a news conference in California.
It’s hard not to enjoy this story, even if you already know all the background. The story unfolds in a way that the caveats and qualifications add rather than subtract from the appeal. .
If the estimate is correct, the nearest ocean planet might be just 12 light-years away, which, though extremely distant for all practical purposes (such as sending a robotic space probe), is just around the corner in our galactic neighborhood.
The AP story by Seth Borenstein also used some previous observations to add to the sense of excitement:
An earlier study found that 15 percent of the more common red dwarf stars have Earth-size planets that are close-in enough to be in the not-too-hot, not-too-cold Goldilocks Zone.