A hospitable star with calm, rare-flare behavior. Nearby, a rocky planet blanketed in warm liquid water and a nice Spring breeze. A sky free of asteroids swooping maddeningly in like meteors from hell. No bureaucratic pantheon of vicious, capricious, wrath-fueled gods. This may not be the planet we deserve, but it's the one we want.
And now, according to a new paper, some scientists have added another necessary want on the list for a habitable exoplanet: gin and tonic.
A toast to exoplanet science
Exoplanets are a hot button in space science, and for good reason: we've found 4,000 exoplanets, with many more soon to be added. We've advanced epistemic light-years in just a few decades since the time when, as far as anyone knew, our solar system was the only one in the universe with habitable worlds.
Then the Kepler mission happened, transforming our view of the universe on the basis of new worlds orbiting distant stars, and the way they did and didn't fit evolving criteria for how an alien world sweeping round an alien sun could be habitable.
Safety from stellar radiation, friendly climate, and water were just basics to liveable conditions. It's time to advance our concept of habitable to include something essential for the best and worst of times, and this is why a team of researchers introduced the notion of the Really Habitable Zone (RHZ).
"In common with much of the world in the field, we rely throughout on assumptions which are difficult if not impossible to test and present some plots which astronomers can use in their own talks, stripped of all caveats," said the authors in the new paper titled "Defining the Really Habitable Zone," reports Universe Today.
Led by author Marven F Pedbost, the study states that the science behind RHZ is still unproven. But this hasn't stopped them from seeing the true compelling core of the concept. As they explain in the introduction: "In common with much of the work in the [exoplanet] field, we rely throughout on assumptions which are difficult if not impossible to test and present some plots which astronomers can use in their own talks, stripped of all caveats."
Human interest into the existence of life is an extremely complex topic, one that uses a wild plurality of convoluted considerations, added Pedbost. This makes it "an ideal theme for telescope and grant funding applications, but a less practical question to answer. Instead, the community has formed a hand-shake agreement to instead investigate the more loosely defined question of habitable zones."
The new study authors said that gin is, in essence, alcohol flavored with a wide variety of "botanical" species. "A precise definition of 'botanical' is lacking, so we assume it is the equivalent of a[n] astronomer's use of 'metal' — including almost everything in the Universe apart from a few common ingredients. Everything is a metal, apart from Hydrogen and Helium, and everything is a botanical apart from water and alcohol," added the authors.
Gin as necessity for habitable worlds
Juniper appears to be the primary botanical in gin, according to spectroscopic analysis, note the authors. And it grows in a variety of conditions on Earth. While a pessimistic mind might think that junipers are rare in the universe, the authors reassure us: "...we should expect exo-juniper to exist on a wide range of planets."
One ingredient down, but what about citrus? It's not as abundant on Earth as juniper, which would suggest it would be even less hardy on exoplanets. The paper says: "In contrast to juniper-related considerations, the region around a star where the conditions are adequate for growing of lemons or limes, fundamental ingredients required for the gin and tonic drink, is sensitive to a number of factors. These necessary citrus fruits thrive in temperatures ranging from 21 to 38? C (botanist, priv.comm.) and require a steady supply of H20, hereafter water."
The paper is ripe with more details, so would-be exo-connoisseurs are encouraged to give it a close reading. Of course, the Really Habitable Zone is just the start of a brave new world in extra-social imagination; one akin to a sound and fury that most trapped inside through the COVID-19 pandemic will welcome with an open glass.
Apropos of this, the authors said: "We suggest that efforts should be directed in the near future towards investigating only those planets whose orbits lie within the RHZ, and made unverified claims about the possibility of detecting relevant features. We're off for a drink."