At Forbes: Maybe fine-tuning doesn’t matter as much as some claim. Many planets might support life…
From Ethan Siegel at Forbes: Based on everything we know, it seems like the conditions that make life possible are a lot more diverse and flexible than most people would expect. … Take Earth’s large moon, for example. The gravitational forces from it keep our planet rotating on the same axis over time. Our present axial tilt is 23.5 degrees, but this will vary over very long timescales between 22.1° and 24.5°. A world like Mars, on the other hand, has almost the same axial tilt as Earth: around 25°. But over tens of millions of years, this will vary by ten times as much as it does on Earth: from a minimum of 13° to a maximum of 40°. Read More ›