On a clear night this month, after you finish eating dinner, step outside and look to the west. High in the sky, about midway between the zenith and the horizon, you’ll see the planet Jupiter.
Now, few people—other than astronomers, perhaps—ordinarily give Jupiter much attention. But that dot of light in the western sky may be absolutely critical to our existence. As University of Washington scientists Donald Brownlee and Peter Ward argue in their new book, Rare Earth, Jupiter acts as our own planet’s protective big brother.
Indeed, they argue that not only Jupiter, but the Moon, the Solar System’s position in the Milky Way, and a host of other special conditions make Earth probably the only environment suitable for human life.
Rare Earth has stirred controversy in the scientific community because it challenges the conventional wisdom that the universe is teeming with intelligent life. But it is controversial for another reason, too. If dozens of conditions—such as the shape of Jupiter’s orbit or its mass—need to be precisely specified for human life to exist, might that not point to divine design?
Of course, that’s exactly what Christian astronomers have argued for years. Thus, some critics are already complaining that Brownlee and Ward are lending support to theism. Reviewers have been speculating darkly about the authors’ motives.
But Brownlee and Ward have no theological agenda to advance. They simply don’t think the evidence supports the view that the universe is full of planets suitable for life. As Brownlee told the New York Times, “Almost all environments in the universe are terrible for life. It’s only Garden of Eden places like the Earth,” he said, “where it can exist.”
The authors point out that Jupiter’s orbit is remarkably stable, and nearly circular. Otherwise, our Solar System could “literally be torn apart” by gravitational forces.
Many recently discovered gas giants, like Jupiter, surprised astronomers by exhibiting wildly eccentric, or highly ellipitical orbits. Such orbits would be utterly destructive to any small, Earth-like planets in the gas giants’ paths.
Finally, Brownlee and Ward argue that Jupiter’s immense size protects the Earth. With its great mass, 318 times greater than the Earth’s, Jupiter scatters comets and other bodies that might otherwise catastrophically collide with our planet.
But the remarkable features of Jupiter provide only one strand in this cosmic tapestry. The Solar System’s position in the galaxy, the Moon’s vital contribution to the Earth’s rotation, the role of plate tectonics—one line of evidence after another lead Rare Earth’s authors to conclude that our planetary home is quite possibly unique.
Brownlee and Ward don’t attribute that uniqueness, however, to design. For them, it’s just a matter of cosmic good luck.
But the evidence, like that reported in their book, makes the case for intelligent design just as the great scientist Isaac Newton understood it hundreds of years ago. With much less evidence than we have today, Newton argued that reason itself was best served by a hypothesis of design. “This most beautiful system of the sun, planets, and comets,” he wrote, “could only proceed from the counsel and dominion of an intelligent and powerful Being.”
What’s exciting is that intelligent design is now returning to science: scientists need only the openness to embrace it.
