Forty years ago, in December of the troubled year of 1968, astronauts Frank Borman, James Lovell and William Anders piloted the Apollo 8 spacecraft into orbit around the moon, the first humans ever to circle any globe but our own. From that unique vantage, they sent back the iconic photograph (taken by Anders) shown below, known as “Earthrise.” It unforgettably captured the fragile beauty of our living planet as it hovered in stark contrast over the arid sterility of the lunar horizon: a precious droplet of life—perhaps the only one we could ever know—in the velvety darkness.
For a world torn by conflicts over an unpopular war and other social upheavals, that photograph was a timely reminder of how inextricably united the fates of everything and everyone on Earth were. Indeed, the image is widely credited with having energized the environmental movement.
The Cassini spacecraft swinging through orbits around Saturn and its satellites has been sending back extraordinary pictures of its own, particularly from the moon Enceladus, and if they are less famous among most of the public, they may be no less inspirational to planetary scientists. In some respects, what Cassini sees is the inverse of what the Apollo astronauts did. Saturn is not a modest, life-bearing planet like Earth; it is a gaudy, frozen colossus decked out in a shining hoopskirt of rings.
More important, though, Enceladus is not a dead, dry bone of a moon. Cassini’s evidence proves that Enceladus—seemingly against all odds—is a tectonically active world that sprays geysers of moisture from deep parallel fissures at its south pole. In fact, Saturn’s feistiest satellite may contain an underground ocean’s worth of water. Furthermore, spectroscopy shows that spouting water vapor is a soup of organic compounds. Enceladus thus flies into the elite ranks, alongside Mars, Titan and Europa, of the most promising places in our solar system to look for extraterrestrial life. NASA scientist Carolyn Porco, who oversaw imaging for the Cassini mission, explains the science arising from the spacecraft’s latest discoveries.
It is wishful thinking, but perhaps the images from Cassini could be a message of hope for our time. Like 1968, 2008 is wracked by political turmoil and war. Epic economic disaster spilling out of the banking crisis has cast a pall over ambitions, both personal and national. But if “Earthrise” reminded us that we are all in this together (and by all means, let us not forget that), then Cassini and Enceladus are proof that beyond our immediate strife, the universe beckons and dares us to a more glorious future. Earth is still rising.
Note: This story was originally printed with the title, "Beacons in the Night".