Earth, Mars, Jupiter, and Saturn: Highlights from the last decade of space photography
We began haltingly, with rockets that scraped the edge of space with their noses; moved on to orbiters that circled us in our small, atmospheric cocoon; and, gradually, we grew more confident, sending not just probes and dogs and monkeys, but our own flesh and blood to the moon.
Today, we have humans living on a semi-permanent basis in space, rovers prowling about Mars, and spacecraft whizzing by planets beyond the asteroid belt. Voyager I, our farthest-sailing creation yet, will soon leave the bubble of our sun's winds and cross into interstellar space -- a boundary we've only begun to understand in the 35 years since Voyager launched. We haven't exactly conquered the solar system, but we have laid our claim.
At the same time, we are getting a better idea of just what a tiny speck in the universe our solar system is. Our telescopes both in orbit and on the ground have provided us with ever-clearer pictures of the universe beyond our solar neighborhood: nearby stars, local galaxies, and the deepest reaches of the universe. In 1995, scientists aimed the Hubble telescope at a tiny, blank patch of the night sky; they found it teeming with *galaxies*. NASA's Kepler mission has identified thousands of probable planets orbiting stars just in the local region of the Milky Way. Just two decades ago, we didn't know there was a single one. Last week, we learned there is at least one planet orbiting Alpha Centauri B, located in the system of stars closest to our own.
But despite all of this -- despite our Voyagers' journey to the heliosphere's edge and despite our portraits of thousands of remote galaxies -- we also know that our solar system is, well, huge. After all, it has taken Voyager 35 years traveling at some 35,000 miles per hour to get to the edge. And it's magnificent too: There are Saturn's icy rings, Jupiter's three-times-the-diameter-of-Earth boiling storm, and Europa's oceans. And all of these are tiny -- tiny -- when compared with the sun, which alone makes up some 99.8 percent of all the mass in the solar system, weighing in at 4,385,214,857,119,400,000,000,000,000,000 lbs, or 333,060.402 Earths.
Almost as though timed to remind us of this majesty, a new book, Planetfall by Michael Benson (Abrams), showcases this small, familiar neighborhood of the galaxy in a way that feels neither small nor familiar. Benson, a longtime self-described "hard-core space freak," narrates the visual journey across our solar system with a rich, beautiful text. But it is his curation -- the selection of portraits of "a kind of Calder mobile of related landscapes all lit by the same key light" -- that adds art to the underlying science. "Human beings," Benson writes, "have been fascinated with the sky since prehistory. It's us, the generations alive today, who get to see these worlds for the first time." These images, all of which were taken since the year 2000, are something to stare at for hours, to marvel at, to behold.
The title, Planetfall, is meant as a 21st-century version of landfall -- that moment when, after months in the void, you spot an edge, a little bit of planet, *a place*, coming in to view. But planetfall has a secondary meaning as well, one that hits a bit closer to home. "If we look closely at our planet in images taken from space during the last decade, it's hard not to notice some troubling signs," Benson observes. He continues, "One definition of the term "planetfall" comes to mind: a decline in the biosphere of a planet, whether due to actions by indigenous species or other causes." [Emphasis in original]
Benson's tour begins with Earth and moves outward from there, covering Mars, the Asteroid Belt, Jupiter, and Saturn (the Sun gets a chapter too, albeit following Earth, out of geospatial order). In the selection of images below, I've highlighted the four planets Benson includes (Earth, Mars, Jupiter, and Saturn), and for each planet I've selected one picture that gives you more of a sense of the planetary body as it hangs in the void of space (as Earth below) and one close-up (click on the images to expand). With Earth and Mars, the close-ups are quite close, giving you a sense of the terrain. But for the planets farther out in our system, ones we cannot and have not reached with the same intimacy, the close-ups and distance shots are more similar, a reminder of how much is yet to be explored and seen.
One realization that comes from looking endlessly at space images, "is that for all the visual splendor and eerie, chilling beauty, there isn't one place out there that can match the beauty and, you know, fecundity, the temperate livability of Earth," Benson wrote to me.
"We were never expelled from Eden, you know, it's yet another Judeo-Christian misconception about the nature of our situation. ... And [yet] there are a number of highly disturbing images of Earth in which you see clearly, in one case from a distance of about 64,000 miles, that there's something rotten going on. In that specific image, you can see dense smoke from Amazon jungle burn-off filling the atmosphere over most of South America. This is of course a total scandal, the hallmark of an out-of-control species."
In the book, Benson includes images of the Earth dominated by the mark humans have left on the planet, still the only place in the universe where life is known to exist, with all the beauty and destruction it entails.
The next stop is Mars, a planet so close and in some respects similar to our own that is "has long had an ineffable hold on the human psyche," Benson writes in the book. "Before spaceflight but after the advent of the telescope, a period of about 350 years, we could see just enough of the planet to recognize that it was a desert world with obscure seasonal changes that -- perhaps -- signified life."
Mars is not the only other planet we've landed on (several Soviet spacecraft made it to Venus) but certainly the one we know best after our own. With two orbiters and two rovers arriving in the first decade of the 21st century (Europe's Mars Express, NASA's Mars Reconnaissance Orbiter, and the twin Spirit and Opportunity mobile labs) and, of course, Curiosity's arrival this past summer, humans are well on their way to mapping and exploring the planet's dusty surface. In the years ahead, with Mars passing closest to Earth in the early 2030s, the question of a manned mission to the red planet will loom larger, but other planets and moons (Benson says he is particularly intrigued by Jupiter's ice-moon Europa) beckon, harder to reach, but with greater promise of truly surprising discoveries.
After Mars, Benson moves on to Jupiter, which he said to me over email is to him "the single most awesome object in the solar system -- apart from the sun, of course." Though Voyager passed by in 1979 and Cassini did so in late 2000/early 2001, no spacecraft have gotten up close and personal with the gas giant, the largest planet in the solar system. "Cassisni's closest approach," Benson writes in the book, "brought it to only within six million miles of the planet -- about 25 times the distance between the Earth and Moon."
In less than four years, our view of Jupiter will change, as the Juno spacecraft, launched into orbit in 2011, begins to orbit the planet. From there, we'll get our best pictures yet of its stormy strata, its massive red eye, and its archipelago of moons -- four large ones (Mercury- or Luna-sized) and 62 smaller satellites. Those four moons -- Io, Europa, Ganymede, and Callisto -- were discovered by Galileo in 1610. Europa, in particular, holds promise as the best candidate for extraterrestrial life within our own solar system. Its ocean may contain as much liquid water as all of Earth's oceans together, Benson wrote to me. With its moons and its storms, "Jupiter's proved to be just as awe-inspiring as the Ancients somehow intuited when they named it after the King of the Gods."
The last stop in our Planetfall journey brings us to Saturn, for me the most visually stunning nearby planet. "It's hard to conceive of a planet more sublime than Saturn," Benson writes in the chapter's introduction. "If Jupiter posses a ferocious magnificence befitting a planet named after the kind of the gods, Saturn has a more feminine beauty -- a grace in part due to its accoutrements, a set of stunningly ethereal rings that float in a kind of superfine liquid suspension around its waist."
Since arriving at Saturn in 2004, NASA's Cassini spacecraft has documented a planet and lunar system far more active than previously known -- as in the pictures of geysers of freezing water on Enceladus, Saturn's sixth-largest satellite, and a storm springtime in the planet's northern hemisphere. It is discoveries like these that continue to keep the door open on solar-system exploration; we may be on the verge of crossing into interstellar space, but there is so much unknown within our solar bubble. "Even as the solar system feels increasingly familiar to me, it has even more ability to blow me away."
"These worlds are our proximate neighbors," Benson writes. "An archipelago in a sea so deep that it's for all intents and purposes infinite, in both space and time."
But in the end, he finds, "there's no place like home. And this is after a lot of research into what Oz is all about, believe me. After you linger a while on the dusty plains of Mars, or the utterly sterile valleys of the Moon, or name your solar-system landscape, the call of a tropical terrestrial beach becomes utterly seductive -- not to mention a glass of wine, a great meal, [and] a beautiful person."
For more information on Michael Benson's work, see http://michael-benson.net. Images from Planetfall will be on exhibition at Hasted Kraeutler Gallery in New York City beginning December 13. His 2002 Atlantic essay, A Space in Time, can be found here.