Read Online Five Billion Years of Solitude by Lee Billings - Free Book Online Page B

first brush with astronomy had come when, as an eight-year-old boy in the soybean country of downstate Illinois, he scraped together enough money to buy a small, simple telescope. He looked at stars, and the Moon. In one early evening’s twilight he turned his telescope toward Venus, low and sparkling in the sky. He had expected to see the same blurry dot he witnessed with his naked eyes, albeit magnified. Instead the telescope revealed a crescent, sharp and whitish-yellow like a nail clipping. It dawned on him that he was seeing both day and night on Venus, and that the demarcation between the two marked a zone of twilight, just like the one he was now in on Earth. The view from his backyard in Illinois seemed at once larger and smaller than ever before; something about seeing an alien planet’s hidden details revealed before his very eyes made his mind effervesce. The feeling faded, only to momentarily return over the years each time he uncovered something unexpected and beautiful. The more he learned, the more profundity he saw in the purity of numbers and equations, the more majesty he found in the lives of planets, stars, and galaxies. Laughlin didn’t know it at the time, staring at sunlight shining on the distant cloud tops of Venus, but the vista spread before him in his telescope would draw him deep into the frontiers of planet hunting.
    “Though closer to the Sun, Venus is covered by so many clouds that it actually absorbs less sunlight than Earth does,” Laughlin was saying to his audience. “And so for many years it was perfectly possible to imagine the Venusian surface looking like this.” On the screen behind him, anaerial photograph appeared of waterfalls cascading through a mountainous forest shrouded in mist. “Then, in the late 1950s, astronomers found that Venus was just spewing out microwaves with an emission corresponding to a temperature on the order of six hundred degrees Celsius. It soon became clear that Venus was a runaway-greenhouse world, a truly terrible place.” Laughlin summoned an image of the true Venusian surface and let it linger silently on the screen—a lifeless, flattened landscape of shattered rock beamed back in 1982 by the Russian Venera 13 lander moments before the probe melted and imploded beneath hellish temperatures and crushing atmospheric pressures.
    “During the 1950s, there was this brief, wild interval when you could realistically speculate that Venus not only had a habitable environment, but also that humans would soon visit it. The Apollo program wasn’t far away, and the ability to travel between planets was just within our grasp—in a way that it doesn’t seem to be any longer. Think what would have happened, how history would have changed, and what our world would look like today if we had found a habitable Earth-like planet literally right next door. It’s an odd, tragic coincidence that these possibilities disappeared for us right around the dawn of the Space Age. And as soon as Venus and then Mars changed from being candidates for full-blown economic colonization to being objects of mostly scientific interest, public interest really shifted to planets orbiting other stars.”
    A few slides later, Laughlin showed a graph plotting all the known exoplanets, with masses on the vertical y-axis and years of discovery on the horizontal x-axis. A lone dot resided in 1995’s column on the plot’s older, sparsely populated left side, high up between the masses of Jupiter and Saturn. The dot represented a gas-giant world in a star-grazing 4.5-day orbit around the nearby star 51 Pegasi. It was 51 Pegasi b, a “hot Jupiter,” the first confirmed exoplanet around a Sun-like star, and a planetary system so bizarre that it spurred theorists to rewrite their models of planet formation. Sweeping forward in time, the dots proliferated across the chart and spread out into a thick wedge spanning a widerange of masses. In a decade’s span, the number of confirmed worlds