For a long time the Big Bang theory had one gaping hole that troubled a lot of people-namely that it couldnt begin to explain how we got here. Although 98 percent of all the matter that exists was created with the Big Bang, that matter consisted exclusively of light gases: the helium, hydrogen, and lithium that we mentioned earlier. Not one particle of the heavy stuff so vital to our own being-carbon, nitrogen, oxygen, and all the rest-emerged from the gaseous brew of creation. But-and heres the troubling point-to forge these heavy elements, you need the kind of heat and energy of a Big Bang. Yet there has been only one Big Bang and it didnt produce them. So where did they come from?
Interestingly, the man who found the answer to that question was a cosmologist who heartily despised the Big Bang as a theory and coined the term Big Bang sarcastically, as a way of mocking it. Well get to him shortly, but before we turn to the question of how we got here, it might be worth taking a few minutes to consider just where exactly here is.
2 WELCOME TO THE SOLAR SYSTEM
totalIn short, there isnt a great deal that goes on in the universe that astronomers cant find when they have a mind to. Which is why it is all the more remarkable to reflect that until 1978 no one had ever noticed that Pluto has a moon. In the summer of that year, a young astronomer named James Christy at the U.S. Naval Observatory in Flagstaff, Arizona, was making a routine examination of photographic images of Pluto when he saw that there was something there-something blurry and uncertain but definitely other than Pluto. Consulting a colleague named Robert Harrington, he concluded that what he was looking at was a moon. And it wasnt just any moon. Relative to the planet, it was the biggest moon in the solar system.
This was actually something of a blow to Plutos status as a planet, which had never been terribly robust anyway. Since previously the space occupied by the moon and the space occupied by Pluto were thought to be one and the same, it meant that Pluto was much smaller than anyone had supposed-smaller even than Mercury. Indeed, seven moons in the solar system, including our own, are larger.
Now a natural question is why it took so long for anyone to find a moon in our own solar system. The answer is that it is partly a matter of where astronomers point their instruments and partly a matter of what their instruments are designed to detect, and partly its just Pluto. Mostly its where they point their instruments. In the words of the astronomer Clark Chapman: Most people think that astronomers get out at night in observatories and scan the skies. Thats not true. Almost all the telescopes we have in the world are designed to peer at very tiny little pieces of the sky way off in the distance to see a quasar or hunt for black holes or look at a distant galaxy. The only real network of telescopes that scans the skies has been designed and built by the military.
We have been spoiled by artists renderings into imagining a clarity of resolution that doesnt exist in actual astronomy. Pluto in Christys photograph is faint and fuzzy-a piece of cosmic lint-and its moon is not the romantically backlit, crisply delineated companion orb you would get in a National Geographic painting, but rather just a tiny and extremely indistinct hint of additional fuzziness. Such was the fuzziness, in fact, that it took seven years for anyone to spot the moon again and thus independently confirm
its existence.
One nice touch about Christys discovery was that it happened in Flagstaff, for it was there in 1930 that Pluto had been found in the first place. That seminal event in astronomy was largely to the credit of the astronomer Percival Lowell. Lowell, who came from one of the oldest and wealthiest Boston families (the one in the famous ditty about Boston being the home of the bean and the cod, where Lowells spoke only to Cabots, while Cabots spoke only to God), endowed the famous observatory that bears his name, but is most indelibly remembered for his belief that Mars was covered with canals built by industrious Martians for purposes of conveying water from polar regions to the dry but productive lands nearer the equator.
Lowells other abiding conviction was that there existed, somewhere out beyond Neptune, an undiscovered ninth planet, dubbed Planet X. Lowell based this belief on irregularities he detected in the orbits of Uranus and Neptune, and devoted the last years of his life to trying to find the gassy giant he was certain was out there. Unfortunately, he died suddenly in 1916, at least partly exhausted by his quest, and the search fell into abeyance while Lowells heirs squabbled over his estate. However, in 1929, partly as a way of deflecting attention away from the Mars canal saga (which by now had become a serious embarrassment), the Lowell Observatory directors decided to resume the search and to that end hired a young man from Kansas named Clyde Tombaugh.