By now you’ve probably heard the announcement that astronomers Konstantin Batygin and Mike Brown think they’ve tracked down “Planet 9,” a long-rumored large world orbiting in the distant wilderness of the solar system. Even if you haven’t heard, the news may sound familiar, since a confusingly similar but completely separate report made the rounds just a month ago. (Students of history will recall that Planet X stories also circulated in 2014 and 2006, and have been a staple of the astronomy hype machine all the way back to the discovery of Ceres in 1801.)
The dreary truth is that the Batygin and Brown claim, while stronger than the ones that came before, is still soaked in uncertainty. But there’s another truth, far more exciting, that goes with it: The latest efforts to find Planet X are hugely revealing, even if these particular ones don’t hold up.
Reason #1: The competing claims starkly illustrate the difference between seeing and believing. The case for Planet 9 is much stronger than for the ones described in December, even though researchers have directly observed the earlier objects but have not seen Planet 9 at all. Better yet is reason #2: These stories keep popping up because overwhelming majority of the solar system is cloaked in darkness, and is just now coming into view. Even the latest maybe-planets turn out not to exist, it’s nearly certain that there are big, exotic things out beyond Pluto waiting to be found.
What was the biggest news in astronomy this past year? The editorial board of Discover has helpfully provided an answer, one that I heartily endorse (and not only because I wrote the related story in the magazine): It was the exploration of Pluto by the New Horizons spacecraft. To appreciate just why that mission was, and still is, such a big deal, join me in a little act of mental time travel.
If you could move 6 months back in time, it would be shockingly simple to summarize what astronomers knew about Pluto–and mind you, they knew more about Pluto than about any of the other myriad frozen worlds out beyond Neptune. The Idiot’s Guide to Pluto would not include an exact diameter (nobody knew it), or structure of the atmosphere, the geology, the topography, the composition, or even Pluto’s distinctive markings (nobody knew any of those, either).
It can feel inappropriate celebrating the exploration of the universe while the media are saturated with grim stories about warfare, terrorism, and other forms of human suffering. The issue boils down to matters of sensitivity and propriety: How can you talk about something so theoretical and remote when there are so many problems all around us? I wrote a column on this theme last year, and it feels especially timely right now as I (like so many other Americans) am stepping back to think about the things I’m thankful for.
What really struck me from that perspective was the sense of progress: The old-fashioned sense of forward motion through history, from less civilized to more, toward a better and more fulfilling lifestyle for all of humanity. It is easy to lose sight of the pattern while being barraged by news stories that give the impression we are living in the worst time ever–but by most measures, we are living in the best time ever. I’m not talking just about scientific exploration (in which 2015 witnessed historic explorations the small worlds Pluto and Ceres), but also about the overall quality of human life. Both are getting better and better, and the reasons why are intertwined.
With its strong showing at the box office, The Martian joins Gravity and Interstellar in the club of science-fiction movies that succeed by emphasizing the science and downplaying the anything-goes fantasy elements. But even in this rarefied company, The Martian stands apart. Unlike Interstellar, it is rooted in present-day technology and challenges. And unlike Gravity, it fully respects the physical rules of space travel; in fact, it makes them central to the plot.
The Martian comes at a pivotal time for NASA. With space imagery getting better and better–taking on an almost cinematic quality–the need for human exploration in some ways seems less obvious than ever. At the same time, the difficulty of getting any concrete answers about life on Mars (or even definitive answers about water and methane) illustrates the huge limitations of doing science using robots. Artificial intelligence and remote control are just not cutting it. By treating the human exploration of Mars with scientific respect and genuine emotion, The Martian make its case more powerfully than NASA’s slick posters and earnest Congressional testimony have managed to do.
The 20-year stretch since the discovery of the first exoplanet—a planet circling a star other than the sun—has seen a wholesale relocation of cool ideas from science fiction over to science fact. By 1999, scientists found a way to study the composition of exoplanets. By 2004, they identified a rocky planet, broadly similar to Earth in structure. By 2014, they tracked down an Earth-size world that is the right distance from its star for liquid water. The Star Trek vision of a galaxy full of habitable planets doesn’t look farfetched anymore.
Despite that remarkable progress, we are still far from answering the big question: Is anybody (or anything) out there? What we all want to find is not just an Earth-size world, or an Earth-temperature world, or a vaguely Earth-like world. We want to find Earth 2.0: a wet, warm, living, breathing planet just like our own. To do that, we need to go far beyond the search techniques that astronomers have used so far. There needs to be a more ambitious plan. And there is.
Twenty years ago today, an invisible object circling an obscure star in the constellation Pegasus overturned everything astronomers knew about planets around other stars. No, the fallout was even bigger than that. The indirect detection of 51 Pegasi b—the first planet ever found around a star similar to the sun—revealed that they had never really known anything to begin with.
At the time, even the most adventurous minds blithely assumed that our solar system was more or less typical, a template for all the others. 51 Peg b threw a big splash of reality in their faces. The newfound world was bizarre, a Jupiter-size world skimming the surface of its star in a blistering-fast “year” that lasted just 4.2 days. Its existence ran counter to the standard theories of how planets form and evolve. It answered one big question: Yes, other planetary systems really do exist. But it raised a thousand others.
NASA scientists were conferring today about a nearby planet that is shockingly similar to Earth. It is just 5% smaller in radius and 15% smaller in mass. It is almost the exact same age as our planet, and gets its warmth from an identical star. The only thing that’s a bit off is that it orbits a bit closer to its star than Earth does, so it receives nearly twice as much radiation. On the other, it also reflects away a lot of that radiation. Its theoretical (equilibrium) temperature is just below freezing, so with a little natural greenhouse warming it would be quite an inviting place.
If we found it orbiting another star, this world would surely be hailed as the most Earthlike exoplanet known: the best place yet to search for alien life.
No doubt you sense there is a catch, and indeed there is. The world I’m talking about is Venus. It is not orbiting another star; it is the planet closest to home right here in our own solar system. But I’m not just being coy. Despite its proximity, Venus is a profound enigma. It really should be a hospitable world, but the truth is that it is more like hell on almost-Earth. Understanding why that is–why our planet went right while Venus went terribly wrong–is crucial for finding out whether habitable planets are common or rare throughout the universe.
NASA generated quite a bit of buzz today with the apparent discovery of flowing water on Mars. Now to anybody who follows science news–especially news about space and alien life–those words may sound awfully familiar. It seems like NASA has been discovering water on Mars every year for the last decade. This time really is different, however. For one thing, scientists are talking about water on Mars right now. For another, the evidence is much stronger than it was in past reports; I wrote about some of those earlier speculations here.
Although the news just broke earlier today, there has already been extensive discussion of the results online. I’ve read through the early conversations (so you don’t have to). Here are some of the key things you should know. I’ll start with the bad news, since I always like to get it out of the way first.
Today is the day when, according to a widely circulated email/Facebook hoax, Mars will appear as large in the sky as the full moon. In reality, nothing short of the catastrophic disruption of the entire solar system could allow such a thing to happen (and if that were happening, you probably would have heard the news). Still, I have sympathy for those who were taken in by the hoax. We live in an age of amazing space imagery: snapshots of nitrogen glaciers on Pluto, a robot bouncing off a comet, ice moons hovering over the rings of Saturn. If you don’t think too hard about it, one more wild view doesn’t seem so implausible.
The barrage of genuine scientific amazement surely also explains why so many people credulously accept other erroneous or at least misleading stories, such as the ongoing reports that NASA has validated an “impossible space drive”–or, in some variations, that NASA “accidentally created a warp drive.” I’m sympathetic again. After all, NASA really did send an ion-powered spacecraft to the dwarf planet Ceres. That’s pretty wild. Again, if you don’t think too hard about it, why not accept another, even more staggering technological breakthrough?
Some quick online research will usually separate the serious stuff from the hoaxes and the hype, but many people lack the time or even the inclination. What would be truly helpful is a set of basic reality-check tests that anyone can apply: an all-purpose science BS-detector kit that requires little more than getting past that first hurdle of thinking. I’m going to attempt to build one right here. I’d love to hear your ideas as well.
The most consistently reliable meteor shower—the Perseids—peaks tonight. Under clear, dark, unobstructed skies you might see 60 to 100 meteors an hour. And this year, nature is cooperating: The moon is a thin crescent that does not rise until dawn, meaning that the astronomical sky will remain wonderfully dark all night through. (Clouds are another matter; getting away from buildings, trees, and city lights is all up to you.)
For tips on how to watch the Perseids, read through this helpful viewer’s guide prepared by our friends at Astronomy magazine. That will tell you what you need to know about how to watch. It’s a lot harder to find good information about what you are seeing. That’s why I’m here.