Under a Sri Lankan Moon

by Paul Gilster on March 30, 2011

Looking to put things into perspective? The recent Kepler illustration of the 1235 candidate planets thus far identified, each shown in transit, is something to revel in. The image, shown below, offers a sweeping look at the range of stellar sizes that accomodate planets, and bear in mind that these are the planets that by the luck of the draw happen to be visible in transit, a small percentage of the stars Kepler is able to look at. We clearly live in a galaxy that is swarming with planets. Be sure to click on the image to blow it up to full size so you can have a better view of the distant Kepler worlds.

Image: Kepler monitors a rich star field to identify planetary transits by the slight dimming of starlight caused by a planet crossing the face of its parent star. Here all of Kepler’s planet candidates are shown in transit with their parent stars ordered by size from top left to bottom right. Simulated stellar disks and the silhouettes of transiting planets are all shown at the same relative scale, with saturated star colors. Of course, some stars show more than one planet in transit, but you may have to examine the picture at high resolution to spot them all. For reference, the Sun is shown at the same scale, by itself below the top row on the right. In silhouette against the Sun’s disk, both Jupiter and Earth are in transit. Credit: Jason Rowe / Kepler Mission.

Shaping a Life by Looking at the Sky

Sometimes an image can change a person’s future — who knows what budding scientist might see something like this and decide, early in his or her life, to embark on a career in astronomy? The things that shape our fortunes are often all but invisible to those around us. I was thinking about this while reading an essay by Ray Jayawardhana (University of Toronto) in the New York Times. The astrophysicist recalls walking as a child with his father in the family garden in Sri Lanka, and being told, as they looked at the Moon, that people had walked on its surface. The boy was astounded, and out of that wonderment grew a career. I couldn’t help but wonder what things I might have said to my own children that changed their direction, perhaps without my realizing it. I hope Jayawardhana’s father is still alive so he can read about his gift.

The essay is excerpted from Jayawardhana’s new book Strange New Worlds: The Search for Alien Planets and Life Beyond Our Solar System (Princeton University Press, 2011), which I’ll review in these pages as soon as I’ve finished it. Suffice it to say that an astrophysicist who is also an award-winning science writer knows how to write compellingly, as he does in this essay, musing on the schoolchildren of today and their sense of wonder when they see images from the surface of Mars or in orbit around Saturn. Ahead lie vistas of planets around other stars, places we can’t see but are slowly coming to understand.

I should qualify that by noting that we do have a few direct images of alien worlds, but we’re working toward something much better, space missions of the sort envisioned by Webster Cash, some of whose occulter designs offer the prospect of looking at a distant exoplanet closely enough to view its continents and seas. That technology may be further away financially than it is scientifically — once we commit to missions like these, we’re learning rapidly how to build them, and views like Cash talks about might be only a matter of two or three decades away if the budgetary situation weren’t so problematic. In any case, they’re certainly something that seems achievable in this century.

The Meaning of Life Elsewhere

Jayawardhana is interested in what happens when we detect signs of life from another world. We live in a culture where such detections are depicted as cataclysmic events, a momentous radio reception, or the landing of a spacecraft hostile or otherwise. But given the distances between the stars and the daunting problems of interstellar flight, Jayawardhana believes the discovery of life elsewhere will be slow and, perhaps, anything but sensational:

The evidence may be circumstantial at first — say, spectral bar codes of interesting molecules like oxygen, ozone, methane and water — and leave room for alternative interpretations. It may take years of additional data-gathering, and perhaps the construction of new telescopes, to satisfy our doubts. Besides, we won’t know whether such “biosignatures” are an indication of slime or civilization. Most people will likely move on to other, more immediate concerns of life here on Earth while scientists get down to work.

And if SETI finally scores a hit? That would indeed be a breakthrough moment, but what would likely follow would be decades of analysis as we tried to work out the contents of the message. In either case, the sheer knowledge that life can be found in a different part of the universe would mark a turning point in intellectual history. And the SETI detection, no matter through what form of SETI it could be achieved, would tell us that not only life but intelligence was observing the cosmos with us. These are the kinds of changes that make their way into a society’s philosophy, slowly but utterly transforming our perceptions long after the initial shock of discovery wears off.

Jayawardhana again:

I happen to be an optimist. It may take decades after the initial indications of alien life for scientists to gather enough evidence to be certain or to decipher a signal of artificial origin. The full ramifications of the discovery may not be felt for generations, giving us plenty of time to get used to the presence of our galactic neighbors. Besides, knowing that we are not alone just might be the kick in the pants we need to grow up as a species.

That’s a view that mirrors my own optimism, one that suggests that while we are impatient for immediate results, waiting a few decades to confirm that we are not alone is insignificant compared to how long our species has speculated on the question. Will we find evidence of life, and perhaps of intelligent life, within our own lifetimes? Nobody can know, but I’m all for the kind of speculation that Duncan Forgan and Martin Elvis engaged in in the paper we discussed yesterday. We need to be creative in looking for extraterrestrial intelligence. We need to think of Ray Jayawardhana’s father pointing at the Moon, and recall the sudden moments of astonished insight we’ve had in our own lives when suddenly our own personal cosmos snapped into focus.



kzb March 30, 2011 at 12:20

Great picture -the planets towards the top left are bigger than the stars at the bottom right ! Also I can’t see Earth at all, no matter how big I make the picture.

Alex Tolley March 30, 2011 at 12:30

It would interesting to see how we as a species handle a gradual, rather than instant, revelation of life elsewhere. Would we grow, or would we cower, retreating into ourselves for fear of some perceived potential threat? I could easily see the “safety and security first” mindset being exploited. The same reasoning that is invoked to find life, especially ETI, could be used to try to cloak our presence and avoid attention.

I would like to think we are more outward looking, but I don’t expect it given our recent history.

kzb March 31, 2011 at 7:20

Alex Tolley, I actually have the safety and security first mindset as do a lot of people.
In fact it is a possible explanation of the Fermi paradox -everyone is hiding :)

Eniac March 31, 2011 at 8:11

kzb: Hiding on your own planet is not a good survival strategy, compared to spreading out. Plus, there really is no way to hide from a star-colonizing species, since it will eventually settle every single system, including your own. If you can make a plausible argument why every single technological species, without exception, will make and flawlessly carry out a “do not spread” policy out of fear, please try….

In my mind, the only way is if they do not exist. Or, star-flight is impossible for some reason we do not know yet. Or, they actually are in our system and we haven’t noticed. In none of these cases is there any danger in proceeding to try and go, is there?

ljk March 31, 2011 at 9:35

Speaking of parents influencing their children: Johannes Kepler, whose family was dysfunctional even by the standards of his place and time, had his mother show him a lunar eclipse as a child which later did much to make him one of the greatest astronomers of his era. I think he also saw a big comet as a youngster, too.

Kepler is the one who found that planets circle Sol in elliptical orbits, not circular as was believed even by Copernicus. He also wrote Somnium (Dream), which we would call science fiction, about a journey to the Moon where we meet native creatures whose makeup and behaviors were based on the scientific knowledge of the day about our celestial neighbor.


As Eniac said, hiding from an advanced ETI is pointless. It is also detrimental to the growth of our society and species. Either we get out there and make our way in the galaxy or we stay on this rock and eventually either stagnate or go extinct.

kzb March 31, 2011 at 12:54

Hiding and making our way into the Galaxy are not mutually exclusive activities. I am not saying for one moment that we do not go out there.

Quite the reverse. In fact I can think of no greater spur to space flight than if we found exo-intelligence. But the spur would really be to find out as much about “them” without giving too much away about “us” I think.

I guess it is unenforcable anyhow. Even if all governments enacted an “Earth’s Official Secrets Act”, someone would go out of their way to break it.

Rob Henry March 31, 2011 at 17:47

Several comments have been about hiding as a strategy to answer the Fermi paradox, and as pointed out this solution is hard to sustain… unless our system was especially privileged toward such behaviour. In an earlier thread here I was involved in a discussion over another proposed Fermi solution, and that was to posit that, given the right environment, the evolution of life into intelligent forms was vanishingly unlikely. This, in turn, highlighted the point that, given sufficient time, it was at least equally valid to argue that intelligence will always result (given our current terrestrial data).

Now, due to geological and gravitational differences, these conducive conditions may have occurred on other bodies (Mars, Europa,?) in our solar system, where they have been thought by some to have incurred a prolonged past phase of high atmospheric or oceanic free oxygen content.

Let me also acknowledge the origin of life as a nearly miraculous event, and that lithopanspermia would have spread life throughout our system.

Perhaps then our galaxy really is full of intelligent life, but they are leaving us alone because this is their home system from which an unpleasant tragedy wiped them long ago.

Rob Henry March 31, 2011 at 22:29

I should have given the above idea a name. How about “The Rare Sol Hypothesis”. It can be simplistically explained as the idea that intelligent life is extremely common in our galaxy, but simpler forms are very rare.

ljk April 1, 2011 at 9:31

ksb said:

“I guess it [METI] is unenforcable anyhow. Even if all governments enacted an “Earth’s Official Secrets Act”, someone would go out of their way to break it.”

That is correct and it is already happening. There are individuals and groups who are conducting METI and state as one of their reasons their right to have the freedom to speak on their own behalf regarding the rest of the Universe.

The same will also happen when we are more established in space. Groups who want to be free of any influences by other human authorities will pack up and leave the Sol system at the first given opportunity. Their encounters with the rest of the galaxy will be out of anyone else’s control.

As for whether life on this planet is common or rare elsewhere, we need to do a LOT more space exploration before we can make such a claim in either direction. We are still at the doorstep of the wide world before us and are just barely on the sidewalk at present.

nat April 2, 2011 at 1:48

If SETI finally scores a hit, it could be disturbing. Consider the messages that many humans would love to relay to sentient life out there. Religious fanatics, once getting a hold on the coordinates, would fund powerful transmitters to beam nonstop to the star system.

Now consider distant insecure beings, enthralled by their unique versions of delusion, who are compelled to beam it to us. If it was as wide and varied as here on Earth, and if they openly squabbled on our behalf, it would be terribly interesting, but a gut-wrenching let down.

Andrew April 2, 2011 at 20:33

I find it kinda weird that some people are afraid we are NOT alone!

On “Stargate” it was a recurring theme that if ETI was found and made public it would lead to social break down.
I just don’t see it that way, especially in the times we live in.
Maybe I’m too optimistic, but I would think it would unite all these damn squabbling tribes of man and make us realise we are all one race.

Rob Henry April 3, 2011 at 17:18

Andrew, the saying “may you live in interesting times” is purportedly an old Chinese curse. If alien contact presented itself to us in a way that was unambiguously threatening, yes, we would unite. But is that likely?

I think that when you find the enemy it may well be us. Think how Heavens’ Gate was inspires to its particular insanity by the mere vista of a comet.

ljk April 4, 2011 at 10:57

Just because humanity may not be ready as a whole for a real encounter with an alien intelligence (think of the bit in the first Men in Black film where Agent K says how an individual person may be smart but people as a group are dumb, panicky animals) does not mean that the Universe is going to kindly oblige us to mature until we are ready for such an event.

Science fiction has played a role in this regard, but since the key word here is fiction with the primary goal of making a profit via entertainment, the genre is not always the best way to go about expanding the public mindset. Even a guy as smart as Stephen Hawking thinks that meeting an alien race will be mainly detrimental for us with nothing more than a single data point to go on.

Scientists in all related fields need to do a lot more to prepare their fellow humans for the big wide Cosmos out there. Even if we don’t run across an alien species any time soon, a better idea of the Big Picture for a society that is slowly emerging into space can only be beneficial.

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