Surveillance from Space?—Part 2

I often think how much more technologically advanced in space humanity could be, had we not invested so much time and energy on warfare. The US space program, for example, consumes a tiny fraction of the money that the military receives. I find it frustrating that Americans often criticize the space budget as being exorbitant, while quietly accepting the enormous amount of money expended on weapons and the military. 

NASA has achieved many impressive feats in space. Some of them have attracted lots of public attention, such as planting human footprints on the Moon, but the more meaningful (and less popular) accomplishments have been in the space science realm—the tremendous telescopes (like Hubble and now the James Webb scope), the geological surveys of Mars, and the lengthy missions to Jupiter and Saturn and their moons. These NASA programs have given us invaluable information about our solar system and outer space—that will inform and allow future space flight and the ongoing understanding of our cosmos.

But these peace-time space science missions of humans are far less interesting and sexy for citizens. How many movies can you remember about the boring aspects of space science? How many news articles have you read about peace-making activities? In contrast, have there not been a plethora of violent movies on space? Think Star Wars or Independence Day. Do the media not feature many articles about human activities on the International Space Station, while they ignore the complex—if not mundane—scientific experiments done there?

When we read about UFOs or advanced outer-space civilizations, it is easy to become fearful that we may be threatened by these advanced societies. Maybe this is an inappropriate response. If we could manage to eliminate our aggression towards each other, maybe we could be allowed to join the Intergalactic Union. Maybe they are waiting to see if we awaken to the truth and discard our war-like behavior.

Aliens Around Us?

I have posted several times on this blog about the possibility of life existing elsewhere than just on Earth. It's a subject that fascinates me and one for which we inch closer to an answer, each year. One important development in the search is that scientists are increasingly broadening the definition of life. Recent discoveries of strange life forms right here on Earth have pushed scientists to ponder the possibilities of alternative kinds of life. NASA's current definition of life is “a self-sustaining chemical system capable of Darwinian evolution.” That's much broader than the thinking was, just a few years ago.

In fact, some microbiologists have proposed an even broader definition of what they have dubbed “lyfe”—trying to become more open to alien possibilities. Lyfe has been proposed by them to have four qualities: it (1) draws on energy sources in its environment, (2) grows through replication, (3) can adapt to a changing environment, and (4) learns and remembers information that it acquires from that environment. Gone are the former criteria that life must be carbon based or even require liquid water.

Additional open-minded possibilities about lyfe are that—other than on Earth—its pace might be far slower or faster than life forms as we know them; thus making it difficult to even notice that it could be lyfe. Furthermore, could lyfe use energy sources that life does not? For example, bacteria have been discovered in deep Earth mines that do not use the sun's energy, but get their energy from radioactivity. Could there even be something that might be called “sub-lyfe,” which doesn't have to meet all four of the above criteria? Or even “super-lyfe,” which surpasses the four criteria? It's possible, furthermore, that a form of super-lyfe might look upon us humans (and all our fellow Earthly life forms) as we do upon crystals; or viruses, which are a form of not-quite-life, (requiring a living biological cell to invade and hijack its life functions).

When pondering the possibilities of life (or lyfe), other interesting questions come to mind. Are there ways to store information, other than by DNA? Where is the boundary between lyfe and non-lyfe? Must lyfe possess sharp, physical boundaries?

This past July, three missions left Earth for Mars—from China, the United Arab Emirates, and the US. They are all aimed at the next step of characterizing the nature of our fellow planet Mars—one that long ago had oceans and an atmosphere somewhat like Earth. The US and Chinese missions are both landers that will seek signs of current or past life there. Should we redefine their quest as one of looking for lyfe?

For future projects NASA is planning missions to Europa—a moon of Jupiter—and Titan—the largest moon of Saturn—both of which have the best chance of nonEarth life (lyfe?) in our solar system. By opening up to the definition and possibilities of lyfe, those undertakings may be more successful and unambiguous.

AI Goes to Mars

Six years ago NASA gently lowered the rover Curiosity into Mars' Gale Crater. It was a risky landing, that entailed lowering the rover onto the surface from a sky crane that slowly and tenderly deposited Curiosity, disconnected from it, and then flew off at a distance and crashed itself. Every NASA employee—as well as millions around the world—chewed their fingernails, until Curiosity radioed back that it was safely down.

Ever since that ground-breaking day, the rover has wandered about Gale Crater at the breakneck speed of 0.02 mph (0.03 kph), scooping up soil samples, drilling holes in rocks, and analyzing the compounds found. Its mission is to evaluate Mars' habitability, i.e., could the Red Planet ever have had conditions that would have allowed life to exist there? Can we detect the signs of those conditions today? I have blogged previously that NASA has learned from its 1970s Viking missions not to try to directly measure life on Mars (due to the ambiguity of the measurements), but to simply try to determine if Mars' climate ever was hospitable for life.

Three years ago NASA upgraded the software in Curiosity's computer to give it artificial intelligence (AI) capability, which is presently operable. Thus the rover now can function autonomously, similar to the self-driving cars and trucks currently being tested here on Earth. Prior to this upgrade, Curiosity had to wait for NASA scientists to order its every movement. Humans decided its targets, based on photos taken by the rover, ordered Curiosity to take certain actions, reviewed the results, and then sent the next commands. 
This procedure made for a lot of downtime, as the rover waited for further instructions.

Now with AI, Curiosity can act on its own, much faster and with greater accuracy than before. It gets occasional overall directions from Earth, but attends to all the details on its own. This is similar to the autonomy that self-driving Earth vehicles have, but without the worry that the rover will crash at high speed, or run over any people—as has happened on this planet with autonomous vehicles.

In NASA's typically cautious manner, the upgrade to AI capability was slowly and carefully tested, using an Earthbound twin to Curiosity, that scientists can play with, at the Jet Propulsion Laboratory in California. And true to NASA's propensity to generate creative acronyms, the new AI software is called AEGIS*, for Autonomous Exploration for Gathering Increased Science. It makes me wonder if NASA may also have an acronym-naming group, possibly called Group of Radical English-Adept Technicians for NASA Acronym Mission Epithets (GREATNAME)? May Curiosity roll on for many more years.

*Aegis is the name of the battle shield of Zeus, and usually refers to the supportive backing given a person or organization.

Unlikely Alone—Part 2

If life is discovered on other worlds, it will have a profound impact on our psyches. Some of us will have the foundations of our beliefs dramatically shifted and will have to rethink our basic convictions. Earth and humans will no longer occupy the pinnacle; this precious little planet will no longer be the only vital place in the universe. Others will rejoice that the cosmos is as rich as we could ever have imagined. 

The discovery of extraterrestrial life—if it comes—will not come any time soon, however. Moreover, the forms of life we discover will quite probably be of a type that we as yet can't begin to guess. Our current expectations of what we might find are probably too restrictive. The various scenarios that TV and movies have portrayed (aliens who usually look and talk like us—especially using modern English) are far too limiting.

Scientists have frequently speculated on what kinds of life we might find out there—describing the conditions under which “life as we know it” may exist. We’re coming to see that that view is too narrow, as we've been taken aback by the new types of life we've found right here on Earth—the so-called “extremophiles” that I mentioned earlier. Clearly our understanding of types of beings that we can't currently conceive of will soon be expanded even more, as we continue to explore our planet. 

I also wonder if we could even recognize some other strange form of life elsewhere in the universe, were we to encounter it tomorrow. It took us a long time to “discover” some of those extremophiles right here on Earth. 

To date, we have only one example of life and only one vital planet that we know about. With just a single sample, there's no saying that life has evolved “out there” as it has here. Even if we could rewind history and replay evolution on Earth, there's no telling what creatures would roam our planet today—but it certainly would be dramatically different. So many random events occurred along the way that would never be repeated—events that changed the course of evolution and altered life. (Think of the improbable asteroid that blew away the dominant dinosaurs, 65 million years ago, removing them and opening up so many niches for mammals.)   

Furthermore, it's taken something on the order of 3-4 billion years for life on Earth to evolve from some unknown ancient seed to the complexity we see today—that’s several billion years for a technologically proficient form of life to evolve on our friendly little planet. The chances of our finding life on some distant planet that is anywhere near as advanced (or immature) as humans are has got to be incredibly remote—given that they may have begun billions of years before us or are just getting started. We might find ourselves unable to communicate with beings who are either primitive or much further advanced than we. 

And the distances involved! The universe may be teeming with life, but those beings could be so unimaginably far away that we may remain ignorant of them forever.

So, where are we, in being able to answer the question, Are we alone? We've no more a definitive answer than 100 years ago. It's still an unknown, even though the likelihood seems to be much greater than even a year ago. Expect to live with the mystery for a good while yet. Don't hold your breath—just open your mind a little more to the possibility.

Unlikely Alone—Part 1

Ever since we humans came to understand that those points of light in the night sky are stars like our sun, many of us have wondered if some of those stars host planets that may contain some form of life. Are we alone in this grand universe? Is it possible that life may be thriving on other worlds out there, just as it does on our precious little planet?

These questions have lingered in people’s minds for millennia, but the means to answer them have eluded us until recently. The pursuit of this inquiry has not been encouraged by our religious institutions—particularly those that teach that human beings are special creatures molded by God, and thus at the center of the universe. This perspective remains convinced that Earth is unique and at the center of the universe. Despite that dogmatic view, many people have wondered if we may not be alone and maybe not that exceptional.

The issue has received increasing scientific attention in the last few decades. A number of projects are actively exploring the matter and are gradually leading us toward an answer. The possibility of life existing elsewhere has recently been given a major boost by two different areas of scientific research: (1) in astronomy, by the discovery of numerous planets around nearby stars by NASA and (2) in biology, by the discovery of several bizarre life-forms right here on our planet.

NASA's Kepler mission has now identified hundreds of planets around close-by stars—evidence we didn't have just a few years ago. Astronomers have for some time expected planets to be common, but until their existence could be demonstrated, we didn't really know. Now we do. The result: it is highly likely that there are billions of planets out there; just in our galaxy alone! So the likelihood of extraterrestrial life is definitely boosted—given that the more planets there are, the more chance that life could have formed on some of them.

The second recent finding—the discovery of Earthly forms of life we once did not think possible—also increases the likelihood of extraterrestrial life. Researchers have found life in forms and locations that surprise us: in rocks far underground where no light ever shines, at high temperatures we once thought would cook any critter, and in very unfriendly locations such as in strong acid environments that would dissolve the skin of any human. If life is this tough, we've had to revise our estimates of the kinds of harsh environments in which life could thrive on other worlds.

So we now have greater expectations of finding life out there. Mars may have once been warm and wet, and thus conducive to life. Jupiter's moon Europa and Saturn's moon Enceladus have scientists excited about the possibility of life there. SETI (Search for Extraterrestrial Intelligence) telescopes constantly scan the skies, looking for electromagnetic signals that alien intelligent species may have transmitted into space. (We ourselves do it all the time—not intentionally as a signal, but via our constant radio and TV transmissions that escape into space.)

With these findings, our level of anticipation of life elsewhere has skyrocketed. We're gaining confidence that we may not be alone. There is still no direct evidence for life elsewhere, but its likelihood is greater, as our understanding of  conditions out there increase.

More on extraterrestrial life next time…

Goldilocks Globe—Part 2

[News flash! It was just announced by NASA on 2 February that the Kepler Space Telescope has discovered 1235 candidate exo-planets as of that date! Of those, some 68 are Earth size! NASA will be further examining these candidates over the next few months, to see which may really be planets. How timely! On to Goldilocks.]

A few months ago a so-called “Goldilocks” planet was found. It got tagged with the name Goldilocks, because its star had two previously-discovered planets that were either too hot or too cold to support life. But a little more analysis of the data revealed a smaller in-between planet, dubbed Goldilocks, and officially given the moniker “Gliese 581 g.” It’s far enough away from its star to be able to have water, rather than either ice (it’s too cold) or steam (it’s too hot). Furthermore, it’s not much larger than Earth, so even its gravity and atmosphere could be like ours. Gliese 581 g is the first planet that we have located that just might support life as we know it! It’s caused quite a buzz in the astronomical community.

Planet Gliese 581 g is orbiting a star some 20 light years (that’s about 120 trillion miles) away. The star itself is named Gliese 581 a—which is a naming system that gives stars and their planets a numerical moniker. This star is quite different from our sun—it’s a red dwarf, it’s about one-third the size of the sun, it’s much older, and it’s a little over half the temperature. That may seem to describe an unusual star, but red dwarfs (which are too dim to see with the human naked eye) constitute as many as 90% of all the many billions of stars in our Milky Way galaxy. So they’re very common, and if life really does exist out there (astronomers get more confident every day that we’re not alone), it likely is orbiting a red dwarf star.

So what more do we know about this Goldilocks Gliese 581 g? It’s probably a rocky planet (like Earth) with enough mass to hold onto an atmosphere, if it has one. It is about 1.5-2 times the size of Earth, so its gravity wouldn’t be so large as to crush life forms similar to Earth’s. Its orbital period (its year) is very short—only about 37 Earth days—because it’s very close to its little, cool star. That brings about the fascinating result that the planet would be tidally locked to its star (like our Moon is to Earth), so it presents just one face to the star. That means that its perpetually daylight face stays boiling hot, while its permanent night face is freezing cold.

So how could it foster life or have liquid water? Because the zone between night and day (Goldilocks’s “twilight zone”) could be just the right temperature for life. In fact, if the planet has an atmosphere, that twilight zone could be quite wide, due to winds blowing around and spreading out the habitable zone.

It would be a wild experience to stand on Gliese 581 g and gaze at its sun. Rather than appear yellow-white, it’d be orange-red. It would appear about twice the size of our sun (since it’s closer), but it would never roam across the sky. Just as if you were to stand on the Moon and watch Earth constantly hovering in the same spot, day after day, year after year, the star Gliese 581 a would be stuck in the same place, and it would remain near the horizon.

Goldilocks has astronomers pretty excited, but mostly its discovery is leading them to expect to locate more habitable planets soon. The race is on! Kepler is continuing to find more planets around neighboring stars (1235 and counting!). We are beginning to document the fact that planetary systems are quite common in our galaxy. Couple this fact with the robustness of life that we’re also discovering right here on Earth, and the probability of life existing on planets other than Earth grows ever higher. Just a couple of decades ago the question “Are we alone?” had to be answered with a high degree of speculation and doubt. It’s beginning to appear, however, that the answer might well be “Not at all.”