Casting Swords into Space Observatories

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Editor’s note – Bruce Dorminey is a science journalist and author of Distant Wanderers: The Search for Planets beyond the Solar System.

Planet hunter extraordinaire Geoff Marcy recently let his frustration surface about the current state of the search for other habitable solar systems. Despite the phenomenal planet-finding success of NASA’s Kepler mission, Marcy, an astronomer at the University of California at Berkeley, correctly pointed out that NASA budget cuts have severely hampered the hunt for extrasolar life.

A decade ago, only a few dozen extrasolar planets had been detected. Today, by some recent gravitational microlensing estimates, there are more planets than stars in the Milky Way. But without the ability to characterize these extrasolar planetary atmospheres from space, we are astrobiologically hamstrung.

NASA’s goal had been that by 2020, we would have a pretty good idea about how frequently terrestrial Earth-mass planets orbit other stars — whether those planets have atmospheres that resemble our own; and, more crucially, whether those atmospheres exhibit the telltale signs of planets harboring life.

But consider how the federal government spends our tax dollars on a daily basis. Each and every day for more than a decade, the U.S. military spent roughly $1 billion a day funding congressionally-undeclared wars in Iraq and Afghanistan.

In contrast, NASA’s cancelled SIM and TPF missions were both originally estimated to have cost less than $1.5 billion dollars each.

Artist concept of the now-cancelled Terrestrial Planet Finder mission. Credit: NASA

SIM, the Space Interferometry Mission, was to have focused on finding extrasolar earths in a targeted search; its follow-on mission, NASA’s TPF, the Terrestrial Planet Finder mission, was to have characterized the atmospheres of these earth twins in an attempt to remotely detect the signatures of life.

The astronomical community continues to be resourceful as it can in working around these problems. But if NASA had followed through with the SIM and TPF missions in the timeframe that it first announced, we would have a very good idea of our own earth’s galactic pecking order by now.

Instead, war-funding has taken priority. On the home front, we’ve let the attacks of 9/11 take us down a road that has resulted in our airports resembling Orwellian netherworlds. Most of us now accept that we must basically disrobe and be physically prodded before boarding an aircraft.

Kids born at the beginning of what was supposed to be a great new millennium — remember 2001: A Space Odyssey, anyone? — have instead grown up accustomed to running the gauntlet just to take their teddy bears onto the plane with them.

Contrast the country’s current poisoned national mood with the heady days of euphoria surrounding this country’s Moon shots.

Dare we attempt to again turn at least a portion of our swords back into ploughshares?

If the U.S. is going to continue to lead the world in science and technology, the country will have to quit living in a state of perpetual geopolitical paranoia and take space seriously again.

No one wants to turn a blind eye to our national defense and NASA may never return to its glory days. But something is amiss when within a generation, we’ve gone from John F. Kennedy pointedly challenging the nation to test its mettle by safely sending a man to the moon and back before the end of the decade to this current era of national teeth gnashing.

Newt Gingrich was openly ridiculed on the morning TV news shows for advocating that the U.S. use private enterprise to help us put a manned lunar colony on the moon. Mitt Romney responded that he’d fire any employee that walked into his office and suggested such a plan.

Perhaps Gingrich is not the ideal messenger for jumpstarting a long dormant manned lunar program. But our country has reached a sad nadir when a presidential candidate is publicly mocked for advocating the hard work of boldly revamping our national space policy.

Op-Ed: Lunar Twitter — Republicans Debate Manned Moon Base

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Editor’s note – Bruce Dorminey, science journalist and author of Distant Wanderers: The search for Planets beyond the Solar System, is a lifelong proponent of lunar exploration.

Newt Gingrich certainly has his own political motives for suddenly deciding that now is the time to see that the decades-long dream of a lunar base finally makes it to fruition. But in addressing the issue of the U.S.’ future role in space, he arguably gave the most informed answer of anyone on stage at Thursday night’s Republican presidential debate in Jacksonville, Florida.

Mitt Romney’s measured response of first consulting with an interdisciplinary group of academics, captains of industry and the military, seemed to leave out NASA itself. But he was right in acknowledging that whatever the country’s next move in manned spaceflight might be, it should be tempered with some realistic rate of commercial and industrial return on America’s investment.

Gingrich seems better versed in the hardware and specifics of what’s needed for a manned return to the moon. But Romney’s admonition to Gingrich about making politically-expedient campaign promises simply to placate Florida’s Spacecoast also rings true.

While it’s heartening that America’s future role in space is being discussed in such high profile public forums, the last thing the U.S. needs is for a presidential candidate to wantonly raise the issue of finally realizing the dream of a manned lunar base in a cynical attempt to lure Florida voters in the space industry.

But given the current level of private space entrepreneurship, Romney’s own admonition that a lunar base would likely cost hundreds of billions of dollars seems a bit out of touch.
While it’s true that the international space station turned into a $100 billion financial behemoth, Gingrich’s ideas about adapting existing Atlas V launcher technology for a return manned trip to the moon sounds interesting, if not altogether feasible.

And he struck the right note when he acknowledged the need for entrepreneurial involvement from the get-go. A public-private partnership, with emphasis on commercial technology spin-offs, might be the needed tonic to restart a serious lunar effort.

A few $50 million prizes for Moon-minded, space entrepreneurs would go a long way in jumpstarting innovation while bringing down costs.

Depiction of possible Lunar Base. Credit: NASA

This whole manned lunar colony issue is likely to be largely forgotten after next Tuesday’s Florida primary, but some version of it will come up again at this summer’s political conventions and again in the general election debates next Fall.

Let’s just hope that when it does, it prompts a national discussion on NASA’s role in the 21st century; and how in these financially-strapped times, the U.S. can mount a manned mission back to the Moon, to an asteroid or even on to Mars in a realistic way.

There also needs to be a serious rethink of how NASA selects and then funds its missions. As any science journalist can attest, too often whole NASA missions are scrapped only months before launch; or launches are rescheduled so many times that the space agency begins to lose credibility with its own proponents. Just who’s to ultimately blame for the current state of affairs is hard to pinpoint. But serious astronomers and space researchers can hardly be thrilled about how such projects are currently funded and implemented.

Unfortunately, the general public is largely out of the loop when it comes to understanding the vagaries of NASA funding. The public’s limited exposure to national space policy nowadays mostly comes in the form of politicians on the campaign stump. There, political candidates use the same hackneyed catchphrases about exploring our “final frontier” just a little too often to evoke any real goosebumps.

But if the U.S. is to maintain its national identity as the world’s premier technological power, it needs to make sure that space is part of that equation. The byproducts of its dot.com generation and social media gurus are a marvel. But a Twitter from a South Pole lunar base would inspire the world.

NASA Considers Sending a Telescope to Outer Solar System

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Editors note — Science journalist and author Bruce Dorminey spoke to two NASA scientists about the possibility of mounting a telescope on a spacecraft for an outer planets mission.

Light pollution in our inner solar system, from both the nearby glow of the Sun and the hazy zodiacal glow from dust ground up in the asteroid belt, has long stymied cosmologists looking for a clearer take on the early Universe.

But a team at NASA, JPL and Caltech has been looking into the possibility of hitching an optical telescope to a survey spacecraft on a mission to the outer solar system.

Escaping our Inner Solar System’s Polluted Purple Haze

The idea is to use the optical telescope in cruise phase to get a better handle on extragalactic background light; that is, the combined optical background light from all sources in the Universe. They envision the telescope’s usefulness to kick in around 5 Astronomical Units (AU), about the distance of Jupiter’s orbit. The team then wants to correlate their data with ground-based observations.

One goal is to shed light on the early universe’s epoch of reionization. Reionization refers to the time when ultraviolet (UV) radiation from the universe’s first stars ionized the intergalactic medium (IGM) by stripping electrons from the IGM’s gaseous atoms or molecules. This period of reionization is thought to have taken place no later than 450 million years after the Big Bang.

ZEBRA, the Zodiacal dust, Extragalactic Background and Reionization Apparatus, is a NASA JPL concept that calls for a $40 million dollar telescope comprised of three optical/near-infrared instruments; consisting of a 3 cm wide-field mapper and a 15 cm high-resolution imager. However, NASA has yet to select the ZEBRA proposal for one of its missions.

But to learn more, we spoke with the ZEBRA Concept lead and instrument cosmologist Jamie Bock and astronomer Charles Beichman, both of NASA JPL and Caltech.

In our solar system, anybody observing the skies on a moonless night far from city lights can see the sunlight that is scattered by dust in our asteroid belt. Called zodiacal light and sometimes the "false dawn," this light appears in this artist's concept as a dim band stretching up from the horizon when the Sun is about to rise or set. The light is faint enough that the disk of our Milky Way galaxy remains the most prominent feature in the sky. (The Milky Way disk is shown perpendicular to the zodiacal light). Credit: NASA/JPL-Caltech/R. Hurt (SSC)

Dorminey: What is zodiacal light?

Beichman: It’s a bright source of diffuse light in our own solar system from dust grains that emit because they have been heated by the sun and are radiating by themselves
or reflect sunlight. If you go out on a very clear dark moonless light, you can see the band of this light from this dust. It follows the plane of the ecliptic. That dust mostly originates from material in the asteroid belt that gets ground up into little particles after some big collision.

Charles Beichman. Credit: NASA

Dorminey: What would getting past this zodiacal dust mean for observations?

Beichman: Imagine sitting in the Los Angeles basin and you’ve got all this smog and haze and you want to measure how clear the air is out at Palm Springs. You have to be able to subtract off all the haze between here and there and there’s just no way to do it with any accuracy. You have to drive out of the basin to get out of the smog.

Dorminey: How would this help in studying this extragalactic background?

Bock: The Extragalactic Background Light (EBL) measures the total energy density of light coming from outside our galaxy. This light gives the sum of the energy produced by stars and galaxies, and any other sources, over the history of cosmic time. The total background can be used to check if we correctly understand the formation history of galaxies. We expect a component of the background light from the first stars to have a distinct spectrum that peaks in the near-infrared; this can tell us how bright and how long the epoch was when the first stars were forming. Unfortunately, zodiacal light is much brighter than this background. But by going to the orbit of Jupiter, the zodiacal light is 30 times fainter than at Earth, and at the orbit of Saturn it is 100 times fainter.

Dorminey: Would you have to hitchhike on a NASA mission or could it be a partnership with another space agency, like ESA for instance?

Bock: We have been exploring the cheapest incremental cost approach, partnering with a NASA planetary mission. But we could partner with another space agency. The European Jupiter Icy Moons Explorer (formerly JGO) is now competing for the next L-class mission launch in the early 2020’s and is an attractive possibility for a contributed cruise-phase science instrument. Each approach comes with a different cost and partnership environment.

Dorminey: Is the prime driver for the EBL telescope to get beyond the zodiacal dust or does 5 AU also offer an observational advantage in terms of achieving faintness of magnitude?

James Bock. Credit: JPL

Bock: There is an observing advantage due to the [darker solar system] background. With such a small telescope, we are not trying to exploit this benefit but future observatories could. We will measure the zodiacal brightness to Jupiter and beyond, and this may motivate astronomical observations with telescopes in the outer solar system in the future.

Dorminey: What sort of data downlink challenges would you encounter?

Bock: The data requirements are perhaps smaller than one might first expect, because our images are obtained with long [observational] integrations at moderate spatial resolution. For the planetary proposal we studied in detail, the total data volume was 230 gigabytes, with about 65 percent of this data being returned from Jupiter and out to Saturn. The telescope pointings operate autonomously.

Dorminey: What about radiation from Jupiter interfering with the optics and CCD cameras on the telescope?

Beichman: What you’d do is stop making the EBL observations while close to Jupiter. The radiation problems are significant, so you would only do observations before and after passing Jupiter.

Panoramic view of the entire near-infrared sky reveals the distribution of galaxies beyond the Milky Way. The image is derived from the 2MASS Extended Source Catalog (XSC)--more than 1.5 million galaxies, and the Point Source Catalog (PSC)--nearly 0.5 billion Milky Way stars. Credit: Thomas Jarrett, et al/Caltech. Click image for more information.

Dorminey: What would your instruments do that NASA’s planned James Webb Space Telescope (JWST) wouldn’t?

Bock: JWST will likely detect the brightest first galaxies, and depending exactly how galaxies formed, will miss most of the total radiation due to the contribution of many faint galaxies. Measuring the extragalactic background gives the total radiation from all the galaxies and provides the total energy. Furthermore, we don’t need a large telescope; 15 cm is sufficient.

Dorminey: What about planetary science with the telescope?

Bock: Our instrument specializes in making low surface-brightness measurements. We made specific design choices to map the zodiacal dust cloud from the inner to the outer solar system. A 3-Dimensional view will let us trace the origins of interstellar dust to comets and asteroid collisions. We know there are Kuiper-belt objects beyond the orbit of Neptune, and it is likely there is dust associated with them as well.

Dorminey: How long would this telescope function?

Bock: After the prime observations complete, it would certainly be possible that the original team or an outside party could propose to operate the telescope. One exciting science case is parallax micro-lensing observations; observations that use the parallax between Earth and Saturn to study the influence of exo-planets orbiting the stars producing a micro-lensing event. Other science opportunities include maps of the Kuiper Belt in the near-infrared; stellar occultations by Kuiper Belt Objects; and mapping more EBL fields for comparison with other surveys.

Dorminey: How would the telescope’s initial observations potentially shake up theoretical cosmology?

Beichman: Whenever you do a measurement that’s a factor of a hundred times better than before, you always get a surprise.

Our Own Private Hell: Unlocking Mercury’s Enigmatic Past

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Editor’s note: Bruce Dorminey, science journalist and author of “Distant Wanderers: The Search for Planets Beyond the Solar System,” interviews NASA’s MESSENGER mission Project Scientist Ralph McNutt about what we are learning about Mercury.

Thirty-five years after NASA’s Mariner 10 interplanetary probe flew by and imaged less than half of tiny Mercury’s surface, NASA’s MESSENGER spacecraft now orbits our Solar System’s enigmatic and poorly understood innermost planet. After a six-and-a-half-year journey — which included three flybys of Mercury — MESSENGER is now the first spacecraft to take up long-term residence around this hard-to-reach and hellish planet.

Crater-scarred Mercury lies at an average distance of only 58 million kms from the Sun, so searingly close that its angular separation (or elongation) from our own star is never more than 28 degrees.  This all makes it extremely difficult to study from Earth.

Thus, planetary scientists are thrilled to finally be analyzing new in situ data from the MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) spacecraft.

To get some perspective on the findings and Mercury itself, we turned to the  MESSENGER Project Scientist Ralph McNutt at Johns Hopkins University’s Applied Physics Lab.


Dorminey — Is the MESSENGER data already shaking up Mercury paradigms?


McNutt — Yes – the biggest issue has been the volatile content which is likely going to lead to an interesting, but productive debate, about implications for planetary origins in the inner solar system.

“Volatile” elements are those with relatively low melting and boiling points. “Refractory” elements have relatively high boiling and melting points. If Mercury has a large core due to the surface being “boiled off” by a hot solar wind or hotter Sun in the early days of the solar system, or by a giant impact, then it is more difficult – but perhaps not impossible – for the volatile to refractory ratio, as exemplified by the potassium to thorium ratio (K/Th), to be as high on Mercury as at Earth, Mars, and Venus.  And yet that is what the data are saying.

Dorminey — What could explain Mercury’s magnetic field being offset north of the planet’s center by 20 percent of its radius?  Was this offset due to a giant impactor?

Ralph McNutt. Credit: NASA

McNutt — My guess would be that the offset is not due to a giant impactor.  But we still do not have a good explanation.

Dorminey — But does the in situ measurement of this magnetic field also confirm that Mercury still has an active magnetic dynamo?

McNutt — There seems to be no way that [Mercury] can escape having a dynamo, so that already makes for implications about Mercury’s cooling history and the chemical mixture [needed] for the dynamo action. There needs to be mostly iron, but something else must be mixed in to help lower the freezing point, otherwise the dynamo should have frozen out some time back.

“Dynamo” in either a planetary or commercial context refers to the generation of electricity by movement of a conductor with respect to a preexisting magnetic filed. Such a movement produces an electrical current, which, in turn, produces a magnetic field.

In a planet, the conductor is a liquid with motion derived from the rotational energy of the planet.  But a full theoretical description of how planetary dynamos work is still lacking and is the subject of ongoing research.

Dorminey — A popular formation theory, which would explain its anomalously large iron core, is that early Mercury was stripped of its outer layers following a giant impact.  Do you adhere to this idea?

McNutt — Nominally, a high volatile content – expressed via a high potassium to thorium ratio (K/Th), which we have measured with the MESSENGER gamma-ray spectrometer, would rule against such a massive impact. The thinking has been that the volatile content would not re-accrete and so one would be left with a low global average such as is measured for the Moon. We will see – I do not think the verdict is in yet on this one.

A global mosaic of Mercury from MESSENGER. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Dorminey — What is the significance of and where did it get its surface sulfur and potassium?

McNutt — Sulfur and potassium were both elements in the initial solar nebula. The real question is what led to their placement and relative concentrations on the surface of Mercury.

Dorminey — What’s the significance of the MESSENGER-imaged volcanic vents?  Is Mercury still tectonically active?

McNutt — The volcanic vents tells us that volcanism was a significant part of the geologic history of the planet.  The planet has cooled a lot since there was a lot of activity and continues to cool. The level of activity is likely low at best – but if we see an active [volcanic] vent, we will definitely let the world know.


Dorminey — We know that Mercury has an exosphere, but could Mercury ever have had anything approaching an Earthlike atmosphere?

McNutt — Any sort of a stable Earth-like atmosphere is not in the cards. Mercury is too small with too small a gravity field to hold on to anything for a long time. If there was sufficiently rapid outgassing , then one could have built up an atmosphere of something that might have Earth-like pressures, but certainly no oxygen, and not for long given the temperature.


Dorminey — What is still the most puzzling to you about Mercury?

McNutt — Right now, the biggest puzzle is how to put together the magnetic field configuration (with the offset), with a dynamo, and the topography and gravity data all in a self-consistent description of the planet. There will be some more papers coming out on these topics in the near future.


Dorminey — If money were no object, what would be the ultimate science exploration strategy for Mercury?  Are there any plans in the works for a lander?

McNutt — To really understand the solar system, we need to put together a coherent chronology of formation and early thermal evolution of the planets and other solar system objects.  To do that “right” one needs well-characterized samples returned from the surface or drilled from the near-surface, in pristine environments and delivered to labs on Earth.  Sample returns are hard – but not as hard as placing such equipment in situ. Following the next level of intense study by BepiColombo (the ESA orbital mission now in development), the next step is a lander. There are no plans for such a mission at present.  An interesting question is which is harder: a sample return mission from Mercury or from Venus.

Dorminey — With dayside temperatures of 630 kelvin and nightside temperatures of 95 kelvin, could Mercury have ever been a candidate for liquid water or oceans?

McNutt — No.

Dorminey — Could Mercury have ever had microbial life?

McNutt — Before it was known that Mercury rotated, there was some speculation that there might be a zone of perpetual twilight between the Sun-facing hot side and the Sun-shadowed cold side a “twilight zone” where something [like microbial life] might be possible.  In actuality, the region between hot and cold would have been fairly abrupt (depending on the thermal conductivity of the rocks). As Mercury does rotate, no such region exists.

The young rays of Mena crater contrast brightly against the surrounding surface of Mercury. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Dorminey — What’s the ultimate significance of planetary science’s study of Mercury? Does it offer a template for what you expect in other solar systems, or does your gut tell you that it’s a total fluke?

McNutt — Knowing more about Mercury, and Venus and Mars tells us about the “terrestrial planets” as a whole and what was common – and special – about ours – and their origins. While the new exoplanet discoveries are extremely interesting, we will not get as close to those planets as we can get to the ones in our own Solar System anytime soon. We have yet to be able to resolve other “Mercurys” in our exoplanet searches, so it is as likely as good a template as any.  In learned circles at one time in the not too distant past, the entire solar system was considered to be a total fluke.

Why Silicon-based Aliens Would Rather Eat our Cities than Us: Thoughts on Non-carbon Astrobiology

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Editor’s note: Bruce Dorminey, science journalist and author of “Distant Wanderers: The Search for Planets Beyond the Solar System,” interviews NASA astrochemist Max Bernstein for Universe Today about the possibility of Silicon-based life.

Conventional wisdom has long had it that carbon-based life, so common here on earth, must surely be abundant elsewhere; both in our galaxy and the universe as a whole.

This line of reasoning is founded on two major assumptions; the first being that complex carbon chain molecules, the building blocks of life as we know it, have been detected throughout the interstellar medium.  Carbon’s abundance appears to stretch across much of cosmic time, since its production is thought to have peaked some 7 billion years ago, when the universe was roughly half its current age.

The other major assumption is that life needs an elixir, a solvent on which it can advance its unique complex chemistry.  Water and carbon go hand in hand in making this happen.

While the world as we know it runs on carbon, science fiction’s long flirtation with silicon-based life — “It’s life, but not as we know it” — has become a familiar catchphrase.  But life of any sort should evolve, eat, excrete, reproduce, and respond to stimulus.

And although non-carbon based life is a very long shot, we thought we’d broach the issue  with one of the country’s top astrochemists — Max Bernstein, the Research Lead of the Science Mission Directorate at NASA headquarters in Washington,D.C.

Bruce DormineyIS IT WRONG TO ASSUME THAT LIFE COULD BE BASED ON SOMETHING OTHER THAN CARBON?

Max Bernstein. Credit: NASA

Max Bernstein — It’s important for us to keep an open mind about alien life, lest we come across it and miss it. On the other hand, carbon is much better than any other element in forming the main structures of living things.  Carbon can form many stable complex structures of great diversity. When carbon forms molecules containing cxygen and nitrogen, the carbon bonds to nitrogen and oxygen are stable.  But not so much so that they can’t be fairly easily undone, unlike silicon-oxygen bonds, for example.

DormineyDOES THE RECENT NASA-FUNDED RESEARCH AT MONO LAKE, CALIFORNIA WHICH TOUTED THE DISCOVERY OF BACTERIA WITH DNA THAT USES ARSENIC INSTEAD OF PHOSPHORUS RATTLE THE CURRENT PARADIGM?

Bernstein — That was a really cool result, but the basic structure was still carbon. The arsenic was said to have replaced phosphorus, not carbon.  The discovery of this putative arsenic organism may prove to be incorrect, but it’s a hypothesis with science behind it, and not just someone tossing out an idea and leaving it at the level of what if you replaced carbon with silicon?

The structure of silane, the silicon-based analogue of methane.

DormineySILICON SEEMS TO BE THE MOST POPULAR NON-CARBON BASED CANDIDATE, ARE THERE OTHERS THAT ALSO MIGHT BE FEASIBLE?

Bernstein — It’s hard to imagine anything that would be more likely that silicon because there is nothing closer to carbon than silicon in terms of its chemistry. It’s in the right place on the periodic table, just below carbon.  On the face of it, [silicon-based life] doesn’t seem too absurd since silicon, like carbon, forms four bonds. CH4 is methane and SiH4 is silane.  They are analogous molecules so the basic idea is that perhaps silicon could form an entire parallel chemistry, and even life.  But there are tons of problems with this idea.   We don’t see a complex stable chemistry [solely] of silicon and hydrogen, as we see with carbon and hydrogen.  We use hydrocarbon chains in our lipids (molecules that make up membranes), but the analogous silane chains would not be stable.  Whereas carbon-oxygen bonds can be made and unmade — this goes on in our bodies all the time — this is not true for silicon.  This would severely limit silicon’s life-like chemistry.  Maybe you could have something silicon-based that’s sort of alive, but only in the sense that it passes on information.

DormineyIF SILICON-BASED LIFE IS OUT THERE, HOW COULD WE EVER DETECT IT REMOTELY?

Bernstein — We are seriously arguing about how we would remotely detect life just like us, so I really couldn’t say.  Presumably technology-using organisms, whatever their biochemistry, will produce technology, so the Search for Extraterrestrial Intelligence (SETI) may be our best shot.

DormineyHOW WOULD YOU LOOK FOR SILICON-BASED LIFE HERE ON EARTH?

Bernstein — When seeking an alien organism its really tough because you just don’t know what molecules to look for.  One would have to be satisfied by something a bit more ambiguous, like sets of molecules that should not be there. For example, if you were an alien Silicon organism, you might not be looking for our biochemistry, but the fact that you kept seeing exactly the same chain lengths over and over again might tip you off to the fact that those darn carbon chains might actually be the basis of an organism’s membranes.

A Horta, a fictional silicon-based life-form in the Star Trek universe. Image from Star Trek: The Original Series © 1967 Paramount Pictures

DormineyWHERE ARE THE LARGEST CONCENTRATIONS OF SILICON HERE?
IN SAND?

Bernstein — In sand or rock. There are literally megatons of silicate minerals on Earth.

DormineyHAS ANYONE EVER CLAIMED DETECTION OF SELF-REPLICATING EXAMPLES OF SILICON HERE ON EARTH?

Bernstein — There have been ideas about minerals holding information just as DNA holds information.  DNA holds information in a chain that is read from one end to the other.  In contrast, a mineral could hold information in two dimensions [on its surface].  A crystal grows when new atoms arrive on the surface, building layer upon layer.  So, if a crystal sheet cleaved off and then started to grow that would be like the birth of a new organism and would carry information from generation to generation.  But is a replicating crystal alive?  To date, I don’t think that there is actually any evidence that minerals pass information like this.

DormineyIS THE CRUX OF THE PROBLEM THAT SILICON-BASED LIFE WOULD BE SO SLOWLY REPLICATING THAT IT COULD NEVER MAKE IT IN A DYNAMIC UNIVERSE?

Bernstein — I don’t think that any Silicon life form could be a biological threat to us.  If they were high tech, they might eat our buildings or shoot guns at us but I don’t see how they could infect us.  We run hot and move fast.  If we don’t, things will catch us and eat us.

If they are also tougher than we are and whatever feeds on them is also slow and Silicon based maybe being slow doesn’t matter.

DormineyWHAT WOULD BE THE SIGNATURES OF SILICON-BASED LIFE?

Bernstein — If they are not technological, they would be very tough to detect.  We could look for unstable, unexpected silicon molecules; some high energy molecule that should not be there, or molecular chains of all the same length.

DormineyDO YOU THINK THAT SILICON-BASED LIFE MIGHT EXIST SOMEWHERE OUT THERE?

Bernstein — Maybe deep below the surface of a planet in some very hot hydrogen-rich, Oxygen-poor environment, you would have this complex silane chemistry.  There, maybe silanes would form reversible silicon bonds with selenium or tellurium.

DormineyIF SUCH SILICON-BASED LIFE DID CROP UP, WHAT WOULD BE ITS EVOLUTIONARY ENDGAME?

Bernstein — If it could evolve past the protist [microorganism] stage, then I think it could evolve intelligence.  I have no idea how likely it is for intelligence to evolve, but I can believe in silicon crystals passing information from layer to layer or in silicon artificial intelligence, but I don’t expect to see silicon apes playing their equivalent of “Angry Birds” on their Silicon-Phones.

DormineyIF SILICON-LIFE DID EVOLVE, WOULD ITS LIFESPAN BE MUCH LONGER THAN ITS CARBON-BASED ANALOGUES?

Bernstein — The replicating mineral that I described earlier would be living very, very slowly on Earth’s surface.  But maybe somewhere very much hotter, its lifespan would be shorter.  That’s because presumably lifespan is connected to the pace of your chemistry, which depends on temperature.

DormineyFINALLY, WHAT WOULD ENDANGER NON-CARBON-BASED LIFE?

Bernstein — Physical harm for sure.  Presumably you could take a jackhammer to it?

But our biochemistry would not be pathogens to it; we could not “infect” them as was the case in “War of the Worlds.”