Home > Newsletter Archive > Newsletter #24
| FRONT PAGE | LATEST NEWS | ARCHIVE | ENCYCLOPEDIA | LINKS | THIS SITE | ME | E-MAIL |
August 24, 2004
Contents
1. Meanderings
2. Have We Found Life On Mars?
3. Bookends
1. Meanderings
October promises to be a double delivery month. First, the copy-edited manuscript
of my next book - Teleportation: The Impossible Leap — should arrive
for final changes before going into production (look for it on the shelves
in May 2005). Second, my daughter is expecting to deliver her first child
- and our first grandchild! — to which the book will be dedicated.
Too bad that babies can't be teleported into the world (although I seem
to remember that this happened in one of the Star Trek Voyager episodes):
it would make things a lot simpler. Anyhow, we'll soon be beaming over to
Scotland for the big event. I'll keep you posted.
There's yet another baby in the works in the form of an intriguing project
that's the brainchild of an astrobiologist at a west coast university. And
with this particular birth we'd like to invite your participation. Basically,
the project, which I've been asked to contribute to and may also involve
a postdoc student, is to identify and catalogue possible signatures of extraterrestrial
visitation, both on the Earth and beyond. It's exciting because not much
work has been done along these lines in mainstream academic departments.
Of course, a lot has been written in the popular press about "ancient astronauts"
and the like, but in some ways this has done more harm than good because
it's meant that many professional researchers won't now touch the subject
with a 10-parsec barge pole. The simple fact is that SETV
(the search for extraterrestrial visitation) and SETA
(the search for extraterrestrial artifacts), as they've become known, are
bona fide fields of inquiry which a number of broad-minded scientists, such
as Freeman Dyson, Ronald Bracewell, and Robert Freitas, have been pioneering
for several decades. It's a mystery to me why mainstream SETI people haven't
got more involved with looking for evidence of advanced extraterrestrials
on our doorstep. Part of it perhaps has to do the fear of being tarred with
the same brush as those on the crankier side of ufology and paleo-contact
(despite some of the good work that's also been done in these areas). But
maybe a bigger factor is that the pioneers of SETI were radio astronomers
and communication engineers who had their sights and minds focussed on the
stars from the outset. Looking for interstellar microwave signals (and,
more recently, optical signals) just became the orthodox approach —
a kind of extension of ham radio to the cosmos — for no particularly
good reason. Which is fine. (A lot of SETI people cut their teeth on ham
radio, as illustrated in the movie Contact.) But wouldn't it be wonderful
if a major organization like the SETI Institute now took on the task of
pushing back the frontiers of local SETI — spearheading the scientific
search for evidence of ETI within the solar system as well as beyond it?
One can envisage some very exciting link-ups with future manned and unmanned
missions.
The basic premise, that the solar system, and the Earth in particular, may
have been visited by alien intelligence makes perfectly good sense. After
all, we're starting to give thought to how we might travel to and explore
other stars. Go here
for some advanced propulsion and interstellar spaceflight ideas.
It's easy to imagine that other beings across the Galaxy may have earmarked
our planetary system as a promising place to explore based on remote reconnaissance,
then sent their robot emissaries or come in person to explore firsthand.
The tricky part is knowing where and how to look for promising signatures
of local ET involvement and then being able to distinguish these signs from
what may be natural or due to human activity. As a first step we plan to
document the work that's already been done and to brainstorm the kind of
archaeological remains and other phenomena that might suggest an alien hand
at work. This is somewhat like the process that SETI researchers are going
through in compiling a catalogue of promising stars to scrutinize for artificial
emissions. If you have any ideas or suggestions, or know of any well-founded
work that's been done on the subject, we'd love to hear from you. Don't
be afraid to chip in - anything goes at this stage.
2. Have We Found Life on Mars?
Mars is at it again. For more than a century it's been teasing and tantalizing
us about whether it harbors life or not. First there was the excitement
over possible canals and intelligent Martians, stirred up by Percival Lowell
in Victorian times. Then came interest in the supposed seasonal comings
and goings of Martian vegetation, to be followed by the Viking landers and
their enigmatic findings of "something" active in the soil of the Red Planet.
Then, in 1996, the saga of the Martian meteorite "fossils" started to unfold.
In fact none of these earlier uncertainties has gone away. There are still
question marks hanging over the Viking results, the supposed biogenic traces
in Martian meteorites such as AL84001 (especially the magnetite crystals,
which may or may not have been produced by bacteria), and the origin and
nature of many surface features, especially the extent to which they involve
liquid water. The latest twists in the tale are being added by a flotilla
of spacecraft currently active on and above the surface of Mars. These include
the twin NASA Mars
Exploration Rovers roaming around Gusev crater and Meridiani Planum,
the European Space Agency's Mars
Express orbiter, and the longer-serving Mars
Odyssey and Mars Global Surveyor
probes, all of which are still working well and sending back torrents of
data.
Sadly, the UK-built Beagle 2, which was the best equipped of all to look
for life directly, suffered some unknown mishap during descent and hasn't
been heard from since it separated from its mothership. A lot of attention,
especially in the States, has been given to the twin Rovers, simply because
they're on the ground and it's always more exciting, from a public perspective,
to see things close up and personal. Both Spirit and Opportunity have turned
up plenty of clues to a watery past on Mars, which is encouraging for astrobiologists.
Here's the latest press
release from JPL's Mars Rover site about evidence of water from bedrock
in the Columbia Hills region of Gusev crater. And here's a list
of links to all the press releases from JPL about the rovers and their
findings.
It's now pretty much beyond doubt that Mars had substantial bodies of standing
water, such as shallow lakes and seas, in the past, which would have been
habitable, at least by some of the primitive kinds of life with which we're
familiar on Earth. You could easily imagine a colony of stromatolites,
for instance, basking in the sunlight of the infant fourth planet. Indeed,
David McKay, chief scientist for astrobiology at NASA’s Johnson Space Center,
whose face is familiar from the 1996 NASA Mars "fossils" announcement, points
to one of the unresolved puzzles of the current Rover missions as evidence
for fossilized microbial mats on Mars. Remember what happened when the Rover
landers' airbags were retracted? The soil underneath looked almost as if
it were muddy — it stuck together, it was cohesive. And the weird thing
is, nobody is talking about it anymore. It's an unfortunate fact that what
conventional science can't explain or come up with a good working hypothesis
for, it conveniently ignores! More on possible Martian microbial mats here.
Well, let me further conveniently ignore this muddy topic, and get back
to the undeniable evidence of past water. While this doesn't imply that
life did evolve on the Red Planet, it certainly suggests that it had the
opportunity — which is very encouraging to many astrobiologists who
tend to think that if life can get a toe-hold somewhere, it probably will.
There's a further common belief nowadays that, if life manages to get going,
it will most likely adapt and survive if it possibily can, even if conditions
later turn nasty. So, the positive news about past water on Mars raises
hopes that some organisms might still be alive and well, and probably underground,
on the planet today.
What the Rovers have found is exciting enough. But potentially much more
sensational are the results coming in from Mars Express — and, in particular,
from an instrument onboard the ESA probe called the Planetary Fourier Spectrometer
(PFS). PFS measures the wavelengths at which molecules in the Martian atmosphere
absorb infrared radiation in the range 1.2-45 microns. (For comparison,
the complete IR spectrum extends from 0.78 microns where it merges with
the visible red, to 1000 microns where it shades into the millimeter-wave
and microwave wave region). In principle, all you have to do is look at
the PFS data, see where absorption is taking place, compare the results
with standard laboratory spectra, and nail down which gases are the culprits,
like a detective identifying fingerprints. If only science were that simple!
Instruments need calibrating, they have limitations (in the case of PFS,
the chief one is spectral resolution) and idiosyncracies, they don't always
work exactly as planned (Mars Express has had some power problems to complicate
matters), and what they tell you is usually open to interpretation, especially
when they're operating tens of millions of kilometers away around another
planet. The whole business of deciding what chemicals are present is made
even more difficult by the fact that many molecules absorb radiation at
similar wavelengths. Given such potential for overlapping spectra —
imagine several fingerprints stacked on top of one another — it's a
tough job deciding exactly which substances are in the mix.
Back in March 2004 news broke that PFS had found traces of methane in the
Martian atmosphere. Here's
how ESA reported it on their website and here's
another take on the same story by David Whitehouse of the BBC.
You can Google your way to other interpretations and descriptions on the
Web. But a key point is that the methane wasn't found just by Mars Express/PFS.
It was also detected, in roughly similar concentrations (about 10 parts
per billion), by two independent groups using ground-based instruments.
Yes, they could all be wrong. But that doesn't seem very likely. Mars probably
has somewhere on the order of 100,000 tons of methane in its atmosphere,
and that stock must have been replenished over the past few hundred years,
otherwise it would have reacted with hydroxyl ions and turned in carbon
dioxide and water vapor. So, how did the methane get there? The explanation
could be biological — methane-producing microbes in the soil. It could
also be geological — the result, for example, of low-level volcanic
activity. Either is exciting and even if the cause turns out to be the less
dramatic one of release from warm spots around the planet, this still builds
a stronger case for life (undergound heat melts ice; water plus heat plus
organic chemicals are the raw ingredients of life). The various scientists
directly involved in the methane discoveries are keeping their options open
but differ in their favored theories. Vladimir Krasnopolosky, who leads
one of the ground-based studies and Vittorio Formisano, the PFS team leader,
have indicated they favor a biological interpretation; Augustin Chicarro,
another Mars Express project scientist, has been quoted as leaning towards
volcanism. As a body, ESA is being conservative and pushing the geothermal
viewpoint. That's the way it goes — and should go — with scientific
research. You gather data, you build hypotheses, you test these further
with new data. Not everyone has to agree. Because of instant reporting and
public dissemination (often well ahead of official publication and based
on off-the-cuff remarks) these days, we see the messy process of science
in action. Things are rarely clear cut. Even scientists on the same team
may disagree on what their results mean. It doesn't mean there's any sinister
cover-up or chaos behind the scenes. The only thing that matters in the
end is gathering more data to decide between the rival theories. That's
the stage researchers are currently at with the Mars methane: trying to
refine the earlier measurements and, in particular, investigate if there
are variations in concentration at different places on the planet. Even
more spectacular, it seemed for a while, was the reported discovery of Martian
ammonia by the PFS instrument. This story emerged in early July, based on
one or more reporters' interviews with Formisiano in which the Italian researcher
had appeared to suggest that his team had made a tentative identification
of the nitrogen-based compound. I passed on the story as it was reported
by the BBC. It now seems, however, that the disclosure was premature. Formisiano
blames over-eager journalism for the confusion. Perhaps the fact that he
was responding in (to him) a foreign language didn't help. At any rate,
Formisiano now insists that no ammonia has yet been detected, although in
a recent
conference abstract he did suggest that his team may have obtained a
positive result. This suggestion wasn't echoed at the conference. Far more
than methane, ammonia would point the finger at a biological source. Ammonia
would be highly unstable in the Martian atmosphere, requiring continuous
production, and, significantly, there are no known geological sources that
can give rise to it. It may yet be found as the Mars Express mission continues.
For the present, Mars continues its age-old game of biological hide-and-seek.
We still don't know if we've found the signatures of life there. But we
do know for sure that our planetary neighbor isn't dead in every sense.
Quite a lot of correspondence has come in over the past few weeks on the
subject of life on Mars and in the universe in general. My apologies for
not being able to cover it all here. Andy Crayston from Lancaster, England,
wonders if any of the possible biogenic gases in the Martian atmosphere,
such as methane, may be coming from bacteria that traveled aboard spacecraft
from Earth, including the twin Vikings, Mars Pathfinder, etc, and have since
been multiplying on the surface. I don't know if anyone has looked closely
at this interesting idea. My guess is it's unlikely because it would require
not only that the right kind of (methanogenic) bacteria had made the journey
and survived but that they'd adapted sufficiently well to thrive in their
new home. But I simply don't know. (We do know that terrestrial bacteria
survived for a year and a half on the Moon — a much harsher regime
than Mars.) Researchers did consider the possibility that the reported methane
may have come from Beagle's burst airbags but decided there was simply too
much of it to be explained this way.
Butjor Laszlo, a paleontologist from Hungary, sent in some intriguing thoughts
about the impact that the discovery of life elsewhere would have on our
culture and religions. He sees this discovery as having a major effect on
religious thinking — overturning some old traditions and perhaps giving
birth to new ones. (I'd love to know what other religions and philosophies
exist out there. That would bring a while new meaning to the term "comparative
religion"!) He also believes that finding life elsewhere could act as a
positive influence on our own planet: "... unifying the different human
races on Earth. It also could give chance to us to end all kind of debates,
genocides, wars, and other harsh violations among human nations." Astrobiology
and SETI couldn't aspire to anything greater than that. On the other hand,
V. Spiegler offers this cautionary note (and possible resolution of the
Fermi Paradox): "Would a truly advanced civilization really want to disclose
themselves to us? Look around the world, what do you see? Peace and Harmony
and "love your neighbors"? More likely, they would expend time and energy
to keep us out of the Universe! Perhaps "quarantine" might be a good word
for what they would do.
3. Bookends
There are a couple of other items of book news in addition to the one I've
already mentioned about Teleportation: The Impossible Leap. This
month has seen the publication of my latest encyclopedia from John Wiley
& Sons — The Universal Book of Mathematics. See the links to
it on my home page.
Also, I've just signed a contract with my present publisher Wiley for a
new book — but more on this later. Let's just say it concerns a matter
of some gravity.
The last few months have seen a massive expansion of my website, more than
doubling its size to some 7,000 pages. All of it's free and is intended
as a helpful resource for students, educators, and the general public alike.
It produces a bit of revenue from Google Ads and Amazon book sales but,
as you can imagine, this nowhere near covers the time invested. One way
you can assist, at no cost to yourself, is to make any purchases of Amazon
products that you're planning — books, DVDs, etc — using my website
as a portal. For example, you could enter through my bookshop
then a small commission from anything you buy is paid to me, which helps
in maintenance and expansion of the site. Thanks for your support and for
all the kind and interesting messages you continue to send.
Have a great summer everyone!
All the best,
David Darling