The Balloon Boy saga from a couple weeks ago will go down in
mass media history as one of the great hoaxes. Network news was riveted on
following the wayward balloon for over two hours because they were convinced
there was a stowaway child onboard. Maybe we were primed for this sort of hoax (more later).
But 71 years ago today the mother of all media hoaxes took
place. On the night before Halloween in 1938 CBS Radio presented an hour-long adaptation
of H. G. Wells' classic science fiction story “The War of the Worlds.”
Lost among other headlines this week -- the heated debated over
government health care, the war in Afghanistan, a mid-air plane collision, and
a 230-mpg automobile -- was a modest-sized news blub about the end of the world.
On Wednesday the National Academy of Sciences released a study
reporting that NASA is inadequately funded to catalog potentially dangerous
asteroids larger than a football stadium, whose orbits carry them near Earth. Congress
was supposed to appropriate funds but didn’t, though they told the space agency
to start the task four years ago.NASA
had to dig deep into its pockets to do some preliminary searches.
I recently had the misfortune of watching the 2009 film Knowing,
which is an utterly nonsensical story woven together from doomsday fantasies,
The Da Vinci Code, and Arthur C. Clake’sChildhoods End.One scene shows Earth
being marshmallow toasted by a solar flare.
Well the sun certainly can’t do that. A gamma-ray burst of
energy hitting Earth like a blinding camera flash could make it look like we
were toast. GRBs are collimated beams of high energy gamma-rays, projected from
the poles of a collapsing super massive star, in an explosion called a
hypernova.
Even if such explosions are common in our galaxy – which they’re
probably not -- the beam from a GRB is very narrow. So to get hurt we’d have to
be in its gun sight.One potential
hypernova candidate that has been compared to looking down a gun barrel is the
Wolf-Rayet star WR 104.
With the Apollo 11 moon landing anniversary just a few days
away, I’m cringing to see if some sensationalistic cable TV news outlets drag out some space-age Inspector Clouseau to claim that the moon landings were faked
on a motion picture soundstage.
This conspiracy fantasy is far from new. It was
dramatized in the B-grade 1978 film Capricorn One and parodied in the 1971 James Bond flick Diamonds are Forever.
The moon conspiracy idiocy has a life – where else – on
YouTube and assorted whacko websites. The ringleader of the current crop of loonies is Tennessee
filmmaker Bart Sibrel. In 2002 Apollo 11’s Buzz Aldrin punched him in the nose,
after Sibrel called the ex-fighter pilot a “coward, a liar and a thief.” The
police did not file charges against Aldrin. Call it “street justice.”
There is a lot of silly hoopla over the end of the ancient Mayan calendar
and therefore supposed “end” of the world in 2012 according to some interpretations (such as a rogue comet whacking us).
But let’s take a step back and consider a real event that happened to Earth
when cosmic stuff really did hit the fan.
This Tuesday June 30 will be the 101st anniversary of the mysterious
Tunguska explosion that flattened a forest in central Siberia with the equivalent of between 5 to 30 megatons of TNT detonating.
Last week the protective light cover was jettisoned off NASA’s Kepler
observatory, taking it another step closer to conducting a historic census of Earth-like planets that lie in the direction of the Summer Triangle.Kepler is now eight times farther from
Earth than the moon.
Kepler’s survey will be completed in less than four years. Then astronomers
will proudly announce a statistical value for the abundance of Earth-like
planets in our Milky Way galaxy.
But, coincidentally there is another, largely unpublicized study going on over the same time
period that potentially would eclipse the Kepler finding and reshape the
astronomical research agenda, with the headline:
Earth-like Planet Found Around Nearest Star to Our Sun
The closest star system to our sun, Alpha Centauri is only 4.3 light
years away. It may be a triple system, with two sun-like stars orbiting each
other at a distance ranging from one to three billion miles. (A small red dwarf,
Proxima Centauri, is on the periphery of the system and may or may not be
gravitationally bound to it)
The two stars have high concentrations of heavy elements, which is
characteristic of stars that are born surrounded by dusty, planet-forming disks.
And, the system is as old as the Sun.
Last May a team of astronomers from U.C. Berkeley, San Francisco State
University, and the SETI Institute started a five-year observing program of
Alpha Centauri B, the fainter of the two stars.The team, led by Deborah Fisher, is intensively monitoring the star using the
1.5-meter telescope at the Cerro Tololo Inter-American Observatory in Chile.The team is trying to measure if there
is a telltale signature of an Earth-mass planet that is inducing a wobble in
the star that would be measured by the Doppler effect. The star’s offset from
its nominal center-of-gravity would be only a few inches!
The optimism of finding a terrestrial planet is based on a computer
model where a group, led by Greg Laughlin, ran repeated simulations of how planets would form around
Alpha Centauri B over a 200 million year period. With each change in the initial conditions of the protoplanetary gas
and dust disk, each simulation led to the formation of a different planetary
system. In every case, however, a system of multiple planets evolved with at
least one planet about the size of Earth. In many cases, the simulated planets
had orbits lying within the habitable zone of the star.
However, another simulation of Alpha Centauri planet formation by
Philippe Thebault or Stockholm Observatory concludes that the dynamics of the
Centauri binary system are hostile to planetesimal accretion required to build
planets. In the complex gravitational field between the two stars, planetesimals
would be accelerated to the point where they would smash together rather than
gently merge. The only way out of this dilemma would be to form a rocky planet closer
in to one of the binary stars and have it migrate out to the Earth-sun separation
distance, he reports.
To me the bottom line is that we don’t know until we look. Predicting
the outcome of an evolving circumstellar disk in a binary system is filled with
so many variables, it’s like predicting the shape of the swirl cream will make
when poured into hot coffee.
Planet Game Changer
The discovery of an extrasolar terrestrial planet so nearby would send
seismic waves across the astronomy community. And it would energize the public about
space exploration. The kicker is that that any such planet, if inhabited, has had
4 billion years available to undergo Darwinian evolution.
This would accelerate popular interest and Congressional support for
building a large enough optical-IR space observatory that could spectroscopically
sample the planet’s atmosphere. At 4.3 light years away, an 8-meter mirror
should do it. Attempts would also be made with the 6.5 meter James Webb Space
Telescope.
If observations confirmed the planet’s atmosphere has biotracers, such
as oxygen, ozone, nitrous oxide, methane, and chlorine, there would be a push
to build a dedicated interferometric array of space telescopes to make an image of the planet.
The picture would be no more than least one or two-dozen pixels
across. That would be enough to monitor the planet. Observations could reveal
the waxing and waning of continents and oceans as the planet rotates, and the
changing tapestry of weather patterns.
A number of SETI
experiments would monitor the planet for evidence of alien telecommunications.
By the dawn of the next century, there would be one or more attempts
by various countries (unless the cost is so exorbitant we all pool resources) to
send a very low-mass probe to fly by the planet at about 1/10th
the speed of light. It would collect tons of close-up data in just a few
precious hours it navigated the system before hurtling back into interstellar
space.
Such a mission would have a cruise phase of only 40 years. So, unlike
other interstellar missions, the builders of the craft could live long enough
to see data returned. Propulsion engineering for such a probe, perhaps boosted
by an interstellar laser or a fusion ramjet engine, should be mature within the
next century.
Depending on the results, the next big push would be to have a probe
land on the planet and study the biology in-situ. By the time we are ready for
such a mission we will have matured the required artificial intelligence and
nanomachine technology. The autonomous probe would, upon arrival, build a variety of nanobots to carry our planetary exploration and direct the survey.
Such a discovery would be terribly ironic and humbling. The question of
life is space has had a high“giggle
factor” through most of astronomy’s history, and has been cast into doubt by such concepts as the Rare Earth hypothesis. But to have an inhabited world so
close by would profoundly alter on our view of universe.
With the passing of the New Year I invariably get e-mails asking about nothing less than the End of the World. We already survived the Y2K soothsayers. But to some people, the end is still right around the corner, as predicted from ancient writings, biblical and otherwise.
By far the so-called prophecies of the 16th century French druggie, er, druggist, Nostradamus are the biggest intellectual fraud when it comes to second-guessing the future (second only to biblical numerologists like radio evangelist Harold Camping who keeps listeners' attention by telling them that the Earth will literally go up in a ball of flames on October 21, 2011).
The latest Nostradamus-driven hysteria is that a comet is going to hit Earth on December 21, 2012. This is somehow entangled in interpretations of the Mayan Calendar which predict a comet collision, grand astronomical alignment, or some other cosmic makeover will happen to Earth on Dec. 23, 2012 (Is Dr. Seus' Grinch part of this conspiracy?)
I recently received an ominous e-mail from a Mayan calendar disciple: “The Mayan long calendar predicts 2012 to be the date the gravity of the planet Venus negatively affects the moon's lunar trajectory and causes disruptions in the weather patterns on the planet Earth. Known only as, and exacerbated by Global Warming. We need to re-engineer the moon's orbit back to a position agreeable with life on earth. This should be the sole focus of Global Warming talks and endeavors.”
Suffice to say that Venus’ gravitational pull on the moon is infinitesimal compared to Earth's pull. For all practicality both planets are nearly the same mass. But Venus, even at its closest approach to the moon, is 140 times farther away from the moon than the Earth is. Consequently its gravitational pull on the moon is nearly 1/20,000th that of Earth's. Astronomy 101 students can calculate this, without the need of the Mayan calendar.
In light of these doomsday predictions I was bemused to see that a team of scientist is reporting that our remote ancestor of 12,900 B.C. may have had to face global cooling --rather than global warming -- as a result of a comet collision with Earth. I doubt that if the Mayans, Mr. Camping, or Nostradamus had lived before this event they would have predicted it.
Possibly the earliest Paleo-Indian inhabitants of North America, called the Clovis people, abruptly vanished. Many of the largest animals including mastodons, saber-toothed cats, ground sloths and giant armadillos went extinct.
Climate change has long been the culprit for the extinctions. Nearly 13,000 years ago the planet's emergence from the last Ice Age came to a halt, reverting abruptly to freezing conditions for another 1,500 years. Nothing of the size, extent, or rapidity of this period of abrupt climate change has been experienced since then, say experts.
The debated smoking gun evidence for a cosmic collision comes from microscopic diamonds, called nanodiamonds. They are found in a rich sedimentary soil called a "black mat,” that dates back to nearly 13,000 years. Beneath the sooty layer fossils of animals are abundant. But just above that layer, the fossils disappear, along with arrowheads and other artifacts from the Clovis culture.
The heat and pressure from explosions in the atmosphere would have transformed carbon on our planet's surface into the tiny diamonds, say researchers James P. Kennett of the University of California at Santa Barbara and Douglas J. Kennett of the University of Oregon.
Their idea is that a comet broke into pieces while approaching Earth. In what must have been the mother-of-all fireworks spectacles, fragments burned up and exploded over a broad area of North America. There are no telltale craters. The researchers describe several Tunguska type explosions going off in sequence, carpet-bombing North America. Each blast would have lit up the sky, brighter than the sun.
Dust from the explosions, combined with soot from continent-wide wildfires could have risen into the atmosphere, blocking sunlight to bring global devastating akin the the effects of a nuclear winter first proposed by Carl Sagan. With vast portions of the landscape burned, even those large animals that survived the sky bombardment would have died off as the food chain collapsed.
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The idea of a comet breaking up is not conjecture. The so-called sun-grazing comets do often disintegrate into football-field sized pieces. In the early 1990s astronomers followed the breakup of comet Shoemaker-Levy 9 (SL9) by Jupiter’s gravitational pull. A total of 23 pieces of the comet slammed into Jupiter in July 1994. So-called crater chains are seen on the icy outer moons. These too must have been laid down by a string of comet pieces.
But a veteran of the SL9 event, planetary astronomer Heidi Hammel, recently told me that the idea of comet pieces barreling into North America all at once is pretty implausible. Impacts would have been scattered across Earth as our planet rotated, as we saw in the the SL9 bombardment.
So the bottom line is that no ancient calendar, scripture or soothsayer can predict what the cosmic roll of dice will deal us. And, evidence for past armageddons can be pretty dicey too. Like a good insurance actuator, we can only look at probabilities, and even these are no all inclusive.
As a follow-up to my previous posting about Saturn’s ring arcs, I’d like you to ponder this question: four of the eight major planets in the solar system have rings of ice and dust; why doesn’t Earth?
If Earth had rings, it would be a spectacular sight at night. The system would form a vast glowing arch spanning horizon to horizon. But during the daytime it would cast a shadow over a strip of Earth that would change latitude with the seasons.
Back in the early 1980s I interviewed John O’Keefe who was then with NASA’s Goddard Space Flight Center in Greenbelt, Maryland, about Earth possibly once having rings. He proposed that volcanic eruptions on the moon hurled dust into orbit around Earth to form a temporary ring.
O’Keefe hypothesized that the equatorial ring cast a shadow on northern latitudes during winter, bringing extremely cold climate. He said that this could explain the Eocene extinctions of 35 million years ago. Hundreds of species, including horses in Europe and plankton in the Caribbean, vanished. O’Keefe proposed that the ring only lasted a few million years before it was dissipated by the pressure of solar radiation.
He had even speculated that some tektites, glassy stones found in so-called "strewn fields" worldwide, are moon-volcanic debris from the ring. Most tektites, regardless of age, look ablated by heat, like meteorites that have been scorched while plummeting through the atmosphere. Tektites dating back to the Eocene era appear to have fallen in a vast arc from Massachusetts to Texas.
In 2002, researchers at Sandia National Laboratories published a study that an asteroid impact on Earth would form an equatorial ring of ejected dust that would blot out light for hundreds of thousand of years. So, the K-T impact (Cretaceous-Tertiary boundary) of 65 million years ago, that likely brought on the extinction of the dinosaurs through a nuclear winter, might have further added insult to injury by blotting out the sun from high above Earth.
No so fast, says amateur astronomer and science fiction author Abdul Ahad. He points out that, unlike the outer planets, Earth has a big moon that is a substantial fraction of Earth’s mass. The tidal pull of the moon would dissipate a ring very quickly, according to his calculations. Add to that the tidal pull of the sun, which is much stronger than it is at Saturn’s distance. Finally, Earth is not absolutely round but pear-shaped. The resulting non-symmetric gravitational field would cause a ring to collapse, he says.
This is bad news for astroengineeering buffs that have proposed building an artificial ring around the Earth. The shadow cast by the ring would cool parts of Earth and could help offset global warming. The ring could even be used to create an artificial ionosphere for radio communications. It would provide nighttime illumination over large cities, reducing the use of electric power.
Of course this celestial light-pollution would destroy ground-based astronomy and ruin the discovery of the heavens for budding amateur astronomers. This would be the Dark Sky Association’s absolutely worst nightmare. It also would likely mess up the habits of nocturnal animals.
Such a ring might be built from placing a captured asteroid into orbit about the Earth and continuously blasting dust off the surface that would go into orbit around our planet – much as I described in the previous blog. It is very improbable that world governments would all agree on such a project. Imagine filing an environmental impact statement for towing an asteroid into Earth orbit!
This type of astroengineeering could already be taking place on an earthlike planet with an advanced civilization. Assuming their politicians are just as oblivious as ours about the damage of global warming until it’s too late, the civilization’s last resort is to build a climate-controlling ring.
It would require an extraordinarily large space telescope array to actually image such a ring around an exoplanet. Observing an earthlike planet passing in front of its star (transiting) could possibly identify a ring. The photometric signature of the dip in starlight caused by the planet would have additional features if a ring were present.
Now, such a ring could easily be explained by natural reasons if detected. But it might not be entirely impossible to discover some sort of exotic ring architecture that astronomers would very reluctantly speculate might be artificially constructed and maintained.
Our first evidence of intelligent life off the Earth may come from stumbling across just such astroengineeering by super-smart extraterrestrials.
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