Core Dynamics

I freely admit that I don’t spend a lot of time thinking about the Earth’s core. Living as I do on the thin outer crust of our planetary home, my focus is on the surface I inhabit and the atmosphere beyond, not on what’s happening miles below my feet.

That’s too bad, because the Earth’s inner core seems to be an interesting, and apparently somewhat quixotic, place. (It’s also the subject of some pretty cool science book-type graphics, like the one above.)

We don’t really know a lot about the Earth’s inner core, because of course no one has visited it. Based on a 1930s study of seismic waves and later confirming data, scientists believe that the inner core is a solid ball of iron and nickel. That solid core is covered by a sheath of liquid iron and other elements, and the interaction between the solid center and its liquid shell creates our planet’s magnetic field. But here’s the weird part: Because the solid inner core is separated from the rest of Earth by that liquid coating, the inner core can spin at its own pace, like a ball bearing covered by a thick layer of hot oil–without regard for what the rest of the planet is doing.

Some scientists have believed for years that the inner core rotates at a faster rate than the rest of the planet (called super-rotation), but there is a lively, ongoing debate about that. The debate has been spurred by some recent findings that the super-rotation has stopped, and that the core might now be spinning at a pace slower than the rest of the planet. If the pace of inner core spin has in fact changed, no one knows exactly why, or what causes the core rotation to slow down or speed up. Only the curious physical forces influencing that inner planet of solid metal and its interaction with its superheated liquid iron coating know for sure.

And there’s another cool element to all of this: the preferred scientific method for studying the inner core is . . . earthquakes. When earthquakes occur, seismic waves pass through the planet and, the data acquired about their variations in speed and direction can equip scientists to draw inferences about what’s happening deep inside our planet. One article described the seismic waves as serving like a kind of geological x-ray. So you can be sure that, the next time an earthquake rattles the cupboards out in California or outer Mongolia, some scientists will be eagerly monitoring the seismic waves that result, looking for more clues about Earth’s quixotic inner core.

Spinning The Shortest Day Ever

When you said–as everyone who is truthful about it must admit they did say–that it seemed like August got here faster than ever this summer. . . well, it turns out you were right. August literally arrived more quickly than ever before because the Earth is spinning faster than ever, producing shorter days. In fact, scientists have determined that June 29, 2022 was the shortest day ever, clocking in at 1.59 millisecond shorter than the average day.

Our planet apparently started to rotate more quickly in 2016, and the quicker spinning seems to be accelerating, with 2022 seeing a speedier spin that 2020 and 2021. Scientists aren’t sure exactly why the quicker cycles began, but think it might have something to do with the tides.

The shorter days may require that atomic clocks and other devices be recalibrated to keep precise time. Because all of those lost milliseconds will add up, scientists have floated the idea of a “negative leap second” to account for the reduction in the length of days, employing the same concept that causes us to add a leap day to the calendar every four years. Engineers hate the idea and raise the possibility that messing with the clocks could have a devastating impact on technology and cause massive outages. Their position may remind some of the dire “Y2K” forecasts of what might happen when we hit the year 2000 that didn’t materialize, but I’m with the engineers on this one: if attempting a “negative leap second” could cause mass failures, panic, and the end of the civilization as we know it, I’d rather live with the fact that our clocks are off by a few milliseconds.

None of this should affect the proud reaction of those who admittedly did say (as I did) that August got here earlier this year. Isn’t it nice to know that your finely honed internal chronometer is working more reliably than our atomic clocks?

Our Alien Moon

For years, scientists have believed that the Moon was caused by a terrible collision between the Earth and a rogue alien planet.  The hypothesis was that the alien planet, called Theia, smashed into the Earth 4.5 million years ago, and the resulting dust and fragments and debris ultimately coalesced to form the Moon.

The theory looked good on the computer simulations and sounded right.  But there was one problem:  there was no physical evidence of the cataclysmic crash.  If Theia had, in fact, collided with Earth and been pulverized, why wouldn’t we find pieces of Theia and its alien geology scattered about like Indian arrowheads?  So scientists refined the theory and concluded that most of Theia ended up forming the Moon.  And they had a way to test the theory — checking out the rocks that the Apollo astronauts gathered from the lunar surface and testing them for signs of their Theianic origin.

Initial tests, however, indicated that the Moon’s geology looked just like the Earth.  It was so perplexing for our scientific friends!  But they kept testing, and now — more than 40 years after the first Moon rocks were retrieved — scientists think they have found traces of Theia.  Some of the lunar rocks show slight differences in their oxygen composition that scientists believe reflect an alien origin, and therefore would be Theia’s fingerprint.

The findings aren’t without controversy, and some scientists argue that the differences are so slight the rocks are still of Earth origin.  Others theorize that the rocks are alien after all, and that scientists were wrong to expect huge differences in planetary composition — a theory that has intriguing implications for the history of our solar system and the possibility that old Earth really isn’t as unique as we once thought.

Red Planet, White Rock, Deep Meaning

NASA’s Curiosity rover has once again excited scientists with some provocative discoveries about Mars.

Curiosity drove over a Martian rock and broke it open, exposing a dazzling white exterior.  The striking ivory color indicates the presence of hydrated minerals in the rock.  As any person who walks around with a water bottle knows, “hydration” requires water, and hydrated minerals are those that are formed when water is found.  Curiosity also has detected clay-type minerals in a different rock — another clue suggesting the presence of water at some point.  These discoveries are part of a growing body of evidence that running water once existed on this part of the surface of Mars.

On Earth, water seems to have been a crucial building block in whatever process, or outside force, first created life.  If water flowed on the Red Planet, the odds are increased that life once existed there — and may exist there still.  Although the surface of Mars is now a dusty red desert, it is possible that water and ice remain in rock formations deep below the Martian surface.  If so, life may be found there, because studies on Earth indicate that life, once established, is remarkably hardy.  The expedition to drill into a lake buried beneath a two-mile thick sheet of ice in Antartica, for example, recently uncovered life forms even in that dark, desolate, and inhospitable location.  Why should life on Mars be any less tenacious?

I’m of the Star Trek generation.  I believe that looking for — and especially finding — life beyond the confines of our home planet is a good way to get squabbling humans to recognize that their differences are minor and not worthy of much attention in the grand scheme of things.  We need to move beyond a mindset that focuses exclusively on our own fleeting creature comforts and recognize that we live in but one tiny, wayward corner of an unimaginably vast universe.  It’s been 40 years since humans walked on the Moon.  When will we take the next step, to Mars and beyond, to see whether life in fact may be found elsewhere?

How Much Would You Pay For Space?

I’ve always wanted to go into space some day.  When I was a kid and Apollo missions were landing on the Moon every few months, that seemed like a real possibility.  Sci-fi features like 2001:  A Space Odyssey forecast that routine commercial travel to the Moon would be available a decade ago.  Of course, that didn’t happen . . . and now time seems to be running out.

But perhaps there’s still a chance for 50-something space traveler wannabes like me.  Virgin Galactic is nearing completion of the beautiful, futuristic spaceport shown at left, called the Virgin Galactic Gateway to Space, in the New Mexico desert.

The company plans on beginning passenger service in 2014.  When the spaceport is operational, would-be astronauts will board a small rocket plane tethered to a mother ship.  When the mother ship reaches a point nine miles above the earth, the rocket plane will be launched, the rocket will be ignited, the passengers will experience 3 gees of force as they zoom through the upper atmosphere until they encounter the blackness of space.  The pilot then will cut the rocket engine and the passengers will experience four minutes of weightlessness and have a chance to enjoy a view so vast they can see the curvature of the Earth.  Then the plane will reenter the atmosphere, hurtle back to Earth, and land on the spaceport’s long runway.

All this will be available to the average Joe — provided the average Joe can pony up $200,000 for the experience.  If I had millions of dollars in the bank, I’d do it.  Because I don’t have that kind of coin, however, I’ll just bide my time and hope that competition brings the price of space down to more manageable levels so that, someday, a codger like me will be able to enjoy the wonders of space.

Disaster Raining From The Skies

A meteor crashed yesterday in Russia’s Ural mountains, injuring at least 500 people and blowing out windows in nearby towns.  And today, Asteroid 2012 DA14 will pass within a hair’s-breadth of the Earth — in galactic terms, at least — when it scoots by at a distance of 17,200 miles.

Scientists say there is no chance that the asteroid will strike our planet.  Nevertheless, at 2:25 p.m. EST, the point of the asteroid’s closest approach, the nervous among us will be watching the live NASA feed, checking their watches, and peering anxiously at the skies, wondering if a computer somehow miscalculated at the 10th decimal point or if scientists really can’t determine, with complete precision, the flight path of a tumbling asteroid navigating through the complex interplay of gravitational forces of the Sun, Earth, the Moon, and other celestrial bodies in the inner solar system.  Or, perhaps, they might wonder if Asteroid 2012 DA14 isn’t a bit capricious and miffed at having been given such an uninteresting moniker and might just decide to veer from its anticipated path to wreak havoc on the residents of Mother Earth and make a more lasting name for itself.

If 2:25 passes without disaster striking, they’ll briefly breath a sigh of relief before starting to worry about the next meteorite fly-by or some possible global epidemic or the risks of a newly discovered food-borne pathogen.

Me, I’ll be driving to and from Cleveland today.  I won’t be thinking about Asteroid 2012 DA14, but I will be worrying about my fellow drivers heading north and south on the I-71 corridor.  They’ll be a lot closer than 17,200 miles away, and a lot more likely to inflict injury, disaster, and chaos.

Alpha Centauri’s Earth-Sized Planet

Science continues to achieve amazing advances in our ability to detect, measure, and analyze planets orbiting stars far outside our solar system.

So far, scientists have discovered and confirmed the existence of more than 800 planets.  Most of the planets, however, are huge gas giants, like Jupiter or Saturn in our solar system.  The latest advance in detection capabilities came this week, when scientists announced that they have detected the lightest planet to orbit a Sun-like star — and the star just happens to be Alpha Centauri, a weird, triple-star system that is the Sun’s nearest galactic neighbor.

Alpha Centauri, for those who fell asleep during astronomy class, is a mere 4.3 light years away.  Of course, one light year is 6 trillion (6,000,000,000,000) miles away, but who’s counting?  The planet scientists have detected is about the mass of our good Earth.

Before you start worrying that little green men might appear on your doorstep tonight, take a deep breath:  the Earth-sized planet is closer to Alpha Centauri B than Mercury is to the Sun, so it’s probably not conducive to life.  Still, the discovery is remarkable.  In the not too distant future, scientists will use this detection technology to find a planet about the size and mass of Earth, orbiting a star a lot like Sol, at a distance that would suggest that it is likely to be temperate.  What will that mean?  My guess is that we will train every radio telescope and sensory device we have in the direction of that planet, listen as hard as we can, and hope.

 

Venus On The Move

Venus is on the move today and tomorrow.  It’s traveling slowly across the face of the Sun, on a journey that astronomers call being “in transit” — as if Venus were hopping a subway to get from one side of the solar system to another.

These kind of astronomical events are very cool, because they happen so rarely.  There’s a “music of the spheres” sort of celestial harmony to Venus’ journey that reflects a special, highly unusual confluence of positioning of the Sun, Venus, and Earth.  It won’t happen again for 105 years.  By then, we hope, the European debt crisis will have been resolved.  In fact, some astrologers are saying that the transit of Venus might help to solve such problems.  It’s is supposed to herald in a new era of spiritual and technological revolution . . . or, it’s supposed to strongly accentuate feelings of love and hate.  With astrology, it always seems to be one or the other.

As with any solar celestial phenomenon, the news stories always caution people not to look directly at old Sol.  It’s hard to believe anyone would try to use the naked eye to check out the Venus transit, because Venus will be only a small speck against the enormous disk of the Sun.  You supposedly can see it safely by creating one of those pinhole-in-a-box projectors that the news stories typically mention in these circumstances.  I tried to make one of those devices when there was a solar eclipse during my childhood, and I gave up in frustration when it didn’t work.  This time, I’ll just rely on the photos, and in the meantime wish Venus well on her cross-town travel.

No Alien Answer — Yet

The search for extraterrestrial intelligence has made huge strides in recent years.

Using new techniques, scientists have identified many apparently habitable planets, thereby suggesting that the first ingredient of extraterrestrial intelligence — a planet where a sophisticated alien race might develop — is much more common than people once thought.  Studies have shown that life has developed and thrived in the most inhospitable climates on Earth, from superhot underseas vents to the coldest ice caves at our poles.  And now, astronomers are targeting specific stars with radio frequency searches designed to hear any radio wave activity.

The astronomers examined Gliese 581, a red dwarf 20 light years away that is orbited by six planets, including two jumbo-sized Earth-like planets.  If Gliese 581 were aiming a similar array at Earth, it would hear countless radio broadcasts from 20 years ago — lots of the music of Nirvana, and reports on the upcoming Bush-Clinton presidential election, no doubt.  But from Gliese 581, the astronomers heard . . . nothing.  If there is life on the planets in the Gliese 581 system, it either hasn’t progressed to the point of using radio technology or uses some other form of communication we haven’t discovered.

The fact that we haven’t heard an answer yet doesn’t mean life isn’t out there somewhere.  The technique used on Gliese 581 was targeted at a small dot in a universe that has countless such dots.  The astronomers could experience years of radio silence from their targets, but the world would change immediately if the radio astronomers heard alien communications from just one target — as was the case in Maria Doria Russell’s excellent novel The Sparrow.

We don’t know if we’re unique, and whether Earth is the only planet in the vast universe where intelligent creatures capable of extraterrestrial communications have developed.  Being something of a skeptic, I’m not willing to accept that proposition.  Time, and some more efforts to listen in on alien radio, will tell.

Our Awesome Earth

The crew of the International Space Station recently took a series of time-lapse photographs of the Earth using a special camera.  The results, when strung together, are stunning.  (Pay no attention, incidentally, to the uninspired music accompanying the photos — these pictures are worthy of accompaniment by the finest Bach cantata, or a Mozart symphony, or perhaps a piece by Louis Armstrong.)

These photos just demonstrate why I would be a worthless astronaut.  I couldn’t resist spending all of my time at the window, staring slack-jawed in amazement as our magnificent world slid slowly by.

Sowing Earthlife

Those who are intrigued by the possibility of extraterrestrial life may be interested in a study that indicates that Earth itself could have been the source of life on other planets and moons in our solar system.

The study looked at the dispersion of debris from asteroid impacts on the Earth’s surface.  It found that such debris is far more likely to reach Mars, or even Jupiter and Saturn and their moons, than was previously thought.  If such debris contained small life forms, they therefore could have reached other places that are capable of sustaining life.  Of course, any microbes and other organisms on the debris would have to be hardy enough to survive years of travel through space, exposure to radiation, the fall to the surface of another planet, and the different atmospheres and living conditions on those planets — but we know that there are organisms that can survive such conditions, and we also know that life is tenacious and is found in even the most hostile and extreme climates on Earth.

We won’t know, of course, whether this scenario could actually have produced life elsewhere until we find such life and test it.  If we do find such life, however, it will give new meaning to the phrase “Mother Earth.”

 

Life, Arriving Via Meteor And Comet

Scientists are debating a provocative new study that suggests that life is found elsewhere in the universe, and may have arrived on Earth by way or meteors and comets.

In an article published in the Journal of Cosmology, NASA astrobiologist Richard B. Hoover reports on his studies of a rare type of meteor.  He concludes that the meteors include fossils of bacterial life.  Some of the micro-organisms are recognizable and closely associated with life found here on Earth, like the gian bacterium pictured above.  Other apparent fossils are of unknown life forms.  Hoover is convinced of his findings.  Other scientists, however, are skeptical — skepticism, after all, is one of the fundamental tenets of good science — and want more proof.

If Hoover’s conclusions are correct, then the implications are Earth-shaking.  The study suggests that life is more common than thought and can survive in the harshest imaginable conditions.  It also suggests that life may have originated elsewhere and landed on Earth via comet and meteor — in effect, that Earth was seeded with life forms from another place.  The apparent fossils that look familiar thrived after they arrived in Earth’s moist, oxygen-rich atmosphere; those that look unfamiliar, however, died out.  And, because scientists are uncovering evidence of increasing numbers of Earth-like planets in the galaxy, the study suggests that life could have been seeded, by the same means, on other planets.  If that is so, then the chances of intelligent extraterrestrial life forms may be greater than previously thought.

Earths, Everywhere

The Kepler mission, a space observatory designed to examine deep space, has only been operational for six weeks but it already is starting to pay dividends.  The observatory has located 140 suspected Earth-like planets among 700 suspected new planet discoveries.  Previously, telescopes looking outside our solar system have identified only large gas giants.

Scientists need to confirm that the suspected planets are, in fact, planets, but their speculation based on the findings to date is that there may be as many as 100 million habitable planets in the Milky Way galaxy.

Imagine — the possibility of 100 million habitable planets in our galaxy, some of which may have their own life forms.  Increasingly, science fiction is becoming reality.  When will we begin to boldly go where no man has gone before?