ARCTIC SEA ICE MELTDOWN--STRIKING 3D VISUALIZATION

The volume of arctic sea ice varies season by season and year by year. Unfortunately, the trend is clearly down, with current ice volume about one-quarter of what it was in 1980. That's not good news, since it's part of a vicious cycle of warming, melting and carbon dioxide release and that impacts the entire northern hemisphere.

NASA finds oldest and thickest Arctic sea ice is melting fastest

Credit: NASA Goddard

You can find more details plus a brilliant 3D visualization of the data -- thanks to physicist and climate expert Joe Romm andmulti-talented IT consultant Andy Lee Robinson -- at this URL.

The loss of Arctic sea ice cover does not only impact polar bears and Inuit communities. Scientists are becoming increasingly sure that a smaller temperature difference between the Arctic and the rest of the northern hemisphere makes for a much wobblier jet stream, which, ironically, can cause much colder winters, for example in the eastern U.S. and the U.K.

For another brilliant--and scary-visualization, check out Ed Hawkins' spiral map of global temperature change from 1850 to 2016. It's the most powerful anti-denial intervention I've ever come across.

Credit: Ed Hawkins

WITH MALICE TOWARDS ALL, WITH CHARITY FOR NONE--TRUMP'S GETTYSBURG ADDRESS

Lincoln Memorial--Credit Chadh

Hopefully the world will little note nor long remember Donald Trump's words at Gettysburg on Saturday. If he was trying to gain stature by standing in Abraham Lincoln's footprints, he failed miserably.

To quote, not from Lincoln's immortal address at Gettysburg 153 years ago, but from his second inaugural address, in 1865:

With malice toward none, with charity for all, with firmness in the right as God gives us to see the right, let us strive on to finish the work we are in, to bind up the nation's wounds, to care for him who shall have borne the battle and for his widow and his orphan, to do all which may achieve and cherish a just and lasting peace among ourselves and with all nations.

And to quote from Trump's comments at Gettysburg:

"Every woman lied when they came forward to hurt my campaign. Total fabrication. The events never happened. Never. All of these liars will be sued after the election is over."

It goes to character.

HEADS I WIN, TAILS YOU LOSE--TRUMP'S VERSION OF DEMOCRACY

In keeping with Trump's incredible refusal during the third debate to commit to accepting the November 8 election results, check out this highly scientific poll on his website.

In case the "poll" is taken down, here's a screenshot:

Credit: Walter Einenkel

To end any "suspense," Donald Trump does not "get" democracy. 

IN U.S. EXPOSURE TO HORMONE DISRUPTING CHEMICALS COSTS HUNDREDS OF BILLIONS PER YEAR

Following up on my recent post "Ten Percent of US have high concentrations of ten or more toxins in our blood,", here's a new study that calculates the costs to the U.S. economy from the burden of disease that some of those chemicals cause.

Plastic bottles--one of many sources 

of endocrine-disrupting chemicals

Credit: Velka/Shutterstock (public domain)

Writing in The Lancet Diabetes and Endocrinology, October 17, researchers at the New York University Medical Center say that even a conservative estimate of the diseases and conditions--including birth defects, autism, attention-deficit disorder, intellectual disability, infertility, obesity, diabetes, heart disease and stroke--caused by exposure to these toxins puts their cost to the economy at $340 billion. That's 2.3 percent of the U.S. Gross Domestic Product (GDP).

Flame retardants alone (found in building insulation, fabrics, furniture and electronics) account for more than $200 billion of those health-related costs.

The researchers say this is the first assessment of the overall costs to the U.S. economy from the buildup of endocrine-disrupting substances in the population.

The major sources of these chemicals include plastic bottles, the lining of metal food cans, detergents, flame retardants, toys, pesticides and cosmetics. These pervasive chemicals build up in our bodies over time. They can impair fetal development in the womb, especially the brain and nervous system, and lead to a variety of diseases in adults.

These chemicals are pervasive and extremely difficult to avoid. To address the problem at the policy level, the authors call for more proactive testing and tighter regulation, starting with the Environmental Protection Agency (EPA). They point out that people living in Europe, where these substances are more strongly regulated, have less exposure, lower levels in the bodies and blood, and reduced risk of disability and disease.

At the personal level, they recommend steps such as not microwaving food in plastic containers or covered by plastic wrap, avoiding containers with the number 3, 6 or 7 on the bottom, which contain phthalates and using fragrance free or "all natural" cosmetics.

You can find more ways to minimize your and your family's exposure to endocrine disrupting chemicals here.

This may seem a daunting or even impossible task, given how ubiquitous these chemicals have become. However, new research shows that avoiding common sources of endocrine disrupting chemicals can quickly reduce levels in the body

OFFICER INVOLVED DEATHS IN BLACK AND WHITE

If you consider yourself a member of the fact-based community, you might be interested in some new research about deaths at the hands of police in the U.S.

Memorial to Michael Brown, Ferguson, Missouri. Credit: Jamelle Bouie

The study was carried out by researchers at the Centers for Disease Control and Prevention (CDC) and at the John Jay College of Criminal Justice of the City University of New York. They analyzed data from the National Violent Death Reporting System for the years 2009 through 2012. The 812 fatal encounters they studied came from 17 states that voluntarily provide the CDC with relevant statistics.


You can access the full report, "Death Due to Lethal Force by Law Enforcement," here. 

I'll list some of their key findings:

The victims were predominantly male (96.1%), as were the police officers involved (97.4%). 

Blacks were 2.8 times more likely to die at the hands of police than whites.

If you assume that blacks are more likely to be armed in these fatal encounters, you would be wrong. Black victims were 1.6 times more likely to be unarmed (14.8%) compared to whites (9.4%).

If you assume that blacks are more likely to have placed the officers involved at risk, you would also be wrong. "Black victims were also significantly less likely than whites to have posed an immediate threat to LE [law enforcement]," the authors write.

The authors cite an earlier study by other researchers using FBI statistics that found that the likelihood of a suspect being killed per 100,000 police stops or arrests was not significantly different among blacks, hispanics and non-hispanic whites. However, the same study showed that compared to whites and Asians, blacks, native Americans and Hispanics were stopped by police significantly more frequently.

That study also produced two statistics that surprised me--a suspect or bystander is seriously injured or killed in one out of every 291 police stops, and U.S. police killed or injured an estimated 55,400 people in 2012.

The 812 deaths in 17 states analyzed in the current study represent just a fraction of the total number of people killed by police during those years. Reliable numbers are hard to come by, but the Nevada-based website fatalencounters.org sets out to count every case by collating information from multiple sources. They list by name 3825 individuals who died in encounters with police during those same years.

If you compare either number with the number of legal executions (i.e. capital punishment) in the United States--never more than 100 in any year since 1976, and just 43 in 2012--it becomes obvious that there is an enormous gap between justice applied with our constitutionally-guaranteed due process and what actually happens many times per day on the street. You'll find a more recent, in-depth post on that subject here.

The authors of the current study take pains not to vilify law enforcement officers. They write about the kinds of implicit biases that almost everyone carries, perhaps exacerbated by negative experiences policing particular neighborhoods, training issues, police culture, and a variety of other factors that together may help explain this disparity.

Whatever the causes, the study provides hard data that support what blacks know all too well--that far too many black men die in encounters with police, including a disproportionate number who are unarmed and non-threatening.

But it's also clear that this isn't just a racial problem--it's a systemic nationwide problem involving the police and the communities they are supposed to serve. Even the "safest" Americans, non-Hispanic whites, are 26 times more likely to die in an encounter with police than, for example, a German citizen. 

Whatever happened to "protect and serve?"

Credit: Thomas Hawk

OBIT FOR AUSTRALIA'S GREAT BARRIER REEF

The Great Barrier Reef is considered Earth's largest living structure. It has survived and grown for 25 million years, providing shelter for thousands of species and uncountable billions of organisms. In recent years rising ocean temperatures and ocean acidification--both driven by the CO2 that we are pouring into the atmosphere--have caused repeated bleaching events, in which the coral-building organisms expel the photosynthesizing algae that feed them. The longer the water around them remains too warm, the more likely the reef-building corals are to starve and die.

It now appears that with more heating and acidification locked in due to the CO2 we've already pumped into the atmosphere, and with CO2 emissions still soaring, the 25-million-year-old Great Barrier Reef is doomed.

Environmental (and food) writer Rowan Jacobsen has written the reef's obituary. It's a must read for anyone who cares about the future of life on Earth--including our own.

Bleached coral, Keppel Islands, Great Barrier Reef: Credit Wikipedia

As many of you may know, Jacobsen's obituary for the Great Barrier Reef has gone viral. It has raised the ire of many scientists, who point out that the reef--while suffering the worst bleaching event in history and clearly threatened--is not in fact dead, and potentially can be saved. I think we can safely assume that Jacobsen knows all that, and is thrilled that his premature obit may in fact galvanize people to face up to the life-or-death climatic challenges it, and we, face.

CO2 RISING--THE SOUNDTRACK

We're currently pumping 2.4 million pounds of the greenhouse gas carbon dioxide (CO2) into the atmosphere per second!

Earth's atmosphere is pretty big, but human activity is measurably changing it.

The longest run of measurements of atmospheric CO2 was started by American scientist Charles Keeling in 1958, from an observatory atop Hawaii's Mauna Loa.

The Keeling Curve--Atmospheric CO2 1958-2015

Credit: By Delorme - Own work. Data from Dr. Pieter Tans, NOAA/ESRL and Dr. Ralph Keeling, Scripps Institution of Oceanography., CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=40636957

Keeling was the first to document irrefutably that atmospheric CO2 was rising, we now know due to the burning of fossil fuels and other human enterprises such as agriculture and deforestation.

That record of the concentration of CO2 in Earth's atmosphere is known as the Keeling Curve. It shows clear yearly cycles as vegetation absorbs and releases CO2 with the changing seasons.

But it also shows the dramatic rise in CO2 levels from 315 parts per million (ppm) in 1958 to today's levels of more than 400 ppm.

Two University of Washington atmospheric scientists, doctoral student Judy Twedt and Prof. Dargan Frierson, decided to dramatize what we're doing to the atmosphere by transforming the Keeling Curve into music.

You can hear and see the resulting YouTube video here. It speaks for itself.

To view a striking visualization of rising CO2 levels, check out item 3 at this URL.

TEN PERCENT OF US HAVE HIGH CONCENTRATIONS OF TEN OR MORE TOXINS IN OUR BLOOD

It's common knowledge that we're all exposed to many different kinds of toxins from the air we breathe, the water we drink, the pesticides and other chemicals we're exposed to and many other sources, and that some of those accumulate and persist in our bodies.

Cycling of POPs. Credit: EUGRIS

What we didn't know but researchers have just discovered, is that at least some of those pollutants are not spread randomly through the population, with some individuals having more of one and others having more of a different one. Much like income or wealth, some people have just a little while some have a lot.

A new study of Persistent Organic Pollutants (POPs)--the first that looked at many different kinds of POPs in the same people at the same time--found that that they were strongly clustered, with more than 10% of the U.S. population carrying ten or more different POPs in their blood at concentrations above the 90th percentile. Blacks, people with low incomes, people with a high body mass index (BMI) and older individuals were more likely to carry heavy loads of multiple organic toxins.

Industrial smokestacks--one source of pollutants

Credit Peter Essick/National Geographic

When I asked physician and epidemiologist Miquel Porta, one of the study's authors, about the implications of his findings, he first cautioned about stirring up fear. "As a physician, I firmly believe that fear is seldom compatible with a broad vision of health," he wrote. 

However, he went on to emphasize that finding that a large number of people have 90th-percentile-or-higher concentrations of 10 or more known toxins needs to be noted by researchers and public health authorities:

"Whatever we know, whatever we think we know about the adverse health effects of a given chemical compound, and about the adverse health effects of several different compounds, simply think that it will not be uncommon for them to be--each and all--present at high concentrations in a significant minority of your patients, constituency, citizens, family or friends. And then think about the plausible negative health effects of the combination or 'cocktail' at high and low concentrations."

As reported in the journal PLOS One, Porta and his colleagues looked at the concentrations of 91 POPs in the blood of 4739 people living in the U.S. They found that 13% of the people studied had 10 or more of the most frequently detected organic pollutants at or above 90th percentile levels. You can view the original article here.

"Decades after the evidence on the presence of toxic chemical mixtures in humans became available, official approaches to assess the risks for human health of such mixtures continue to lag tragically behind scientific evidence of the adverse effects of individual compounds and the potential effects of mixtures," Porta writes.

"We provide a method to improve exposure assessment. Our method is an important complement to what is usually done."

In other words, it's no longer justifiable to study one toxin at a time in one group of people at a time. Now that we know that many different toxins pile up in certain populations, with the odds tilted by race, age, income and other factors, studies, recommendations and regulations that don't take that into account from the start are likely to seriously underestimate the risks to the health of a significant number of people.

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You can find a follow-up to this research, detailing some of the health impacts of POPs, here.
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GALAXIES LIKE GRAINS OF SAND

The universe just got ten times more crowded.

Less than a century ago, astronomers believed that the Milky Way galaxy--our home galaxy--comprised the entire universe. In 1924, astronomer Edwin Hubble discovered galaxies, "island universes" far beyond the Milky Way. As telescopes got bigger and better, and eventually were sent into space, researchers estimated that the observable universe--the part of the universe from which light has had time to reach Earth--contained some 120 billion galaxies.

Hubble Ultra-deep field, 2014. Credit: NASA

Today, a team of researchers from NASA and ESA (the European Space Agency) released the results from a new and more accurate 3-D galactic census. The find that for every galaxy astronomers can see with today's telescopes, there are at least 10 that will be detected by the next generations of instruments.

"It boggles the mind that over 90% of the galaxies in the universe have yet to be studied," says the study's lead author, Christopher Conselice.

So it looks as though we live in a universe not with 120 billion other galaxies, but 1.2 trillion. With an average galaxy containing, say, 100 billion stars, that makes the star count around 10 to the 23rd power, or 10 with 23 zeroes after it.

It seems like pretty much every astronomical discovery, starting with Copernicus' shocking revelation in 1543 that Earth is not the center of the cosmos, has had the effect of pointing out that we're not quite as significant in the big scheme of things as we might like to think. 

The good news is that knowing that we're just the inhabitants of the third planet around one star out of a hundred billion in one galaxy out of a trillion does put our current worries--right down to the size of a particular presidential candidate's hands--into perspective.

(And hats off to British science fiction author, Brian Aldiss, for the evocative and prophetic title of his 1960 book, Galaxies Like Grains of Sand.)

Roy Cohn would be proud of Donald Trump

After viewing the second presidential debate, historian Lev Adler posted this commentary on the Daily Kos. He paints Trump as Roy Cohn's prize pupil, a master of the dark arts of demagoguery that Cohn honed as Joseph McCarthy's hit man during the infamous House Un-American Activities Committee (HUAC) witch hunts of the 1950s.

Donald Trump at a 2016 rally. Credit Wikipedia

DO THE MATH--THE CLIMATE CAN'T TAKE ANY NEW DRILLING OR DIGGING

In the Paris Agreement reached last year, the international community, represented by 195 nations including the U.S., agreed that it's vital to keep global warming well below 2 degrees Centigrade (3.6 degrees Fahrenheit) compared to pre-industrial levels. 

Dignitaries celebrating the Paris Agreement, 12/12/15--Credit U.S. Dept. of State

As reported by environmentalist Bill McKibben, writing in the New Republic, the latest calculations show that if we burn the fossil fuels in the mines and wells that already exist, Earth's surface temperature rise will exceed that 2 degree limit.

Open-pit coal mine in Dhanbad, India--Credit Wikipedia

According to these new calculations, adding 800 gigatons (800 billion tons) of CO2 into the atmosphere will push the climate through the 2 degree C. limit. There are 942 gigatons waiting to be extracted from existing mines and wells to be burned. Do the math.

The sobering conclusion is that we can't afford to drill any new oil wells, dig any new coal mines, or open up any more territory for fracking.  If we're serious about controlling global warming, McKibben writes, "we're done expanding the fossil fuel frontier."

The problem is that fossil fuel companies have no intention of abandoning the reserves and leases that are crucial to their future profits--their potential "stranded assets." According to Carbon Tracker, that could amount to some $2 trillion. Two trillion dollars represents a lot of motivation to keep drilling and digging no matter what the environmental and societal costs, and makes investing a few hundred million to influence elections, lawmakers and regulators seem like a pittance.

Still, if we're in the biggest hole ever, as McKibben says, the simple answer is, "stop digging." 

POLICE BODYCAMS DRASTICALLY REDUCE CITIZEN COMPLAINTS

New research involving six police departments in the U.S. and the U.K. tracking nearly 1.5 million officer-hours found a striking 93% reduction in public complaints against police officers. 

The researchers conclude that the consistent use of body-mounted cameras has a dramatic positive impact on people's behavior and on police officers' compliance with correct procedures. In effect, bodycams make cooler heads prevail.

Police officer with body-mounted camera--Credit Ryan Johnson

"Cooling down potentially volatile police-public interactions to the point where official grievances against the police virtually vanished may well lead to the conclusion that the use of body-worn cameras represents a turning point in policing," says Barak Ariel, a criminologist at Cambridge University, in the U.K., and lead author of the study, which appears in the journal Criminal Justice and Behaviour.

With the current challenge to police credibility due to a seemingly endless stream of officer-involved shootings, the resistance of some police officers to the use of bodycams, and many states restricting access to videos from police encounters, this research--one of the largest randomized and controlled experiments in the history of criminology--deserves to be taken seriously by police departments across the U.S. Video footage may show some officers acting badly, but overall it appears to protect the police and the public.

I FINLLY GET IT! TRUMP AND HIS SUPPORTERS ARE "ROLLIN' COAL" IN OUR FACES AND LOVING IT.

You've may have heard about dudes "rollin' coal"--modifying their diesel trucks to belch clouds of oily smoke.

Credit: Wikipedia

Sometimes they blast out the soot on the open road, but at times the blasts target bicyclists, pedestrians, and--a favorite--those environmentalist Prius drivers. 

You can see rollin' coal in action here. 

It's not cheap. According to Wikepedia, it can cost up to $5000 to make the changes.

What's the payoff? I'm guessing it's basically the pleasure of saying "fuck you" to the world, written in black smoke. The bigger and blacker the cloud, the stronger the statement.

Finding out about rollin' coal helped me to wrap my head around Trump's core supporters, and especially why it is that the worse Trump acts the more popular he gets. (See my post, "Most Trump Supporters Extremely Enthusiastic," Sept. 16, 2016, or at the Daily KOS).

Like the good old boys rollin' coal, Trump gives his followers a thrill and an ego boost every time he insults women, threatens to ban Muslims, deport Mexicans, stop and frisk African Americans, or floats a mind-bending new lie. The more outrageous the statement, the more exciting it is, especially when it elicits outraged howls from such despised others as liberals, progressives, and the press.

You can read a similar take on the smug satisfaction Trump and his Alt-Right supporters get from saying (and soon doing) outrageous things in a piece by Jeremy Sherman at this URL. 

As the pollsters and pundits have been saying for months, there are a lot of aggrieved and angry people out there. I respect their intelligence enough to find it hard to believe that many of them really think that Trump can or will live up to his grandiose promises--re-open the coal mines, bring back all those blue-collar jobs, make America great again, whatever that means, and actually make their lives better in any tangible way. With the exception, of course, of his billionaire backers, who will make billions more through deregulation of financial markets.

But the aggrieved and angry can see that Trump is making the lives of the rest of us worse every time he opens his mouth. What a rush that must be. 

Credit: Mike Licht/NotionsCapital.com

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10/4/18--Trump exhibited an especially ugly version of this in his mocking of sexual assault victim Dr. Christine Blasey Ford at a rally in Mississippi. As Atlantic author Adam Serwer summarized, "the cruelty is the point."

Link to Nate Silver's FiveThirtyEight site

We've all heard of statistician and author Nate Silver's acumen in predicting the outcome of political races, not to mention baseball, football, Oscars, etc. 

Here's a link to the presidential page of his website, FiveThirtyEight, where you'll find great stats and probably the best available prognostics about Clinton vs. Trump, the state-by-state races, the Electoral College, etc.

FiveThirtyEight

As of today, 9/20/16, Silver is estimating Clinton's odds of winning at 56.2% vs 43.8% for Trump.

If you want to know what goes into his predictions, you can get all the details here.

STEPHEN COLBERT DISSECTS TRUMP'S BIRTHER LIES

In case you missed Stephen Colbert on The Late Show last night, he brilliantly took apart Trump's about-face on where Obama was born and his head-spinning claim that Hillary started the birther slur.

You can view the YouTube video here.

OF MICE, MEN AND DEPRESSION

Why do antidepressants not always work?

As many people suffering from depression know all too well, even the best available antidepressant medications often don't work. A new study sheds some light on this problem.

Vincent Van Gogh/1890/Wikipedia

Silvia Poggini and her colleagues studied the effects of selective seretoninin reuptake inhibitors (SSRIs) in mice.  Writing in the 27 July edition of Brain, Behavior and Immunity, they report that the SSRIs don't directly reduce depression, but instead seem to make the brain more responsive to the environment and more open to change.

“This work indicates that simply taking an SSRI is probably not enough. To use an analogy, the SSRIs put you in the boat, but a rough sea can determine whether you will enjoy the trip. For an SSRI to work well, you may need to be in a favorable environment, "says Poggini.

It's always a stretch to generalize from animal research to people, but this certainly suggests that people suffering from depression can't rely only on antidepressant medication, but need to work on their life circumstances as well.

Robert Reich on Trump vs. Hillary

If you're a progressive or undecided voter who finds it hard to like or trust either candidate, take a minute to read this piece by Robert Reich. 

Credit: Wikipedia

He takes on the "lesser of two evils" argument and explains very clearly why this is not the time for a protest vote or not to vote at all.

WELCOME TO 1984, BIG BROTHER AND THE MINISTRY OF TRUTH

"WAR IS PEACE."

"FREEDOM IS SLAVERY."

"IGNORANCE IS STRENGTH."

--GEORGE ORWELL, Nineteen Eight-Four

"HILLARY CLINTON . . . STARTED THE BIRTHER CONTROVERSY."

--DONALD TRUMP, 2016

Credit: Stephen Bettany

Doublethink at its best. The Ministry of Truth will be very busy rewriting the history of the last five years.

For a quick review of Orwell's Nineteen Eighty-Four, click here.

MOST TRUMP SUPPORTERS EXTREMELY ENTHUSIASTIC--OMG!

Polls show Clinton-Trump "enthusiasm gap."

According to the latest PDP tracking polls of likely voters, most supporters of Trump are highly enthusiastic about their candidate; far more than are excited about Hillary Clinton. 

PDP writes:

However, turnout in a close election will likely decide the winner of the race and, even though Mrs. Clinton definitely has the larger GOTV [get out the vote] operation, her supporters are markedly less enthusiastic than Trump voters. A whopping two-thirds (66%) say they are “Extremely Enthusiastic” about voting for Mr. Trump in November, while less than half (45%) say the same about voting for Mrs. Clinton. Another roughly one-fifth (22%) of Trump voters say they are “Very Enthusiastic” juxtaposed to 28% for Mrs. Clinton.

That makes 88% of Trump supporters either highly or extremely enthusiastic about him--so very likely to vote--vs. 73% for Clinton. We can expect to hear Trump bragging about that the next time he's in front of a TV camera.

But, more importantly, as PDP points out, " . . . turnout in a close election will likely decide the winner of the race . . . "

White nationalists are among Trump's enthusiastic supporters
Credit: Reuters;Chris Keane

Almost a century ago, in the aftermath of World War I, Irish poet William Butler Yeats wrote in The Second Coming . . .

Things fall apart; the centre cannot hold;

Mere anarchy is loosed upon the world,

The blood-dimmed tide is loosed, and everywhere

The ceremony of innocence is drowned;

The best lack all conviction, while the worst

Are full of passionate intensity.

Credit: Wonkette

Those of us who think that a a Trump presidency would be catastrophic in terms of human rights, the economy, the environment, jobs and climate--not to mention what having an angry, thin-skinned narcissist's finger on the nuclear trigger might mean--had best look to our own convictions and find our passion. As Hillary has pointed out, this isn't a reality show. In this election, it's our one and only reality that's at risk.

Note (January 5, 2017): It looks as though this post was right on target. Today, Nate Silver's 538 published an analysis entitled "Registered voters who stayed home probably cost Clinton the election." 

It's no fun having been right in predicting a tragedy.

The "Big Splash" that formed the Moon was ten times bigger than we thought

Astronomers think that the Moon was formed when a Mars-sized planet smashed into the still-growing Earth some 4.5 billion years ago--a titanic collision often called the "Big Splash."

New high-precision comparisons of the ratio of potassium isotopes in rocks from the Earth and Moon make that collision even more catastrophic than previously thought—releasing so much energy that all of the impactor and most of Earth's mantle were splashed into orbit, forming a hot, dense rapidly-rotating disc from which the Moon quickly condensed.

Artist's conception of Moon-forming impact

Credit: NASA/JPL-Caltech

“Our results provide the first hard evidence that the impact really did—largely--vaporize Earth,” says Kun Wang, a geoscientist at Washington University in St. Louis, Missouri. He and Harvard University researcher Stein Jacobsen detailed their findings in a Nature article published today.

Wang and Jacobsen developed analytic techniques that let them measure minute differences between Earth and Moon rocks for the first time. It turns out that Moon rocks have significantly more heavy isotopes of potassium than Earth rocks, which is best explained by partial condensation from a superheated disc with a high internal pressure. That, in turn, requires a collision ten times more powerful than previously estimated.

Old and new collision models: In the lower-energy collision (top), the Moon has no more heavy potassium than Earth. In the higher-energy collision (bottom), the Moon has more heavy potassium than Earth, as the new study found. Credit: Kun Wang

What was earlier hypothesized to be a Mars-sized object--named Theia after the mythological mother of Selena, the Moon--crashing into the proto-Earth might have been hurtling through space much more rapidly than thought, or it might have been much more massive, perhaps as large as Earth. “It does not have to be Mars-sized anymore,” says Wang.

Many scientists think that our unusually large Moon—one quarter of Earth's diameter—has played a vital role by stabilizing and slowing Earth's rotation, making it easier for life to develop here. If they're right, we may owe our existence to a 4-billion-year-old smashup that almost vaporized Earth.