Dorian: All those people who evacuated north? Oops

Spread the love

There was always a chance that Dorian was going to make a right turn. In fact, it wasn’t just “a chance” but a very high probability. But a day or so ago, it was reasonable to say that Dorian would likely, but not necessarily, make that turn AFTER coming ashore in Florida.It now looks like Dorian may make that turn sooner, while still at sea.

We have already seen major news outlets walking all over their own tongues trying to describe that might happen, and thus quite possibly misleading people in a dangerous way. Here, I’ll focus on a new way of explaining the Dorian dilemma.

First, think of a hurricane as a car. The driver is the eye. Perhaps imagine a car where the driver sits more in the middle, like this one:

Now, imagine this car is coming at you, right at you like it is going to run you over. You are frozen in place in terror and can not move aide. But,at the last second, the car, which was about to hit you head on at 125 miles per hour, turns slightly so it hits you on its right front bumper instead of in the middle.

You are totally fine, because the part of the car that is the driver did not actually run you over. Only the part of the car that is over on the right third. So, no problem, right?

I don’t think so. This is you:

If Dorian turns soon enough, so the outer tropical wind force bands are too far from the coast to come ashore, then Florida will have some high winds, and high surf, and beach erosion. Boats trapped to the north of Dorian’s original course that can’t get out of the way may be trapped in dangerous seas.

This is Dorian driving by all the people in Florida:

If Dorian turns later, stays at sea but not too far at sea, then hurricane force winds and storm tides will affect coastal communities not just where a straight-running storm would come ashore, but over many hundreds of miles as the storm parallels the coast. It would be like when one of those Grand Prix cars takes out the first two rows of spectators in France.

That is a picture of Florida, Georgia and South Carolina standing too close to the ocean.

One major news agency has already messed this up with a headline like “‘Extremely dangerous’ Hurricane Dorian barrels toward Carolinas, likelihood of direct hit on Florida decreases”

That makes it sound like Florida may be out of the woods, and the Hurricane is instead going to hit somewhere else. What could really happen is havoc along the coast of Florida, followed by the storm weakening, then lumbering ashore as a big wet spot at some later time. The last person to get run into by that car taking out all the spectators just got a bruise. That sort of thing.

Or, Dorian could stay far enough off shore to retain its immense power as a hurricane for long enough to suddenly turn left and plow into some harbor in the Carolinas and wipe out all those motels the good people of coastal Florida are staying in because they fled Dorian in the first place.

Here is the current best estimate from the National Hurricane Center for the what and when on Hurricane Dorian:

As 2:00 AM EDT Tuesday morning, September 03, Dorian will be well into its right turn to the north, far enough away from the coast that the shores near Port St. Lucie will probably not experience hurricane force winds or storm surges. Dorian will be a Category 4 hurricane at that time, with maximum winds of 130 mph, gusting to 160 mph.

Between then and 24 hours later, 2:00 AM EDT Wednesday morning September 04, Dorian will be near Palm Coast, heading more or less north, but probably sneaking closer to the coastline, and probably having nasty impacts on the coast the whole way. It will not weaken much during this period, with maximum winds just a little slower than at the time of the turn (125 mph, gusting to 155 mph)

Over the next day or so, Dorian will probably continue to menace the coast of Florida and Georgia, and weaken to a Category 1 storm. At this point it will be hard to not run at an oblique angle into the bulgy part of the eastern US, near or north of the Georgia-South Carolina border. This could be anywhere in South Carolina, or even southern North Carolina. This is probably one of the hardest things to predict because the exact course of the Hurricane and it’s impact on land depend on so many different factors.

So, instead of saying “Florida is out of the woods, there will be landfall (meaning, the driver/eye passes over the coastline) at a later time” the papers should be saying “Major Hurricane Dorian will menace the coast from the central Florida Atlantic coastline through somewhere in South Carolina to an unknown degree at unknown locations.”

In short, Hurricane Dorian is almost certain to crash into the crowd somewhere, we don’t know where.


Spread the love

Dorian Could Be A Big Problem IMPORTANT UPDATES

Spread the love

UPDATE for Friday 20 Aug AM:

The information below is still pretty accurate for Dorian, except a few important details.

1) The storm is now expected to move more slowly as it gets closer to the Florida coast. This means that the timing is shifted later, possibly by a half a day or more. But, this is not certain, so if you were planning on buying umbrellas don’t put that off. Or, evacuation. Don’t put that off either.

2) For the same reason, the slowdown, Dorian may spend more time in a position to remain strong off the coast but still hitting the coast with severe winds and storm surges, for a longer period of time.

With hurricanes, fast is better, once you know they are coming.

Chances are about even that Dorian will affect the Florida coast as a Category 3 or a Category 4 hurricane. The centerline prediction from the National Hurricane Center has Dorian as just barely a Category 4 as it makes landfall, but as a mid-range Category 4 (i.e., more severe) prior to getting near the coast. This will, of course, cause confusion as reporters spew poorly formed sentences like “Dorian has weakened” instead of “Dorian has made the expected adjustment from a very very very dangerous storm to a very very very dangerous storm because it lost some of its energy scraping your homes and beaches into the sea” or words to that effect.

Best guess right now: Dorian will be a Category 3/4 hurricane as it moves onto land over a several hour long slog centered on about 2:00 AM on Tuesday morning. It will remain a hurricane, but weakening to a Category 1 storm over the next 24 hours as it moves well inland, veering north. Tropical storm force winds will be arriving on the Florida coast early Sunday morning.

The center point for landfall of the eye, with lots of areas to the north and south affected, is West Palm Beach or a bit north of there. 24 hours later, still as a hurricane, the storm may be just south of Orlando.

The norther Bahamas are going to have something very close to a direct hit.

The Hurricane Center has not yet put out information about storm surges, because the possible range of actual landfall is still too uncertain. Indeed, it is still possible that the storm will turn north and hardly hit anything.

It was looking for a while there that Dorian, after moving well inland in Florida, would then stay inland a couple/few hundred miles and find a track across all the states to Maine. Now, it is looking more like it will pop back across the coast and go up the Atlantic, either near the coast nor farther at sea. That would make Dorian’s future very unpredictable, and I suppose it would open up the possibility of reforming as a hurricane.

OLDER POST:

Most of the models show Hurricane Dorian striking the Atlantic Coast of Florida, though the exact location is not something that can be predicted yet. Somewhere between Palm Coast and Miami, most likely near Melbour, Palm Bay or Port St Lucie. That’s a pretty large area.

This depends, however, on a weather system that is only now forming up north of Dorian, which would cause the storm to not to the usual pull-out where the storms go north and head in the general direction of Bogna Riva.

And, if that weather system forms, some models say its western end will weaken, and that would be an escape door Dorian might use for that northward turn.

So, there is maybe a one in ten chance Dorian will bug out before hitting Florida. There is a small possibility it will come right up to Florida and then bug out, meaning, it would scrape the coast of Florida and Georgia, or just inland, at first as a hurricane then as a tropical storm.

But most likely, Dorian is going to slam into the Atlantic coast of Florida, then move inland. After moving inland, it is very likely to then stay inland, as a major storm of some sort, dumping rain and blowing winds in inland Florida, Georgia, maybe all the way up to Maine. That should be interesting. Wet, and interesting.

How strong will Dorian be? Don’t believe the hype Major news outlets are suddenly saying that Dorian may be a Category 4 storm. Maybe. But almost every model puts Dorian squarely in the extremely dangerous major-storm Category 3 range, with just a couple of models showing it forming into a Category 4 storm. One model actually shows it becoming a Category 5 storm.

But these categories are felatas. You evacuate and/or batten down the hatches for a Category 3 storm because that is a killer storm. You can save the discussion of whether your house was flattened, flooded, or flew away by a Cat 3 vs a Cat 4 storm felata.

When will Dorian strike?

As you know, “ladnfall” is not when a hurricane strikes. It strikes when the storm’s outer bands come ashore and start making for a lot of rain, some wind. It strikes when a storm surge comes through, and the timing of that can vary a lot. It strikes when the hurricane force bands arrive, which can be hours before, and continue hours after, the eye comes ashore.

The Center of the storm is currently predicted to be in “striking” distance at about sunup on Monday morning. SO, overnight Sunday to Monday is a safe estimate of when Dorian might be “strking.”

By sunup the next day, the storm should be well inland, probably turning north, and very large, wet, dangerous, but probably not really a hurricane any more.

The National Weather Service suggests that tropical storm force winds will arrive on the coast of Florida between nightfall Saturday and maybe midnight.

One more small detail: It is possible that Dorian, if it strikes Florida, will pass into the Gulf. If it does, then that will be interesting.


Spread the love

“Am I going to have access to food or water when I’m 30?” — the question your kids are asking now.

Spread the love

If you do not understand that this is a valid question, then you do not actually deserve to be breathing our chemically-altered air right now. No excuses.

Continue reading “Am I going to have access to food or water when I’m 30?” — the question your kids are asking now.


Spread the love

Reconstructed Fairy Tales, Holmes, Anthologies, Cheap

Spread the love

I know you either have these or want these, and they are now cheap in Kindle form:

Happily Ever After edited by John Kilma, with modernized fair tale stories by Gregory Maguire, Susanna Clarke, Karen Joy Fowler, Charles de Lint, Holly Black, Garth Nix, Kelly Link, Peter Straub, Neil Gaiman, Patricia Briggs and others.

The Improbable Adventures of Sherlock Holmes by John Joseph Adams.


Spread the love

A good reason to oppose development of nuclear power in the US

Spread the love

… is the fact that you can trust the nuclear power industry about as far as you can throw an elephant.

If you can’t trust an entire industry to even look at you and not lie, then why do we trust them to do anything important?

For example, Ohio.

In Ohio, there has been a long term somewhat complicated fight over nuclear energy.

In a nutshell, and possibly oversimplified:

The Ohio nuclear power industry seeks major public funding to extend the lives of existing projects.

A bill is passed, HB6, which affords this bailout. The fight over that bill and similar initiatives fueled the development of a fairly impressive pro-nuclear lobbying effort which has spilled out into other states including Minnesota. The idea is that the nuclear industry wants states to pass bills supporting nuclear energy development, and/or remove restrictions or disincentives.

A citizens group, “Ohioans Against Corporate Bailouts” is trying to get together a petition opposing the bill, asking for a statewide referendum abrogating it.

Now, there is a pro nuclear group claiming that the anti-nuclear effort is a Chinese Plot. Here is their over the top ad, showing now in Ohio, which is expected to be the beginning of a long and intense flood of rhetoric Ohio voters can expect between now and … well, whenever.

Just look at those poor frightened Ohioans being all plotted by the Red Chinese and stuff.

For the record, there is zero evidence that the Chinese are involved in any of this.

The actual opposition to HB6 “…includes consumer advocates, environmentalists, free market groups, health experts, and manufacturers”

Oh, the Chinese are involved. They have been funding the pro-nuclear side in this Ohio debate. Ironically.

Lots more detail here.


Spread the love

A Hurricane Named Dorian Likely To Hit Florida UPDATED

Spread the love

Dorian is a poorly to moderately organized tropical storm just west of the northern reach of the Leeward Islands, expected to affect Puerto Rico by the end of the day today, then to move into the Southwest North Atlantic, where it will likely become a hurricane between 36 and 48 hours from now.

It is highly likely that Dorian will strike the US 48 this weekend or Monday, somewhere, as some kind of storm. There is a very good chance this will be Florida as a Category 2 Category 3 or 4, i.e., MAJOR hurricane, but it is very early to be sure of that.

Where will Dorian strike?

The full range of spaghetti strands projecting Dorian’s ultimate path include turning north before wandering into the North Atlantic, turning left and passing through the Gulf and making landfall anywhere from Texas to the Florida Panhandle. But most of the pasta is pointing to the Atlantic coast of Florida.

Way to early to say this, but I’ll say it anyway and revise later: The most likely zone of impact of hurricane force winds in Florida is somewhere between West Palm Beach and Saint Augustine. Vacationers in Orlando this coming weekend may expect rain.

How strong will Dorian be?

UPDATE: The National Hurricane Center is now saying that Dorian will become a Major (Category 3 or 4?) before it makes landfall in, probably, Florida.

The National Weather Service hurricane experts are cautioning that predicting Dorian’s intensity and size are both very difficult. The current estimate from the Hurricane Center is that Dorian will reach mid to low Category 2 strength, and be a moderately sized to small hurricane, prior to landfall in Florida, but with the caution that the full range of models includes a stronger and physically larger storm. The “Experimental late-cycle intensity guidance” for Dorian, as of this morning, has about an 80% chance (my estimate) of the storm reaching Category 3 or above, with a very strong possibility of Category 4 or even 5. But the more traditional models suggest something closer to a 50-50 chance of Dorian reaching Category 3. It is, of course, way to early to say much, but the chance that Dorian won’t be a hurricane as it reaches landfall somewhere in the US is nil.

It is possible that Dorian will intensify and then weaken while out over the Atlantic. This usually causes chaos and dumbosity in the news reports. Once a hurricane reaches a certain category, the news reporters add that category value to the name of the storm and it stick. Any time a storm reduces in strength it is denigrated as a lesser storm no matter what it does later to redeem itself. You know the drill.

When will Dorian hit something?

Dorian is likely to hit a lot of things, directly or indirectly, starting very soon. This morning Dorian is bearing down on Pueto Rico as a tropical storm. The storm may scrape the Turks and Caicos Islands and will almost certainly affect the Bahamas. This will happen between the wee hours of the morning tomorrow and late Friday.

Some time Saturday morning the outer reaches of the storm may be lashing the Florida coast and landfall could occurover night or the next day, possibly as late as Monday AM, if the current projections, which are VERY EARLY, are proven. Or, as noted above, something entirely different can happen.


Spread the love

Best Of Everything Books Cheap

Spread the love

You know those books that anthologize the best of this and the best of that? A bunch of them are now cheap in Kindle form:

The Best American Mystery Stories 2018 (The Best American Series ®)

The Best American Comics 2018 (The Best American Series ®)

The Best American Travel Writing 2018 (The Best American Series ®)

The Best American Sports Writing 2018 (The Best American Series ®)

And since you are busy looking at books, look at mine! In Search of Sungudogoby Greg Laden.


Spread the love

Your chance to get Mayer’s Dark Money cheap

Spread the love

Dark Money: The Hidden History of the Billionaires Behind the Rise of the Radical Right by Jane Mayer is now cheap in Kindle format. With a new preface.

In her new preface, Jane Mayer discusses the results of the most recent election and Donald Trump’s victory, and how, despite much discussion to the contrary, this was a huge victory for the billionaires who have been pouring money in the American political system.

Why is America living in an age of profound and widening economic inequality? Why have even modest attempts to address climate change been defeated again and again? Why do hedge-fund billionaires pay a far lower tax rate than middle-class workers? In a riveting and indelible feat of reporting, Jane Mayer illuminates the history of an elite cadre of plutocrats—headed by the Kochs, the Scaifes, the Olins, and the Bradleys—who have bankrolled a systematic plan to fundamentally alter the American political system. Mayer traces a byzantine trail of billions of dollars spent by the network, revealing a staggering conglomeration of think tanks, academic institutions, media groups, courthouses, and government allies that have fallen under their sphere of influence. Drawing from hundreds of exclusive interviews, as well as extensive scrutiny of public records, private papers, and court proceedings, Mayer provides vivid portraits of the secretive figures behind the new American oligarchy and a searing look at the carefully concealed agendas steering the nation. Dark Money is an essential book for anyone who cares about the future of American democracy.


Spread the love

Politics 101: Knowing When To Hold ‘Em, When To Fold ‘Em

Spread the love

Press your preference, hold back your hate. Don’t damage the duck until you know which duck is yours. We all do better when we all do better, even those you disagree with. There is an endless list of rhetorically clever utterances to make the same point: express your passion inside the Party, but then, get in line and vote blue. (Or red if you are for some strange reason a Republican interested in my advice, which is highly unlikely).

Here is the argument for not hating on candidates that you don’t like, and for NEVER claiming that you will NEVER vote for that one candidate you can’t stand even if they are selected by your party to wear the mantle. If I suggested that you read this as part of some online conversation, then yes, this is me referencing myself. That’s what blog posts are for.

If there is a position of power, even a little power, some of those interested in power may try to move into it. The power-hungry gravitate to the power places.

If there is a way to increase the power of that position, the power-hungry will likely try to do so, and over time, that position will become more and more power-containing.

An illustration of the phenomenon is the US Presidency. Originally conceived as being powerful but not too powerful, the Presidency was given additional power at the time of America’s first war, temporarily, for the purposes of effectively conducting the war. But when that war was over, some of the power stuck and the Presidency was more powerful after he war of 1812 than before it.

Every war after that had a similar effect, up to the point that war-related changes in policy and procedure as a pathway to power became saturated, probably in the mid 20th century. (See Presidents of War by Michael Beschloss for an analysis of this.)

It is possible that a positive feedback loop could emerge, where the more power-hungry vie for being in the increasingly powerful positions, and they are more equipped to increase the power held in that position, and on and on.

Article One, Section 5 of the Constitution states that “Each House [of Congress] may determine the rules of its proceedings.” Over time, these rules can be changed. The process is overseen by a hierarchy of elected individuals with different levels of power, consisting mainly of two categories: Overall leadership (such as the “Speaker” in the House) and committee leadership. How the rules work in detail is ultimately determined by negotiations and decisions among these leaders.

Rarely do leaders of the two chambers, or of committees, take action to reduce power. Rather, they increase the power of the chair, and of the committee.

Over time, the rules, created or amended entirely within, among, and by, the elected participants — not by passing laws or amending the Constitution — conferred more and more power to committee chairs, and the committees they chair.

And, over time, more and more power was absorbed by the partisan leadership in each chamber.

We are now at the point that the party in charge of a chamber (House or Senate) determines who is in charge of each committee or subcommittee, and those committee chairs determine almost 100% of the time what bills are considered, and which of those bills are ever brought to the floor for a vote.

If a particular political party is not in charge of BOTH houses of Congress, it is very unlikely to be able to carry out actual change by introducing and passing bills. If one of the parties is in the minority but only barely, in the Senate, it may have the power to sometimes interfere with the leading party’s efforts, and thus could have a small degree of fleeting relevance. At best. But hardly so.

For this reason, each of the two chambers of Congress (House and Senate) can be divided into two parts. Those in the majority party, including chamber wide leadership and committee leadership, and those not. The former have power, the latter not.

This is why, in a general election, citizens should vote for party and not individuals.

The greatest power we as citizens have is to influence which party is in power in each chamber (and the Executive, the President). We can also try to influence, often to measurable effect, the behavior of individuals in the party-in-charge once they are elected. Influencing those not in charge has little actual effect.

This means that voting to support individuals who happen to agree with our own positions is an ineffective strategy in general elections. Finding a member of Party A who we like and supporting them is a waste of time if Party B is in charge. If we like, more or less, the policies of Party A and dislike Party B’s policies overall, we should work to support any individual who is a member of Party A over any individual who is a member of Party B, in a general election.

People who say to me “I’m not a partisan” or “I’m independent” might as well be saying “I don’t really understand the system, please tread on me.”

The part of our political power manipulation, as voters or volunteers, that influences the finer detail of our preference happens within the party itself. We should be working hard to support individuals who feel like we do about the various issues, or whom for some other reason we would prefer to be eventually elected. But once the party has finished that decision making process, we should then fully support whom the party has chosen. There is no other procedure that is rational or that moves us as individuals towards more power.

It is logical, then, that while we are busy fighting for Mary over Albert for our party’s nomination, because we like Mary better, we should avoid doing material damage to Albert, just in case Albert ends up being the party-wide choice. The reason for this is blindingly obvious yet seems to be often missed, so I’ll state it. Damage we do to Albert now may weaken Albert in the general election, causing him to lose, and thus, causing all of us of (more or less) like mind to lose power in government.

The level of passion in our dislike of the candidates perceived as flawed, the ones that are imperfect, can be astonishingly strong. This passion is reflective of peronsal conceit. One’s own opinions are, in the realm of politics, one’s very self. Those that differ in policy from one’s own can rightfully be seen as different, but they are often also seen as inferior. It is with the utmost sense of self-supremacy that we strongly disdain politicians tho do not think, feel, and act, exactly as we think they should.

People need to learn to not treat others of the same party with that sense of self-supremacy.

It is understandable that there would be a certain degree of disdain, especially for politicians that are far, far away from ourselves in their positions on key issues. There is nothing wrong with rhetorically punching Nazis. But when a member of a certain political party disdains a politician enough to effectively support a candidate from the opposing party who stands against nearly everything we all believe in, that is the ultimate selfishness. It is a nearly unforgivable hubris, to believe that someone who is modestly different from oneself — even critically different in one issue but not likely in most issues — is worthy of sufficient disdain that one must punish one’s friends, family, fellow partisans, and all the future children over that difference.

So, please, don’t do that.


Spread the love

Franken Anounces Run for Senate

Spread the love

As outlined here in a post at Get Energy Smart Now, there is a new candidate in town in a major mid western Senate race. Siegel notes:

Today, a Climate Hawk is announcing his candidacy in the crowded Iowa Democratic Party primary for the chance to send Koch-funded, Koch-created, Koch-parroting climate-science denier Jodi Ernst to the pasture.

As his announcement video makes clear, Iowa farm boy Vice Admiral Mike Franken, U.S. Navy (retired), places climate change as core to his priorities, as core to his campaign, as core to his understanding of Iowans’ concerns about today and tomorrow.

This is important because Franken has an excellent chance of doing well in this race and replacing an in place Republican and climate change denier. Michael Franken is a true climate hawk.

He will be seeking the nomination of the Democratic Party.


Spread the love

The cold spot caused by global warming and why it should scare you

Spread the love

You saw the film The Day After Tomorrow. This is that. Not like in the movie, but still…

Warming causes melting of ice, adding fresh water into the North Atlantic, which interferes with a major current system that at present warms Europe.

Consequence: The planet warms dangerously, while at the same time, large parts of Europe become much cooler, to the extent that people may not be able to live there in the manner they do now, or produce very much food there. Gibraltar would have a climate similar to the coast of Maine, and Berlin would have a climate similar to the Northwest Territories or northern Hudson Bay.

The models have predicted this, but it now seems that they’ve under-predicted it. It appears to be happening faster, and more furiously, than expected.


Spread the love

The Biology of Extremes: Superlative by Matthew D. LaPlante

Spread the love

Superlative: The Biology of Extremes by Matthew D. LaPlante is not just about extremes, but about all the things in between that make the extremes extreme. LaPlante looks at size, speed, age, intelligence. For all the various subtopics that come up in such an exploration, LaPlante does a great job of bringing in the latest research. Mostly, this is a collection of interesting evolutionary and biological stories that happen to involve tiny things, giant things, old things, fast things, or things that are in some other way — superlative.

Go for a swim with a ghost shark, the slowest-evolving creature known to humankind, which is teaching us new ways to think about immunity. Get to know the axolotl, which has the longest-known genome and may hold the secret to cellular regeneration. Learn about Monorhaphis chuni, the oldest discovered animal, which is providing insights into the connection between our terrestrial and aquatic worlds.

I’m not endorsing every idea or story in this book. One can not write a book about adaptations and have any evolutionary biologist worth their salt not bump on things. But the author does an honest and straightforward job of representing the research, and you’ll learn quite a bit that is new, see new perspectives on things you’ve considered in the past, and you’ll enjoy LaPlante’s writing.

I will probably be recommending this volume as a holiday gift for the Uncle who has everything or the teenager who likes natural history. Teachers of wildlife biology, evolution, or related topics will be able to mine this volume for stories. The use of footnotes is notable.* I recommend Superlative


  • … and well done.

Spread the love

Everything you always knew about Jupiter is slightly different

Spread the love

A science rocket sent to Planet Jupiter collected information on that giant gas planet’s gravitational field. This has led, through the use of modeling, to the idea that Jupiter was smacked into by another planet early in its life. Bottom line: There should be heavy stuff (heavier than the gasses that make up gas planets) only in a compact core in the middle of the planet, over which the gasses that make it a gas planet accreted. The gravity information seems to suggest that heavy material is distributed more widely.

From the abstract of the paper just out in Nature:

The Juno mission1 has provided an accurate determination of Jupiter’s gravitational field, which has been used to obtain information about the planet’s composition and internal structure. Several models of Jupiter’s structure that fit the probe’s data suggest that the planet has a diluted core, with a total heavy-element mass ranging from ten to a few tens of Earth masses (about 5 to 15 per cent of the Jovian mass), and that heavy elements (elements other than hydrogen and helium) are distributed within a region extending to nearly half of Jupiter’s radius. Planet-formation models indicate that most heavy elements are accreted during the early stages of a planet’s formation to create a relatively compact core and that almost no solids are accreted during subsequent runaway gas accretion. Jupiter’s diluted core, combined with its possible high heavy-element enrichment, thus challenges standard planet-formation theory. A possible explanation is erosion of the initially compact heavy-element core, but the efficiency of such erosion is uncertain and depends on both the immiscibility of heavy materials in metallic hydrogen and on convective mixing as the planet evolves. Another mechanism that can explain this structure is planetesimal enrichment and vaporization during the formation process, although relevant models typically cannot produce an extended diluted core. Here we show that a sufficiently energetic head-on collision (giant impact) between a large planetary embryo and the proto-Jupiter could have shattered its primordial compact core and mixed the heavy elements with the inner envelope. Models of such a scenario lead to an internal structure that is consistent with a diluted core, persisting over billions of years. We suggest that collisions were common in the young Solar system and that a similar event may have also occurred for Saturn, contributing to the structural differences between Jupiter and Saturn

From the press release:

HOUSTON — (Aug. 14, 2019) — A colossal, head-on collision between Jupiter and a still-forming planet in the early solar system, about 4.5 billion years ago, could explain surprising readings from NASA’s Juno spacecraft, according to a study this week in the journal Nature.

Astronomers from Rice University and China’s Sun Yat-sen University say their head-on impact scenario can explain Juno’s previously puzzling gravitational readings, which suggest that Jupiter’s core is less dense and more extended that expected.

“This is puzzling,” said Rice astronomer and study co-author Andrea Isella. “It suggests that something happened that stirred up the core, and that’s where the giant impact comes into play.”

Isella said leading theories of planet formation suggest Jupiter began as a dense, rocky or icy planet that later gathered its thick atmosphere from the primordial disk of gas and dust that birthed our sun.

Isella said he was skeptical when study lead author Shang-Fei Liu first suggested the idea that the data could be explained by a giant impact that stirred Jupiter’s core, mixing the dense contents of its core with less dense layers above. Liu, a former postdoctoral researcher in Isella’s group, is now a member of the faculty at Sun Yat-sen in Zhuhai, China.

“It sounded very unlikely to me,” Isella recalled, “like a one-in-a-trillion probability. But Shang-Fei convinced me, by shear calculation, that this was not so improbable.”

The research team ran thousands of computer simulations and found that a fast-growing Jupiter can have perturbed the orbits of nearby “planetary embryos,” protoplanets that were in the early stages of planet formation.

Liu said the calculations included estimates of the probability of collisions under different scenarios and distribution of impact angles. In all cases, Liu and colleagues found there was at least a 40% chance that Jupiter would swallow a planetary embryo within its first few million years. In addition, Jupiter mass-produced “strong gravitational focusing” that made head-on collisions more common than grazing ones.

Isella said the collision scenario became even more compelling after Liu ran 3D computer models that showed how a collision would affect Jupiter’s core.

“Because it’s dense, and it comes in with a lot of energy, the impactor would be like a bullet that goes through the atmosphere and hits the core head-on,” Isella said. “Before impact, you have a very dense core, surrounded by atmosphere. The head-on impact spreads things out, diluting the core.”

Impacts at a grazing angle could result in the impacting planet becoming gravitationally trapped and gradually sinking into Jupiter’s core, and Liu said smaller planetary embryos about as massive as Earth would disintegrate in Jupiter’s thick atmosphere.

“The only scenario that resulted in a core-density profile similar to what Juno measures today is a head-on impact with a planetary embryo about 10 times more massive than Earth,” Liu said.

Isella said the calculations suggest that even if this impact happened 4.5 billion years ago, “it could still take many, many billions of years for the heavy material to settle back down into a dense core under the circumstances suggested by the paper.”

Isella, who is also a co-investigator on the Rice-based, NASA-funded CLEVER Planets project, said the study’s implications reach beyond our solar system.

“There are astronomical observations of stars that might be explained by this kind of event,” he said.

“This is still a new field, so the results are far from solid, but as some people have been looking for planets around distant stars, they sometimes see infrared emissions that disappear after a few years,” Isella said. “One idea is that if you are looking at a star as two rocky planets collide head-on and shatter, you could create a cloud of dust that absorbs stellar light and reemits it. So, you kind of see a flash, in the sense that now you have this cloud of dust that emits light. And then after some time, the dust dissipates and that emission goes away.”


Spread the love

The Mysterious Russian Nuclear Disaster

Spread the love

Are you following this story from Russia? The Russians lied about it numerous time, and I don’t think we can expect them to ever tell the truth. But it appears to have been a test of a highly improbably weapon (a nuclear powered missile) that resulted in either an explosion that shoved a lot of radioactive material into the atmosphere, or an actual but accidental nuclear explosion.

A village was ordered to be evacuated. Then they cancelled the evacuation.

There is evidence that the bodies of the slain scientists, and/or others injured at the site, who were blasted in the explosion, were so radioactive that the doctors that attended to them also need to be treated. It also may be the case that the nuclear device is in the sea and needs to be recovered.

This is a real mess.


Spread the love

Do Recycle. Don’t Relax

Spread the love

I have two quick things to say about recycling, and these are narrowly focused comments, but please feel free to discuss the issue more broadly in the comments, because I’m writing something more detailed and you can possibly influence that.

1) Do recycle. We have seen a handful of recent reports on authoritative (supposedly) media (like public radio) explaining how the entire recycling industry has collapsed and all the recycling goes into the trash, so YOU should therefore put your recycling in the trash as well. This is INCORRECT at several levels. More on that later. The short version: Let the recycling company decide what gets put in the trash. Your information will never be accurate or up to date compared to theirs.

2) Don’t feel too good about recycling, even if you do it all the time. It isn’t enough to save the planet. Do more. Now. More than that even.


Spread the love