Category: Science

Paleontology News for June 2020.

There have been a number of small but important discoveries recently illuminating portions of the history of life here on Earth. As usual I think I’ll start with the earliest and move forward in time.

One of the most common modes of life in the natural world is parasitism, where an individual of one species spends a large part of its life literally living off of a member of another species. While parasitism is technically a form of symbiosis it differs from mutually beneficial symbiosis in that the parasite gains at the expense of its host.

In addition to feeding off of our blood, external parasites such as this tick cab carry illnesses like Lyme disease. (Credit: Science Insider)
Internal parasites, such as this tapeworm, may also cause illness. (Credit: WebMD)

A very large number of different species, spread across every major taxonomic group of both animals and plants are parasites for at least a part of their lives. There are so many parasites out there that you would expect that there would be a lot of evidence of parasites in the fossil record.

A lice from the Cretaceous period preserved in amber. Could it contain any dino DNA? (Credit: Daily Mail)

It’s not that easy, a lot of parasites don’t fossilize well, think of a tapeworm. Or consider a dinosaur that is infected with fleas. If that dino dies the fleas will quickly leave to try to find another host, they won’t be fossilized with the dinosaur.

Even if you do find two different species fossilized together you have the problem of determining whether your fossil is a true example of parasitism. For example in my collection I have a small clamshell from the cretaceous period that has the tube of a feather duster worm attached to it. For all I know the worm could have built its home on the shell after the clam had died. So trying to figure out when one creature is benefiting by harming the other isn’t easy.

Fragment of clam shell from the Cretaceous period in my collection with the tube of a feather duster worm attached. This is not an example of parasitism because the tube is on the inside of the shell which means the clam was already dead when the worm attached itself. (Credit R. A. Lawler)

Nevertheless a team of paleontologists from Northwest University in Xi’an China, the Swedish Museum of Natural History and Macquarie University in Sidney Australia has announced what they assert is the earliest known example of parasitism. Their evidence comes from the Cambrian period, approximately 515 million years ago and resembles in many ways my fossil mentioned above.

The fossils consisted of a large number of shells of a species of brachiopod, a creature whose shell resembles that of a clam although the animal inside is totally different. While brachiopods today are quite rare, in the early period of life’s history, more than 250 million years ago, they were more common than clams.

Some of the Brachiopod shells used in the study of ancient parasitism. (Credit: Macquarie University)

Examining the brachiopod shells the paleontologists found that approximately half were encrusted with the tubes of worms, just like my fossil, while the other half were not. Measuring the shells of the brachiopods and using that as an indication of the animal’s health the researchers discovered that the encrusted brachiopods were consistently smaller, by about 26%. This is clear evidence that the worms were harming the brachiopods. In other words the worms were parasites.

Artists impression of a Brachiopod shell infested with parasitic worms. (Credit: Ars Technica)

Not only that, but because like a clam, the shells of brachiopods grow outward from their edges the scientists were able to determine how early in the life of a brachiopod it had become encrusted. Again, those brachiopods that were encrusted earlier in their lives showed the most pronounced size reduction, further evidence of parasitism.

So it appears that parasitism as a mode of life has existed for nearly as long as multi-cellular creatures have. Another common mode of life that has also recently been found to have ancient roots is suspension feeding; animals that swim with their mouths wide open, filtering plankton and other small creatures out of the water. In today’s oceans baleen whales and basking sharks are the best known suspension feeders and are among the largest creatures on Earth.

Now a new study by paleontologists at the Universities of Bristol and Zurich of an ancient fish from the Devonian period, about 380 million years ago, has provided strong evidence that at least one of the ocean’s largest inhabitants back then lived in much the same way. The animal in question belongs to the group of armored fish known as placoderms and is formally called Titanichthys. A giant for its time Titanichthys measured more than five meters in length but crucially its jaw was more than a meter in length. Modern suspension feeders also have greatly elongated lower jaws allowing them to scoop up the greatest amount of water as they swim.

School of Titanichthys feeding as they swim. At five meters in length Titanichthys was one of the largest living things during the Devonian age. (Credit: Sci-News.com)

The new research also found that while the lower jaw of Titanichthys was long it wasn’t very strong, neither the bones themselves nor the muscles attached to the jawbones would have been sufficient to deliver a strong bite, further evidence of the fishes lifestyle as a suspension feeder.

The fossilized skull of Titanichthys. That huge open mouth certainly could have collected a lot of food. (Credit: Black Hills Institute)

Moving forward in time we come to my final story for this month, which concerns the asteroid that is presumed to have caused the extinction of the dinosaurs. It was only about twenty years ago that geologists succeeded in finding actual site of that impact, the Chicxulub crater in the Yucatan peninsula of Mexico.

The Chicxulub crater in the Yucatan peninsula of Mexico. The asteroid that struck here is generally considered to have caused the extinction of the dinosaurs. (Credit: Wikipedia)

Ever since that discovery geologists have surveyed Chicxulub, hoping to learn as much as they can about how the 10 kilometer wide space rock caused so much damage. Destruction so great that it led to the extinction of about 75% of all of the species on Earth. In a paper published in Nature Communications scientists from the University of Texas at Austin, the Imperial College London and the University of Freiberg in Germany have used computer simulations to investigate what the likely initial conditions of that asteroid strike were in order to order for it to have produced the effects seen in the Yucatan today.

Based upon the diameter of the Chicxulub crater, its depth and the observed distribution of ejected material from sites around the world the team of geologists have concluded that the asteroid struck the Earth at an angle of 60º, an angle that they argue produced the greatest amount of destruction. According to the simulations a steeper angle, say 70-90º would have produced a deeper crater but one where the ejecta was more confined to the area around the crater, in other words the other side of the Earth might have been subjected to considerably less devastation. On the other hand, if the asteroid had struck at a shallower angle, say 30º or less, the crater would have also been shallower and the distribution of ejecta would have been much more concentrated in the direction of the asteroid’s motion, which again might have spared some parts of the Earth from baring the full brunt of the asteroid’s destructive power.

Computer simulation of the asteroid strike with the asteroid coming in at an angel of 60 degrees. (Credit: Collins, Patel, Davidson et. al.)

If the simulations produced by the team of geologists do in fact correspond to what actually happened 66 million years ago then the dinosaurs were doubly unlucky. Not only did the asteroid strike suddenly from out of the depths of space but it also struck in just the right way to both produce the maximum destruction and to spread that destruction evenly around the entire world.

Of course as mammals we should remember that what was bad luck for the dinosaurs was good luck for us!

Astronomers debate whether or not there is a ninth planet in our Solar System, and I’m not talking about the argument over Pluto.

The argument over Pluto’s status as a full fledged planet or not has been going on now for almost 14 years and there appears to be no end in sight. I grew up without ever questioning Pluto’s designation but admittedly even back in the 1960s Pluto was considered something of an oddball for a planet. Smaller even than Mercury, much smaller than it’s gas giant neighbors Pluto’s orbit even occasionally brought it closer to the Sun than the eighth planet Neptune. Crossing the orbit of another planet seemed like something no self-respecting planet would ever do.

The dwarf planet Pluto with its largest moon Charon to the upper left. Both are now considered to be Kuiper Belt Objects (KBOs). (Credit: Astronomy Magazine)

Then, starting in the 1990s a number of other icy bodies with even more unusual orbits were discovered not far beyond Pluto. These objects were grouped together as Kuiper Belt Objects (KBOs) and the debate over what kind of body Pluto was, a planet or a KBO began.

The dwarf planet Eris, artists impression shown, is also a KBO and may even be a bit larger than Pluto. (Credit: Space.com)

The current definition of a planet basically consists of two criteria. One, a planet must be large enough, massive enough that it’s gravity pulls it into a nice spherical shape. Pluto passes this criterion easily, as does Ceres in the asteroid belt.

The second criterion is that a planet’s gravity must be strong enough to sweep out any other object from its orbital region. This is the test that Pluto and Ceres both fail. Ceres fails because of the other asteroids while Pluto fails because of the other KBOs. That is the official position and I don’t intend to take sides one way or the other. I’ve never liked arguing over definitions. To me Pluto is what it is no matter what we choose to call it.

The eight recognized planets in our solar system. This image clearly shows the great difference between the rocky inner planets like Earth and the enormous gas giants like Jupiter. Maybe these eight should be split into two groups? (Credit: Britannica)

All of which has nothing to do with today’s actual topic, the continuing search by astronomers for an as yet undiscovered ninth planet, a tenth planet if you insist on Pluto being a planet. So why do astronomers think that there could be another planet out there, and how are they going about looking for it?

It all has to do with the pulling and tugging that the gravities of the planets have on each other’s orbit around the Sun. Because the Sun’s mass is so huge, about 500 times the mass of all of the planets, moons and everything else in the solar system added together, the orbits of the planets are pretty close to ellipses, just as Kepler’s first law requires.

Kepler’s First Law states that planets orbit the Sun in ellipses. This isn’t absolutely accurate because of the gravitational pulls of the other planets. (Credit: Quora)

Nevertheless the pulling of the gravities of the other planets does have an effect that astronomers can measure and compare to their calculations. If any discrepancy is found, even the tiniest will cause astronomers to start searching for the cause.

This happened in the first half of the 19th century when the measurements of the orbit of Uranus, the seventh planet, did not match calculations. It was suggested that another planet beyond Uranus might be the cause and after twenty years of calculations planet number eight, Neptune was found exactly where the math said it would be.

Then the same thing happened to the orbit of Neptune, the planet wasn’t quite moving as the calculations said it should be. So the hunt was on for a ninth planet, which finally led to the discovery of Pluto in 1930. Pluto was so small however that it didn’t seem able to account for all of the discrepancy in Neptune’s orbit. So, for the next five decades astronomers kept looking for a tenth planet beyond even Pluto without success.

Clyde Tombaugh discovered Pluto by noticing the movement of a tiny dot of light, indicated by the arrows, between images taken a week apart. (Credit: The Planetary Society)

Things have gotten a lot more complicated since then, and I’m not talking about whether or not Pluto is a planet. I mean with all of those Kuiper Belt Objects orbiting around out there it’s difficult to calculate just what all is going on. Do the KBOs together account for the problem with Neptune’s orbit or do we still need another planet, or would several more KBOs do the trick? And what about the orbits of the KBOs themselves? Are their orbits matching the calculations or does it seem as if there could be another big body out there affecting their motions? Plotting the orbit for one object in our Solar System is a lot of math, even using a computer. I know, I had to do it back in grad school. Trying to do the same for the over 1500 known KBOs is beyond my programming skills.

Sample of an old fashioned FORTRAN computer program. This is the way I had to calculate planetary orbits back in grad school! (Credit: Stack Overflow)

Fortunately it’s not beyond the skills of Samantha Lawler, Assistant Professor of Astronomy at the University of Regina in Canada. Using observations and discoveries made by the Outer Solar System Origins Survey Dr. Lawler, no relation, has calculated the orbits of the known KBOs for the purpose of finding where that ninth planet could be hiding. If it exists that is.

A fair amount of Dr. Lawler’s work actually consisted of recognizing observational biases in earlier searches for KBOs. First of all since KBOs are so far from the Sun they hardly move at all against the background of fixed stars. Because of that the regions of the Kuiper belt that lay in the same direction as the Milky Way have been ignored because of the enormous difficulty in distinguishing a small icy body from one of the millions of distant stars in our galaxy. Other biases arose when certain telescopes were employed in searching the Kuiper belt during certain times of the year, again neglecting whole sections of the solar system.

The orbits of KBOs as discovered by the best conducted surveys to date. Notice how the region to the lower left is empty. Is this because there are no KBOs in the region or is it because of unconscious bias in the surveys. (Credit: Sci-News.com)

Adjusting for these biases in her simulations Dr. Lawler has shown that KBOs are actually more uniformedly distributed that other surveys had indicated and that the orbits of the known KBOs can be explained without the need for the gravity of a ninth planet to shepherd them.

So it appears that there probably isn’t another planet out there beyond Neptune and Pluto waiting to be discovered after all. Instead there are thousands of small, icy KBOs. Tiny little worlds that never managed to come together to form a single big planet.

Maybe, in some ways that’s even more interesting.

U.S. Navy successfully tests shipboard Solid-State Laser system for anti-aircraft defense. Is the time of Gunpowder’s dominance on the battlefield coming to an end?

On the 29th of May in the year 1453 CE one of the turning points in world history occurred as the great city of Constantinople fell to the might of the Turkish military. Often referred to as the final end of the Roman Empire it is fitting that the massive walls of Constantinople were breached not by any weapon that Julius Caesar would have recognized but rather by the cutting edge, high-tech weapon of its day, the cannon.

Contemporary depiction of the fall of Constantinople emphasizing the Turkish use of artillery. (Credit: Ancient History Encyclopedia)

For the past 600 years wars have been fought with guns, cannons, shells, mines and rockets of various kinds, all of which derived their lethal force from the explosive release of chemical energy. It is true that bayonets, lances and even swords can still be seen today at parades and other military pageants but it is gunpowder and its derivatives that dominate today’s battlefield.

With today’s plastic explosives you can mold your bomb into almost any shape you want and yes that’s an explosive penis he is holding. (Credit: Reddit)

That may not be true for much longer. You see for the last decade or so the U.S. Military, particularly the Navy, has been putting a great deal of money and effort into the development of what are officially known as ‘Directed Energy Weapons’ or DEWs, weapons that derive their power from electricity instead of explosives.

In an earlier post, see post of August 2nd 2017, I discussed the Navy’s Rail Gun which employs magnetic fields to hurl a shell up to 400 kilometers at a velocity of 5 to 6 times the speed of sound. The shells fired by the rail gun travel so fast that they don’t even need an explosive warhead to destroy their target. The shell is solid metal and kinetic energy does all the damage. Meanwhile the Army has been testing an anti-personnel microwave generator that causes pain by radio waves.

The U.S. Navy’s Rail Gun being tested. No explosives are needed, it’s all electricity and magnetic fields! (Credit: YouTube)

Now the Navy has tested a shipboard solid-state laser, using it to intercept, that is shoot down a robotic drone aircraft. Many of the details of the test are secret but it is known that the laser was mounted aboard the U.S.S. Portland, an Amphibious Transport Dock Ship and the test took place on the 16th of May 2020 in the ocean somewhere south of the Hawaiian Islands.

USS Portland firing the Navy’s new Laser Weapons System Demonstrator. (Credit: US Naval Institute)

The two most important parameters of the test, and therefore the most secret, are the power of the laser and the range at which it destroyed its target. Based on a 2018 report from the International Institute for Strategic Studies however it is estimated that the laser’s power was somewhere in the range of 150 kilowatts while from the released images of the test the target was destroyed at a distance of at least several kilometers.

Earlier version of the LWSD mounted aboard the USS Ponce. (Credit: Wikipedia)

Officially the laser on board the Portland is called a ‘Laser Weapons System Demonstrator’ (LWSD) and current plans are for the LWSD to be used to provide protection for naval vessels against small attacking boats as well as aircraft. According to the Portland’s Commanding Officer, Captain Karrey Sanders. “With this new advanced capability, we are redefining war at sea for the navy.”

Official Navy image of drone aircraft being shot down by Laser aboard USS Portland. (Credit: US Navy)

Currently most of the effort being carried out to develop these new DEWs is being undertaken by the Navy. Still, you have to know that in some defense contractor’s labouratory somewhere they’re looking at putting a laser, or perhaps a rail gun on a tank. Slowly but surely the new high-tech weapons of war are becoming powered by electricity not explosives.

Science Fiction has had ray guns for decades. I guess we’re finally catching up to Buck Rogers! (Credit: NASA Science and Entertainment Exchange)

“…Redefining war…,” that’s what Captain Sanders said. And maybe he’s right; maybe gunpowder’s dominance of the battlefield is nearing its end. Too bad we just can’t get rid of battlefields instead!

NASA’s Commercial Crew Program finally begins with the first manned launch of a manned space mission by a private company, Space X.

In the beginning of the Obama administration NASA, the U.S. space agency faced a major dilemma. It’s remaining fleet of three Space Shuttles was growing older, increasing of possibility of another space disaster. At the same time the International Space Station (ISS), which NASA had spent so many years and so many billions of dollars constructing, was only starting its useful lifetime.

The International Space Station (ISS). NASA would like to both keep it manned while at the same time move beyond it to explore beyond Low Earth Orbit (LOE). (Credit: NASA)

To make matters worse, during the Bush administration NASA had been directed to develop a program called Constellation for returning America to the Moon, a program whose enormous cost Obama had little liking for. Without the shuttle or an equivalent man capable launch system how would NASA astronauts get to their brand new ISS?

Often referred to as ‘Apollo on Steroids’ the constellation program was an ambitious program for a return to the Moon. It’s huge cost caused it to be canceled. (Credit: Wikimedia Commons)
The Space Launch System (SLS) is a remnant of the constellation program. Plagued by delays and cost overruns it may fly someday, maybe. (Credit: NASA)

It was decided that NASA would use launch systems that would be developed and operated by commercial aerospace corporations. Contracts had already been given to several such companies to develop robotic capsules to ferry supplies to the ISS. Why not fund those companies to develop manned capable capsules that could take astronauts to Low Earth Orbit (LOE) as well? NASA could then ‘hire’ space capsules to take their astronauts to the ISS while the companies would then be free to use their technology to further the commercial development of space.

So it was that in 2011 four aerospace companies, Boeing, Space X, Blue Origins and Sierra Nevada submitted design proposals for a man capble space capsule and after two rounds of review and competition in 2014 Boeing was awarded a contract for $4.2 billion while Space X was awarded a contract of $2.6 billion to aid them in the design and development of their manned space capsules.

Despite failing to win a contract from NASA’s Commercial Crew Program, Sierra Nevada Corporation continues to work on its version of the shuttle called the ‘Dream Chaser’. (Credit: Space News)

With the retirement of the shuttle in 2011 NASA became dependent on Russian Soyuz rockets to take its astronauts to the ISS so it was hoped that either Boeing or Space X would be ready to begin manned operations by 2017. Developing a man capable space system is not that easy however and the delays mounted.

Taking Cosmonauts to orbit since the mid 1960s the venerable Soyuz has been the only way to reach the ISS for the past 9 years. (Credit: The Verge)

At first everyone expected that Boeing, with its long history in aerospace technology, and with the larger amount of money, would be the first to actually succeed in taking astronauts into space. Over the last several years however the aerospace giant has been plagued with a series of problems. So it was that the mini-space race between Boeing and Space X was finally won by the younger, more aggressive company. See my post of 28 December 2019.

Boeing’s Starliner has flown into orbit on an unmanned test flight but problems with the craft’s software caused the test flight to be considered a failure and the necessary fixes are ongoing. (Credit: Boeing)

Designated as the Demonstration Mission 2 (DM-2) the flight of the Space X Crew Dragon capsule was originally scheduled to take off from Kennedy Space center in Florida on the 27th of May. Less than twenty minutes before take off however bad weather caused the flight to be scrubbed for the day. The next possible launch date was three days later but again the Florida weather was questionable. This time however the rain and winds held off and at 3:22:45 EDT the engines on the Space X Falcon 9 rocket ignited and astronauts Bob Behnken and Doug Hurley had a flawless eight-minute ride into LOE. To make their success complete Space X even managed to recover the Falcon 9 first stage so that it could be used again, an operation that has now become routine for Space X.

The launch of the Space X Falcon 9 rocket with the Crew Dragon capsule carrying astronauts Bob Behnken and Doug Hurley to the ISS. (Credit: SciTech Daily)

About 45 minutes after take off the Dragon capsule, crewed by veteran space shuttle astronauts Bob Behnken and Doug Hurley, completed an orbital adjustment burn, the first of five that would bring them to their rendezvous with the ISS. On the morning of the 30th of May, just 19 hours after lift off the Dragon capsule smoothly docked with the ISS.

The Crew Dragon with Astronauts Behnken and Hurley as seen from the ISS moments before docking. (Credit: NASA)

Now the mission of astronauts Behnken and Hurley is ongoing. For at least the next month they will function as members of the ISS crew but NASA could extend their mission to as much as three months. Then astronauts Behnken and Hurley will complete their mission with a return to Earth in the Dragon capsule, splashing down in the Atlantic off the Florida coast. The next manned launch of the Dragon is currently scheduled for September and will be the first official mission of NASA’s Commercial Crew Program. A little late perhaps but nevertheless, so far so good!

Extraterrestrial Life and Extraterrestrial Intelligence how likely could they be and what are the chances that we may soon discover one or the other.

Certainly one of the biggest questions that anyone can ask is, is there life out there? Are there other planets that have life or even intelligent life living on them? At the present time we really have no idea, our exploration of the Universe has only just begun. We have landed robotic probes on only a very few celestial bodies and even on those we have see so little that some form of life could be hiding from us! Still as the famed science fiction author Arthur C. Clarke once asked, the question of whether we are alone in the Universe can have only two answers and either one is awe inspiring.

Thanks to Steven Spielberg this is most people’s idea of an Extraterrestrial. (Credit: Dred Central)
Unless that is you prefer this one! (Credit: Paramount)

Many would say that the Universe is so large, there so many places that life could exist and evolve into intelligence that surely there must be some life out there. That position, however reasonable, isn’t evidence. So the study of extraterrestrial life remains a science without a subject, a science of conjecture and hypothesis rather than solid fact.

Every little dot in this image is an entire galaxy with billions of stars. In such a huge Universe how can we possibly be alone? (Credit: NASA)

When I was an undergraduate all of that conjecture was summed up in ‘Drake’s Equation’ named for a U.S. astronomer who first explicitly wrote down all of the factors in one equation. Using Drake’s equation it is possible to calculate the number of intelligent species in a galaxy, assuming you have accurate numbers for all of the factors in the equation.

                                Equation 1

In this equation I is the number of intelligent species in a galaxy, say our own Milky Way. You calculate I by multiplying the factors on the right hand side.

N is the number of stars in that galaxy, about 200 billion for the Milky Way.

FP is the fraction of those stars that have planets orbiting them. Therefore FP must have a value of between zero and one.

FH is the fraction of planets that orbit in a ‘habitable zone’ around their star; I’ll explain what that means below. Again, FH is somewhere between zero and one.

FL is the fraction of habitable planets where life actually arises. Again, zero to one.

FI is the fraction of planets with life on them where intelligence evolves. Zero to one.

Back when I was in college the only factor on the right hand side of Drake’s equation that astronomers had any accurate measurement for was N, the number of stars in the Milky Way. Every other factor was totally unknown so any attempt to actually use the Drake equation was just pure guesswork.

Our Milky Way itself contains 200 Billion stars, any one of which could have planets with life on them! (Credit: Forbes)

We’ve made some progress since then. In particular thanks to the discoveries made by the Kepler space telescope and other astronomical programs we now know of the existence of thousands of planets outside of our solar system. Because of these discoveries we can now say with reasonable confidence that at least half of all stars must have planets orbiting them, perhaps 90% or even more. So if even half of the Milky Way’s 200 billion stars have planets, then there are an awful lot of planets out there.

Thanks to the Kepler Space Telescope we know of the existence of thousands of planets outside of our solar system. (Credit: Vox)

We’ve also made some progress with FH, the fraction of planets that could be habitable for life. Thirty to forty years ago ‘habitable’ would have meant liquid water on the planet’s surface, which in our solar system meant only Earth, one out of eight planets. However our space probes to the outer planets have discovered that Mars once had oceans and maybe still has water beneath its surface. Also, data from other probes have raised the possibility that Europa and Enceladus, the moons of Jupiter and Saturn respectively, may have large oceans of liquid water beneath their icy surfaces. That means that our solar system might actually have at least four habitable bodies, not just the Earth. So it appears that FH might actually be larger than we thought just a few decades ago.

Both Jupiter’s Moon Europa (L) and Saturn’s Moon Enceladus (R) are believed to have oceans of water beneath their icy surfaces. This means that more planets than we thought might actually be ‘habitable’. (Credit: NASA)

That leaves us with just the last two factors, FL that fraction of planets with a habitable environment that possess life and FI the fraction of planets with life where intelligence evolves. The only way to get an accurate measurement for these two numbers would be to closely study a few hundred or more habitable planets or moons and just see how many have developed life and how many go on to evolve intelligence.

The evidence from geology is that it didn’t take long for Earth’s Primordial Soup to evolve into living things. (Credit: Scoopnest)

We can’t do that however; it will probably take decades for our space technology to even find life on Mars or Europa if it’s there. The only real example we have to study is Earth. Can we learn anything about FL and FI from studying the history of life on here?

A new study says that we can. Authored by David Kipping of Columbia University’s Department of Astronomy “An objective Bayesian analysis of life’s early start and our late arrival” uses probability mathematics to calculate values for FL and FI that would best simulate life’s history here on Earth.

Bayesian analysis is a mathematical technique for studying complex problems with a large number of parameters. Heavy on calculations it’s often performed by computers. (Credit: Mondo 2000)

You see we know that our planet is about 4.5 billion years old and there is growing evidence that life was well established here as far back as 4 billion years ago. Indeed it looks as though life began on Earth as soon as its surface had cooled enough for life to exist. On the other hand complex, multi-cellular life took 4 billion years to evolve and even then intelligence took another half billion years.

Life may have existed early in Earth’s history but it took a very long time to evolve into complex multi-cellular forms. (Credit: Expii)

So what Doctor Kipping did was to develop a computer program that would vary FL and FI across all of their possible values and see which values succeeded in reproducing life’s history here on Earth. The result that Dr. Kipping obtained is that while life itself could be quite common in the Universe, intelligence is very rare. Mathematically what he found was that FL is close to one but FI is very, very close to zero. Thousands of planets may have life on them for every one that possesses an intelligent species.

I have to admit that I agree with Dr. Kipping. The more we learn about life at the biochemical level the more it seems to be something that will inevitably happen at least once on any planet that it can happen on, and once it happens it spreads everywhere on that planet. However intelligence is so complex, so dependent on the twists and turns of evolution that intellect, mind may be the rarest thing in the Universe.

The philosopher Socrates advised us all to “Know Thyself”, the world would still be a better place if more of us followed his suggestion! (Credit: New Intrigue)

Maybe we should take a lesson from Dr. Kipping’s work. If intelligence is the rarest, most valuable thing in the Universe it might behoove us to use ours a little more often, to appreciate it a little more, to realize that it is all that really separates us from… just biochemistry.

Social Distancing, Herd Immunity, and R-naught, just a few of the concepts developed by the science of Epidemiology.

With the Covid-19 virus continuing to spread, causing an ever growing number of illnesses and deaths across our planet the science of epidemiology has gone from being a little known branch of medicine to arguably becoming the most vital topic in the world. Literally ‘the study of what is on or among the people’ epidemiology was once the most successful branch of medicine, helping to eliminate such deadly diseases as cholera, typhus and yellow fever. Indeed the doctors and scientists who developed epidemiology succeeded in controlling many infectious diseases without any kind of a cure or in some cases having the slightest idea as to what was causing the illness.

It’s all Greek to me! (Credit: Pinterest)

The ancient Greeks recognized that while some diseases could spread from person to person throughout a population, other illnesses like epilepsy or cancer were not infectious. It wasn’t until 1543 however that an Italian doctor named Girolamo Fracastoro speculated that diseases could be spread by living particles too small to be seen that floated through the air. The invention of the microscope and the discovery that there actually were microscopic living creatures lent considerable weight to Fracastoro’s theory.

Fracastoro and a few other early researchers into the germ theory of disease. (Credit: Open Texbooks)

About a hundred years later in 1662 a part time mathematician, his day job was haberdasher, named John Graunt performed a statistical analysis of the mortality rolls of the city of London before and after the great plague of 1665-66. Graunt’s work provided much evidence supporting some theories about the spread of infection while at the same time disproving others and it established the use of mathematics in the study of diseases.

During the 16th and 17th centuries the city of London had so many plagues that the one of 1665 -1666 is know as ‘The Great Plague’. (Credit: The Lost City of London)

Another Londoner named John Snow became known as the father of modern epidemiology thanks to his work in 1854 leading to his discovering the cause of a number of cholera outbreaks striking the Soho section of London every few years. By simply marking the home addresses of cholera victims on a street map of London, see map below, Snow correctly concluded that the source of the infection was a water pump located on broad street. By disinfecting the water with chlorine and removing the pump’s handle Snow succeeded in ending the outbreak.

John Snow and his map of the distribution of cholera in London.(Credit: The Vintage News)

Another early pioneer was the Hungarian doctor Ignaz Semmelweis who dramatically reduced the infant mortality rate at his Viennese hospital by insisting on rules that promoted cleanliness. Then in the first decade of the 20th century Walter Reed achieved great success in fighting yellow fever in Cuba not by curing his patients who had contracted the deadly disease but by eradicating the mosquitoes who carried the disease from person to person.

Comic book describing how Walter Reed discovered it was mosquitoes that transmitted yellow fever. Yes they used to print comic books about real superheros! (Credit: news.hsl.virginia.edu)

You get the point; the purpose of epidemiology is not to treat the sick but instead to stop the spread of a disease in order to keep other people from becoming sick! That means that often times great advances in epidemiology are made by mathematicians rather than physicians. It has also allowed epidemiology to become the technique used to study social diseases such as obesity, deaths caused by smoking and even gun violence.

The science of Epidemiology being used to study homicides in the city of Detroit. (Credit: Alex B. Hill)

Right now of course the lessons learned from epidemiology are the only weapons we have with which to fight the viral disease Covid-19. Until we have either a vaccine or some really effective anti-viral drug all that each of us can do to protect ourselves is to practice the guidelines developed by epidemiology.

With that in mind it would be a good idea for all of us to understand some of the technical concepts that epidemiologists use to understand how a disease spreads and how we can reduce and control that spread. Probably the factor that is most important in determining, and controlling the spread of a disease is known as its Basic Reproduction Number oftentimes referred to as R-naught or just R0.

Simply put, for each person who becomes infected with a disease, R-naught is the average number of healthy people they will in turn infect. In others words, if you catch a cold and become infectious, R-naught is the number of members of your family, or your co-workers or just people you come into contact with that will catch a cold from you. This also means that if R0 for a disease is greater than one, then the number of people infected is going to grow. For example if R0 for a disease is two then one person will infect two people, those two will go on to infect four and the four will infect eight and so on until almost everyone has, or has had the disease.

A small change in R-naught, say from 2 to 3, can make a huge difference in the number of infected people in a very short period of time. (Credit: University of Scranton)

Under normal conditions in human society there are many diseases that have an R0 much greater than one.  The table below shows the estimated R0 numbers for some well-known diseases.

Table of R-naught for several well known diseases. (Credit: Wikipedia)

Obviously the goal of epidemiology is to find methods and procedures that a community can take that will reduce R-naught for a disease below one. Perhaps the simplest technique is called ‘Social Distancing’ and it just means having everyone in a community reduce the amount of contact that they have with everyone else. No shaking hands when you meet someone, no hugs for friends you haven’t seen in years, also no parties and no big crowds at sports events or concerts. Social distancing works because less contact between people makes it less likely that a germ will pass between them.

Some of the rules of Social Distancing. (Credit: Orange County N. C.)

Looking back at the table you can see how many diseases spread through particles or droplets in the air. Those particles can only travel through the air for about three or four meters so if everyone stayed more than four meters apart those diseases could not spread. R0 would go very close to zero.

Of course such extreme social distancing is not really possible, we live in families and the jobs of many people are so essential that society cannot get along without them. We live in a society and that society requires a certain amount of contact between its members. That’s why other procedures, such as washing hands, disinfecting everything other people touch, and wearing face masks become so important. In fact anything that we can do to reduce R-naught is important, it is at present the only way we have to fight Covid-19. 

Now for many viral diseases those people who are infected and recover acquire an amount of immunity to being re-infected. In such cases, once a majority of the population has been infected the spread of the disease is inhibited because there are now fewer victims left to infect. Not only that but actually the people who have become immune get in the disease’s way, getting between those who are infectious and those who have not yet been infected, effectively generating a macabre form of social distancing. This acquired immunity of the majority of a population is known as ‘Herd Immunity’.Herd immunity should be considered the last resort in fighting a disease however because it results in the maximum number of deaths and hospitalizations of sick people. Basically getting to herd immunity means not fighting a disease and just letting people get infected.

Herd Immunity without a vaccine, top. With a few people getting a vaccine, middle and with a large majority getting a vaccine. Which do you prefer? (Credit: Wikipedia)

Surprisingly there are many people who believe that is the best solution to Covid-19. Indeed the entire nation of Sweden has decided to forego all social distancing measures and just let the disease die out on its own.

One last point, when and if a vaccine is developed that is effective against Covid-19 it will grant immunity to people who have not yet been infected by the disease. In epidemiological terms a vaccine therefore works by getting a population to herd immunity without people dying or being admitting to a hospital, without them getting sick at all. Something I’m certain that we are all looking forward to!

Paleontology News for May 2020. What’s there to do when you’re ordered to stay at home during a pandemic? Why study dinosaurs of course!

We tend to think of paleontologists as working out in the field, digging around in some barren, rocky terrain unearthing the remains of long extinct forms of life. That’s partly true of course, after all you have to find some fossils before you can study them. And most paleontologists do prefer being on site where the discoveries are made, never knowing what they’ll see in the very next rock they turn over.

Although it is often hard, dirty, sweaty work take it from me fossil hunting is the pure joy of discovery. (Credit: CBS Denver)

Still, a lot of the work in studying ancient life can only be accomplished back in the lab or in the office. Cleaning fossils, examining fossils, comparing them to similar fossils and of course, writing up the papers that will tell your colleagues, and interested laymen like me, what you’ve found. A lot of that work can safely be accomplished even during the ‘social distancing’ needed to stop the spread of Covid-19. So let’s take a look at some of the work that’s being accomplished by paleontologists even in the shadow of a deadly disease.

Cleaning fossils has to be done in the lab where you can take your time and do a meticulous thorough job. (Credit: Wikimedia Commons)

Spinosaurus aegyptiacus is one of the most intriguing dinosaur species known to science. Originally discovered in Egypt back in 1912, Spinosaurus is a large predatory dinosaur belonging to the group known as theropods, the group that includes the mighty T rex and Allosaurus along with the smaller Raptors. Spinosaurus lived during the middle to late Cretaceous period (112 to 93 million years ago) and had one distinguishing feature that set it apart from its relatives, a broad, sail like flap of skin along its back that was held up by spines coming off of the animal’s vertebra. See image below. Large, floppy skin features like Spinosaurus’ sail are usually either for thermal regulation or display or both.

Artist’s impression of a Spinosaurus with a human figure to give scale. (Credit: New York Times)

The loss of the only known skeleton of Spinosaurus during World War 2 brought all research into the creature to a halt, and Spinosaurus was almost forgotten by science. Then in the 1990s further fossils belonging to another species of Spinosaurus, S maroccanus were discovered in Morocco by a National Geographic team led by Doctor Nizar Ibrahim of the University of Detroit Mercy along with Professor Paul Sereno of the University of Chicago. Exploring a layer of rock that has been named the Kem Kem group and which is exposed across a wide area of Morocco the team has unearthed fossils of many different species including specimens of Spinosaurus that have allowed paleontologists to resume the study of this odd dinosaur.

University of Chicago paleontologist Paul Sereno with a skeleton of Spinosaurus. (Credit: The Telegraph)

Actually there is a lot of disagreement over whether S maroccanus is a second species. With the original S aegyptiacus destroyed it is impossible to make a direct comparison and the drawings that remain of the bones of S aegyptiacus are insufficient to determine just how different the new specimens are with certainty.

The new specimens have re-ignited several debates about the nature of Spinosaurus, these include whether or not the predator was actually larger than the famous T rex and whether or not Spinosaurus was at least semi-aquatic, spending a large fraction of its life in the water. Based on the examination of the fossils discovered during the 1990s the full length of Spinosaurus was between 12.5 and 18 meters while the animal’s weight was between 6.5 and 7.5 tonnes. If these estimates are true that would in fact make Spinosaurus a fraction larger than the venerable T rex.

As to the question of Spinosaurus being semi-aquatic the dinosaur’s long narrow, crocodile like snout along with its short, powerful legs do indicate a life style similar to that of…well crocodiles. Add in the fact that the fossils of Spinosaurus were discovered in the same rock beds that yielded numerous specimens of an ancient and extinct sawfish named Onchopristis and it seems clear that Spinosaurus lived in an environment that was as much water as land, such as a swampy river delta.

The extinct fish Onchopristis. Measuring eight meters in maximum length this creature was a monster itself! (Credit: Prehistoric Life -Wiki)
Artist’s impression of the sort of environment and life that Spinosaurus lived. (Credit: BBC)

Now perhaps the crucial piece of evidence has been unearthed, as bones from the tail of Spinosaurus have recently been discovered. Based on those bones the tail of Spinosaurus was a long, flexible and fin like. A tail well suited to providing propulsion in the water. This latest discovery pretty much clinches the hypothesis that Spinosaurus is the first type of dinosaur known to have evolved into a swimming creature.

Tail bones tell the story. The tail of Spinosaurus was big and powerful, perfect for propulsion underwater! (Sci-news.com)

These new discoveries make Spinosaurus an example of how varied and diverse the group we call dinosaurs was, and the research published by Ibrahim and Sereno provides an example of how scientists can continue their work even during a pandemic.

A star orbiting the black hole at the center of our galaxy provides direct observational evidence that Einstein’s theory of gravity is more accurate than Newton’s.

One of the basic laws of physics that students learn in high school is that the planets orbit around the Sun not in perfect circles by rather in the flattened circles formally known as ellipses, see image below. This idea of orbits being ellipses is Johannes Kepler’s first law of planetary motion.

Kepler’s first law is a direct consequence of Newton’s law of Gravity, but the gravity of a third body, not shown here, will cause the ellipse to wobble! (Credit: Quora)

A few decades after Kepler Sir Isaac Newton showed that it was the gravitational pull of the Sun that pulled the planets into those elliptical orbits. However, an orbit is only a precise ellipse if there is just a star and one planet. In our Solar system the other planets have their own gravitational pulls as well, although they are not nearly as strong as the Sun’s. Nevertheless because of the planets all pulling on each other those elliptical orbits aren’t exact, they all wobble around a bit.

In our Solar System the Planet Jupiter weighs as much as all the other planets combined so it causes most of the wobble in the other planet’s orbits! (Credit: Hubble Space Telescope)

In fact after the planet Uranus was discovered astronomers found that its orbit had a wobble in it that couldn’t be explained by the gravitational pulls of the then known planets. In the year 1821 it was suggested that another planet, further out than Uranus could be the culprit and after a lot of math, more than 20 years of calculations by hand, the planet Neptune was discovered in 1846 right where Newton’s gravity said it would be.

It was a wobble in the orbit of Uranus (l) that enabled astronomers to find Neptune (r). (Credit: Daily Mail)

Just a few years later, 1859 to be exact, a peculiar kind of wobble, known as the precession of perihelion, was found in the orbit of Mercury. Now perihelion is the closest point to the Sun in the orbit of a planet and a precession would mean a shifting of where, relative to the Sun, perihelion occurs. See image below.

The precession of perihelion could not be explained by the pull of the other known planets. Was there another planet even closer to the Sun? (Credit: Independent BD)

By the way, this shift measured by the astronomers was tiny, amounting to only 43 seconds of arc per century. If you recall that a complete circle has 360 degrees and each degree is made up of 60 minutes and each minute has 60 seconds then you can see that a change of 43 seconds in a century is very small indeed.

Once again it was suggested that another planet, one even closer to the Sun than Mercury, was the cause of the precession. After their success with Neptune the astronomers were so certain that they gave this ‘new planet’ the name Vulcan before they even found it. In fact they never found it, despite searching for more than 30 years.

In ‘Star Trek’ Mister Spock’s home world Vulcan was named for the hypothetical planet inside the orbit of Mercury! (Credit: Pinterest)

It was Einstein who finally figured out what was going on. In his General Theory of Relativity in 1915 the physicist described gravity not as a force that passed between two massive bodies but rather as a bending of space-time itself. This bending of space-time causes the motion of objects to deflect from a straight line and if the bending is enough, if gravity is strong enough, the ‘straightest path’ for an object can be a closed elliptical orbit.

In Einstein’s General Theory of Relativity the mass of an object bends Space-Time itself caused the path of other objects to bend, even into an orbit! (Credit: Extreme Tech)

For a weak gravitational field the difference between Newton and Einstein is extremely small. So small that when NASA sends a space probe to another planet it uses Newton’s equations not Einstein’s. The math needed with Newton is just so much easier, trust me.

Einstein’s equation for the gravitational field. This is actually shorthand for a system of 16 equations all of which must be solved simultaneously! (Credit: WordPress.com)

As the strength of gravity grows however the difference between the two theories grows exponentially. That’s why Einstein’s theory predicts the existence of black holes, objects with gravity so strong that nothing can escape them, while Newton’s theory doesn’t. And if you get close enough to our Sun, say where Mercury is, the difference becomes large enough to be measured, it works out to be 43 seconds of arc per century. When Einstein solved his field equations the solution to Mercury’s precession just popped right out. This was in fact the first evidence that Einstein’s theory was correct.

Now astronomers with the European Southern Observatory’s (ESO’s) Very Large telescope (VLT), located in the Atacama Desert in Chile have found another example of precession as predicted by Einstein. For the past 27 years the team have been studying a star called S2 as it orbits around the supermassive black hole Sagittarius A* in the very center of our galaxy.

The center of out Glalxy lies between the constellations of Sagittarius and Scorpio. Try to find it some clear night this summer! (Credit: EarthSky)
At the center of all large galaxies lies a supermassive black hole. Our galaxy’s is called Sagittarius A. (Credit: Daily Mail)

S2 completes an orbit around Sagittarius A* once every 16 years and at its closest point the star comes closer than 20 billion kilometers to the black hole, a distance that is about 120 times that between our Earth and the Sun. At that closet point S2 has to move at 3% of the speed of light in order to not be swallowed by Sagittarius A*. Just imagine that, an object as big and massive as a star moving at 3% the speed of light!

Artist’s impression of the star S2 at it’s closest approach to the supermassive black hole Sagittarius A. (Credit: Wikipedia)

Analyzing their data the astronomers, led by Reinhard Genzel, Director at the Max Planck Institute for Extraterrestrial Physics, have now published their results in an article in the journal Astronomy and Astrophysics. What the astronomers have found confirms Einstein’s theory once again. Even at a distance of 26,000 light years they were able to measure the precession of S2’s orbit around Sagittarius A* and it matches up with Einstein’s theory nicely. In fact their results have allowed them to make the most precise measurement yet of the mass of the black hole itself, 4 million times the mass of our Sun.

Because of the precession calculated from Einstein’s theory, S2’s orbit around the black hole will make a lovely Rosetta shape. (Credit: Syfy)

Future observations of S2 and the region around Sagittarius A* will be even more precise and detailed once construction is completed on the ESO’s new Extremely Large Telescope (ELT) in 2025. The astronomers hope to find fainter stars that come even closer to Sagittarius A*, perhaps even close enough to feel the dragging of space-time caused by the spin of the black hole. That’s another prediction of Einstein’s theory that has yet to be observed anywhere. That would be further proof that General Relativity is the most accurate theory for space-time outside of a black hole.

But as for what goes on inside a black hole? That’s going to have to wait for the physics of the future.

What is Soap?

In this era of Covid-19 we hear one piece of advice dozens of times everyday, ‘Wash Your Hands’, ‘Work up a good lather of Soap and Warm Water and Wash your Hands while singing Happy Birthday Twice!’ Which begs the question, what is Soap? Why is Soap so central to both cleanliness and good hygiene?

Just a little friendly advice!

Chemically soaps are a class of compounds known as salts of fatty acids and are produced by combining fats or oils with an alkaline base in solution under heat, a process technically known as Saponification. Soaps include a wide range of substances used for a variety of purposes from thickening agent to lubrication but the most familiar use of soap is undoubtedly as a cleaning agent and in this post I will mainly be referring to these types of soaps.

The Chemical reaction that produces soap, call saponificaction. (Credit: Thought Company)

Toilet soaps as they are known are produced by using either Sodium Hydroxide (NaOH) or Potassium Hydroxide (KOH) as the alkaline. When sodium hydroxide is combined with a thick fat such as lard or tallow the result will be a hard soap while potassium hydroxide and a light oil, such as olive oil, will produce a softer or even a liquid soap. When Lithium Hydroxide is used as the alkaline the result is lithium stearate a common industrial lubricant.

Making soap is actually pretty easy, many people do it as a hobby. (Credit: The Spruce Crafts)

So how do soaps perform their job as a cleaning agent? Well, remember that oil and water don’t mix because oils are non-polar molecules while water is a polar molecule. However a soap molecule is a combination of an alkaline and fat. That arrangement produces a molecule that is polar at one end, attracted to water, but non-polar at the other end, attracted to fats and oils.  

Basic layout of a soap molecule. One end can dissolve in water while the other end can dissolve in fats or oils! (Credit: Nature on the Shelf)

Because of that when used in combination with water soap acts as a surfactant, a material that breaks the surface tension of water allowing the water to more easily dissolve dirt and grime, along with such polar molecules as proteins and sugars, so that they can be washed away.

Soap’s greatest trick however is its ability to encase droplets of oil or fat in tiny spheres of soap molecules called micelles. Unlike oils and fats that do not dissolve in water, these micelles do dissolve allowing the oils and fats to be washed away with the dirt and grime. In other words not only does soap help water to better dissolve the substances it usually can, it also enables water to dissolve substances it generally can’t.

Molecules of soap form ‘Micelles’ around fats and oils allowing them to be dissolved in water and washed away! (Credit: Quora)

This also makes soap an effective anti-biotic because the harsh alkaline at one end of the soap molecule can break up the protein shells that protect viruses. At the same time the micelles can absorb the fats in the cell walls of bacteria, killing them. Of course modern, manufactured soaps often have various chemicals added to them in order to make them even more ‘anti-bacterial’ but it is worth remembering that any soap can be used as a disinfectant.

Soap by itself can help protect you from germs but modern soaps often have other chemicals added to make them true disinfectants. (Credit: Medium)

Archaeological evidence for the manufacture of soap dates all the way back to ancient Babylon with a cuneiform tablet dated to 2200 BCE that describes the earliest known recipe for soap making. The Egyptians, Greeks and Hebrews all had their own varieties of soaps, mostly produced with olive oil and potash, an alkaline solution made from the ashes of a fire, along with a bit of quicklime. This method of soap making produced a strong and particularly harsh soap.

Babylonian table with a recipe for making soap! (Credit: KU Chemistry)
Egyptian ladies washing themselves with soap! (Credit: Realm of History)

Surprisingly the Romans, who are well known for their baths, did not care very much for soap. They preferred to clean their bodies by rubbing them with olive oil and then scrapping the oil off with a dull knife called a strigil. They considered the harsh types of soaps made in the eastern Mediterranean as harmful for the skin. Only after becoming familiar with the milder soaps of the Celts and Germans did the Romans start using soap. (Imagine that, the fierce northern barbarians had the gentler soap!)

A Roman bronze Strigil used to scrap oil off of the body in a Roman bath. I think I’ll stick with soap and water! (Credit: Christie’s)

Both medieval Europe and the Islamic world had soaps but these soaps were generally harsh with an unpleasant smell and so expensive that only the very rich could afford to bathe frequently. Large-scale manufacture of soaps only began in the late 18th century and coincided with a campaign that linked daily washing with good hygiene, ‘cleanliness is next to Godliness!’

In the 19th Century Cleanliness, Hygiene and Morality were pretty much equated. (Credit: Alamy)

Today of course there is a tremendous variety of different kinds of soap available in your local supermarket. There are soaps that can remove the toughest dirt and grime, soaps that actually soften the skin and even soaps that are 9944/100 % pure soap. There are solid bar soaps and liquid soaps, advertised as ‘body wash’, there are even powered soaps. Whatever kind of soap you prefer we all know that regularly washing your hands with soap and warm water is our first line of defense against Covid-19. So wash up and remember, ‘I’m pulling for ya, we’re all in this together’! 

The BepiColombo Space probe is on its way to Mercury, this will be only the third mission to the Solar system’s innermost world.

The BepiColombo robotic probe to Mercury is in many ways the most complex space mission yet attempted. For one thing it is actually three spacecraft in one. Two Mercury orbiters, the Mercury Planetary Orbiter (MPO) designed and built by the European Space Agency (ESA) along with the Mercury Magnetospheric Orbiter (MMO) constructed by the Japanese Aerospace Exploration Agency (JAXA). These two scientific missions are stacked together on top of a propulsion module called the Mercury Transfer Module (MTM). Simply organizing a mission combining two probes from two space agencies had to be a challenge.

Artist’s impression of BepiColombo approaching Mercury. (Credit: New Scientist)
Breakout of the separate modules of the BepiColombo space probe. (Credit: YouTube)

Still, that was child’s play when compared to the task of getting BepiColombo to Mercury. Launched on 20 October 2018 the spacecraft will not enter orbit around Mercury until 5 December 2025. During that long voyage BepiColombo will flyby and receive gravity assists from Earth once, Venus twice and Mercury itself six times. The difficulty of getting to the Sun’s closest planet is the big reason why there have been more unmanned missions to distant Saturn, two Voyagers plus Cassini, than to comparatively nearby Mercury, one Mariner along with the Messenger mission.

BepiColombo’s complicated flight path to Mercury. (Credit: SlidePlayer)

That true, although Mercury is actually only about 20% further away from Earth than Mars is, 90 million kilometers versus 75 million. On the other hand Saturn is fully 17 times further from Earth than Mars is. So why have we sent more spacecraft to Saturn than Mercury?

Speed is one big reason. Orbiting so close to the immense gravity of the Sun Mercury has to possess a very high orbital velocity. In fact if you consider the difference in their orbital velocities, delta vee as astronauts put it, Mercury is only a little ‘closer’ to Earth, 18 km/sec, than Saturn is, 20km/sec. And when you’re sending an unmanned robotic probe to an extraterrestrial body the length of time the journey takes doesn’t matter, which makes speed matter more than distance since that requires more fuel.

Another reason that sending a spacecraft to Mercury is difficult is that the nearby Sun’s gravity is so strong, while Mercury’s is rather weak. This makes finding a stable orbit around Mercury rather difficult, especially an orbit that allows you to investigate all of the areas on the planet you want to observe.

Tiny Mercury is so close to the enormous Sun that finding a stable orbit around the planet isn’t easy. (Credit: Forbes)

BepiColombo has just completed the first if it’s flybys, saying a last Goodbye to Earth on the 11th of April, see image below. Later this year in October the probe will make the first of two consecutive flybys of Venus. Hey you known, Venus is big and bright in the evening sky right now so if you go outside on a clear night not long after sundown, BepiColombo will be somewhere between you and that big, bright evening star to the west.

One of the last images of Earth taken by the BepiColombo space probe as it flew by on 11April2020. The spacecraft used Earth’s gravity to give it a push on its way to Venus for its next flyby. (Credit: European Space Agency (ESA))

Once the combined spacecraft finally settles into Mercury orbit the two orbiters / instrument packages will separate and begin their studies of Mercury. The ESA’s MPO orbiter is outfitted with an array of cameras and spectrometers along with a radiometer, a laser altimeter magnetometer and accelerometer for the study of Mercury’s composition as well as compiling a more accurate map of the planet’s surface.

The planet Mercury as photographed by the Messenger space probe. Nice as this image is scientists would like to see a lot more of the details on the planet’s surface. (Credit: The Independent)

Japan’s MMO probe on the other hand carries instruments designed to study Mercury’s extremely thin atmosphere, the planet’s magnetic field and the way in which they both interact with the power of the Solar wind blowing past the planet. The results of these observations could be especially interesting since they will tell us a great deal about how the evolution of both Mercury and nearby Venus were influenced by the power of the Sun.

The Solar Wind has been buffeting the planet for billions of years. How much damage has it caused on Mercury? And how much will it cause on Earth over the next few billion years? (Credit: Scirence / How Stuff Works)

The proposed time frame for the scientific portion of BepiColombo’s mission is for one year after orbital insertion but with the possibility of an additional one-year extension for both orbiters. It’s possible that the success of BepiColombo will not only provide much valuable data about the Sun’s closest planet, but an example of how the space agencies of different nations can work together.

If only the politicians of different nations followed that example.