We hear all of the time about how Carbon Dioxide (CO2) in our atmosphere traps the heat from our Sun causing the Earth to grow warmer. That’s the basic science behind the idea that burning of fossil fuels, which release large amounts of CO2 are causing the now obvious rise in our planet’s average temperature.
So if too much CO2 in the atmosphere can cause the Earth’s temperature to rise, then what part, if any, did CO2 play in the Ice Ages, those long periods of cold climate where huge sheets of glacial ice covered entire continents. The geological evidence for the Ice Ages is extensive and can be found across the temperate regions of the world. Whether it be the large number of fjords along coastlines or glacially carved valleys or deposits of boulders, rocks and soil pushed southward by the advancing ice and left behind as moraines when the ice retreated.
Ever since the existence of Ice Ages was first debated during the 18th and 19th centuries scientists have proposed many different theories to explain why the Earth goes from long periods of cold to equally long periods of warmth. One factor that is thought to possibly trigger the start of a glacial period is a shift in Earth’s orbit due to the gravitational pull of Jupiter and the other planets. These perturbations can occasionally lead to a slight increase in our planet’s average distance from the Sun.
Such
an increase in distance would obviously cause a reduction in the Sun ‘s energy
that Earth absorbs and there is in fact some correlation between the
perturbations to Earth’s orbit as calculated by astronomers and the start of
recent ice ages. However the variations in sunlight due to changes in Earth’s
orbit are considered to be far too small to be the dominant factor causing an
ice age.
In fact it is clear from both geological and climatological evidence that the conditions necessary for an Ice Age are only possible when the CO2 levels in the atmosphere fall below even the level at the start of the industrial age more than a hundred years ago. And chemical analysis of ice cores obtained from Greenland and Antarctica dating back tens of thousands of years have shown that the CO2 levels in the atmosphere during the glacial periods was as much as 30% less than during the warmer interglacial periods.
So where did all of that CO2 go? If there was 30% less CO2 in the atmosphere during the glacial periods what happened to it? Well, back in the 1970s oceanographers were able to show that oceanic diatoms, single celled algae with calcium-carbonate shells, absorb CO2 as a part of photosynthesis. When these diatoms die their protective shells then drop to the bottom of the ocean taking some of that CO2 with them. The huge amount of CO2 in the ocean depths has been measured from deep water samples gathered by submersible vehicles.
Some of that CO2 is then brought back to the surface by deep ocean currents and under normal circumstances there is a balance between the CO2 sinking to the ocean floor and the upwelling currents bringing it back to the surface. However if anything was to change the rate of upwelling it could change the level of CO2 in the atmosphere and therefore the Earth’s climate.
Now researchers from Princeton University and the Max Planck Institute have succeeded in adding another piece of evidence to that model. The scientists, led by first author Ellen Ai, a graduate student at Princeton, recognized that the same upwelling currents that brought the CO2 to the surface also brought large amounts of nitrogen that would enrich the amount of dissolved nitrogen in the upper layers of the ocean. By measuring the ratio of nitrogen isotopes in the shells of the diatoms from deep sea cores they could obtain an indication of the amount of upwelling occurring as a function of time.
According to fellow author Alfredo Martinez-Garcia. “This allowed us to connect many features in the diatom nitrogen record to coincident climate and ocean changes from across the globe. In particular, we are now able to pin down the timing of upwelling changes, when the climate starts to cool, as well as to connect upwelling changes in the Antarctic with the fast climate oscillations during ice ages.”
So
climatologists now have a new tool that will allow them to better understand
the timing of past, and future ice ages. In fact scientists have long
recognized that we are currently living in a warm period between two ice ages,
and the next cold period is predicted to start about 50,000 years from now.
It’s ironic therefore that our immediate problem is too much CO2 in
the atmosphere causing global warming when our fate in the future may be
decided on there being too little.
We all learned about sunspots back in high school. You know those dark patches on the Sun’s surface that are actually magnetic storms the size of our entire planet or even larger. And you may recall that sunspots have an eleven year cycle starting with a minimum where few if any sunspots occur, growing to a maximum where the Sun’s face looks like it’s broken out in acne and then back to a minimum eleven years later. (That figure of eleven years by the way is approximate. The actual length of a solar cycle often varies by one or two years either way.) Finally, if you were interested you may have also heard that since sunspots are magnetic in nature they come in pairs with one being a north magnetic pole and the other a south magnetic pole.
Earlier this year the Sun went 200 consecutive days without a single sunspot showing on its visible face, and that was on top of a very small number of sunspots last year so obviously that period was a very deep minimum. Over the last four months or so however things have definitely started to pick up with a small number of fairly strong sunspots developing on the Sun’s surface.
This increase in solar activity marks the beginning of solar cycle number 25, which since a solar cycle is about eleven years means scientists have been keeping track of sunspots for 260-270 years! The question now is whether the upcoming solar maximum, expected in 2025, will be another weak one as the last two have been, or will there be a dramatic increase in the number and strength of sunspots during the next maximum. The answer is important to our modern technological civilization because more solar activity means more solar flares blasting out powerful Coronal Mass Ejections (CMEs). These CMEs can collide with the Earth as powerful electrical disturbances that interfere with satellites in orbit, power grids here on the ground and radio transmissions around the world.
The official estimate coming from NASA and NOAA is that Cycle 25 will be a relatively weak one similar to the last two. However a team of solar scientists from the University of Warwick and the National Center for Atmospheric Research (NCAR) are using a new theory of solar activity to predict that the upcoming solar cycle will be one of the most powerful ever recorded.
The new theory pays attention to those sunspot cycles that are either longer or shorter than average and maps them against a 22 year long cycle. What they found was that a long solar cycle, such as cycle 23 which lasted 13 years, is followed by a weak sunspot cycle while a short cycle, cycle 24 was not only weak but also quite short at a little less than ten years, gets followed by a strong, active sunspot cycle.
The new theory already seems to be gaining evidence because cycle 25 is off to a strong start. In addition to several large sunspots there have been two powerful solar flares, one of which on December 7th sent a CME headed straight at Earth. The CME arrived here on the 9th producing auroras that were more powerful, and came further south than any in recent years.
And solar astronomers now have newer, better more sensitive instruments with which to observe the forthcoming Solar Cycle. One of these is the Parker Solar Probe that is currently in an orbit around the Sun that is slowly getting closer and closer and which will come as close as 6 million kilometers in the year 2025. I wrote about the Parker probe in my posts of 12Feb20, 18Dec19, 3Nov18 and 5Sept18 but today I’d like to discuss the National Science Foundation’s brand new Inouye Solar Telescope.
Now nearing completion as the world’s largest solar telescope, the Inouye is named for Hawaiian Senator Daniel J. Inouye, who was a strong supporter of the Mona Kea observatory on the island of Maui, the big island in the Hawaiian chain. Possessing a primary mirror 4 meters in diameter and with the latest advanced optics the Inouye will increase by a factor of 2.5 our resolution of Solar images showing previously unseen details that the theoreticians can use to check against their models.
With
that improved resolution it is expected that the Inouye will be able to see
structures as small as 20 km across on the Sun’s surface. Since it is designed
to capture and observe the light of the Sun the Inouye also has some equipment
not normally found in a telescope, specifically a cooling system to keep the
energy gathered from the Sun from overheating the entire system.
With
advanced equipment like the Inouye Solar Telescope and the new theories
developed by Solar astrophysicists Sunspot Cycle 25 promises to be an exciting
one. Hopefully over the next few years many new discoveries will be made as we
seek to learn the secrets of our nearest star.
Last
month the big news from space was all about manned spaceflight. After all Space
X had successfully launched its second manned mission to the International
Space Station (ISS) just a matter of days after the ISS had celebrated its
twentieth year of continuous occupation.
This month’s post on the other hand is going to be all about the robots who are exploring space and in particular two robotic missions that have just returned bearing with them samples of material from other worlds. This material will soon be analyzed in labouratories here on Earth in order to reveal some of the secrets of what the other bodies in our solar system are like. Another big difference between this post and the last is that whereas the construction and operation of the ISS has primarily been a US and Russian show the two nations who built, launched and operated the two robotic space probes were those two far eastern powers Japan and China.
I’ll start with Japan’s Hayabusa 2 probe because it was the first to leave Earth back in December of 2014 on its mission to the asteroid Ryugu. I’ve written about Hayabusa and its mission to Ryugu several times, see my posts of 27Nov2019, 20Apl2019, 6Mar2019 and 30Jun2018. Arriving at Ryugu in 2018 after a voyage of 300 million kilometers Hayabusa spent more than a year studying the space rock. During that time the robot dropped several small landers onto the asteroid’s surface, fired a copper projectile at Ryugu in order to dig a crater that allowed the main spacecraft to land and collect samples from beneath the asteroid’s surface.
Then in November of 2019 Hayabusa fired its rockets and began the return journey to Earth. As the main spacecraft skimmed past our planet on December 6th, it released a small 40cm in diameter capsule that contained the samples it had collected from Ryugu. That capsule reentered our atmosphere and deployed a parachute bringing it to a soft landing in the Woomer Prohibited Area of the Australian state of South Australia. Members of the Japanese Space Agency JAXA quickly found the capsule, declaring that the priceless cargo was in perfect shape and that the probe had brought back at least 100mg of material from Ryugu.
As for the Hayabusa 2 probe itself, well it used Earth’s gravity to give it a velocity boost and it’s now on its way to another asteroid, one named 1998KY26. That will be another ten year journey but I think Hayabusa 2 is up for the challenge.
And if you think the mission of Hayabusa 2 was complex, well China’s Chang’e 5 robot mission went a step or two farther with an orbiter, lander, rover to gather samples, a blast off from the surface and docking in orbit. All that before a final return journey to Earth with the collected samples. To be honest the Chinese do have the advantage that the Chang’e 5’s target wasn’t 300 million kilometers away, it was right next door, the Moon.
Building on the success of their Chang’e 4 lander and rover, which made the first ever landing on the lunar far side, the Chang’e 5 spacecraft was launched on November 24th from the Wenchang space facility on the Island of Hainan. Entering lunar orbit the landing module then detached from the orbiter and on December 1st the lander touched down in the Moon’s Ocean of Storms region at a volcanic area known as Mons Rümker.
The lander then deployed a small rover, which was equipped with a scoop for the collection of as much as 2kg of lunar ‘regolith’. After spending two days, two Earth days that is, collecting and photographing the area around the lander the rover transferred its bounty to the lander’s ascent stage. Then on December 3rd the ascent stage blasted off carrying the samples with it and reached lunar orbit where it rendezvoused with the waiting orbiter.
The two spacecraft then successfully completed the first robotic rendezvous and docking in lunar orbit. Once docked the canister containing the lunar material was transferred from the ascent stage to the orbiter. With its job completed the ascent stage was jettisoned and ordered to crash back into the Moon’s surface in the central highlands region on December 7th. The orbiter then waited for a narrow launch window to open so that it could begin its return to Earth.
Firing
its engine on the 13th of December set the recovery capsule on a three day
journey back to Earth. Finally, on Wednesday the 16th the capsule entered our
atmosphere, slowed its speed by air friction before releasing a parachute. At
about 3AM local time the capsule came safely to the ground in the Siziwang
district of China’s Inner Mongolian region. Following a transmitted radio
beacon scientists with China’s space program quickly located the capsule and
within hours it was on a airplane bound for a labouratory in Beijing where it
will be opened up and its precious cargo removed.
So
in the space of less than a month robotic probes have brought back to Earth
material samples of two different celestial bodies. In the long debate over
whether humans or robots should explore space this month the robots won. Of
course the debate isn’t over yet, it still has a long way to go!
After intelligence probably the most astounding ability created by evolution during the history of life is the miracle of flight. The ability to fly gives such an advantage to any living creature that wings have evolved at least four separate times in different animal groups. These groups include the insects, the birds, the mammals and even the reptiles.
The insects were the first to take to the air and fly. We have fossil evidence of flying insects from as far back as the Devonian period when our vertebrate ancestors were just climbing out of the water. Evolutionary biologists have for many years theorized that the first insect ‘proto-wing’ developed not as a organ of flight but instead as an organ to help an insect regulate its body temperature.
You see insects are cold-blooded and on a chilly morning many use the light of the Sun to try to warm up their metabolism. A knob on the insect’s back would increase the amount of the Sun’s heat that the insect could absorb, just like a solar panel, and the bigger the knob the better. Natural selection would then act so as to increase the size of the knobs until they became ‘proto-wings’ that an insect could at first use to glide or even catch the wind for a free ride. As the new wings grew even larger, and acquired muscles that allowed them to move, eventually the insect was able to fly.
Some modern insects still use their wings in that way. If you’ve ever taken a walk in a swampy area early in the morning you can find dragonflies and damselflies climbing up the stalks of tall grasses or reed. Climbing not flying because their metabolism hasn’t warmed up enough to produce the energy needed to fly. Once near the top the dragonfly will spread it’s wings to face the Sun in order to absorb the warmth of the sunlight which will increase its body temperature so that it can fly.
So the question for biologists to answer was, where did those original knobs come from? For over a century entomologists looked in vain among the closest relatives of insects the myriapods, that is the centipedes and millipedes for some structure that could have evolved into those knobs. The search was in vain however because, as modern DNA analysis has shown, insects are actually more closely related to crustaceans, shrimp, lobsters and crabs than they are to centipedes and millipedes.
And now a new study from biologists at the Marine Biological Labouratory (MBL) at Woods Hole has discovered the original bump on a shrimp’s leg that developed into the wings of insects. In a paper published in the journal Nature Ecology & Evolution, Research Associate Heather Bruce along with MBL director Nipam Patel have used the gene editing tool CRISPR to demonstrate how a lobe on the seventh, innermost segment of a crustacean’s leg was incorporated into the body of the ancestors of early insects as they moved onto the land. This segment provided extra strength to the exoskeleton of the early insects. In time the lobe then grew to become the long sought after ‘proto-wing’.
Doctor Bruce began by comparing the genetic instructions for the segmented legs of a tiny beach hopper shrimp called Parhyale to those in the fruit fly Drosophila and the beetle Tribolium. Now Parhyale, like all crustaceans have seven segments in their legs while both Drosophila and Tribolium, like all insects have only six segments. However all three species have an identical sequence of five genes that code the instructions for leg development.
Using CRISPR Bruce disabled those five genes in embryos of all three species one at a time and monitored the results. What she found was that eliminating the genes eliminated the six leg segments farthest from the body. She also found that the seventh, nearest segment of the leg of Parhyale corresponds to a section of the back of the exoskeleton of the insects. Most importantly, a lobe on that seventh segment, called the Tergal Plate moved with the segment becoming a perfect candidate for the knob that evolved into the insect wing. The story of the evolution of the insect’s wing clearly demonstrates the power of natural selection in taking a structure in the body of an animal and altering its shape to perform an entirely new function. The story of how DNA analysis and gene editing have enabled scientists to work out the details of that evolution clearly show the power of the newest tools that biologists possess in their study of life here on Earth.
Invasive species, those creatures that have succeeded in leaping out of their original environment into a foreign habitat are becoming more and more of an environmental problem. In many ways the problem of invasive species is one that is becoming as difficult to solve as global warming or pollution. Most of these invader species are animals that have managed to hitch a ride on the international and intercontinental traffic and trade that we humans have developed. Once established in new habitats without their natural predators to keep their numbers in check these trespassers can squeeze out native species often causing economic as well as environmental damage.
In this post I’d like to discuss two species that have recently been spotted in new ecosystems and for whom there are now efforts underway to eradicate the new colonies before they spread too far. One of the species you may never have heard of but I’ll start with the one who’s gotten a bit of press coverage because it has a ‘Murder’ nickname.
And Asian Giant Hornets, now commonly referred to as Murder Hornets do in fact kill around one hundred human beings every year. At a size of 45mm in length their 6mm long stinger is quite painful and when you add in their venom the sting of a dozen or so can often prove lethal. It’s not human beings who have the most to worry about from these monsters however; it’s their insect relatives the honeybees that are most in danger.
Taxonomically
the Asian Giant Hornet, Vespa mandarinia is the largest member of the genus
Vespa, the true hornets. Native to East Asia, South Asia and Southeast Asia they
are a predatory species that hunt medium to large sized insects, particularly
bees, other hornets and mantises. With its large crushing mandibles a single
Murder Hornet can decapitate 30-40 honeybees a minute and a score or more of
the hornets can wipe out a hive of thousands of bees in just a few hours. While
the adult Giant Hornets feed by sucking out the juices of their prey the whole
carcass is fed to their larva, who digest the proteins to build their own
bodies.
Now the Asian Giant Hornet is invading North America, specifically the Pacific Northwest region including British Columbia and the state of Washington. The first sighting came in August of 2019 when three hornets were found on Vancouver Island. Those three were traced back to a nest that was then destroyed. That did not end the threat however as more than a dozen other sightings were made over the next year cumulating in the discovery of a large nest in a tree in Blaine, Washington. When that nest was destroyed it was found to contain over 500 hornets, including 200 queens.
So
the odds are that there are other Asian Giant Hornet nests out there as well
and that the pest will continue to spread.
Beekeepers and farmers in the region have been asked by their
Departments of Agriculture to be on the alert and report any sightings. Like
most invasive species they have no natural enemies in North American so human
intervention is the only way the Asian Giant Hornet is going to be
controlled.
There is one good thing to report about the Asian Giant Hornets, they’re supposed to taste pretty good. In Japan the larva are consumed fried while several cultures roast the adults on skewers over a fire. Personally I’d rather not have the opportunity to try one.
The
next invasive species I’ll talk about today is actually one I’ve already
discussed in my post of 31May2018, hammerhead worms of the genus Bipalium. In
that post I described how these alien looking worms, which are native to Asia,
had invaded Southern France and were preying upon the beneficial native worms
who help keep the soil fertile by aeration and mixing. In addition to having no
natural enemies outside of Asia the hammerhead worms also excrete toxic
chemicals through their skin that may not be harmful to humans but which will
make any bird who tries to eat one very sick.
As I said in my earlier post these hammerhead worms are spreading across southern Europe, causing a great deal of damage, and now they’re in the United States. That’s right hammerhead worms have been collected in Texas, Illinois and now Georgia. Over one hundred of the creatures have been reported recently in the Atlanta area so there must be thousands going unnoticed.
If these predatory worms continue to spread they could become a real menace to agriculture, but presently we don’t even have a strategy to deal with them. To my knowledge we haven’t even identified how they are spreading across states, countries and continents. Much more research is needed on these invaders before we can even attempt to control, much less eradicate them.
Every invasive species is a Pandora’s box of its own. You can never tell what horrors are going to come out once opened and once they’re let out it’s almost impossible to put them back in.
Extra: No sooner had I finished writing this post than a new study has announced how the Asian Honeybee protects itself from the Asian Giant Hornet. Researchers in Vietnam from the Vietnamese Academy of Science and Technology in Hanoi have observed that whenever a honeybee hive is threatened by a hornet attack the worker bees will gather animal feces and spread it around the entrances to the hive.
It is currently not known whether the smell of the poop actually repels the hornets or if it simply disguises the smell of the hive confusing the hornets but it certainly does appear to work. This also represents the first discovery of bees using a tool in the wild adding these social insects to the small by growing group of animals that know how to use tools.
Unfortunately
the European honeybees that are most common here in the US have not acquired
this defensive strategy so the threat posed by the Giant Asian Hornet to
American bees populations is still present.
On the 24th of November a mass stranding of over 120 pilot whales along with a half dozen dolphins was discovered on the Chatham Island group some 600 km east of the main Islands of New Zealand. Now the Chatham islands have long been known as a whale ‘hot spot’, an area were large numbers of many different species of aquatic mammals congregate, and unfortunately often die by swimming right up onto the sandy beaches.
Because
of the remoteness of the islands getting help to the beached animals was
difficult and in the stranding on the 24th ninety-seven pilot whales were dead
before rescuers could arrive and the remaining twenty-eight were in such bad
shape that they had to be euthanised. Such mass deaths are common on the
Chatham islands with an average of over 300 dolphins and whales dying there
each year. Indeed the largest mass stranding in recorded history, over 1,000
animals, occurred there in 1918.
So why do such mass beachings happen, what causes otherwise healthy marine whales and dolphins, collectively known as cetaceans, to just swim onto a beach where, unable to get back into the water, they die of exposure? To scientists it’s pretty much of a mystery but there are historical records of such events happening dating back thousands of years so at least this time it’s not our fault. Well, not all our fault as we shall see.
One important clue to the beachings is the fact that virtually all of the animals involved are toothed whales and dolphins, active hunting animals who prey on fish and other marine life. The big filter feeding baleen whales appear to be relatively immune to whatever it is that causes the strandings. Another clue is that it is whale and dolphin species that usually live in deep water that are most susceptible to beachings, animals that are more familiar with shallow water environments rarely strand themselves.
Some of the most often discussed hypothesis to explain the mass beachings include animals chasing their prey too close to unfamiliar shores and getting caught by a falling tide. Or in some cases the animals themselves could be chased by their predators onto the shoreline. Animals who normally live in deep water and are using their echolocation ability to navigate might be fooled by the gently sloping rise of a sandy beach into thinking they are in deeper water. Also mass beachings often occur in species with strong herd instinct and it might be that an illness in the lead animal, even just an earache, could lead to the stranding of the entire pod.
Some scientists have also suggested that, if whales navigate by using Earth’s magnetic field, as Pigeons appear to do, Solar storms could be the cause. A few researchers have even suggested that global warming and ocean pollution, that is plastics, could be making the problem worse. Finally there is growing evidence that high-powered Sonar pulses generated by naval warships searching for submarines does cause damage to the ears of whales and dolphins and a link between Sonar and some cetacean strandings now seems very likely.
There was a time, not so long ago that people considered beached whales to be a fortuitous event and they would rush to kill and harvest the helpless animals for food or their oil. It’s really only been in the last 50-60 years that serious attempts have been made to help the stranded animals and refloat them back into the ocean. So far those efforts have had mixed results, often because the beachings are not discovered until it is too late for many of the animals.
Still we are trying to help and the more we try the better at it we will get. It’s nice to see that for a change human beings are doing what they can to alleviate a tragedy in the natural world rather than being of cause of one.
Every year there are events taking place in the sky above our heads that are worth taking a few minutes to check out. Problem is that, unless you know that something like an occultation or conjunction is coming up it’s easy for even someone who keeps his eyes to the sky like I do to miss them.
That’s even true of big events like a lunar or a partial solar eclipse. O’k a total solar eclipse is kinda hard to miss but let’s be honest most people wouldn’t notice a partial eclipse that covers half of the Sun unless they’d heard about it on the news. It helps therefore to have a listing of upcoming astronomical events to refer to over the course of a year in order to catch at least a few of them. That’s what I hope this present post will be, and if I can get a few of my readers out there to take a few minutes now and then to go outside on a clear night and appreciate the view of heaven above them I’ll have done my job.
Now
conjunctions are the most common astronomical event and the easiest to miss. A
conjunction is simply two bright objects in the sky coming close together and
since the real stars don’t move that means at least one object has to be either
the Moon or a planet.
This month a very close conjunction between two of the planets is going to occur. At about midnight UTC on December 21, that’s around 7PM EST for folks on the US east coast like me, Jupiter and Saturn will appear closer in our sky than they have since the 4th of March in the year 1226, that’s nearly 800 years! The angular distance between the two planets will be less than 1/5th the diameter of the Moon making them look like a double planet.
Now
if you live a part of the world where midnight UTC is daytime for you or if it
happens that your sky is cloudy on December 21st don’t panic. You see Jupiter
and Saturn both move pretty slowly across the sky so they’ll be real close
together for several days. For nearly ten days, from Dec 16 to the 25th the two
planets will be closer than the width of the full Moon.
And I hope everybody realizes that when I say the two planets will be close together that only means that they appear close together from our point of view. Jupiter and Saturn will still be hundreds of millions of kilometers apart but the Earth, Jupiter and Saturn will basically be in a line across the Solar system more than a billion kilometers long. This is true for all conjunctions, the two planets, or Moon and planet only appear to be close from our point of view.
Then
during 2021 there will be another four planet to planet conjunctions. On the
5th of March, at about 5AM UTC the planets Jupiter and Mercury will be a little
more than half the width of a full Moon apart. Now remember Mercury never gets
very far from the Sun so it’s only visible shortly before dawn or shortly after
sunset. During March it will be a morning star so you’ll have to get up early
in the morning to see it so close to Jupiter.
Then on the 29th of May at 3AM UTC Mercury will be close to Venus, just about a full Moon diameter apart. This time Mercury, and Venus will be evening stars, and quite close to the Sun so make certain that you have a clear horizon to the west as the Sun goes down if you want to see their conjunction.
At the height of the summer it will be Venus and Mars who will be coming together. On the 13th of July around 1AM UTC the two planets will be about a full Moon diameter apart and get this, the Moon itself will be right above them so close that you could cover all three of them with the palm of you hand!
The
last planet to planet conjunction of 2021 will take place on the 19th of August
when Mercury and Mars will approach to less than one sixth of a Lunar diameter
at 3AM UTC. Again this conjunction will take place in the evening very shortly
after sunset.
Now
remember, all of the times I gave are for the moment of closest approach of the
two planets but as I said above planets don’t move very fast in our sky so if
it happens that it’s daytime where you are at the precise time I gave, or if
it’s cloudy don’t panic. You can still see a good show anytime within say 48
hours on either side of the time I listed.
Now as I mentioned above the Moon can also come close to a planet, in fact it can even pass in front of one completely covering it in a way similar to a solar eclipse. These events are known as occultations and like eclipses only a small part of the Earth actually sees the Moon pass in front of the planet, the rest of us only get to see a conjunction. The first occultation takes place on the 17th of April at about 1500 hrs UTC when the Moon will cover Mars. At least it will for those people in India and southeast Asia, the rest of us will see Mars come closer than a fifth of the Moon’s diameter.
The second occultation will involve the planet Venus when the Moon passes in front of it on the 8th of November as seen by people in Japan, Korea and the far east Russian city of Vladivostok. This occultation or conjunction, depending on where you live, will take place in the early evening after the Sun sets.
Finally,
and appropriately on the last day of the year December 31st, the Moon will pass
in front of Mars putting on a great New Year’s Eve show for people in
Antarctica and southern Australia. The rest of us will get to see the Moon pass
by close to Mars.
O’k so what about the big celestial events, the eclipses. Well it turns out that 2021 will be a good year for Solar eclipses, if you happen to live at one of the poles. On June the 10th the North pole and a bit of Northern Quebec will be treated to an annular eclipse of the Sun, that’s where the Moon doesn’t quite cover the Sun but instead blots out most leaving a ‘Ring of Fire’. Then on December 4th the South pole gets to see a total eclipse, the rest of us will just have to wait for other years. There is going to be one total Lunar eclipse on the 26th of May at 1:20AM UTC that will be visible for Southeast Asia, Australia and the West Coast of North America.
Those
are going to be the major astronomical events over the next year. I hope to be
able to check out a few of them and I hope that you will too.
This
month I’ve got three new stories that span half a billion years in time and
different aspects of how the study of ancient life is carried out. As usual
I’ll start with the earliest and work my way forward in time.
The first period in Earth’s history to display a large number of different kinds of fossil species is technically known as the Cambrian period. Thanks to the fossils found in the Burgess Shale fossil site in British Columbia from 520 million years ago the Cambrian period has become well known for the many weird and wonderful creatures that existed during that period of time. Two of the best known, and weirdest of the Burgess Shale animals are Opabinia and Anomalocaris, shown below. Both possess a segmented body plan similar to that of modern arthropods but lack the jointed limbs that are the very meaning of the word arthropod. At the same time each creature has strange features unlike those of any modern animal.
As
you can see in the illustration Opabinia has a trunk like appendage with a claw
at the end coming out of its face while at the same time having five (!) eyes
on top of its head. Anomalocaris on the other hand has two backward curved
segmented tentacles near a circular (?) mouth. Over the years many
paleontologists have tried to insert both Opabinia and Anomalocaris into the
phylum Arthropoda but those strange features have made the fit awkward at the
very least.
But now a new species from the same period has been discovered in China that is an almost perfect ‘missing link’ between Opabinia, Anomalocaris and more familiar arthropods. In a paper published in the Journal Nature the new creature has been described and given the name Kylinxia zhangi. According to co-author Diying Huang, a professor at Nanjing Institute, Kylinxia is named for a mythological Chinese version of the Chimera, a creature that combined the heads of a lion, a goat and a snake.
And like the Chimera, Kylinxia has a combination of the features of several other Cambrian animals. For one it has the five eyes of Opabinia along with the segmented arms of Anomalocaris, although in Kylinxia the arms are curved forward rather than backward. At the same time it has other features typical of better known arthropods such as a hard exoskeleton in addition to a large number of jointed limbs.
The
discovery of creatures like Kylinxia zhangi is something of a Holy Grail for
paleontologists, where just a few fossils, sometimes only one, can answer many
of our questions about the history of life.
More often answering those questions requires the careful analysis of a large number of fossils, along with other evidence. One such question is whether or not the dinosaurs were already in decline when the asteroid struck giving them a final ‘coup de grace’ or were they in fact still flourishing and would probably still be dominating the world today if not for that asteroid?
Naturalists today have a hard enough time trying to determine whether some species are in decline or not, and if so by how much. Tigers and elephants may be easy to count but how would you decide if the numbers of honeybees or frogs are increasing or decreasing, and they’re alive today not dead for 66 million years. Doing population studies for long extinct species, let alone groups of species, is obviously a very difficult task.
Which makes a new study published in the journal Royal Society Open Science from researchers at Bath University and Natural History Museum all the more remarkable. Using statistical modeling techniques the team studied the diversity of dinosaur species and groups that were present in the late Cretaceous, the time just before the asteroid hit.
What they found was not only were most groups of dinosaurs doing quite well, in terms of number of species, but there was also clear evidence that two groups, the duck-billed Hadrosaurs and horned Ceratopsians were rapidly increasing in diversity. In fact, according to study lead author and Ph.D. candidate Joe Bonsor, “…there’s no evidence to suggest they (the dinosaurs) would have died out 66 million years ago had the extinction event not happened.”
And if that assessment is accurate, where would that have left our mammalian ancestors, the largest of whom was about the size of a rabbit and who were shoved into the shadows of their world by the dominate dinosaurs? Was our very existence, the very dominance of mammals in our world today only possible because of a stray piece of space rock that just happened to collide with Earth 66 million years ago?
But it was our ancestors and not the dinosaurs that managed to somehow survive the destruction caused by that asteroid. How did they do it? What was there about those small mammals that allowed them to stay alive while all the dinosaurs died? Paleontologists have offered a lot of different explanations for what characteristics allowed the mammals to live to tell the tale.
One of the most commonly made suggestions is that, because mammals were forced to live in the ecological edges they had to live on whatever they could find. In other words the mammals were forced to become generalists while the dominant dinosaurs became specialists. Then, when the world was pushed to the edge they managed to cling to life whereas the dinosaurs couldn’t.
Another possibility is that the mammals survived because they helped each other, because they lived together and worked together. The benefits of living in a society are well known and include more eyes to help avoid predators, sharing of resources and for warm blooded animals, sharing body warmth. Those last two items would have been a big help in surviving a disaster like the asteroid strike.
Now the earliest known evidence for social behavior in mammals has been discovered and it comes from the Cretaceous period just a few million years before the asteroid. In an article published in the journal Nature Ecology and Evolution paleontologist Luke Weaver from the University of Washington describes the fossils he found at Egg Mountain in Western Montana.
The fossils in question are of a rather familiar looking rodent-like animal named Filikomys primaevus which means ‘youthful friendly mouse” and which were dated to some 75.5 million years ago, about 10 million years before the asteroid. What the fossils discovered by Professor show is the complete remains of many individuals, both adults and young, all contained within the same chunk of rock. Because of the completeness and articulation of the remains Prof. Weaver is certain that the fossils were not accidentally brought together by water currents or some other geological force. These animals lived together, and died together.
Professor Weaver interprets the fossils as being similar to an underground nest of ground squirrels or prairie dogs, which are actually squirrels not dogs. Such groups of mammals today are known to possess quite complex social relationships, see my posts of 20 January 2018 and 11 July 2020 discussing prairie dogs.
Now
just how complex was the social behavior of F primaevus we may never know. The
fact that these animals were living together in large groups 77 million years
ago however is strong evidence that social behavior in mammals, that includes
us, has been around a long time. And those social skills just might have given
our ancestors an extra edge for survival when that asteroid hit. Maybe, rather
than going extinct like the dinosaurs, we’re only here because our ancestors
helped each other get through a big disaster. Something worth thinking about
right now.
I’d like to start this month’s space news post by taking a moment to celebrate twenty years of continuous human occupancy aboard the International Space Station (ISS). It was on November 2nd, 2000 that a Russian Soyuz capsule brought American astronaut William Shepard along with Russians Yuri Gidzenko and Sergei Krikalev to the not nearly completed ISS as it’s first official crew. Since that time human beings have had an uninterrupted presence in Low Earth Orbit (LOE).
Of course the idea of a space station dates all the way back to the early Russian space theorist Konstantin Tsiolkovsky. In fact in 1961 President Kennedy considered ordering NASA to build a space station before deciding instead to start the Apollo Moon program. Then in 1984 President Ronald Reagan formally ordered NASA to use the new Space Shuttle to construct ‘Space Station Freedom’ a program that I actually did some work on dealing with the communications systems.
Unfortunately the loss of the space shuttle Challenger along with a growing federal deficit caused Space Station Freedom to be canceled during the first Bush administration. It was left to President Clinton to revive the idea of a space station and use it’s construction as a means to promote cooperation between the US and the Russian Federation after the collapse of the Soviet Union.
So
briefly that’s how we humans came to construct our first permanent outpost off
of our planet. A home in space, the beginning of many homes on many worlds in
the years to come hopefully. Officially the ISS will continue to operate until
2024 but the indications are that the time limit will be extended until at
least 2028.
And there’s currently also talk of several other possible space stations being constructed in the near future. The aerospace company Orion Span hopes to begin construction of an LEO station called Aurora as early as 2021 while Bigelow Aerospace also has plans for a private space station. Both of these stations are intended to cater to a growing space tourist demand using commercial launch systems as a means of getting their customers to their space stations. Meanwhile the growing space superpower of China is also making progress in its space station plans.
And getting to the ISS just got a lot easier because on November 15th Space X Corporation launched the first mission to the station in their contract under NASA’s commercial crew program. Now you should remember how back on the 28th of May a Space X Falcon 9 rocket launched two astronauts to the ISS in the company’s Dragon capsule, see my post of June 3rd 2020. Well, legally that was the last test flight for Dragon while this new mission is the first contract flight.
Irregardless of what the lawyers call it on the 15th of November the Space X Dragon capsule lifted off from Kennedy Space Center carrying four astronauts who are expected to remain aboard the ISS for the next six months as regular crew members. After a short voyage of about 27 hours the capsule successfully docked at the ISS perhaps beginning a new chapter in manned space exploration similar to the one that began with the first commercial airline flights more than 100 years ago.
All of this progress comes right after a tumultuous election here in the United States and while space exploration never became much of an issue during the campaign the incoming Biden administration will certainly be looking to make a few changes at NASA. One change that is certain to occur is the appointment of a new Chief Administrator for the space agency since its current head Jim Bridenstine has announced that he will be leaving his post once Biden becomes president.
Bridenstine
was an unusual choice in the first place since the former Oklahoma congressman
is the only NASA head ever to have a political rather than a science or
engineering background. Nevertheless I have to admit that Bridenstine has done
a better job that I feared successfully managing not only the commercial crew
program but also the ramping up of the Artemis Moon program. In fact if I have
any criticism of the NASA administrator it is that as a former republican
congressman he should have been able to generate a little more support, i.e.
funding for Artemis.
So what changes can we expect from a Biden administration with respect to space exploration? For one thing the commercial crew program is undoubtedly safe since during his term as Vice-President Biden oversaw the initial start of the program.
Throughout
his career Biden has been a supporter of space exploration but with the huge
number of problems facing the new President it will all come down to the
question of how much resources can we afford to spend on space. The answer to
that question will have a great impact on the Artemis program and its plan of
returning US astronauts to the Moon in 2024. In these posts I have often
questioned the feasibility of that schedule suggesting that a first Artemis
lunar landing is more likely to take place in a 2026-28 time frame. It seems
likely that the new Biden administration will continue to provide enough
support to Artemis to keep to that more reasonable schedule.
At least the President-elect has begun to assemble his NASA team choosing eight former NASA employees, including former astronaut Pam Melroy and several chief scientists, Ellen Stofan and Waleed Abdalati as advisors. For the moment these are temporary advisors rather than permanent appointees but at least their participation in Biden’s transition team indicates the incoming president’s commitment to space exploration.
On
the whole I expect that NASA under a Biden administration will receive as much
support and funding as can be spared from trying to solve all of the other,
more pressing problems facing our nation.
The Hyperloop transportation system may seem high tech and futuristic but the idea behind it is simple enough. A high-speed train of some sort, like the magnetic levitation (maglev) trains in Japan for example, is placed inside a tube with most of the air removed. With 99% of the air gone from the tube the high-speed train will encounter virtually no air resistance allowing it to travel even faster and with greater energy efficiency.
The basic idea of railroad trains running through evacuated tubes has been around for nearly a hundred years now but the technical difficulties were so great that nobody gave it much thought. At least not until Elon Musk, of Tesla electric cars and Space X first began taking about it in 2012, and at the same time giving it the name by which it’s now known, the Hyperloop. Musk himself hopes that one day the Hyperloop will achieve speeds even greater than those of airplanes, supersonic or even hypersonic and he has also described the Hyperloop as a ‘cross between a Concord and a railgun and an air hockey table”.
In his effort to develop the Hyperloop Musk has taken advantage of the engineering skills of both Tesla and Space X corporations. So far the collaboration has resulted in the building of a 1.6 km (1 Mile) long tube to be used as a test track for validating various designs. Musk has even opened Hyperloop development up for competition from other engineering firms along with University engineering teams in order to help speed up progress. In Musk’s Current Alpha Hyperloop design the passenger carrying pod glides above its tracks lifted by air bearings and is propelled down the tube by a linear electric motor.
Musk’s goal is to develop the technology to the point where construction of a line to provide passenger service between San Francisco and Los Angeles can begin. Such a Hyperloop line could cut surface travel time between the two cities from its current 12 hours to less than one hour. Then, once the technology has proven itself the plan would be to extend Hyperloop service throughout the country providing a low cost, more energy efficient alternative to air travel.
With all of that effort by Elon Musk and his companies it was something of a shock therefore when the first manned test of a Hyperloop vehicle was performed by a competitor, Richard Branson’s Virgin Hyperloop Corporation. On the eighth of November two executives of Virgin, co-founder Josh Giegel along with Director of Passenger Experience Sara Luchian, took their seats inside a new pod design from the engineering firms Bjarke Ingels Group and Kilo Design. Employing maglev technology the pod was accelerated to a velocity of 172 KPH in a little under 6 seconds. At that speed the pod raced down Virgin’s 500 meter test track without any problem. If you’d like to see a short video of the test click on the following link to be taken to a YouTube video. https://www.youtube.com/watch?v=_w2lo5h3D5E
So how soon can we expect construction to begin, how soon will we be able to ride the Hyperloop? Well you better be patient, there are a lot of technical problems to overcome. Chief among these is probably just the difficulty in maintaining a near vacuum inside a nearly thousand kilometer long tube, especially in earthquake prone California.
To my mind however the biggest challenge facing the Hyperloop is going to be legal, not technical. You see I’ve driven from San Francisco to LA several times and there are few areas on Earth as densely populated, or as commercially valuable. The idea of trying to buy the land, or at least obtain right of way, over a line straight through the heart of California is hard to imagine. Oh I suppose you could plan your route so as to go around San Jose, Salinas, San Luis Obispo, Oxnard and Santa Monica but remember every curve you put into your course adds cost and time.
I
wouldn’t be surprised if the first Hyperloop isn’t built in some less
populated, but fast growing region such as Phoenix Arizona to Albuquerque New
Mexico, with a later extension to Fort Worth Texas. Such a route would allow
the Hyperloop to be constructed at a lower cost, with far fewer lawyers getting
involved. Then once the system is up and running it could prove its value,
increasing both the economic and political will to replace our out of date and
decaying rail systems with a brand new, state of the art transportation system.