An Interstellar Visitor enters our Solar System. What is A/2017 U1 and what can we learn about what it is and where did it come from.

Over the past twenty years or so NASA has been working on a effort to find and catalog all of the small objects in our Solar System that could one day pose a threat to us here on Earth. A critical part of this effort was the design and construction of telescopes especially suited to surveying large parts of the sky in very fine detail.

One of these telescopes is Pan-STARRS at the observatory atop Mona Kea in Hawaii. With a mirror of 1.8 meters in diameter the telescope is smaller than most professional instruments, but with a 1.4 Gigapixel camera Pan-STARRS can photograph the entire sky several times a month.

That’s what you need in order to find Near Earth Objects (NEOs). Take two pictures of the same part of the sky a couple of weeks apart and compare them. Anything that moves between the two images is an NEO.

Just a few weeks ago on October 19th, Doctor Rob Weryk of the University of Hawaii’s Institute for Astronomy found something special with the Pan-STARRS telescope. At first Dr. Weryk thought he’d just found another

space rock, there are literally thousands out there. Dr. Weryk gave the 500-meter rock the designation A/2017 U1.

When he calculated the object’s position and velocity however Doctor Weryk realized that whatever it was it was moving too fast to remain in orbit around the sun. The object was a visitor from interstellar space making its first and only trip around our Sun. The photograph below shows the small dot that is A/2019 U1.

Interstellar Visitor A/2017 U1 (Credit: Alan Fitzsimmons, Isaac Newton Group)

 

Astronomers had long been expecting a visit from such an object. Many models of how solar systems form have a certain amount of matter being expelled as the star and planets condense. These outcasts would then wander between the stars where they could occasionally be drawn into the gravitational field of another star.

The orbits followed by these temporary visitors are not closed elliptical paths like those of planets or very comets but are an open-ended curve known as a hyperbola. Whereas the planets repeat the same orbit over and over again, an object on a hyperbolic trajectory is on a one time only orbit around a star. The figure below shows the difference between an elliptic and hyperbolic orbit.

Elliptic and Hyperbolic Orbits (Credit: R. A. Lawler)

A/2017 U1 made its closest approach to our Sun back on September 9th, more than a month before it was discovered. Coming within 23 million miles of our star A/2017 U1’s velocity increased to almost 90 kilometers per second. It passed within 15 million miles of Earth on October 14th at a velocity of 60 kps; three times the velocity that the New Horizons space probe had on its way to Pluto. In ten years or so, when it has left our Solar System behind A/2017 U1 will still have a velocity of about 25kps, faster than that of the Voyager I space probe, the first man made object to leave our Solar System. The image below shows the path of A/2017 U1 as it swung around the Sun.

Path of A/2017 U1 through our Solar System (Credit: NASA-JPL-Caltech)

So, what was A/2017 U1? What was it made of? Where did it come from?

To be honest we didn’t learn a great deal about A/2017 U1. It was very small, didn’t come that close and is already too far away for even the most powerful telescopes to see anymore. Really all we know for certain is that A/2017 U1 came from the direction of the constellation of Lyra and that it looked more like an asteroid than a comet.

But we know it came from the beyond, from outside out little neighborhood of the Galaxy. And that means there will be others, and each time one visits we will learn a little more about them. That’s the way science works after all.

Solar Eclipse of 1207BC helps to date Pharaohs? Interesting but I’m not so sure about the connection.

Back in August I was lucky enough to have had an almost perfect view of the recent total Solar eclipse that crossed the USA, (See Post of 24August17) so went I came across an article entitled “Solar Eclipse of 1207BC helps to date the Pharaohs” I was instantly intrigued. It only took me a few minutes to find and download the original article at the journal ‘Astronomy and Geophysics’. What I read was certainly interesting but also clearly displayed some of the difficulties in trying to use modern science to study ancient, semi-legendary records of past events.

The article was written by Colin J. Humphreys of Selwyn College at Canbridge University and Graeme Waddington, an independent scholar. What Humphreys and Waddington propose is that the astronomical miracle described the Old Testament book of Joshua (Joshua 10:12-14) was not as usually translated the Sun and Moon standing still at Joshua’s command but rather a description of a Solar eclipse.

This idea is not actually new. As Humphreys and Waddington themselves point out the linguist Robert Wilson realized over a hundred years ago that the Hebrew words dôm and ‘amad could also mean that the Sun and Moon stopped shining, i.e. an eclipse. However, when astronomers did the calculations to find that ancient eclipse they discovered that there was none appearing in Canaan around the right time.

What Humphreys and Waddington realized was that the earlier calculations of ancient Solar Eclipses ignored the possibility of the event being an annular solar eclipse. Now an annular eclipse occurs when the Moon is at the farthest point in its orbit and therefore appears smaller in our sky, too small in fact to completely cover the Sun leaving a bright annular ring of sunlight. See picture below.

An Annular Eclipse (Credit: The Cosmos Within)

Doing the calculations Doctors Humphreys and Waddington found that there had been an annular eclipse across North Africa and Canaan on the 30th of October in the year 1207 BC. This eclipse they claim is the miraculous event depicted in Joshua, chapter 10. The image below shows the path of the annular eclipse.

Path of Eclipse of 1207BCE (Credit: C. Humphreys and G. Waddington)

Now to the ancient Hebrews an annular eclipse of the Sun would still be more than spooky enough to be remembered and connected to their legendary hero Joshua. At this point however the authors indulge in some hand waving, just suppose type arguments to provide a little more evidence. For example they claim that the reduction in sunlight during the afternoon, followed by the return of light after the eclipse’s maximum and then concluding with a real sunset could very easily be described as “The Sun did not hurry to set for about a whole day” (Joshua 10:13 New Revised Standard Version or NRSV).

To me this is part of the problem of trying to use modern science to describe biblical or mythological stories IN DETAIL! These stories have been so elaborated, so dramatized that any historical reality is deeply buried. You have to massage the surviving evidence to make it appropriate for the scientific explanation you’re suggesting.

In fact the very existence of the biblical hero Joshua and the Israelite “conquest” of Canaan has been seriously called into question. Professor Israel Finkelstein of the Department of Archeology at Tel Aviv University has published a series of papers and books detailing a broad spectrum of evidence that the Hebrew people developed in situ, that is the Hebrews were originally Canaanites who developed a different culture and came to consider themselves a different people, not an outside people who conquered the central highlands region of Canaan. According to Doctor Finkelstein, the stories of Exodus and Joshua are simply that, stories. There is no archeological evidence to support them. Trying to connect an astronomical event to such “history” may be completely impossible.

(If you’re interested in leaning about Doctor Finkelstein’s work I heartily recommend his “The Quest for Historical Israel” available at Amazon)

Still, up to this point I was with Doctors Humphreys and Waddington, but then they made a connection that just went to far for me. At the time of their eclipse, 30Oct1207BC, the Pharaoh in Egypt was named Merneptah, the son and successor of the famous Rameses the second. Now it happens that we know the number of years these men reigned better than the actual dates. The first year of Mernephat’s reign is considered to have been anywhere between 1213BC to 1204BC.

However, Merneptah is also know for having inscribed a stone slab with details of his victories (such a stone slab is known as a stele), including his victory over Israel! The images below show the entire stele along with the section mentioning Israel.

Merneptah’s Victory Stele (Credit: Wikipedia)
Section of Stele mentioning Israel (Credit: Bible Probe)

Based on this stele Humphreys and Waddington have concluded that Merneptah’s first year as Pharaoh was either 1210BC or 1209BC. As I first read their conclusion I didn’t see the connection to Joshua’s eclipse, Mernephat’s stele mentions Israel but says nothing about anything like an eclipse. Then I thought, are they assuming that Mernephat’s victory over Israel was also Joshua’s victory over the Amorites!!!

That’s way too much of an assumption for me! There is no evidence of any kind that Mernephat and Joshua fought each other or indeed existed at the same time, if Joshua existed at all. Assuming that the two stories of battles are about the same battle is just pure speculation.

I have decided to attempt to contact Doctors Humphreys and Waddington to ask for a little clarification, who knows maybe I missed something somewhere. I’ll let you know when and if I receive an answer.

If you’d like to read the original article ” Solar Eclipse of 1207BC helps to date Pharaohs” click on the link below.

https://academic.oup.com/astrogeo/article/58/5/5.39/4159289/Solar-eclipse-of-1207-BC-helps-to-date?guestAccessKey=96454415-36e7-4640-9fde-d942f3ad00b4

UPDATE: I received a reply from Sir Colin Humphreys, one of the authors of the article. (I didn’t know he was a Sir! The Queen’s birthday honours list of 2010 according to Wikipedia.)

Anyway, Sir Colin accepts that the battles fought by Joshua and Merneptah were not the same but he does believe that the two campaigns were near enough in time to allow him to use Joshua’s Miracle (The Eclipse of 1207BCE) to more accurately date Merneptah’s reign as Pharaoh.

I can only say once again that I am reluctant to accept the bible that literally. Or Merneptah for that matter, remember his stele states that “Israel is laid waste, his seed is not”. Well that’s a boast that rings pretty hollow. And Merneptah’s stele is contemporary with his campaign while the book of Joshua is considered to have been written 500 years later!

Paleontology News for October 2017.

The science of paleontology has been a very active and exciting field of research over the past few years and this past month has seen the announcement of several new discoveries. I’ve chosen three items to discuss in today’s post.

The first discovery I’d like to discuss concerns new evidence about the appearance and skin colouration of dinosaurs. Now everybody knows that most of the dinosaur fossils that are found are just the bones of the animals. And you certainly can’t tell what colour a creature was from its bones. Impressions of the skin of dinosaurs are rare and those impressions with traces of skin colour rarer still.

Because of this fact for many years dinosaurs were usually portrayed as having rather bland colouration, normally just a shade of green. The illustration below from Sinclair Oil Company (Their symbol is an Apatasaurus) shows what we thought dinosaurs looked like in the 1950s and 60s. Notice how the animals are all green or gray and even on those with strips the strips are just a different shade of the main colour.

Dinosaur Colouration as imagined in the 1950s (Credit: Sinclair Oil, Matthew Kalmenoff)

Scientists are a patient bunch however, they kept looking for evidence of soft tissue and there are a lot of fossils out there to find. Over the last twenty years a number of fossil specimens have been found that now tell us a great deal about dinosaur appearance. It turns out that some dinosaurs at least had either vibrant colours or elaborate patterns, or both on their skins, or feathers! Yes, we also now know that many dinosaurs were covered in feathers to keep them warm.

In fact a recent paper published in the journal ‘Current Biology’ describes how small theropod dinosaur from China called Sinosauropteryx, in addition to being feathered was also decked out in alternating dark and light bands similar to the way a raccoon looks. The image below shows what the animal looked like according to co-author Fiann Smithwick of Bristol University.

Drawing of Sinosauropteryx (Credit: Robert Nicholls)

Doctor Smithwick and his colleagues came to their conclusions after an extensive study of three excellently preserved specimens of Sinosauropteryx. The specimens were not only examined under a microscope but the researchers also used cross-polarized filters to bring out the contrast in the colour patters. The image below shows one of the fossils used in the study as seen under cross-polarized light, the areas of light and dark pigmentation are evident.

Sinosauropteryx Fossil (Credit: Jacob Vinther)

This pattern of colouration is known as counter shading and is a common pattern in living animals. Doctor Smithwick suggests that the dark patches around the eyes may have served to reduce glare the same way that athletes today paint a dark stripe under their eyes.

The second news item I’d like to discuss is about the discovery of two-foot long footprints of a predatory dinosaur from Lesotho in southern Africa. While not as large as Tyrannosaurus Rex the theropod that made the footprints came from a much earlier time, the beginning of the Jurassic period about 100 million years before T rex.

According to paleontologist Fabien Knoll of the University of Manchester “Our finding corroborates the hypothesis that theropods reached a great size relatively early in the course of their evolution, but apparently not before the Triassic-Jurassic boundary.” Despite the fact that no remains of the animal have been found so far it is estimated to have been about 10 meters in length and has been given the name Kayentapus ambrokholohali. The picture below shows the footprints of Kayentapus ambrokholohali.

Footprints of Kayentapus ambrokhlolhali (Credit: Reuters)

Finally, we don’t often hear about fossil discoveries from India so the discovery of a well preserved specimen of an ichthyosaur certainly deserves a quick mention. For those who don’t know ichthyosaurs were reptile versions of dolphins that lived during the time of the dinosaurs. Returning to the sea their ancestors had left behind these air breathing lizards evolved fins in place of legs and a fish like tail. The image below shows a typical ichthyosaur.

Ichthyosaur Illustration (Credit: Sedgwick Museum)

The specimen was discovered near the Indian city of Kutch in the province of Gujarat. According to Guntupalli Prasad of the University of Delhi the 5.5 meter fossil is believed to belong to the ichthyosaur family Ophthalmosauridae and lived between 90 and 165 million years ago. The photo below shows the ichthyosaur fossil as it was being unearthed.

Fossil Ichthyosaur in India (Credit: The Hindu)

With these and other exciting fossil finds coming to light on a regular basis this is obviously a good time to be a paleontologist.

Movie Review: Blade Runner 2049, the Original was more Original.

Based upon the Philip K. Dick science fiction novel ‘Do Androids dream of Electric Sheep?’ the first ‘Blade Runner’ movie was one of those films that under performed at the box office back in 1982. Even at the time however the film had a large number of genuine admirers both for the originality of the novel’s plot and director Ridley Scott’s gritty vision in filming it. Today Blade Runner has achieved much better reviews and a growing number of fans.

Original Blade Runner Poster (Credit: Warner Brothers)

For those who don’t know or remember the original movie, in the post-apocalyptic year 2019 humans are busy developing “the outer worlds” and are using ‘replicants’, human appearing androids as a slave labour force. Some of these replicants have escaped and come to Earth where they are hunted down and eliminated by ‘Blade Runners’ like Rick Deckard, played by Harrison Ford in both the original and the sequel. The original film ends with Deckard and a replicant named Rachel leaving together as lovers. The entire film, and the novel before it were a comment on what it really means to be human. Blade Runner was just one of those movies some people loved because it was so different, while others just didn’t understand it for the exact same reason.

So it was inevitable that sooner or later someone would get around to making a sequel and we now have Blade Runner 2049, directed by Denis Villeneuve with executive producer Ridley Scott. The fact that Ridley Scott had a major role in the sequel ensured that ‘Blade Runner 2049’ has much the same gritty feel as the original.

Blade Runner 2049 Poster (Credit: Columbia Pictures)

Without giving too much away the sequel’s plot concerns the hunt for a child that the human Deckard and the replicant Rachel had after the end of the original. It’s the job of the new Blade Runner ‘K’ played by Ryan Gosling, to hunt down this impossible child. By the way ‘K’ is himself a replicant!

That’s one problem I had with “Blade Runner 2049′. In the original film replicants were eliminated just for being on Earth but now there are replicants everywhere, replicants are even hunting other replicants. As an explanation we’re informed that most replicants are a newer, obedient model. I might have accepted that explanation if at the end of the movie we weren’t introduced to a waiting rebel army of ‘obedient’ replicants. In other words the movie changed its own rules in the middle of the story and that’s never a good thing in science fiction.

The bigger problem however is simply a lack of anything really new. If the original Blade Runner was so original that many people couldn’t accept it, the new Blade Runner 2049 certainly doesn’t have that problem. In fact Blade Runner 2049 just a rather obvious take off on the first film.

So much for the bad parts, this film does have a few good things in it as well. As I already mentioned the new Blade Runner maintains much of the same feeling, the same atmosphere as the original but with improved special effects. The effects themselves are very good being a nice mixture of real sets and CGI images. (I think some films just use too much CGI and end up looking like a cartoon.) The two images below allow a comparison of the design of the two films.

Los Angeles in the Original Blade Runner (Credit: Warner Brothers)
Los Angeles in Blade Runner 2049 (Credit: Columbia Pictures)

My favourite part of the film however was that of K’s computer generated girlfriend Joi, and not just because the actress playing the role, Ana deArmas was quite pretty. To me the technology of Joi, both hardware and software were the most original part of the film. When we first meet Joi her image is being generated by a projector in K’s apartment. The projector runs along a railing mounted on the ceiling allowing Joi to move around but only inside the apartment.

K brings Joi a present, a handheld projector that enables her to go outside, even with him on his missions. In terms of hardware that made me wonder how a handheld projector could generate a stable image, especially when K kept putting it in his pocket. More interesting however was the idea of a computer program, however sophisticated, developing a truly individual personality, and Joi had as much personality as any character in the film.

What I would have liked to have seen would have been a couple more computer generated people like Joi. Since these image people would all be developed from the same program could they really be individuals, really be different from one another? Exploring that idea could have been original!

On the whole Blade Runner 2049 wasn’t a bad movie, but with all the money and effort that went into it, it could have been better.

 

Gravity Wave Detection on 17Aug17 quickly becomes the most thoroughly studied Astronomical Event ever.

The past week has been quite an exciting one for astronomy and the scientific community in general. We already knew a part of the story; indeed I mentioned it in a previous post (7Oct17). As a reminder, back on the 17th of August this year the LIGO gravity wave observatories in Hertford Oregon and Livingston Louisiana along with the new Virgo detector in Italy announced that they had made the third ever detection of gravity waves. We now know however, that was just the start of the story.

You see, even as the detectors at LIGO and Virgo were gathering their measurements, in orbit above the Earth the Fermi Gamma Ray Space Telescope was also busy detecting a Gamma Ray Burst, a short sharp pulse of gamma rays that occurs about once a day somewhere in the Universe. Gamma ray bursts are known to be amongst the powerful events ever seen.

Could these two completely different instruments have detected the same event, and if so could other astronomers with other telescopes also observe the event?

Boy did they. Within literally seconds emails were being sent out to astronomers around the world giving the approximate location of the event, a small region in the constellation of Hydra. As quickly as possible other astronomers were using their instruments see what they could find.

It was the Swope telescope at Cerro Las Campanas observatory in Chile that succeeded in finding the exact location, inside the galaxy NGC 4993 at a distance of about 130 million light years. Within hours four more telescopes were also making observations and by the next day the Chandra X-ray Space telescope, the Swift Ultra Violet Space telescope along with the Very Large Array Radio telescope in New Mexico had joined in.

The image below is the event as seen by the Dark Energy Camera at the Cerro Tololo Interamerican Observatory, also in Chile. The picture on the right shows the area of the sky before the event while the picture on the left shows a tiny new dot above the bright object in the center. That small dot is the source of the gravity waves and gamma ray burst.

Source of Gravity Waves (Credit: National Optical Astronomy Observatory)

The event, which has been given the names GW170817 for the gravity wave observation and GRB170817A for the gamma ray burst, has become one of the most studied phenomenons in the history of science. A compendium paper of all of the observations has been submitted to ‘The Astrophysics Journal’ with 4,500 listed authors from 910 institutions. That’s about one third of all professional astronomers in the world.

So what was the event, and what did we learn for it. First of all the observations are consistent with our theories about the merger of two neutron stars into either a larger neutron star or more likely a black hole. And as for what we learned, it’s a little too soon to tell but the fact that our theories were so close indicates that we are making great progress in our understanding of some of the rarest and most powerful events in the Universe. The image below shows an artist’s representation of a neutron star merger.

Artist’s View o9f Neutron Star Merger (Credit: Robin Dienel, Carnegie Institute for Science)

In some ways however, the most impressive thing about the observations of 17August is that the new gravity wave detectors have now been integrated into an ever growing network of astronomical observatories. This network has been developed over the last ten years or so and uses the Internet to maintain instantaneous cooperation between some of the most advanced instruments ever developed. In this way astronomers around the world are ready at a moment’s notice to swing into action to study the most powerful and transient events in the Universe.

All of the papers written thus far have been from observing astronomers; the theoreticians haven’t had the time to study the data. When they do they’ll refine their models and make new predictions. Based on those predictions the observatories will have a better idea of what to look for the next time.

This is how we progress, getting closer to the truth with each event we study. The gravity wave observatories are a new way of looking at the Universe and so far it appears that we’re going to be learning a lot from them.

 

Star Talk for 15Oct17. Neil deGrasse Tyson’s interview with Jane Goodall.

Last night on Star Talk, seen Sundays on the National Geographic channel, host Neil deGrasse Tyson had a very interesting and important interview with Jane Goodall, the noted anthropologist and one of the most influential scientists of the last fifty years. Doctor Goodall is of course best known for her intimate studies of Chimpanzee behaviour, studies that have taught us as much about ourselves as our closest relatives.

Neil began the interview by asking Dame Jane, she has been knighted by Queen Elizabeth, how she first got interested in science. Goodall’s answer was rather typical of many scientists. From her earliest days she remembers liking animals and when she was four she and her family visited a relative’s farm where she was given the job of collecting eggs.

After asking the adults where the hole was that the eggs came from, and being given an unsatisfactory answer, Jane proceeded to follow a hen into the henhouse and watched her for four hours. She was gone for so long that her family thought she was lost, the police were even called. Still, she found out where the eggs came from. The image below shows Neil with Jane Goodall.

Jane Goodall with Neil deGrasse Tyson (Credit: Star Talk, National Geographic Channel)

Every time I’ve seen Jane Goodall interviewed she never fails to mention her mentor the paleoanthropologist Louis Leakey, the man whose discoveries at Olduvai Gorge in what is now the nation of Tanzania gave us the first evidence for the earliest tool using hominids.

In the early 1960s Leakey had learned much about the physiology and tool making abilities of those hominids but “behaviour doesn’t fossilize” and he realized that the best way to understand the behaviour of our ancestors would be to study our closest relatives the Chimpanzees.

Leakey reasoned that any common behaviour shared between ourselves and chimps would probably also be shared with our ancestors. The person he choose for the job was Jane Goodall, who didn’t even have a bachelor’s degree at the time, but she liked animals.

Goodall spent the next five years at Gombe Stream National Park in Tanzania revolutionizing the field of animal research by almost becoming a member of a group of Chimpanzees. Her biggest discovery in those years was the tool making ability of chimps, behaviour that at that times was believed only humans possessed. The image below shows the first photograph of a Chimpanzee using a tool it had made for catching termites from a mound.

First Photograph of a Chimpanzee using a Tool (Credit: Star Talk, National Geographic Channel)

Goodall then returned the UK to get her doctorate, her thesis was ‘The Behaviour of Free Living Chimpanzees’. After receiving her degree Goodall returned to Gombe and spent over thirty years studying the Chimpanzees there. She made many more discoveries, such as the fact that chimpanzees hunt; by cooperating they’re actually successful more often than lions are.

Goodall also saw the dark side of chimp behaviour, murder, rape and even war between different groups. Jane Goodall certainly fulfilled Louis Leakey’s desire to learn about the behaviours we share with the chimpanzees.

As always Neil deGrasse Tyson was joined by a couple of guests in the studio at the Hayden planetarium. One was the comic Chuck Nice, a frequent guest who always succeeds in bringing a few laughs to the discussion. The other guest was Anthropologist Jill Pruetz who had clearly been inspired by Jane Goodall in her early life. Doctor Pruetz, who is studying Chimpanzees in Senegal, discussed one aspect of chimp behaviour that even Doctor Goodall missed; Culture!

You see Doctor Goodall spent her career studying a single chimpanzee group in a small area. It wasn’t until other researchers like Doctor Pruetz studied chimps in other parts of Africa that Chimpanzee culture became evident. The evidence of different types of tool use, different styles of nest building and other behaviours, even differences in vocal calls (Language!!!) Show that chimps in different regions have differences that can only be described as cultural. Yet another way that chimpanzees resemble us.

Jane Goodall’s legacy lays in illustrating humanity’s true place in the World, in showing us how we are not as different as we’d like to think we are. The show Star Talk continues to be a place where scientists like Jane Goodall, and their discoveries can be discussed.

 

 

Space New for October 2017.

Space X is once again heading our space news for the month. On October 11th the privately owned space corporation successfully reused one of its Falcon 9 first stage booster rockets for the third time . The rocket that put the Echo Star 105/SES-11 satellite into orbit had been used previously back on February the 19th to launch Space X’s Dragon resupply capsule on a mission to the International Space Station.

That launch back in February had been Space X’s first launch from NASA’s historic pad 39A, the same pad that had seen so many of the Apollo and Space Shuttle take offs. This was also Space X’s second successful launch in three days demonstrating the company’s increasing skill and competence in the task of launching payloads into space. The image below shows the liftoff of Space X’s Falcon 9.

Launch of Space X’s Falcon 9 (Credit: Space X)

Both of the first stages used in this week’s missions landed intact on Space X’s recovery barge. In fact Space X has now recovered their first stage boosters 18 times making the feat seem almost routine. By making both the recovery and reuse of their boosters routine Space X hopes to reduce the cost of getting into space, dollars per kilo to orbit, enough to greatly increase the amount of cargo going into space. This is something business types call ‘Economies of Scale’ which will help to drive down the cost of space travel even further.

One last word about Space X. Next year the company, along with their rival Boeing, is scheduled to begin test flights of their manned orbital capsules. According to NASA’s commercial crew program each company will perform one unmanned test flight to be followed by a manned flight late next year. Those flights will be the first time in seven years that astronauts will fly into orbit from American soil.

Another space event that got a bit of news play involved the close approach by the asteroid 2012 TC4. The asteroid, which is estimated to be about 30 meters across, came within 43,000 kilometers of Earth on the night of 12 October. Now 43,000 km may sound like a long way off but in terms of the solar system it’s a near miss. It is in fact only a little more than a tenth of the distance to the Moon. The image below shows a NASA illustration of what 2012 TC4 looked like as it passed by Earth.

Illustration of Asteroid 2012TC4 passing Earth (Credit: NASA)

In fact since 2012 TC4 was coming so close NASA decided to use the encounter as the first test of their ‘Planetary Defense System’. A system which one day may be used to deflect, or if necessary destroy, an asteroid on a collision course with our planet.

This initial test simply used NASA’s network of observatories to keep a closer watch on the asteroid’s trajectory as it went by. In 2024 however, NASA hopes to arrange a mission to actually alter the course of an asteroid. Not one on a collision course but another close encounter like 2012 TC4.

The mission is being called DART and the target is actually a pair of asteroids called Didymos that are bound together by their mutual gravity. The test will involve slamming a space probe into the smaller (~150m) asteroid in order to see how its orbit around its larger (800m) companion is effected. From the results of the experiment NASA hopes to learn just how much push would be needed to alter an asteroid’s course enough to prevent a collision in the future. The long term goal would be protect the Earth from disasters such as the one that killed off the dinosaurs.

One final item before I leave. Last month (13Sept17) I wrote a post about the final days of NASA’s Cassini spacecraft before it plunged into the atmosphere of the planet Saturn. Now the Jet Propulsion Labouratory (JPL) and NASA have released some of the details of the doomed space probe’s final minutes. According to JPL Cassini ‘put up a fight’ and fired it thrusters for 91 seconds trying desperately to keep its antenna pointed toward Earth and transmitted data until the last second.

By greatly exceeding its designer’s expectations it’s as if Cassini had acquired something of a personality, a determination to carry out its mission to the end. And it’s not just Cassini. The Voyager probes are still sending us information on interstellar space after more than 40 years and the Lost Horizon spacecraft is now preparing for a flyby of a Kuiper belt object. It’s almost as if these interplanetary explorers are becoming the first mechanical heroes.

Oh I know that’s kind of silly. Or is it, after all who knows what our space probes will be like a hundred years from now. Cassini’s final image, transmitted to Earth even as the probe was falling into Saturn’s atmosphere is below.

Cassini’s Final image (Credit: NASA-JPL)

 

 

 

 

The Highest Energy Cosmic Rays come from outside our Galaxy, and just what are Cosmic rays anyway?

Even after more than a hundred years of study the origin and to a lesser extent the nature of Cosmic Rays is still something of a mystery. It was in 1912 that Victor Hess used a balloon to sent three electrometers, an early device for measuring radiation, to an altitude of 5300 meters. His discovery that the intensity of radiation increased as you ascended into the atmosphere stunned scientists. For his discovery Hess would be awarded the Nobel Prize in Physics in 1936.

It was quickly realized that the radiation being detected by Hess and others was actually the secondary products of collisions taking place in the upper reaches of our atmosphere between atoms of gas and some very powerful sources of energy coming from outer space. At first scientists believed that the primary component of the radiation was some form of X-ray or Gamma Ray, hence the name Cosmic Rays. It wasn’t until 1927 that physicist Jacob Clay was able to demonstrate that the source of Cosmic Rays was affected by the Earth’s magnetic field and therefore had to consist of charged particles.

In the years that followed physicists slowly learned that most (~90%) of cosmic ray showers are produced when a proton, with velocity nearly that of light slams into an atom in the air, shattering the atom and producing a spray of particles. In very energetic events the secondary particles produced by the initial collision may still have enough energy to strike and shatter further atoms leading to a cascade of sub-atomic particles. The diagram below illustrates such a cascade.

Primary cosmic ray. Development of an extensive air. shower in the Earth’s. atmosphere. Mostly muons, electrons and photons at Earth’s surface. (Credit: Pierre Auger)

Now I said that 90% of the primary particles are simple protons but about 9% have been found to be the nuclei of Helium atoms (two protons and two neutrons). The last 1% is composed of the nuclei of all the known atoms up to and including Uranium. In many ways the primary Cosmic Rays look just like the nuclei of the elements that the Sun is made of, accelerated to nearly the speed of light.

That resemblance to the composition of Stars gives us a clue as to where the Cosmic Rays get their energy. Our best model for the generation of Cosmic Rays uses the powerful explosions known as Supernova to boost some atoms to incredible energies. However calculations show that even Supernova are not powerful enough to produce the most energetic Cosmic Rays. Over the last 30 years astrophysicists have added black holes to the list of possible Cosmic Ray factories but not even black holes can account for some of the most energetic Cosmic rays that have been observed. Where these Ultra High Energy Cosmic Rays (UHECR) come from is still a hot question in astrophysics. The Cosmic Ray spectrum, that is the number of incident particles as a function of energy, is shown in the diagram below.

Cosmic Ray Flux. Number of Particles vs. Energy (Credit: Sven Lafebre)

It should be mentioned at this point that some of the Cosmic Ray particles that have been observed are millions of times more energetic than the particles accelerated in the Large Hadron Collider (LHC) at CERN. Now the LHC is the most powerful particle accelerator humanity has ever built, accelerating protons to an energy of 13 Trillion electron volts. That amount of energy would be about in the middle of the diagram above. Therefore all of the Cosmic Rays on the right hand side of the diagram are more powerful than anything humanity has ever produced. It’s easy to understand why physicists are so curious about where their energy comes from.

The Ultra High Energy Cosmic Rays (UHECR) are being studied by the Pierre Auger experiment, a vast array of detectors spread out over 3,000 square kilometers of the grasslands of Argentina. Since the more powerful the initial Cosmic Ray particle the larger the cascade it produces at Earth’s surface the Pierre Auger experiment must be physically large in order to capture the largest, most energetic cascades.

Recently the scientists at Pierre Auger have published a paper in which they announce that the very highest energy Cosmic Rays, those more than a million times the energy of the LHC, come from outside our Galaxy. This result comes from the study of 30,000 such particles. This is only one more clue in our attempts to unravel the mystery of Cosmic Rays but we have already learned much in the last century. If you’d like to learn more about Cosmic Rays or the Pierre Auger experiment click on the link below to be taken to the Pierre Auger website.

https://www.auger.org/

2017 Nobel prizes in Medicine, Physics and Chemistry.

Over past week the Nobel committee has been announcing their selections for this year’s prizes. This year it seems as if trios are popular because each of the prizes for science was awarded to a trio of researchers.

The award for medicine / physiology was the first to be announced on Monday. The winners were Jeffery C. Hall and Michael Rosbash, who worked together at Brandeis University in Massachusetts along with Michael W. Young at Rockefeller University in New York. See Picture below.

2017-Nobel Winners for Medicine. L-R Jeffery Hall, Michael Rosbash, Michael Young. (Credit: Nobel Foundation)

The Three scientists were honoured for their research into the biological rhythms built into living creatures, a phenomenon known as the Circadian clock, the 24 hour day-night cycle caused by the rotation of the Earth.

The two teams conducted their research using fruit flies, a species that has been center stage in biological studies for over a century now. What they discovered was that the mechanism of the clock consisted of a network of genes and proteins that time the release of hormones turning on then turn off sleep, raise and low body’s temperature and blood pressure while regulating other body processes. Occasional disruptions in this genetic rhythm results in the familiar ‘Jet-Lag’ while prolonged disruptions can result in a number of serious health problems.

Before I move on I would to mention that much of the original work on circadian clocks was carried out by two scientists named Seymour Benzer and Ronald Konopka. It was these two men who discovered the ‘Period’ gene that initiates the entire process. Benzer and Konopka are ineligible to share in the prize however as they are both deceased. Alfred Nobel’s will specifically states that only living scientists can receive the award and this is not the first time that a scientist worthy of the honour has died before the committee saw fit to select them.

On Tuesday it was the Physics prize that was announced and I was very pleased to learn that it had been shared by Rainer Weiss of the Massachusetts Institute of Technology (MIT) along with Kip Thorne and Barry Barish of the California Institute of Technology (Caltech not CIT). See picture below.

Nobel Physics winners. Rainer Weiss, Kip Thorne and Barry Barish (Credit: Getty Images)

The work for which these scientists won the prize was the detection and measurement of Gravitational waves, a phenomenon predicted by Albert Einstein in his Theory of General Relativity almost exactly a century before they were finally detected.

Professors Weiss, Thorne and Barish are the principle designers and leaders of the Laser Gravity Wave Observatory (LIGO) project. I have written posts about the LIGO project earlier (14Jun2017) but simply put the LIGO project consists of two, four kilometer long L shaped laser detectors, one in Hanford Washington the other in Livingston Louisiana.

By comparing the laser beams traveling up and down the two arms of the L the detector is capable of measuring tiny distortions in the fabric of space-time itself. Using the two detectors allows the direction of signals source to be estimated and now that a third detector in Italy (VIRGO) has come on line the accuracy of the direction measurement will increase.

Detecting gravity waves is a completely new way of looking at the Universe and every time science has succeeded in doing that we’ve discovered thousands of new wonders. We can only hope that the study of gravity waves will prove to be as fruitful.

On Wednesday it was the Chemistry prize that was announced. The recipients were Jacques Dubochet of Lausanne University in Switzerland; Joachim Frank of Columbia University in New York along with Richard Henderson of Cambridge University’s Labouratory of Molecular Biology. It’s worth noting that Professor Henderson is the 15th Nobel laureate from the Lab (Not 15 Nobel laureates at Cambridge, 15 at just that lab at Cambridge!!!). See picture below.

Nobel Chemistry. Jacques Dubochet, Joachim Frank, Richard Henderson (Credit: EPA-EFE/REX/Shutterstock)

The work these three men carried out was the development of a series of techniques that have enabled scientists to better image complex organic molecules and structures with electron microscopes. Electron microscopes are similar to the microscopes you used back in High School but because the wavelength of an electron is so much smaller than that of visible light an electron microscope can magnify an image thousands of times more. I’ve had several occasions in my career to use electron microscopes to study electronics and they are wonderful instruments that can provide so much useful data.

Electron microscopes have problems when used to study living tissue however. First of all the electron beam must be in a vacuum, a condition that is not only lethal but can also cause the water in the cells to evaporate explosively, and remember we are composed of 70% water. Also the beam of electrons itself can be powerful enough to physically alter the specimen being studied.

Professor Henderson developed a technique for replacing the water in organic structures with a sugar cocktail that could withstand the vacuum. Professor Dubochet took a different tack, creating a process that quick froze the specimens so that the water in them did not crystallize. This process is called Cryo-electron-microscopy. Finally Professor Frank used computer algorithms to increase the precision of the data allowing scientists to learn even more from their instruments. An example of just how detailed the images provided by an electronic microscope have become the picture below shows a protein molecule.

Improvement in Electron Microscope Resolution. (Credit: Nobel Foundation)

The discoveries made by this year’s Nobel laureates have brought great advances to human knowledge. In a world filled with an almost daily barrage of bad news maybe we should think of a way to honour our scientists more than three days a year!

Season Premier of Star Talk with Neil deGrasse Tyson, where Science and Pop Culture Collide.

Sunday night, 1Oct17, the National Geographic Channel broadcast the fourth season premier of Neil deGrasse Tyson’s Star Talk from the Hayden Planetarium in New York’s Museum of Natural History. The show included Neil’s interview with Lance Armstrong the bicyclist who won the Tour de France seven consecutive times only to have his titles taken away from him because of his use of performance enhancing drugs. The choice of Armstrong as the interview choice for the first show of the season was an unusual one but the show was both interesting and informative. The image below shows Neil with Lance Armstrong.

Neil deGrasse Tyson with Lance Armstrong (Credit: Star Talk, National Geographic Channel)

Now the interview with Armstrong was taped but Neil had two guests with him live at the Hayden Planetarium. One of the guests was Scott Adsit, a comedian who has appeared on the show several times now. Neil always has a comic as one of his guests to interject a few laughs into the more serious discussion. To provide the background on the science of bicycling the other guest was Max Ginskin, the author of the book Cycling Science.

The first half of the show dealt with the history and science of cycling discussing topics such as the history of the Tour de France along with the importance of aerodynamics in cycling. There was also a segment on the way the performance of a cyclist is measured using the ratio of the power his muscles can produce to his body mass in kilos. The image below shows one of the show’s regulars undergoing the sort of testing professional athletes use to measure their performance.

Athletic Training (Credit: Star Talk, National Geographic Channel)

The second half of the show dealt with the more controversial subject of Lance Armstrong’s admitted use of performance enhancing drugs or PDEs. For this segment Professor Arthur Caplan, a bioethicist from New York University joined Neil and his live discussion.

As I said, Armstrong has now admitted to using PDEs but maintains not only that everybody was using them but also that the drugs had become so powerful and pervasive that it was impossible to compete without them. Without absolving Armstrong, Professor Caplan agreed the governing body in cycling shared the responsibility for failing to address the problem with adequate testing and appropriate penalties.

To challenge Professor Caplan, Neil brought up the argument that, if everybody is using PDEs then the playing field is still level, the competition still fair so why not let the athletes use PDEs if they want. Professor Caplan replied with three points that I’d like to repeat.

  1. If everyone uses PDEs the competition is only longer between athletes but between drug companies negating the whole point of athletics.
  2. For those who love their sports part of the fun is comparing past performances to modern ones. Just this past season in Major League Baseball’s Juan Carlo Stanton hit 59 home runs leaving him just one short of a level of success that only two players in history have ever fairly attained! Like cycling the MLB has to confront its having turned a blind eye to drug use in the past.
  3. (And this is the most important point). These drugs are not safe. Even the use of cortisone for pain relief should be done cautiously. Steroids and other even more powerful drugs have numerous long term health risks. And even if you think adults should be allowed to take such risks if they choose to, what about the 16, 17 hey even 14 year old who dreams of a career in sports? For a teenager to use PDEs will certainly lead to severe health problems when they are in their 40s or 50s.

That’s the value of science, that it gives you the facts so you can make an ethical, reasonable judgment. And that’s the value of Star Talk with Neil deGrasse Tyson. If you’d like to learn more about the show ‘Star Talk’, find out where you can watch it, click on the link below to be taken to the Star Talk website.

http://channel.nationalgeographic.com/startalk/