Tiangong-1 is falling, Tiangong-1 is falling, but don’t worry, it won’t hit you on the head.

Over the last several weeks it’s been next to impossible to avoid all of the news stories telling you about how China’s first space station the Tiangong-1 is out of control and will come crashing back to Earth any day now. The headlines grab you by announcing the crash is bold letters while the small print inside reveals that there’s a one in ten billion, or less, chance that anything will actually hit you.

The Tiangong-1 station, Tiangong means ‘Heavenly Palace’ in Chinese, was launched by China in 2011 as both a target for practicing rendezvous maneuvers in space as well as some extra living space for the crews of their Shenzhou manned spacecraft. The design of the Tiangong-1 station is based upon the design of the Shenzhou but with a slightly larger habitable section giving it a slightly greater mass (8500kg versus 7840kg for the Shenzhou). The image below compares the Tiangong and Shenzhou.

Tiangong-1 space station and the Shenzhou-8 spacecraft. (Credit: The Daily Mirror)

Like the United States’ Skylab and Russia’s Salyut early space stations the Tiangong-1 was launched into space unmanned and in one piece and then visited several times by manned spacecraft. The Shenzhou-9 mission rendezvoused with the Tiangong-1 in June of 2012 with a crew of three and stayed for ten days while the Shenzhou-10 mission, also with a crew of three, visited the Tiangong in June of 2013.

In both of these missions China’s growing space program demonstrated the ability to carryout the routine operations necessary for more complicated space missions in the future whether that be building a modular space station or even missions to deep space. The image below shows the launch of the Shenzhou-9 mission on its Long March 2F rocket.

Launch of Shenzhou-9 on a Long March 2F rocket (Credit: CCTV)

After the two successful missions to Tiangong-1 China launched the Tiangong-2 station as a replacement for Tiangong-1 and the first station was then placed into a sleep mode. The plan was to maintain Tiangong-1 in orbit as a test platform for the longevity of both components and systems in a space environment before the station was brought back to Earth in a controlled reentry into an ocean.

Apparently that test didn’t go so well because on 21Mar2016 China’s Space Engineering Office announced that they had lost their radio telemetry link with the station. Amateur satellite watchers soon confirmed that the Tiangong station was tumbling out of control. Notice how China never actually admitted that the station was out of control.

It wasn’t long before scientists were calculating that the Tiangong-1 would be making an uncontrolled reentry back to Earth sometime in either March or April of 2018. That estimate has since been fine-tuned down to between 29Mar and 9April of this year.

So here we are, all of the news stories loudly telling us that Tiangong-1 is falling out of control, is there any real danger? Well first of all let me tell you that most of the station will burn up during reentry, only a few hundred kilograms of material are expected to survive to reach the ground. Also remember that the Earth’s surface is 70% ocean so Tiangong will probably sink without a trace.

Then, even if Tiangong does hit dry land there are literally millions of square kilometers of emptiness out there so the odds of anyone being hurt are less than ten billion to one. In fact when the much larger and heavier US Skylab station also fell to Earth in an uncontrolled reentry back in 1979 pieces of it fell near the city of Perth Australia but no one was injured in any way. A few people did get some really neat pieces of space debris however as souvenirs.

Finally, the orbit of Tiangong is tilted at an angle of 42.8º to the equator. That means that Tiangong never goes further north than 42.8º of Latitude nor further south than 42.8º. If you live outside of that band you have absolutely nothing to fear.  See the image below to know if you should be worried. I live in Philadelphia at a latitude of 40º  but I ain’t gonna fret!

Tiangong-1 will fall somewhere between 40N and 40S (between the Lines) (Credit: Mail Online)

Ball Lightning: The Mysterious Phenomenon that has produced more Theories than detailed Observations.

Descriptions of the strange, almost unearthly phenomenon known today as Ball Lightning date back as far as Aristotle. However the recorded incidents of ball lightning have been so infrequent, and the behavior of the phenomenon so varied, even contradictory that up until the mid-twentieth century many if not most scientists regarded ball lightning to be an imaginary rather than a real physical event. The image below shows an illustration of a nineteenth century occurrence of ball lightning.

19th Century Illustration of Ball Lightning (Credit: Public Domain)

It is true that ball lightning can range in size from less than a centimeter to as much as a meter in diameter. The colour of ball lightning can also vary tremendously although red, orange and yellow predominate. The movement of ball lightning is generally horizontal but they have been known to move up or down or even remain motionless. They can even appear right out of walls or other solid objects.

Perhaps the greatest variance in the different observations of ball lightning however is in the way they dissipate. Sometimes they can just disappear like a light bulb that’s turned off while sometimes they disappear by passing into walls or other solid objects. And then sometimes they can explode doing considerable damage and even death. The image below shows of modern photograph of ball lightning.

Photograph of Ball Lightning (Credit: Miyuki Ishikawa)


About the only things that all the different reported incidents agree upon is that ball lightning usually occurs during a thunderstorm and normally right after ordinary cloud to ground lightning bolt has struck nearby. Over the last century however reports of ball lightning have also been connected with heavy electrical equipment like generators and there are even reports of ball lightning occurring in submarines during World War II went the sub was switching from its diesel engines to battery power.

Theories about the nature of ball lightning abound and over the last 50 years scientists have even succeeded in produced ball lightning-like objects in the labouratory. Despite these successes there are arguments as to whether those labouratory creations are the ‘real’ ball lightning. The image below shows one of the labouratory attempts to create ball lightning.

Ball Lightning in the Lab (Credit: Narod.ru)

The best data concerning natural ball lightning comes from a group of scientists from Northwest Normal University in Lanzhou China who in July of 2012 were studying ordinary cloud to ground lightning on the Tibetan plateau. While they were making their observations they spotting ball lightning and were able to record 1.6 seconds of video of the event. Because the cameras that the scientists were using in their cloud to ground lightning observations were equipped with slitless spectrographs the researchers also succeeded in obtaining the first ever optical spectra of ball lightning.

The spectra obtained by the scientists showed strong emission lines for the elements of silicon, calcium, iron, nitrogen and oxygen. The spectra also showed that the ball lightning had a temperature of less than 14,000K. See spectra below.

Spectra of Ball Lightning (Credit: Wikipedia)


This remarkable data has bolstered one of the leading theories about the origin of ball lightning, the ‘Vapourized Silicon Hypothesis’. In this model ordinary lightning strikes the ground vapourizing and ionizing the silicon-dioxide in the soil. As the vapour cools the silicon becomes an aerosol that is bound together by the charges on the ions. The glow of the ball lightning is produced as the silicon recombines with the oxygen.

There are rival hypotheses however, some rooted in solid science, some a little bit kooky. The Microwave Cavity Hypothesis considers ball lightning to be generated by microwave radiation that ionizes the air with the discharge of that ionization causing the glow. The problem with this idea is that while ordinary cloud to ground lightning does produce a lot of radio energy most of it is in the AM and short wave bands rather than microwaves.

Then there’s the Electrically Charged Solid Core hypothesis where a solid object acquires a positive electric charge and becomes surrounded by a layer of electrons. A microwave field keeps the positive and negative charges apart and the high voltage generated between the charges is what we see as the ball lightning. In addition to requiring microwaves again this hypothesis also requires a solid object inside the ball lightning, something not seen in any observations, as well as being something that would have difficulty in passing through solid walls!

Among the more outlandish suggestions there is the mini-black hole model where an atom sized, primordial black hole is passing through our atmosphere and we see it as ball lightning. However there is no reason for a mini-black hole to be as closely associated with ordinary lightning or large electric generators as ball lightning certainly is. Also a mini-black hole would not simply blink out of existence as ball lightning is known to often do.

The mystery of ball lightning will probably continue for some time into the future. However, with so many people nowadays carrying cell phone cameras with them we are likely to get more and better observations of the phenomenon. At the same time scientists will continue working in their labouratories to discover more ways of creating ball lightning-like objects. Considering only 50 years ago some scientists even doubted the existence of ball lightning we’ve made a lot of progress. Clink on the link below to be taken to a youtube video of ball lightning taken outside New Orleans in 2015.



Volcanic ‘Hotspot’ that formed the Hawaiian Islands moved about 50 Million Years Ago.

Geologists have learned a great deal in the last fifty years about the mechanics of how volcanoes are created and operate. According to the modern theory of ‘Plate Tectonics’ the surface of the Earth consists of a number of hard plates that ride over our planet’s softer, more fluid mantel. These plates move around the surface of the earth very slowly with time. As the plates move they can either pull apart from or collide into each other and those are the areas of the Earth where seismic activity like earthquakes or volcanoes normally occurs.

Normally, but not always, the volcanoes that have formed the Hawaiian Islands are a major exception to this model. Geologists have recognized the existence of a stationary ‘Hotspot’ in the Pacific Ocean that is presently feeding the active volcano of Kilauea on Hawaii’s big Island.

The Kilauea volcano is only about half a million years old however and before then the hotspot generated the now extinct volcanoes of Mauna Kea, Diamond Head and all of the other volcanoes of the Hawaiian chain. The images below show Kilauea and Diamond Head.

Kilauea Volcano (Credit: Milliyet.com)
Diamond Head extinct Volcano (Credit: lexpress.fir)

In fact, as the Pacific Tectonic Plate has moved northwestward over the last 70 million years the hotspot has generated a long series of now extinct volcanoes known as the Hawaiian-Emperor chain. Most of these volcanic peaks have now dropped back below the surface of the ocean but the entire chain stretches in a straight line from Kilauea almost to the Aleutian Islands. The illustration below shows what the Hawaiian-Emperor chain would look like if the water of the Pacific Ocean were removed.

Hawaiian Emperor Volcano Chain (Credit: Earth Science)

Recently more accurate underwater mapping of the Hawaiian-Emperor chain has led researchers at the GFZ Research Center for Geosciences in Germany to conclude that the Hawaiian-Emperor chain may not be as straight as was thought. According to the scientists at GFZ about 47 million years ago the chain took a temporary bend to the left, as seen from Hawaii, an indication that the hotspot had moved several dozen miles to the south over the course of around a million years. The image below shows the bend identified by the geologists.

Bend in the Hawaiian-Emperor Hotspot (Credit: T. Torsvik, GFZ)

“If you try to explain this bend with just a sudden change in the movement of the Pacific Plate.” Says Bernhard Steinberger a researcher at GFZ. “You would expect a significantly different direction of motion at that time relative to adjacent tectonic plates. But we have not found any evidence for that.”

The scientists also checked the position of the Hawaiian hot spot against two other hot spots, the Rurutu volcanic chain in the western Pacific and the Louisville chain in the southern Pacific. The results indicate that it was the Hawaiian hotpot that moved some 50 million years ago.

The geologists at GFZ will continue to study the movement of the Hawaiian hotspot. “With more field data and information about the processes deep in the mantel, we hope to explain in more detail how the bend in the Hawaiian-Emperor chain has evolved.” Steinberger said.

The more we learn about volcanoes the better we will be able to understand how the Earth itself works. I look forward to hearing more from the GFZ Research Center for Geosciences about their work on the Hawaiian hotspot.


Movie Review: Annihilation. H. P. Lovecraft’s ‘The Colour out of Space’ updated with a lot of Unnecessary Emotional Baggage.

Annihilation (Credit: Paramount Pictures)

At the beginning of Paramount Pictures new Movie ‘Annihilation’ we witness a meteor streaking through the atmosphere to wind up crashing into a small lighthouse. A little while later we learn that the lighthouse has become the center of an unearthly ‘shimmer’ that is slowly growing and that anyone who enters the shimmer never returns.

After several failed expeditions a team of five women enter the shimmer to discover that the plants and animals are all mutating. It was at this point, not quite halfway into the film that I said to myself: ‘this is the Colour out of Space by H. P. Lovecraft’. Actually ‘Annihilation’ would have been better if it had just stuck to being an update of Lovecraft’s story.

For those who haven’t read Lovecraft, in the ‘Colour out of Space’ a meteor lands on a New England farm and a strange unearthly colour (Lovecraft was thinking of something like Ultraviolet or Infrared light but somehow alive) begins to spread. The colour proceeds to suck the life out of every living thing on the farm.

O’k so in ‘Annihilation’ the meteor lands in a lighthouse instead of a farm, it generates a shimmer rather than a colour and causes mutations instead of sucking the lifeforce but those are just details. It’s really the same story plot.

Some of the Mutations in Annihilation (Credit: Paramount Pictures)

The only part of ‘Annihilation’ that is different is an idea that gets mentioned along the way that anyone who volunteers for a suicide mission must have something terribly wrong with their life. The main character Lena, played by Natalie Portman certainly does. Her husband joined an earlier mission into the shimmer because he found out she was having an affair and now she feels guilty about him so she volunteers for the next mission. Much too much of the movie is taken up with this pointless subplot.

Oh, I know. Nowadays when you tell a story you simply have to have well-developed characters that your readers or viewers can care about. You can take it from me however, there’s no one in this movie to care about. Also you can add the fact that the ‘surprise ending’ simply wasn’t.

Now Annihilation wasn’t all bad, the special effects were good and the basic idea of something really alien coming to our world on a meteor is intriguing. In fact it is revealed later in the movie that the shimmer isn’t causing mutations so much as mixing the DNA of different creatures.

Then when Lena finally reaches the lighthouse we see things like glass trees along the beach. Since glass is made out of sand I started to wonder if the shimmer is now mixing life and non-life! That would have been cool but nothing is done with the concept!

Glass Trees that nothing is done with! (Credit: Paramount Pictures)

Really, eliminating the trite infidelity subplot and putting a lot more thought into the Science Fiction elements would have made Annihilation a much better film. As it is we never learn anything about why this ‘Shimmer’ came to Earth or where it came from or what it is trying to do.

Annihilation is based on a novel of the same name by Jeff VanderMeer (who also wrote the screenplay with director Alex Garland) and is the first part of a trilogy. Maybe in the other novels we get some of the answers but frankly I don’t know if I’m interested. I think I’ll reread ‘The Colour out of Space’ instead.

The Colour out of Space by H. P. Lovecraft (Credit: Classics Illustrated)


Amateur Astronomer trying out his new camera accidentally photographs the first instant of a Supernova explosion.

Supernovas are among the most energetic events in the entire universe. A star, at least five times the mass of our Sun ends it’s life in a tremendous explosion that for a few weeks can be as bright as an entire galaxy of 100 billion stars. Supernovas are so bright in fact that they are usually observed and studied in other galaxies sometimes billions of light years away. Supernovas are also one of the most keenly studied class of objects in the Universe with astronomers and astro-physicists searching tirelessly for any new scrap of information, any new observation.

Now supernovas might be very bright, but usually they’re also very far away and since they occur randomly anywhere in the sky, they can often be hard to spot. The way that astronomers find a supernova is to compare a picture of a far off galaxy with a picture of the same galaxy taken a month or more ago. If a new star appears in the latest picture, you’ve got a supernova.

The problem with that technique is that astronomers have only ever seen a supernova several days or more after the explosion has taken place. They’ve never actually seen the first moments of the supernova explosion itself.

Until now, in September of 2016 an amateur astronomer named Victor Buso of Argentina was testing out a new camera with his 16-inch telescope when a supernova happened right in his field of view. Buso was taking one exposure every thirty seconds of a galaxy designated NGC 613 for a period of twenty-five  minutes and managed to capture the rapid increase in brightness, what astrophysicists call the ‘Shock Breakout’ of the supernova. The image below shows an image of NCG 613 with the supernova bracketed by the red lines.

Supernova SN2017 gkg (bracketed by red lines) Credit: Carnegie Institute of Science, Las Campanas Observatory)

Four of the images captured by Mister Buso are shown below with the supernova, which has been designated SN 2016 gkg, inside the red circle.

Four of the Images Captured by Victor Buso of SN 2017 gkg (Credit: Victor Buso)

In the first image, labeled 1:44 AM, the supernova is not visible but in each of the succeeding three images it grows brighter. According to astronomer Alex Filippenko of the University of California at Berkeley, “Professional astronomers have long been searching for such an event.” Adding. “Buso’s data are exceptional. This is an outstanding example of a partnership between amateur and professional astronomers.” The image below shows Mister Buso proudly standing by his telescope, and he has a great deal to be proud about.

Victor Buso and his 16″ Telescope (Credit: Nature)

Once Mister Buso realized what he’d discovered he quickly contacted the Instituto de Astrofisica de La Plata in Argentina and within hours astronomers around the world were hard at work learning everything they could about Buso’s supernova.

Examining the spectra of the SN 2016 gkg enabled an international team of astronomers to determine that the supernova is a type IIb. The spectra of this type of supernova is rich in hydrogen and is the violent death of a star calculated to be five times the mass of our sun.

There are several well-known stars in our night sky that could be headed toward the same end as SN 2016 gkg. Betelgeuse and Antares are large, very massive stars that are approaching the end of their nuclear fuel and it is believed that they will both become supernovas ‘sometime in the next million years’.

Right now however scientists do not know how to predict exactly when a star will go nova but a lot of progress has been made in the last twenty years. (See my post of 11January 2017) Hopefully Victor Buso’s discovery of SN 2016 gkg will provide more data for astro-physicists to check their current theories against, and to help them generate newer, more accurate models of supernovas.