Astroblog

Last night a short news segment on herbal medicines ran on Channel 9 which I not only appeared on, but actually referenced my research. You can see the interview here:
https://www.youtube.com/watch?v=3audRUF7C2I&feature=youtube_gdata_player

I have done a lot of radio, but I'm pretty much a newbie at television.  Despite me not looking at the interviewer, waving my arms around and having the camera peer up my nose, the interview that went to air was a lot less mortifying than I thought it would be.

Unfortunately in the clip they kept on saying "I" did the study and "I" purchased the medicine (that was the first author Lauren)

Emeritus Professor Alastair MacLennan was quite direct, but it was amusing that it was a Naturopath that they got to give the advice to always check with a health care provider.

You may be surprised that it took nearly and hour and a half to film those tiny segments. There was a lot of stuff that got left out, or was covered by voice-overs, and I did a fair few retakes as I stuttered a lot. Maybe I should run some workshops on how (not) to give TV interviews. 

Labels: Friends of Science and Medicine, herbal medicine, public outreach, science, televison

My first, rubbish image of ISON.

Comet C/2012 S1 ISON has come out from behind the sun, and around the world amateur and professional telescopes alike are focusing on it, trying to follow the evolution of this visitor from the frigid depths of space. But faster than the information comes from these scopes comes misinformation, misunderstanding and outright hoaxes.

 For many of us this is Deja Vu. Virtually everything that is being said about ISON was said about comet C/2010 X1 Elenin.

But it is worth dispelling some of the misapprehension about ISON so people can enjoy the spectacle of the comet without fear.

So, I heard comet ISON has broken up.

No, it was found where it was predicted to be and it's brightness is pretty much as predicted.  The hoax images going around of comet ISON's "breakup" are from the breakup of comet 73P.

Will it hit the Earth? 

No, it comes nowhere near the Earth, the closest it comes is 0.4 AU from Earth. This is just under half the distance between the Earth and the Sun. Venus comes closer to us than the comet. To give you a feel of the distances involved, get a soccer ball, a pea and a sesame seed (or a grain of salt). Go to your back door, then place the pea there. That represents the Earth. Now walk towards your back fence with 10 full strides. Place the soccer ball there. That represents the Sun. Pace out 4 full strides at right angles to the soccer ball pea axis (you may need to go into your neighbours yard to do this) and place the sesame seed/grain of salt. That's the comet (and this exaggerates the size of the comet). See the illustrations below for more context.

Comet ISON in relation to Earth on 1 November, when it crosses Earth's orbit. Top view above, side view below. The comet is marked with a red cross. You will probably need to click on the image to embiggenit to see that the comet passes above, not through, Earths' orbit.	Comet ISON in relation to Earth on 26 December, when it is closest to Earth. Top view above, side view below. The comet is marked with a red cross. You will probably need to click to embiggen the image.	Comet ISON in relation to Earth on 14 January 2014, when it is crosses the point where comet ISON crossed Earths' orbit back on 1 November. Top view above, side view below. The comet is marked with a red cross. You will probably need to click to embiggen the image.

There is a video claiming that NASA has slowed down Earth in a simulation of the orbit so that Earth will miss the comet in the simulation. However, everything has been slowed down to show ISON at perihelion clearly. As you know from the explanation and images above, and this Celestia simulation (nothing to do with NASA) you can clearly see Earth is nowhere near the comet.

But surely the comets encounter with Mars and the Sun will alter its orbit! 

This is already accounted for in the orbital calculations. We have a very good understanding of gravity and the interactions of bodies with each other, and use these interactions to slingshot spacecraft very precisely into the depths of space. There is some uncertainty involved, we don't know the precise mass of ISON, and non-gravitational effects from the gas and dust blasting from the comet will alter the orbit slightly. However, from our experience with past sun grazing comets we can estimate the range of orbits we could have, and none of these come anywhere near Earth.

Again, go back to your sesame seed/grain of salt, move it 10 millimetres closer to the pea. That's the level of variation involved. When comet C/2011 W3 Lovejoy, a smaller comet than ISON, slingshoted around the Sun in 2011, it turned up pretty much bang where it was predicted to be.

What if the comet breaks up? 

Comet 73P after breaking up. Image Credit: NASA/Spitzer via Wikipedia Commons 

Hollywood script writers should be smacked along side the head with the thickest astronomy textbook you can find. They are responsible for the idea that comets (or asteroids) break up and shower chunks in every direction.

What will happen is that the chunks will carry on in the same orbit as the original comet. Just as Ikea-Seki did. It may be possible we will see a spectacular "chain of pearls" effect as seen with comets 73P and Shoemaker-Levi. But the chunks will come nowhere near us, just like the original comet. Even if it completely disintegrates, like C/2010 X1 Elenin or C/2011 W3 Lovejoy, the cloud of dust will continue on the same orbit just as it did for these comets. Again, it will come nowhere near us.

What about all the objects following ISON? 

There are no objects following ISON, people have been misinterpreting hot pixels on some animations. In most CCD camera chips, there are always a few pixels that are permanently on, these are the "hot" pixels.

What about the "UFO" image?

Combination of three separate Hubble images of ISON aligned on the background stars. Image credit NASA/Hubble.

That was a combination of three separate images taken when Hubble was tracking the stars. Not only does ISON move in regard to the background stars, Hubble is also orbiting the Earth, so it's view of ison while it is pointing towards the stars changes considerably with time. if you just combine these separate images so that all the stars are aligned, the comet will be seen in different places. See here for a more detailed explanation with images.

Will we go through the comet ISON's tail? 

No.

But the tail will be enormous! 

And nowhere near us. The comet crosses above Earths' orbit on November 1, at that time the comet and its tail will be 0.023 AU above Earths' orbit, that's 10 times the distance from Earth to the Moon. On our backyard model, the sesame seed will be the length of your foot away from the line that defines the Earth's orbit. But at this time Earth itself is over 12 full strides away from the comet and its tail. The tail always points away from the Sun so it can't come near Earth. Replace the sesame seed with a piece of string one stride long, that will give you a sense of the scale of the tail within the solar system (and it's relation to Earth)

Tails actually, there is the gas tail, which points directly away from the Sun, and the dust tail, which points away from the Sun but follows the comets orbit (so it looks curved to us). The particles in the dust tail follow the comet in its orbit, so two and a half months, when Earth reaches the point in its orbit where the comet crossed above it, all the dust and gasses will be long gone. Also remember that the tail will not be as big in November, the tails of comets only reach their fullest extension after perihelion, when the comet is closest to the Sun and the rapidly sublimating ices blast lots of dust and gas into space.

See this post on the tail of ISON and the animations in it. Also, scroll back up to the illustrations of the comets orbit.

So, no meteor shower then?

No. we might get some increase in noctilucent clouds, but not a meteor shower (NASA PR flacks should be whacked with an astronomy textbook for describing noctilucent clouds as a meteor shower).

But it would be really bad if we went through the tail wouldn't it? 
 
No. Remember that a comets tail is a fairly good vacuum, it's less of a vacuum than the interplanetary medium and solar wind, but still it's mostly nothing. People get upset at the idea there is cyanogen in the gases of the comets tail, but cyanogen only represent 0.5% of the gases, and 0.5% of what rates as a pretty good vacuum isn't dangerous.

We have been immersed in comets tails before, notably comet Halley, the Great Comet of 1861 and we were in the tail of the Great Comet of 1853 for two whole days. Nothing happened.

To give you a feel for how little material is in a comets tail, I' ll use the gas density (dust density is similar, but the gas density is more easily comparable. In one cubic centimetre of air in Earths' atmospher there at around 10²² air molecules, in the dense coma of a comet the average density is 10¹¹ molecules, just under a trillion times less, in the tail (depending on how far you go out, the further along the tail, the less gas there is) around 10² molecules, just short of a billion trillion times less.

So if you took a volume of comets tail equal to ten volumes of Earths' atmosphere, and dumped it in Earths' atmosphere, you would have much much less than a trillionth of the gas coming form the comet (and most of that is water). A similar proportionality holds for comet dust, so the answer to "how much dust or gas will we get from ISON's tail" is "almost unimaginably tiny, and well below the threshold that could possibly cause any harm"

What about Earthquakes?

No, just no. Just like comet C/2010 X1 Elenin (which didn't cause any earthquakes) Comet C/2012 ISON has less than a billionth of the tidal force of the Moon at closest approach (as well as a negligible magnetic field). If the Moon can't cause the poles to tip, cause massive tidal floods or earthquakes, C/2012 ISON won't (and the previous Comet of Doom Comet 2010 X1 Elenin didn't). We've been closer to other comets before with no ill effect. See this link for comprehensive discussion of solar system objects and Earthquakes.

Giant Solar Flares?

No. Comets don't cause solar flares.

What is the size of the comet? Some say it is bigger than Mars

Comet ISON as imaged by Hubble in May 2013, Image Credit NASA/Hubble

Independent measurements from the Spitzer telescope and the Hubble telescope put a maximum size of around 5 kilometres in diameter for comet ISON's nucleus, it is probably a bit smaller.

Some people are confusing the size of the coma, the thin envelope of dust and gas around the comet nucleus, with the enormously smaller chunk of dust and ice that is the nucleus. Remember that the coma, like the tail, is still a pretty good vacuum by Earth standards.

One commentator is claiming the nucleus is as big as Mars, but its is easy to see that it is not. Comet ISON is almost at the orbit of Mars. If you go out around 5 am this morning Mars is easy to see at magnitude 1.5, ISON is around magnitude 12 (just below Mars), many times fainter the threshold the unaided eye can see (magnitude 6).

Even if ISON was as dark as charcoal (like the Moon is) it should be an easy unaided eye object of around magnitude 2 if it was the same size as Mars (using this formula to work out how bright any given astronomical object is (http://space.wikia.com/wiki/Absolute_magnitude), see also here). For comparison, the 400 Km diameter asteroid Vesta is currently 3.3 AU from Earth in comparison to ISON's 2.7 AU, and it is magnitude 7.8, so ISON must be much, much smaller than Vesta.

Oh, Okay. So, brighter than the full Moon at Perihelion then?

No. When it was first seen some tentative predictions suggested it could get as bright as the full Moon. But it turns out that ISON is an Oort cloud comet on its first visit to the solar system, and these don't brighten as much as comets that have been around several times. Current predictions based on over 3000 observations by amateur and profession astronomers suggest it will probably get as bright as Venus, maybe a bit more, when it is closest to the Sun.

While that is bright enough to see in the daytime, the comet is so close to the Sun that only very seasoned observers have a chance to catch it. See this post on seeing comet ISON at its brightest.

So, a bit disappointing then.

No, provided that comet ISON does not break up before perihelion (when it is closest to the Sun), it will be a nice little comet, even with the most pessimistic of projections. We can only make tentative guesses about how long and bright the tail post perihelion will be, as it depends on details of ISON's composition we don't know yet (like the exact ratio of dust to gas).

It might sport a spectacular tail like C/2006 P1 McNaught, or a thin searchlight like C/2011 W3 Lovejoy. If it breaks up into chunks post perihelion it might become as spectacular as Ikea-Seki, if it falls apart completely it might be more like C/2011 W3 Lovejoy.

All we can do is watch and wait as it evolves.

So where can I get good information on comet ISON then?

Well, this blog for a start.

Comet ISON in Celestia
Seeing ISON at its brightest
No meteor showers from ISON

Then there is

Comet ISON news
Waiting for ISON (with good northern hemisphere spotters charts)
ISON Observers Page  and its blog.
ISON Atlas
Hubble ISON Blog
Comet ISON ephemeris
Comet ISON Factsheet

Keep watching the skies and happy observing!

Labels: C/2012 S1 ISON, science

In honour of the 100 years of computer pioneer and code breaker Alan Turing, I give you two cool Turing machines

This elegant one with real paper tape and a Lego Turing Machine (for mega awesome)

Labels: miscelaneous, science

Labels: homeopathy, public outreach, science, science communicators

Remember  the Solargraphy project? This  multi-month solar photography project organised by the Royal Institution (Australia) using home-made pinhole cameras has finally come to an end.

My Kayaking mate and I have taken our cameras down (see debris above), scanned the images and sent them in. The right hand image is my attempt to process the raw image. The bright white lines are the sun passing through the sky over two months, the gaps are caused by clouds. You can also see the neighbours roofs, trees on the horizon and telegraph poles (plus dots that are probably due to rain getting in).

As I noted, I tried to set the camera to get the best horizon shot, but I ended up aiming the camrea too low, and the bottom half of the image (cropped away) was jts darkness.

Still what I got was pretty good, and you can clearly see e movement of the sun over the weeks.

Labels: astrophotography, citizen science, public outreach, science, Sun

Here's an amazing project for Australian Citizen Scientists to get involved in. Via the Royal Institution (Australia), you can be involved in a multi-month solar photography project, the Solargraphy project. Just email the good folks at RiAus for the special photography paper, and follow the instructions here to make the ultra-cheap pinhole camera, expose for a couple of months and viola!

You can even enter your photos into the Solargraphy Project exhibition as part of the Winning Sky Photos: the David Malin Awards 2011 exhibition (if received before 5pm on 31May 2012).

Give it a go! I am!

Labels: astrophotography, citizen science, science

The Federal Government allegedly plans to cut biomedical research in the next budget by reportedly $400 million. As the total National Health and Medical Research Budget is only around $750 million this would slash medical research in Australia by nearly half (State and philanthropic funding of medical research is a minor contributor to all over medical research funding). Australia punches well above it's weight in research in terms of discoveries and publications, with relatively low funding levels. To cut research funding this savagely defies belief.

Apart from blocking the discovery pipeline for new disease treatments in Australia, the flow on effects in lost jobs, stifled career prospects and loss of talent overseas will be substantial. Research and Development not only increases the health of ordinary Australians, but we get $3 back in economic growth for every dollar spent on research. At the moment, only roughly one in 5 research applications are funded, and as a long term reviewer of grants for the NH&MRC I can say that world class grants are currently missing out on funding. If the proposed cuts come through less than one in ten grants will be funded, with enormous loss. Read more at discoveries need dollars.

Rallies are located at:

MELBOURNE - State Library of Victoria (Swanston St) - Tuesday 12 April @ 12:45-2PM (AEST). RSVP via Rally for Research Facebook page (you need to be logged into Facebook to view this page). Download the Melbourne rally flyer

SYDNEY - Belmore Park (Near Central Railway station) - Tuesday 12 April @ 12:45-2PM (AEST) RSVP via Rally against NHMRC Budget cuts Facebook page (you need to be logged into Facebook to view this page). Download the Sydney rally flyer

ADELAIDE - Steps of Parliament house, North Terrace - Tuesday 12 April @ 12:30PM (Adelaide time) RSVP via Rally for Research Facebook page (you need to be logged into Facebook to view this page).

CANBERRA - John Curtin School of Medical Research, ANU Bldg 131, Garran Road - Tuesday 12 April @ 12:30PM (AEST) RSVP via Rally Against NHMRC Budget cuts Facebook page (you need to be logged into Facebook to view this page).

More information here. If you can't come, there is a virtual rally here.

Please also sign the electronic petition (you may need to wait because of the number of hits it is getting).

Labels: miscelaneous, science

Elenin as seen from the southern hemisphere at closest approach in October.

As I’ve written before, I am not sure why comet C/2010 X1 Elenin is attracting so much attention from the Doom and Gloom brigade, when C/2009 P1 was predicted to be about as bright (it’s been downgraded now). But ironically there has been a new spate of videos (and here) claiming Elenin is a Bad Thing ™ at the same time as there has been lots of discussion in the comet observers lists as to whether the comet will survive its passage of the Sun.

The various claims about Elenin include a) it will hit us, b) it will cause earthquakes c) we will pass through the tail and unspecified Bad Things ™ will happen.

The Earth as seen from Elenin at closest approach on 16 October (in this Celestia simulation)

Elenin will not hit us. The closest it will come is around 0.24 AU (where an AU is the distance from the Earth to the Sun). That’s only a little closer than the closest approach of Venus to Earth, and roughly 100 times the distance from the Earth to the Moon. That’s really, really far away (you think it’s a long way to the shop if you want a sausage roll, but that’s nothing compared to space*).

As the comet passes through the asteroid belt as it is doing now, and is exposed to the small gravitational tugs its orbit will change very slightly. This is important to us guys with big telescopes who need to point them really, really accurately, but even if the orbit changes by the distance of the Earth the to Moon (which would be a pretty big shift), then Elenin is still nowhere near the Earth. Nor is the debris in the comets orbit going to hit. We might get a decent meteor shower, but I wouldn’t hold my breath. As it is, the comet has passed it closest encounters, and its orbit hasn’t changed appreciably.

Eleinin will not cause earthquakes, as I’ve written before, even at closest approach Elenin has less than a billionth of the tidal force of the Moon. It will do nothing. Passing through Elenin’s tail will do nothing, its tail will be doing a very good approximation of a vacuum (and its not even clear its tail will reach Earth). We’ve been through cometary tails before of bigger and brighter comets (eg Halley), and nothing has happened.

How big is comet Elenin, then. Lots of people are claiming it is “big” for example “..when i look at the size of the orbit that this thing is huge, heavy…”. Well, orbital radius has nothing to do with the size of a comet, lots of long period comets are quite small. In the case of Elenin, it’s around 3-4 km in size, a bit smaller than Halley (6x 16 Km). We have a reasonable idea of its size from its brightness. Roughly speaking, at a given distance from the sun, the bigger an object is, the brighter its is. Of course, this also depends on how dark it is as well. Comets mess things up a bit as they are brighter than you expect from their size alone, as they are surrounded by a coma of gas and dust reflecting the light of the Sun. Now, comet Elenin is currently roughly magnitude 14, if it were the size of say, the asteroid Vesta, with a diameter of 530 Km, it would be at least magnitude 7 at its current distance. So Elenin has to be fairly small.

We’ve seen all this panic before. In 2006 Comet 73P/Schwassmann-Wachmann came within 0.08 AU of Earth, 3 times closer than Elenin. The comet disintegrated spectacularly, and Earth passed through its tail. There were cries of doom, destruction and catastrophic earthquakes …. and nothing happened. Just as no disaster struck in 1996, 1983 (two very close comets), 1961 and so on when other, more impressive comets came closer to Earth than comet Elenin will.

Now I mentioned that comet Elenin might evaporate. The cometary community has been keeping a close watch on Elenin. It’s not spectacular but still interesting and should be a nice binocular comet. If it survives perihelion. It is an intrinsically faint comet, and its light curve is developing in a manner similar to other comets that have vaporized on perihelion approach. After all, they are just dirty snowballs, or icy dirt balls, often barely hanging together. The gas pressure that develops as the comet comes close to the Sun can tear it apart into small icy chunks which rapidly evaporate.

Currently opinion on the comets list is that Elenin has a 50% chance of surviving. But as with all comet predictions we will need to keep a close eye on Elenin as enters the inner solar system. I hope it makes it; I’m looking forward to imaging the comet. Still, it would be interesting to see the conspiracy theorists reactions if Elenin evaporated when it got close to the Sun.

* Obligatory Hitch-Hikers guide to the Galaxy reference.

Labels: comets, Pseudoscience, scepticism, science

Over at Science in Pen and Ink Lelia Battison has an in-depth discussion of Richard Hoovers' paper on alleged "fossil" bacteria in CI1 Carbonaceous Meteorites in the Journal of Cosmology. It is an excellent article that covers a lot of issues not previously covered, and brings together some other information that has been scattered around. I'm referenced as well. Go have a read of Microbes on a Moonbeam, disentangling the Meteorite Microbe claims.

(for reference my posts on the subject are here and here)

Labels: Meteors, origin of life, review, science

The Journal of Cosmology has now posted 21 commentaries on the "Fossils of Cyanobacteria in CI1 Carbonaceous Meteorites" paper by Richard Hoover that I have critiqued in my "Life from Beyond Earth on a Meteorite, or Pareidolia?" post.

The majority are uncritical (some don't even seem to have read the actual paper), and zoom off on tangents assuming the Hoover's paper is valid. Two posts are critical (commentary 5 and commentary 9), and bring up the same issue I do (but with more references), that abiotic minerals can imitate the shapes of bacteria, and that without further tests, there is no way to say these filaments are fossils of any sort.

As for the majority, well, largely I think they are sad. The near complete absence of any critical engagement with the paper is very telling, and there is much leaping to unsupported conclusions. I would dearly love for extra-terrestrial life to be found, but I'm not going to grasp at epsonite straws to pretend it's been found. Hoover's flawed paper is not evidence of extra-terrestrial life.

Oh, and the journal has added a long rant to before the main article:

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Have the Terrorist(sic) Won? Only a few crackpots and charlatans have denounced the Hoover study. NASA's chief scientist was charged with unprofessional conduct for lying publicly about the Journal of Cosmology and the Hoover paper. The same crackpots, self-promoters, liars, and failures, are quoted repeatedly in the media. However, where is the evidence the Hoover study is not accurate?

Few legitimate scientists have come forward to contest Hoover's findings. Why is that? Because the evidence is solid.

But why have so few scientist come forward to attest to the validity? The answer is: They are afraid. They are terrified. And for good reason.

Apparently I am a crackpot and charlatan (sighs expressively), at least I'm in good company with Phil Plait, PZ Myers and Rosie Redfield (and really, read commentary #9 carefully).

Labels: comets, Meteors, review, science

Fossils of life or inorganic fibers? Image of alleged "microfossils" from "Fossils of Cyanobacteria in CI1 Carbonaceous Meteorites: Implications to Life on Comets, Europa, and Enceladus Richard B. Hoover Journal of Cosmology, 2011, Vol 13, xxx.

A recent paper published in the Journal of Cosmology has claimed to have discovered evidence of fossil bacteria in a rare subclass of carbonaceous meteorite. The implications of this paper, should it be correct, are enormous and the blogosphere has gone into overdrive discussing it. There are interesting analyses by the Bad Astronomer, PZ Myers and Rosie Redfield.

Rosie Redmond's analysis is more detailed (and Rosie being the microbiologist who burst the "Arsenic Bacteria" bubble, knows she her stuff), but all posts quickly get to the heart of the matter; the "evidence" is a bunch of squiggly stuff that bears little resemblance to actual bacterial fossils unless you obscure the details by rescaling the images.

Magnesium Sulfate nanobelts from J. Phys. Chem. B, 2006, 110 (27), pp 13387–13392

That's my conclusion too. While I'm not a professional astrobiologist (nor do I play one on TV), it is a hobby of mine and I've spent a fair amount of time looking at genuine images of cyanobacterial fossils (it's all part of my project). And once upon a time I worked (very briefly) as a microbiologist. I've also been exposed to far too much X-ray spectroscopy, due to a collaboration with the Chemistry Department in my waking hours.

I won't cover the ground already covered by Dr. Redmond and the others, but to briefly recap, trying to establish that rods and spheres seen in rock represent actual bacterial fossils is incredibly difficult. These things look like a wide variety of filamentous non-fossil inorganic material (here's one example) such as you can find in a variety of rocks. From cyanobacterila fossils in ancient earth rocks, to the Alan Hills Martian meteorite, establishing that a suite of features is distinctively biogenic is a nightmare. There have been several reports of supposed bacteria in meteors before with contamination being the culprit (and Dr. Hoover has reported fossil bacteria before as well, to little effect).

One major bugbear is contamination of samples. Bacteria are everywhere on earth, and can get into the most difficult places, so decades old meteorites can be presumed to be contaminated. Dr. Hoover used X-Ray spectroscopy to do elemental analysis on the presumed fossil structures, so as to eliminate the possibility they were modern contaminants. Despite the strange choices of controls (Skin flakes from mummies?), I think he shows fairly convincingly that these structures are not modern contaminants.

What he doesn't show anywhere near convincingly at all is that they are fossil biological structures. The elemental signature is quite interesting, with high levels of magnesium and sulfur. Almost like, well, magnesium sulfate. It ought to, as the idea put forward in the paper is that the magnesium sulfate in the meteorite 's parent body has infiltrated and replaced the organic material of the original bacteria.

But, and this is a big but, magnesium sulfate can produce ribbon-like structures that look very like the supposed "fossils" (see image above, and compare with the supposed fossil image, as well as supposed "fossils" from Figure 2 and Figure 3). So, how do we decide between ribbon-like magnesium sulfate structures that have replaced bacterial structures and ribbon-like magnesium sulfate structures that form abiotically?

There's a bit of carbon in it, but contamination of magnesium sulfate with magnesium carbonate (which is quite common) would produce this spectrum (see the spectra in the J Phys Chem paper). Also, the whole meteor is full of organic kerogens, which can be produced abiotically (eg the Urey-Miller reaction, or the UV-mediated reactions that make kerogen in the atmosphere of Titan). So merely having a little bit of carbon is no evidence of a biotic origin.

The paper makes much of differences in sulfur abundances between the filaments and the bulk meteorite. However, the elemental profiles and concentrations are virtually identical between the "fossils" and the matrix, and the variation is almost certainly no more than instrumental error (the X-ray spectroscopy person was not impressed and is on the inorganic, magnesium sulfate/carbonate whisker side)*.

So, the evidence that these filaments are fossil microorganisms is
a) They are not modern bacteria (good evidence and a good first step) and that
b) They are inorganic (this does not establish that they are fossil organisms at all).

Summing up, what has been reported is a bunch of filaments that look like a variety of mineral filaments (especially figures 2 and 3), and don't look much like actual cyanobacterial fossils at all. To support the existence of extraplanetary life, you are going to need more than what looks like SEM and X-ray images of magnesium sulfate whiskers.

UPDATE: Smoking gun, observations of magnesium sulfate bacteria-like structures forming in the meteors due to post-landing changes in water content.
http://onlinelibrary.wiley.com/doi/10.1111/j.1945-5100.2001.tb01827.x/pdf
Thanks to commenter Anb at Bad Astronomy for finding the paper

*It would help if they had decent tables, and scaled the X-ray profiles to the same scale, instead of being all over the place. The wildly varying scales of the filament images has also been mentioned, making comparison difficult. And they never actually show elemental analysis of fossil cyanobacteria beyond the amount of nitrogen, you would think this kind of data critical. The control data on the magnesium sulfate is never presented either. The whole paper is a dogs breakfast.
**The publicity claims the Journal of Cosmology will publish all the commentaries they have received, but as of writing none have appeared.

UPDATE: Commentaries have now been mounted.

Labels: comets, Meteors, review, science

Left panel, northern horizon as seen from Adelaide at 22:00 daylight saving time on Monday January 17 showing the stars that form some of the zodiacal constellations (similar views will be seen elsewhere in the southern hemisphere at the equivalent local time. Right panel, stars with constellation figures overlain (click to embiggen).

One of the reasons that the recent zodiac kerfuffle became a news item is that, amongst other things, most people don’t know that the star sign in their daily newspaper horoscope is not actually associated with the constellation of the same name (and hasn’t really been so since around 1600) and most people can’t find their zodiacal constellation in the sky.

But this is a teachable moment. Most people do know their star sign, and although astrology is rubbish it would be fun to try and find your star sign in the sky. Finding a number of the zodiacal constellations can be difficult as they are dim and hard to see in our light polluted skies, but it’s worth the effort.

If you go outside tonight at 10pm local daylight saving time, Southern hemisphereians can see five of the 12 Zodiacal constellations (Pisces, Aries, Taurus, Gemini and Cancer). Tonight (January 17), if you look due north you will see a bright red star which forms part of a V shaped group of stars. This is the head of the constellation Taurus, the bull. To the right you will see the Moon. It is between the two stars that from the tips of the bulls horns. To the left you will see a small pretty cluster of stars, the Pleiades (well worth viewing in binoculars). The diagram above shows what you should see, and has the constellation figure shown as well on the right (for northern hemispherians, look south, the constellations will appear upside down to the depictions shown here).

Diagram showing the zodiacal signs in relationship to the constellations, The yellow band is the zodiacal sign location, and the red block is the zodical sign of Taurus in the newpaper horoscopes (click to embiggen).

That’s the constellation of Taurus, but not the zodiacal sign of Taurus. The horoscopes you read in the papers start the astrological zodiacal signs from the position of the sun at the Vernal Equinox (in the northern hemisphere). Due to the precession of the equinoxes, as the Earths axis of rotation changes its direction like a spinning top, the location of the Vernal Equinox has shifted by 23 degrees over the last 2000 years. As well, the astrological zodiacal signs are not associated with the boundaries of the constellations, but are slabs of sky 30 degrees long by 14 degrees wide[1].

So the zodiacal sign of Taurus (indicated by symbolic bulls horns (♉), now covers the constellation of Aries (and a bit of the tail of Cetus, the whale, and the left leg of the bull). In fact the three brightest stars of Aries lie entirely outside the chunk of sky that makes up the zodiacal sign of Taurus. In the diagram the zodiacal constellation band is shown in yellow, and the zodiacal sign of Taurus in red.

The constellation of Taurus is covered by the zodiacal sign of Gemini (symbolized by two parallel lines (♊) . The Constellation of Gemini is to the right of the constellation of Taurus in the north-east, the bright stars Castor and Pollux (the twins) being easily visible (tomorrow night, January 17, the Moon will be in Gemini, and on the 19th it will be in cancer). The zodiacal sign of Cancer (symbolized by stylised crab claws (♋)) covers the constellation of Gemini (excluding the star Castor), bits of the constellations Orion, Auriga and a sliver of Cancer.

And so it goes; the constellations that symbolize the zodiacal signs are no-longer associated with associated with those signs. Not that it matters, the properties of the zodiacal signs are purely imaginary constructs, but it is worthy of reflection that the zodiacal sign of the mighty, charging bull is now represented by an unprepossessing collection of faint stars (as is spectacular Scorpio).

Still, getting out in the fresh air and seeing the constellation that gave your zodiacal sign its name over 2000 years ago is a good excuse for some sky watching.

[1] There are 4 different major forms of astrology, some set the zodiacal signs by the vernal equinox, some don’t, the newspaper ones do.

Labels: astrology, constellations, science, zodiac

A horoscope I’d like to see:

(This follows on from my article on the recent Astrology kerfuffle and was written (but not used) in 2005 for Australian Sky and Space. The positions are correct for 2005, but Mars has obviously moved by now)

Even though the Sun passes through the classical constellation Ophiuchus, it is not included in the astrological zodiac. Also Cetus, where several planets can spend some time, is excluded (most recently Mars was briefly in Cetus). As well, Pluto wanders a bit further from the Zodiac than the others due to its high eccentricity, but the constellations it wanders into are excluded from the astrological zodiac. And what about asteroids, Kuiper belt objects and Plutinos? Astrologers are divided over whether to include them in charts, and although you can find astrological predictions on the internet that do include these objects, your average horoscopes exclude them. And what about space probes? Size and mass is no obstacle to astrological relevance, surely these messengers of human curiosity and hope should be included? Sadly, they are not.

I think it is a great shame that these constellations and objects are excluded from western horoscopes, they would be far more colourful than the wishy-washy current versions that suggest that Mars may be making you a little more aggressive. So I have written the kind of horoscope I would like to see.

Camoleopardis, the Giraffe

You may have to stick you neck out on this occasion. With Voyager 1 in your sign, you have a restless urge to go boldly where no hominid has gone before, but you only get as far as the video store before the bow shock hits. On the 12th of September 2013, a piece of shuttle booster will fall in the garden of all maiden aunts of Camoleopardians.

Ophiuchus, the Serpent bearer

You will find yourself tied up in knots today. The influence of Quaoar would normally help you find a creative way out of the loop, but Varuna will rain on your parade. You may, or may not, have a life changing decision to make on an odd numbered bus. Flipping a coin may, or may not, assist you to come to a decision of some kind.

Serpens: The serpent

You may be feeling a little bit snaky today, if not positively Stygian, and the influence of Pluto in this constellation will make you feel colder and glummer than before. At 12:15 am on Tuesday the hot water heater of all Serpians will explode, making cold showers inevitable.

Cetus: The Whale

With Mars in conjunction with Sedna, International Whaling Commission Members should beware of angry Inuit trying to sell blubber sandwiches. On Friday all Cetians will find a harpoon embedded in their fishpond, even if they didn’t have a fishpond to start with.

Some explanation:

Sedna is the Innuit goddess of the sea, and protector of seals and whales. Quaoar is a North American creation deity and Varuna a water deity. The Kuiper Belt objects named after them really were in the constellations named in 2005 when I wrote this, as was Voyager and Pluto. Mars was in Cetus at the same time as Sedna .

Labels: astrology, scepticism, science, zodiac

The Sun in the constellation Ophiuchus on December 12.

A recent article by astronomer Parke Kunkle has had the twitterverse and astrologers in an uproar by pointing out that Sun no longer enters the constellations associated with the zodiac due to precession of the equinoxes.

Tropical Astrologers are boasting that Kunkle is wrong, and their system is better than that of Sidereal Astrologers, because their constellations are defined by the Vernal Equinox, and yar-boo-sucks to those silly astronomers.

However, in Tropical Astrology the zodiacal sign Aries (the Ram) actually points to the constellation we call Pisces. Now, most people couldn't find their own constellation in the sky, but I'm sure they would be perplexed to know that Astrological Aries is the constellation known to and ourselves and the ancient Greeks as Pisces (also, the vast majority of horoscopes that people are familiar with are Sun Sign horoscopes which Tropical Astrologers look down on in the first place). So Parke Kunkle is correct, the Zodiacal signs most westerners are familiar with are not associated with the constellations they are named after.

Yes, zodiacal constellations and actual constellations are two entirely different things. The astrological signs of the zodiac may bear the same names as modern constellations but have little correspondence to either modern constellations or constellations as ancients such as Ptolemy knew them. Both Astrological Tropical and Sidereal zodiacal signs are sections of the sky 30 degrees long and 14 degrees wide, centred on the Suns path. No matter how big or small the actual constellation, the sign associated with that constellation is one twelfth of the length of the Suns yearly journey. Again, we will pass silently over the fact that the tropical zodiac signs are named for constellations that no longer reside in their 30 degree swath due to precession of the equinoxes.

The other thing exercising the astrologers is whether Ophiuchus should be part of the zodiac. Now, boundaries for the astronomical constellations have varied quite a bit since the time of Ptolemy (whose astronomical constellations had very different boundaries to the zodiacal constellations) , but both the modern constellation of Ophiuchus and the ancient Greek one defined by Ptolemy had Ophiuchus crossing the ecliptic, as do all the other constellations of the Zodiac. Now we have an astrologer fulminating:

"This is an old hoax. Historically, Ophiuchus has never been listed as a constellation in the sidereal zodiac. It is a constellation out there, but it’s off the ecliptic (that is, it’s not along the path of the Sun through the sky). I’ve read that Ptolemy mentions it in his literature as an off-zodiac constellation, meaning that the Sun never travels through it...."

Sorry mate, the Sun does travel through it (and has done so since Ptolemy described it back around 100 AD, and probably even earlier based on the Farnese Atlas see the image above), as does the Moon and planets, in fact the Sun spends more time in Ophiuchus than it does in Scorpius. It's good that astrologers are so familiar with the sky they get their predictions from.

What's more, several astrologers have suggested that Ophiuchus should be incorporated into the zodiac (see here, here and here). So I wouldn't call the proposal for Ophiuchus to be a Zodiacal constellation a "hoax", Mr. Astrologer.

Labels: astrology, scepticism, science, zodiac

Einstein rings, a spectacular prediction of relativity, taken from Hubble (Image credit Hubble/NASA)

You may remember a little while back I wrote about a conference of modern Geocentrism (Galileo was Wrong). Geocentrism is the belief that Earth is the centre of the Solar system, nay the entire Universe and everything revolves around it.

Todd Wood attended the conference, and you can read the about his growing sense of incredulity in his posts (part 1, part 2, part 3, part 4, part 5).

It turns out that these folks are relativity deniers.

Image of the crescent Earth and Moon on October 3, 2007, taken by the HiRISE instrument of the NASA’s Mars Reconnaissance Orbiter.

Which is pretty strange, the usual tack is to argue for Geocentrism based of relativistic frame equivalence. Arguing against relativity is pretty hard, as it is one of the best confirmed theories of physics we have. From gravitational lensing (see images above) to frame dragging, relativity has passed increasingly stringent tests with flying colours.

These geocentricists apparently need relativity disconfirmed so the the Michelson-Morely experiment proves the Earth at rest.

Now there is a lot of problems with this (not the least because they need a non-moving ether to explain the M-M experiment, then a moving ether to explain Foucault's Pendulum) and other geocentrist positions. Some of the problems can be demonstrated with intensive mathematics, some with not so much maths (like the claim that GPS doesn't use relativistic corrections, which is untrue.)

Earth as seen from Mars taken by the Spirit rovers' panoramic camera in 2004.

However, in the spirit of my first post on this conference, where I tried to get people to do observations themselves that disproved first the Ptolemaic then the Tychonian systems, I want to get people to do something much simpler, related to observational astronomy.

Also in the spirit of Einstein, who tried to imagine what the word would look like if you were travelling on a photon, I want you to imagine your are standing on Mars.


The evening sky on Mars on April 29, 2005 as simulated by Stellarium (the location isn't at the same latitude and longitude as opportunity, so the view is slightly different from the rover).

What would you see from the surface of Mars that would be different in a Tychonian system (the system favoured by our modern geocentricists) versus a heliocentric system system?

As the Tychonican system is an inverted Copernican system, things like the phases of the Earth would be identical (see this JAVAscript model, advance the time to October 3, 2007 to match the image of crescent Earth and Moon above, and flip between the Tychonian and Heliocentric models to see what I mean).

Earth imaged by the panoramic camera of Opportunity an hour after Sunset on April 29, 2005 (Image Credit NASA/JPL).

There is a big difference that would be immediately apparent. Whether in the Tychonian or Heliocentric systems, from the point of view from Mars, Earth would appear to be a morning or evening star that appeared to revolve around the Sun.

However, the geocentricists are using a geostationary model, where the 24 hour day is produced by the Sun rotating about the Earth. So in a period of 24 hours, an observer on Mars (armed with an occultation disk) would see Earth rise from the sun, then fall back, then reappear on the other side of the sun and repeat the process again.

During the period that the Mars rovers took images of the Earth, at maximum elongation Earth was 42-47 degrees from the Sun as seen from Mars. For the Earth to move from maximum elongation to inferior or superior conjunction (at least, as it would appear from Mars, because in the Tychonian system Earth can't have conjunctions) takes 6 hours (in a 24 hour day there will be four 6 hour segments as the Earth goes out, comes back, goes out and comes back again from the solar disk).

So the Earth will appear to move 42 degrees (taking the lowest figure) in 6 hours, or 7 degrees per hour against the background stars (approximately, it's slightly more complicated than this, but rough figures are all we need). That's 14 Lunar diameters per hour! Earth is fairly hooting along compared to the background stars. In one minute Earth would move 1/4 of a Lunar diameter which is quite noticeable.

Now look at the image above. It is a composite of 3 x 15 second images taken with the panoramic camera, you can see the image of Earth is slightly elongated. However, remember that Mars rotates, and any 15 second exposure will cause slight star trailing due to its rotation. The trail we see of Earth is nothing like what we would expect if it was moving to a 24 hour rhythm, as it hares along the sky (roughly 1/5th of a Lunar diameter). Still, for confirmation we have to check Earth's movement against that of the background stars.

Fortunately, in the original image there is a background star just above Earth (it's best seen in the TIF file). It has the same degree of elongation that the Earth does. This falsifies the Tychonian system, thus the solar system is heliocentric.

So "Eppur si muove" because it um, doesn't move (with respect to the background stars as seen from Mars).

Labels: Galileo, science, Science Blogging, science matters

I'm trying to watch and listen to the NAI Workshop Without Walls on Molecular Paleontology and Resurrection: Rewinding the Tape of Life. However, I'm also making breakfast and getting kids ready for school. It's very interesting though.

If you are interested, the workshop is scheduled for 1pm-5pm EST on November 8, 9, and 10, 2010. A detailed agenda and other information is posted online at http://astrobiology.nasa.gov/nai/ool-www/ and you can register to join in there, everyone is welcome.

Labels: science

I've updated my post about measuring the parallax of Iridium satellites, it looks like we are closer to a resolution.

Labels: iridium flares, science

Iridium flare captured simultaneously at a) Largs North, SA and b) Black wood SA. You may need to click on the image to embiggen and see that the flare trail is shifted with regard to the stars.

Back on October 8 I and some other people were fortunate to witness a bright Iridium flare near Jupiter. I got a nice shot from my camera (mounted on my telescope with the drive going to stop star trailing), and Dean Male from Blackwood kindly sent me his image captured at the same time.

One thing that I noticed was that the image of the flare was slightly shifted with regard to the background stars. This represented a great opportunity to measure parallax in these images and do ... something.

Parallax is the slight shift in a nearer object against a simultaneously viewed distant background object. Parallax is used to measure the distance to the Moon, the planets and the stars. Amateur photographers have used their images of the Moon and nearby stars to measure the distance of the Moon to within 3%. So could I use the parallax shift in the images of the flare to measure the height of the satellite?

Highly sophisticated parallax measuring system.

Well, I measured the separation of the trails, using the sophisticated method of scaling SkyMap charts to the same scale as the images at full resolution, and using a bit of paper to plot the flare location.

I came up with 36' 57"
separation, or 0.6158 degrees (about a Lunar Diameter). Using the formula used for Lunar parallax:

and estimating that Largs and Blackwood are roughly 25 km apart as the crow flies I get .... the iridium satellite was 2,326 Km up.

Which, as they orbit around 800 Km up, is a 300% error. I tried the formula out on the lunar separation measured here, and got the right result. Using the more complex formula:
Where D is the distance to the object, b is the separation between observers and Theta is the angular separation between the two images with respect to the background stars gives the same result.

Either Dean and I were 8 Km apart or the flare images separation was 3 times larger than I measured (not likely) or I'm doing something very wrong, or the formula is not appropriate for small separations of observers (The amateur Moon calculation was done from observers over 2000 Km apart, this won't work fro iridium flares which are only observed in a small area).

Anyone have any ideas? UPDATE: There is at least a partial solution to the Puzzle. In my original posting I had estimated that Dean and I were 25 Km apart, based on my rough measurements from Google maps. But that was from points that Google decided were Largs North and Blackwood. Dean sent me the flare information from his site, and from that I could calculate that we were 13 Km apart, not 25.

This gives a distance of 1209 Km, within 20% of the distance to the satellite from my site (1022 Km given by CalSky), still not the orbital distance (790 Km) but a heck of a lot better than 200%. JupiterIsBig (see comments) sent me the following diagram:

Modified from http://www.ifa.hawaii.edu/~barnes/ASTR110L_S03/parallax.html

which illustrates the sorts of correction we need to fix our calculations. I'm waiting for JIB to give this math's challenged biologist explicit instruction on how convert Altitude and Azimuthal data into correction factors.

Labels: iridium flares, science

The Florey Lecture is an Annual Public Lecture at the University of Adelaide where a distinguished international scientist talks about some aspect of medical science and how it touches our lives.

This year the Scientist is Baroness Susan Greenfield, a renowned scientist and top notch communicator, I can promise that her talk will be fascinating. This year it's on how technology may be rewiring our brains.

The lecture is 5:30-7:30 pm Bonython Hall,University of AdelaideNorth Terrace, Adelaide
South Australia (L11 on this printable Map). Entrance is by gold coin donation, and you can register for entry here.

Labels: science, science communicators, science matters

As part of National Science Week, Ask The Naked Scientist is happening on Monday, August 16 at 7.00pm in the Napier Theatre, University of Adelaide, North Terrace, Adelaide (K12 on this printable Map). Entry is free and no bookings are required.

This is an audience-interactive science question and answer show. Taking questions from the public on any science-related topic, Dr Chris Smith of Cambridge University responds in innovative, informative – and sometimes hilarious – ways.

A medical doctor and clinical lecturer in virology at Cambridge University, Chris Smith founded The Naked Scientists, an award-winning radio program on the BBC (and one of the world’s most down-loaded podcasts) that aims to strip science down to its bare essentials. Chris is one of the international guests touring the country in National Science Week.

Held in conjunction with Australian Science Communicators SA.

Labels: science, science communicators, science matters, science week