Some time ago, I discussed the concept of a mineral moon shot. Basically, you take a photo of the moon, or a stack of photos, and then process them to bring out the colouration of different areas of the surface. Different areas, the seas, the mountains, the plains, have different minerals on the surface that scatter light of different wavelengths in different ways so that reds, blues, purples, and even yellows, can be brought out in a photo of the moon that will most likely have appeared as nothing more than fifty shades of grey to the naked eye.
Waning gibbous moon, Canon R7 with Canon 100-500 at 500mm. Handheld, shutter 1/640s, F/7.1, ISO 800. Denoised in DxO PureRaw4, levels adjustments in PSP.
Well, you may recall I had a Sigma 150-600mm lens that I originally bought to take photos of the moon but that became my mainstay through various cameras for bird photography. I have now traded-in that lens for one more suited to my Canon R7 mirrorless camera, the Canon RF 100-500mm L series F4.5-7.1L USM. The above moonshot was taken using that kit and denoised in DxO PureRaw 4 and levels adjusted to taste in PaintShopPro. PSP was then used to incrementally raise the saturation to reveal the minerals in the image below.
Mineral moon – Additional saturation adjustments done incrementally in PSP
The quality of the photos with the R7 and this new lens are far better than the ones I was getting with this camera and my 8-year old Sigma lens despite, the additional reach of the Sigma at 600mm as opposed to 500mm. The photos are even better than those I’ve got with a smartphone camera clamped to the objective lens of a 5-inch reflector telescope! I’ve not successfully used a dSLR with my telescope, unfortunately.
Processing a RAW photo of the moon to enhance the subtle hues of different areas of the surface needs to be done in stages for best effect. The yellows and blues reveal areas on the surface made up of different minerals, which scatter the incident sunlight to different degrees.
Mineral Moon – 94% waxing gibbous. Blue regions have more titanium-containing basaltic ilminite (titanium iron oxide), yellower regions less.
A quick glance at the moon in the night sky and you might imagine the surface is fifty shades of grey. But, take a photo, preferably with a telescope or a big zoom lens and you can process the image to bring out the colours in the surface. These colours essentially represent different regions of minerals scattering sunlight in different ways. So with just the right kind of enhancement you can create a geological map of the moon.
I’d heard about this technique some time ago, but hadn’t given it much thought since. But, the moon was lovely and bright last night, waxing gibbous, not full, and I got a quick snap at 600mm on a 2/3 frame mirrorless camera.
The chemicals on the surface of the moon’s seas, the maria (first %), and its highlands (second %)
Here’s the RAW shot, unprocessed and loaded into my photo editor. Obviously, I’d messed up, it’s massively underexposed.
So, I re-opened the RAW file out of the camera in DxO PureRaw to apply some initial denoising and let it do some automated camera adjustment based on my lens and camera.
Well, that’s a bit better, but I could perhaps adjust exposure in the photo editor’s own RAW import function and brighten it up properly. The highest exposure compensation is +3.0 in the software and it’s basically done some of the work, but still not enough.
So, I needed to do some basic levels adjustments to get it to this state and you can already see some of those mineral colours showing more than you would see with the naked eye or even through your telescope.
Now, before doing any more, it’s worth applying the photo editor’s automatic colour fix to correct white balance and other potential problems.
Now, to bring out the colours. It would be possible to simply whack up the saturation, but if you do that you get a noisy and solarized (ironically) mess. Although it’s worth trying that, say increasing saturation by 80%, just to see what it looks like. It does show the variations in surface colour that your camera picks up, but like I say it’s an over-the-top result.
So, I reverted that and went to the “layer adjustment window” in my photo editor instead. Ramping up the saturation is possible with multiple adjustment layers so that the effect can be done in a more gradual way to the same level but without losing as much information in one fell swoop as would happen with an 80% saturation boost applied. So, you apply multiple saturation adjustment layers, setting the boost to 20% or so for each, and looking to see how well it works at each step. Alternatively, in my photo editor, I can add a vibrancy adjustment stepwise. That’s what I did for the following image, which had five vibrancy layers of 20% each. Six was too many.
At this point, one might stop. It looks good as it is. But, I next applied a local tone mapping adjustment, which adds a bit more definition to the different coloured regions.
There’s now a need to sharpen and denoise the image again, which I will do by importing into Topaz Denoise AI and choosing some basic settings just to give the final image a bit of a visual bump and tighten things up.
I re-did the whole process using four 20% saturation adjustment layers instead of the more subtle vibrancy to get the following image. I can’t decide which I prefer the previous one or this one.
Mineral Moon – Photo processed to show up the different colours of the surface of the moon that reveal the different mineral present by how they scatter sunlight
To take it to the next level, it is worth doing a burst mode shot of the moon and then using stacking software to overlay them, this is a way to reduce noise. Noise is random in each frame and so overlaying and discarding noise succesively in the software boosts the amount of information you can see in the image and so improves clarity. Applying the above process to such a stacked shot should give you a much better final image.
It’s also worth noting that getting the exposure right in the camera from the off, using a tripod, and live view with either mirror up or in a mirrorless camera will all help improve the images you get.
*More properly known as iron(II) oxide, the lower oxidation state as opposed to ferric, iron(III) oxide more commonly found on earth and as rust.
TL:DR – The Northern Lights, Aurora Borealis and their antipodean equivalent, the Southern Lights, Aurora Australis, are a visible phenomenon seen in the polar skies as particles from the solar wind interact with particles in the earth’s upper atmosphere.
Lots of lucky locals, by which I mean people a bit further north in Norfolk saw the northern lights, the Aurora Borealis, in Norfolk and elsewhere. There is a slight possibility of seeing them in Cambridgeshire although finding somewhere with little light pollution around here is a tough call, but more to the point it’s been cloudy and wet when other places have had their lightshow these last couple of nights. In recent years they have been observed from Devon and Cornwall.
Aurora borealis at Vestrahorn, Southern Iceland (Credit: Simaron)
So, what are the northern lights?
The northern lights are a natural phenomenon generally occurring close to the poles, in the high or low latitude regions of the Arctic and Antarctic. The phenomenon is caused by the interaction between charged particles from the Sun and the Earth’s protective magnetic field.
The Sun constantly emits a stream of charged particles, called the solar wind, which travels through space and interacts with the Earth’s magnetic field. When these charged particles collide with the oxygen and nitrogen in the Earth’s atmosphere, they gain energy, they are excited, when the excitement passes, the particles release energy in the form of light. This produces the glowing, coloerful display that we see as the Northern Lights, or the Southern Lights, the Aurora Australis.
The colours of the Northern Lights depend on the type of gas particles that are colliding with the charged particles and the altitude at which the excitement occurs. Oxygen at higher altitude will glow red and at lower altitude will grown green. Nitrogen produces blue and purple hues.
Usually, seeing the Aurora Borealis involves heading to the colder regions Iceland, Norway, Sweden, Finland, or Canada during the winter months and hoping for a strong solar wind, caused by lots of activity on the surface of the sun. Occasionally, activity and conditions are just right for people to see them farther from the poles as has happened in recent days.
Aurora comes from the name of the Roman goddess of the dawn. It’s related to the name of the Indo-European goddess of the dawn and ultimately the root is from ancient Greek “to shine” with particular reference to the dawn sky.
Borealis comes from the Latin Boreas meaning the “north wind” and from the Greek Boreas, also the name of the god of the north wind.
Australis derives from the Latin word auster meaning “south wind” and hence relates to the southern part of the world.
I haven’t ever managed to see nor photograph the Northern nor the Southern Lights hence the allusion to the lyrics of a 1978 song by progressive rock band Renaissance. The singer with the band, Annie Haslam, was renowned for her operatic training and her five-octave vocal range. I recently updated an article you might like on how to sing.
The photo above was taken by Simaron at Vestrahorn, Southern Iceland in September 2022.
TL:DR – Towards the end of 2024 there may be a bright, new comet in the sky. Comet C/2023 A3 Tsuchinshan-ATLAS
If you’re lucky enough to get a clear sky…it’s snowing here, so no chance…look up at the constellation known as constellation Serpens Caput with your big telescope and you might see a faint fuzzball. It’s an icy visitor from the far reaches of the solar system, the Oort Cloud, and it’s heading this way. Give or take. Thankfully, it is not on a collision course.
Right now, this comet, which was first spotted in early January is about a billion kilometres from Earth, just past the orbit of Jupiter. But, as we approach Christmas 2024, we might be in for a treat as it flares up and becomes visible to the naked eye. You can find all the details of the discovery, the name, and what to expect from Comet C/2023 A3 Tsuchinshan-ATLAS on the Universe Today website.
Comet NEOWISE in 2020
Late last year, you may well have caught sight of another comet, the green comet, C/2022 E3 (ZTF), which never did live up to hopes of outshining the stars. And, of course who can forget the early months of COVID when some of us were distracted by Comet NEOWISE [C/2020 F3 (NEOWISE)]. I managed to get some mediocre photos of that comet when we escaped COVID lockdown and had a few days at the coast.
Comets are typically named after their discoverers or a group of discoverers, with the addition of a prefix indicating the type of comet. The prefixes used are:
“C/” for non-periodic comets (i.e. ones that appear irregularly)
“P/” for periodic comets (one’s that return within 200 years)
“D/” for comets that have been lost or have disintegrated
“X/” for comets that are of an uncertain
Here are a few examples of some well-known comets with their colloquial names:
Comet Halley – This is perhaps the most famous comet, named after astronomer Edmond Halley who calculated its orbit and predicted its return in 1758. It is a periodic comet with an orbital period of approximately 76 years and was last seen in the inner solar system in 1986.
Comet Hale-Bopp – This was a non-periodic comet discovered in 1995 by Alan Hale and Thomas Bopp. I remember it being very bright in the sky for many months and would endlessly point it out to family and friends on night-time pub trips.
Comet Shoemaker-Levy 9 – This was a non-periodic comet that collided with Jupiter in 1994 and was destroyed. It was named after its discoverers, Carolyn and Eugene Shoemaker and David Levy.
Comet Lovejoy – This is a periodic comet discovered by Australian amateur astronomer Terry Lovejoy in 2011. It has an orbital period of approximately 7 years and was visible to the naked eye in the Southern Hemisphere.
Of course, whether Comet C/2023 A3 Tsuchinshan-ATLAS lives up to expectations in late 2024 will depend on the local solar weather conditions as the comet’s orbit brings it closer and closer to the sun. If conditions are right, it may well flare up and become visible to the naked eye, we’ll have just have to wait and see, with our telescopes, binoculars, and cameras at the ready.
Jupiter and Saturn will appear very close together in the night sky on 21st December in what astronomers refer to as a rare ‘Great Conjunction’. They are not literally close together, they will be millions of kilometres apart but as viewed from Earth they will appear to be separated by less than a fifth the diameter of the full moon as it appears in the sky. This is the closest they have been in conjunction, just 0.1 degrees of arc, since the seventeenth century (the year 1623), in a rare ‘Great Conjunction’. In that year, Wilhelm Schickard invented his Calculating Clock, a mechanical precursor of the pocket calculator.
When that last similar conjunction occurred the two planets were close to each other in the sky but also appeared close to the Sun so would’ve been difficult to observe. Prior to that, an observable conjunction occurred in 1226 long before the invention of the telescope in the year that Saint Francis of Assisi died, apparently.
Just to clarify, as planets orbit the Sun, they occasionally appear to be close to each other in the sky, it’s an optical illusion. On 21st December, Jupiter and Saturn will be almost 800 million kilometres apart in the solar system.
To see the conjunction, look low in the south-west after sunset. As the sky darkens, first Jupiter and then Saturn will become visible. Both planets are bright — in the case of Jupiter brighter than all the stars — so will be obvious in a clear sky. By 17h00 GMT both planets will be less than ten degrees above the horizon for UK observers, so it is important to find a line of sight without tall buildings or trees that will block the view.
They will be visible to the naked eye, but with a small telescope you will be able to see both planets in the same view and Jupiter’s cloud belts will be apparent as will Saturn’s rings. The peak of the conjunction is the 21st, but they will appear to move apart from each other only slowly in the days that follow. There is lots of musing as to whether such a conjunction in history was the origin of the myth of the Star of Bethlehem.
UPDATE: Night of 17th December, the Moon, Jupiter, and Saturn will form a pretty little triangle together in the night sky
Later in the summer of 2020, NASA will launch its latest Mars rover, Perseverance. To coincide with that important scientific occasion, Elizabeth Howell, PhD and Nicholas Booth have told the greatest scientific detective story of all time in The Search for Life on Mars. Their approach and style are unique, they break many a convention of the scientific history books to make this truly accessible read with none of the bluff and bluster of so many so-called popular-science books and all of the guts and glory of a gripping wouldbe bestseller.
The world next door, otherwise known as the Red Planet, has intrigued humanity for centuries. From ancient astronomical observations to the science fiction of the modern era HG Wells’ The War of the Worlds to Andy Weir’s The Martian and to the amazing photography of the robotic rovers Curiosity and Opportunity.
For the first time in forty years, the missions heading to Mars – from the USA and China – will look for signs of ancient life. This is the latest chapter in the story of the Red Planet where fact is stranger than fiction, myths and false starts abound while red herrings and bizarre coincidences astound. Here are the triumphs and the heartbreaking failures.
This is the definitive story of how life’s extraterrestrial discovery has eluded us to date and how it will be found somewhere and sometime this century. The Search for Life on Mars is based on more than a hundred interviews with experts at NASA’s Jet Propulsion Laboratory and elsewhere, who share their insights and stories.
The Search for Life on Mars: The Greatest Scientific Detective Story of All Time by Elizabeth Howell, PhD and Nicholas Booth, Arcade Publishing; On sale: 23rd June 2020 | ISBN: 9781950691395 US edition here | UK edition here
If you came looking for my cover version of Life on Mars, the Bowie song, you can find it here.
That blurry smudge in the middle of my photo? I think…I think…that’s the Andromeda Galaxy. It’s the most distant object humans can see with their unaided eyes. Here, we’re aided, zoomed in quite a lot. There’s blur due to camera shake, unfortunately, or is an 8-second exposure too much to not get star trails with a 150 mm zoom…
If it’s not Andromeda I’d like to know what it actually is as it was definitely a barely visible smudge in the sky away from the big “arrowhead” of Cassiopeia and in a line from Mirach and Mu Andromedae in the constellation of Pegasus.
TL:DR What is the correct pronunciation for the star named Betelgeuse. It’s not “beetlejuice”, it is Beh-tell-jerrz.
Betelgeuse is the bright red star you see in the constellation of Orion. It’s actually a red supergiant and looking at the constellation you might imagine it as the top of his right shoulder (top left of the constellation, assuming he’s standing facing you) It is a variable star and brightens and dims periodically. Betelgeuse is so big that if you swapped our Sun for it, it would reach as far as the solar system’s asteroid belt, engulfing the orbits of Mercury, Venus, our own planet, Earth, and Mars.
Betelgeuse is occasionally in the news because some astronomers think its recent unprecedented dimming might indicate that it is about to explode and become a supernova. If it did, it would be bright enough to be visible to the naked eye even during daylight hours if it were above the horizon during the day. Of course, because Betelgeuse is so far away, if we see it go supernova, then we know that explosion will actually have happened some time in the Middle Ages and the light has only just reached us after centuries of travelling across space to reach us.
Meanwhile, the far more controversial issue is how does one pronounce the name of this star. It’s definitely not Beetle Juice, regardless of the movie title, although far too many American astronomers and pundits do pronounce it like that.
The name comes from an Arabic phrase meaning “the armpit of Orion”
That phrase is pronounced ebt-el-jowzah, roughly. The “j” is a zh sound like the G in the name Genevieve. It’s not a hard j as in June and it’s definitely not the “g” of Gloria. Etymology does not define pronunciation, but the closer to the root we can be the better, I’d say, and astronomical writer Paul Sutherland agrees with my pronunciation and if it’s good enough for him, it’s good enough for me:
Bettle Jerrz – with that softer sounding “J”
Oh, and one more thing, despite all the hyperbole about Betelgeuse, Sutherland points out that by definition it’s a variable star and they vary, sometimes quite a lot. [UPDATE: My friend Paul, sadly died on 20th June 2022]
Meanwhile, check out my photography guide on taking snaps of the stars, including one about Orion’s Sword and the Orion Nebula.
I totally forgot that I’d had another got a photographing the International Space Station, ISS, as it flew overhead a few nights ago. The photos were not very good, so I headed outside to try and catch this evening’s very bright, overhead flypast and was a little more successful.
If it’s flying over where you live and it’s night time and the sky is clear, look to the western horizon for a steady, bright light that travels across the sky heading East, it will take several minutes to cross the sky, it moves quite quickly so hard to get a focus lock on with a big lens. There’s no twinkling, no flashing lights, just a very bright steady and steadfast light.
This was the best of a large sequence of photos I snapped where you can definitely see the shape of the beast and how it is rotating as it travels across the sky. Full-frame SLR with a 600mm zoom lens, EV turned down a few notches, ISO as low as I could go and get an exposure. f/5.6 but that’s irrelevant and a short shutterspeed to preclude shake while handholding the machine.
This is a 48×48 pixel crop from my original 5472×3648 photograph scaled up 4x and coupled with a NASA photo of the ISS so you can see better what it is you’re actually looking at here!
Below is a 768 pixelwidth crop of the original. The white speck in the middle is what I’ve cropped to in the view above
