A Saturnine and Jovial conjunction

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

The search for life on Mars

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.

Photographing the Andromeda Galaxy

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.

ISO 3200
f/6.7
t 8 seconds
150mm focal length

How not to pronounce Betelgeuse

The giant red star you see in the constellation of Orion, which you might think of as his right shoulder (top left of the constellation) is a variable star. It brightens and dims periodically. It’s been in the news a lot recently because some astronomers think its recent unprecedented dimming might indicate that it is about to explode and become a supernova , one that we would be able to see in the sky even daylight hours. Of course, if we see it happen, then it will actually have happened some time in the Middle Ages and the light from said explosion has taken centuries to reach us.

Betelgeuse captured by ALMA

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 a “g” as in 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 a lot.

Meanwhile, another thing, check out my photography guide on taking snaps of the stars, including one about Orion’s Sword and the Orion Nebula.

The International Space Station, ISS

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

The Moon in Ely Cathedral

Somebody has only gone and squeezed the Moon into Ely Cathedral! Well worth a trip to the city to see it and while you’re there take a hike up the 288 steps to the top of the West Tower 90 metres above sea level for fantastic views of the cathedral and the surrounding fenland that stretches away to a 20-mile horizon.

Plenty of other lunar and astro exhibits for their Sky’s the Limit science festival in this the 50th anniversary year of the first man on the Moon, Neal Armstrong.

The views from the West Tower are stunning, 90 metres above sea level and 30 km to the horizon. The Cathedral’s famous and unique octagonal tower looked amazing from above. Those columns are lead-clad oak, and the whole thing is estimated to weigh a mere 200 tonnes, far less than it would if it were hewn from rock.

Oh and while we had our lunch break on the lawn, a Peregrine landed on the very tower we had ascended and descended just minutes before, which was nice. The cathedral staff were wholly unaware that they had Peregrines.

L竞技

Here’s a shot of the waxing gibbous moon I just snapped from our bedroom window. It was just after 5pm. Camera settings: 600mm lens, f 9.5, t 1/1000s ISO 200, ev -1. Sigma 150-600mm lens handheld with no image stabilisation on Canon 6D full frame. Final image cropped to a square with side 768 pixels from original 5472×3648 for the website.

In July, it will be 50 years since humans first set foot on Earth’s biggest natural satellite. You did know we have more than one moon, didn’t you?

Coastal moon shot

It’s perhaps not a surprise that you’re going to get a crisper, sharper photo of the Moon on an evening at the coast. Sun just setting, Moon waxing gibbous heading towards Monday’s blood moon (which will be the last in the UK this decade, and there won’t be another here until 2021).

Here’s a shot I took at RSPB Snettisham on a chilly, windy, but sunny and bright evening (2019-01-17:16h02). Camera: Canon 6D with Sigma 150-600mm. Settings: 600mm, shutterspeed 1/2000s, aperture f/5.6, ISO 640.

Last UK Blood Moon for a decade

There will be a total eclipse of the Moon visible from the UK on 21st January. This will be the last total lunar eclipse here until 2029. A total lunar eclipse occurs when the Earth passes exactly between the Sun and the Moon. The Sun is behind the Earth, and the Moon moves into the Earth’s shadow.

Sometimes an eclipsed Moon is a deep-red colour, other times it remains quite bright. The exact colour depends on how light from the sun is being scattered, Rayleigh scattering, by molecules and particles in the Earth’s atmosphere, blue light is scattered away more than red.

You only get to see a total solar eclipse if you are in the narrow path of the Moon’s shadow, but a lunar eclipse is visible wherever the Moon is above the horizon at the time, so each one can be seen from a large area of the Earth. For that reason, they are much more common from any given location. Lunar eclipses always happen at a full Moon as this is when it moves behind the Earth and into line with the Earth and Sun. A full Moon happens every month, but most of the time no eclipse takes place.

The lunar eclipse on 21st January begins with penumbra at 02h35 GMT, umbra at 03h33 GMT and totality from 04h40 GMT. Mid-eclipse is at 05h12 GMT, which is when the whole Moon will appear red. The red will fade by 05h43 GMT. Coming out of the other size penumbra ends at 07h49 GMT.

the lunar eclipse will also be visible from north-western France, north-western Spain, Portugal, a small part of West Africa, almost the whole of North and South America, the eastern Pacific, and the north-eastern tip of Russia.

Lunar eclipses are very easy to witness as no special equipment or safety precautions are required. To watch the lunar eclipse on 21st January all you have to do is get up early, wrap up warm and step outside, unless of course you’re lucky enough to have a bedroom window facing the moon at that time. If you can see the full Moon you will be able to observe the eclipse as it happens.

I double-checked that this is the last proper total lunar eclipse for the UK until 2020. Astrobuddy confirmed that is indeed the case: “That’s the next that is fully observable from the UK. There are others that we see parts of before then, e.g. May 16, 2022, when the Moon sets during totality,” he told me.