35 years in science communication
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?
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.
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.
Although we in the Northern hemisphere are fast approaching the Winter Solstice and the feeling of the nights drawing out again. There is a seeming paradox that for a few days more sunrise will continue to get later in the day although sunset will be nudged back ever so slightly.
Indeed, as I write this, there is light in the South-eastern sky, it’s 07h40 but sunrise does not occur until 08h04. Sunset will happen at 15h47 with those starling murmurations taking place hopefully during the 30 minutes or so around that time.
The Solstice occurs on the 21st December at22h22. On that day, sunrise will be two minutes later than today, and sunset will be at 15h48. Giving us the shortest day. However, sunrise will continue to get later for several days after. On New Year’s Eve, it will be 08h08, but sunset will also be a little later at 15h56 and the daytime consequently ever so slightly longer.
Across the Northern Hemisphere, the earliest sunset always occurs a few days before the Winter Solstice and the latest sunrise several days after. This seeming paradox is simply an artefact of the way we set the calendar and our time-keeping methods and the fact that the Earth’s orbit around the Sun is an ellipse not a circle, so time measured by watching a sundial varies throughout the year when compared to the time set by your mobile phone. The solar day near the Winter Solstice is in fact more than 24 hours. Whereas our clocks keep it as close to 24.00.00 as possible…
"It's increasingly recognised that the more diverse a group is, the more robust, the more flexible and more successful a group is"
Professor Dame Jocelyn Bell Burnell, discoverer of the first pulsar while a post-doctoral astrophysics researcher in 1967.
Prof Dame Jocelyn Bell Burnell was not named in the Nobel Prize that her male supervisor Antony Hewish and astronomer Martin Ryle collected in 1974 for the discovery but more than half a century later she receives the £2.3 million prize for the 2018 Breakthrough Prize in Fundamental Physics. Speaking on BBC Radio 4 this morning she explains why she is donating that prize money to help increase diversity in physics.
UPDATE: Actually… You will see them anywhere in the sky, just watch for light trails.
Find somewhere dark on a clear night this weekend, away from light pollution, if you can, after 11pm or thereabouts. Look North East…find the constellation of Perseus (it’s just below the constellation that looks like a big stretched out letter W, Cassiopeia). The Perseids, as their name suggests will radiate from Perseus. At the peak, night of 12th August, you could be lucky and see them at a rate of one every minute for several hours.
VirtualAstro just got in touch to alert me to the fact that the Perseid Meteor Shower will peak this weekend. He has the skinny on when and how to watch. “I want to make things easy for people who haven’t done meteor spotting before,” he told me. “This year, I want people to easily understand how to meteor watch and spend more time looking up rather than down at their phones etc. Meteor showers are perfect for introducing people to stargazing and hopefully it will inspire more people to do it more regularly and get more and more people interested in science, nature and the night sky.”
There is a caveat though…it’s raining here right now after the longest hot and dry spell for many years, let’s hope the skies are clear again this weekend.
The Perseids are a prolific meteor shower associated with fragments from the comet Swift—Tuttle. They get their name from the radiant point at which they appear to emerge, which is seen in the constellation Perseus.
The International Space Station (ISS) pass overhead twice while we were in the pub garden last night. It often does, obviously, and none of was simply seeing double. There are numerous websites that let you know when you can next see the ISS pass over your neighbourhood, VirtualAstro on Twitter puts out alerts, and thare are also smart phone apps that will push a timely notification.
Here are a few facts about the ISS:
TL:DR – My sorry attempts at photographing Saturn and Jupiter in 2018.
I love the late light of midsummer, the long, drawn out sunsets, the dying embers as our star ducks below the horizon, the afterglow, the gradual emergence of the stars and planets. Jupiter and Venus in opposite skies last night. Venus lamenting the Sun’s demise and hugging the sun North Western sky as we approach the solstice. Jupiter higher and dominant in the South. The asterisms we know as the Northern Cross and The Plough way above.
I was pondering life, the universe, and everything when it occurred to me that there was no moon last night. So, I grabbed my Canon dSLR and Sigma 150-600mm zoom lens in the hopes of snatching a glimpse of Jupiter’s moons, the four Galilean moons to be specific. I’ve tried before with this camera setup and got something bearable, but although I could see Jupiter was very much not simply a stellar pinprick in the frame, the moons did not show up in this frame.
Perhaps, they’re eclipsed right now, hiding behind their giant gaseous parent, or maybe it was more about camera settings. It was too late in the evening after a day with a heavy workload to hunker down with tripod and remote shutter to get a longer exposure. Anyway, here’s a crop of the best of a handful of Jovial shots.
In the above shot, you can just about see the striations that band Jupiter, although you obviously cannot discern its Red Spot (which apparently has shrunk in size since I first read a stars and planets book as a child in the early 1970s). Settings were: Handheld with two-stop image stabilisation, full-frame camera, 600mm zoom, f/5.6, t 1/1500s, ISO 12800.
The shot was good enough to inspire me to turn my attention to Saturn, but I needed to find it in the night sky first. A quick look at a sky map revealed it was above the horizon in the Southern sky some way East of Jupiter and much lower. Spotted from “down the street”, a fairly orangey, diffuse-looking star. I didn’t feel like setting up the tripod (moreover the street lamps were going to spoil the view with their brightness, anyway. I didn’t have high hopes. I used the same camera settings, and was really surprised with what came out of the camera. Obviously, the photo is cropped, but you can clearly see Saturn’s rings in this shot.
I posted this photo to some acclaim on Facebook a few moments after snapping it and one commenter suggested they might buy a similar 600mm lens. I should point out that there’s a Tamron equivalent of the Sigma I use. Reviews say it is marginally better. That said, if you calibrate the Sigma to your specific camera you can adjust back/foreward focusing and improve clarity somewhat, I discussed this on the blog last year; you should calibrate all your lenses to your camera(s). If you don’t want to go to the expense of a full-blown astro kit (telescope and dSLR adapter), I reckon it would be worth buying the associated 1.4x multiplier for the Sigma or Tamron.
Conventional astronomical wisdom (as cribbed from Wikipedia) suggests that the Moon formed from the debris left behind when an object the size of Mars collided with the Earth about 4.5 billion years ago in the Hadean aeon, just a few dozen million years after the solar system itself first coalesced. This is the known as giant-impact hypothesis, the Big Splash, or the Theia Impact.
A new theory suggests that this may not be quite right. Instead, it seems there is evidence to suggest that the Moon actually formed within a spinning cloud of vaporized Earth following a collision, this spinning object is known as a synestia which would have been in orbit around the early Earth.
Sarah Stewart of the University of California Davis, USA points out that, “The Moon is chemically almost the same as the Earth, but with some differences.” It is those differences that have led to various hypotheses about the Moon’s formation. Now, Stewart and her colleagues have developed a new picture that meshes more closely with the differences in composition of the Moon and the Earth.
More here.
If you grew up on space books you will be well aware that Jupiter has a great red spot, it’s an enormous anticyclonic storm that has been raging on the planet for centuries with “wind” speeds of around 600 kilometres per hour. It was first recorded by polymath Robert Hooke (he of the (kyphotic) shoulders on which Newton was to stand) who spotted it in May 1664.
The present great red spot was first properly measured in the nineteenth century and has been monitored continuously ever since. Now, here’s the thing, nothing lasts forever and that includes Jovian hurricanes. It used to be described as four times the size of the Earth in terms of area subtended. However, by the time Voyager 2 hurtled past in 1979 it was just twice the size of the Earth.
NASA’s Juno probe recently showed it to be barely a third bigger than Earth now and astronomers reckon it will have disappeared completely within a decade. As such, they’re going to try and get new detailed measurements with Juno before the great red spot finally disappears up its own pressure differential. Indeed, NASA will deliberately crash Juno into Jupiter rather than risk contaminating the planet’s moons and in particular watery Europa, which may well support life. For the next generation of avid juvenile space fans, those space books will perhaps talk with nostalgia about Jupiter’s great red spot just as one generation laments the loss of Pluto from the list of planets we used to learn…
More about the demise of the great red spot and Jovian weather forecasting here.