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MESSAGE OF THE MONTH
A simple yet dramatic capture
This is an image of the Moon’s clair-obscur effects, the Lunar X and V, as taken on Friday 8 April around 9:30pm, which were forecast in BBC Sky at Night Magazine. They are sometimes elusive from my location as they appear either at daytime or after the Moon has set.
I was at my usual Friday night haunt, the Chesterfield Observatory on the evening of the 8th. Here, we are lucky enough to have a big 18-inch reflector housed in the dome, so I took my chance. This all sounds like technical stuff, but the reality is that this was taken using my old, ‘not too smart’ phone, handheld to the 40mm eyepiece in the 18-inch telescope.
If I had been at home I would have used my much smaller telescopes, which would have been quite adequate. It just shows that you don’t need too much technical or expensive equipment, or even expertise, to achieve good results. I’m really pleased with this and the simplicity of it. Anybody can do it, just give it a try!!
Sue Silver, Sheffield
What a fantastic image, Sue, the two clairobscur effects really stand out. Well done! –Ed.
This month’s top prize: two Philip’s titles
The ‘Message of the Month’ writer will receive a bundle of two top titles courtesy of astronomy publisher Philip’s: Nigel Henbest’s Stargazing 2022 and Robin Scagell’s Guide to the Northern Constellations
Winner’s details will be passed on to Octopus Publishing to fulfil the prize
Manhattan morning
Towards the end of March this year I took an icy walk in Manhattan, back and forth from 2nd Avenue to the East River in the two hours before dawn, stalking the triangle of planets in the constellation of Capricorn, the Sea Goat. On the other side of the constellation, the 28th-day waning crescent Moon was to slowly process across the planets and then slide below them towards Aquarius a few nights later. I was reminded of how, for four days after Hurricane Sandy in 2012, here in New York you could see every star in the sky before electricity was restored.
Felton Davis, 2nd Avenue Star Watchers, New York City, US
Bright flashes
Do you have any idea what these bright streaks in my image are? I’ve recorded meteors many times and these leave a bright, thin trail as they streak across the sky. But these bright objects startled me when they flashed by NGC 2362 on 10 February 2021. They were accompanied by additional ‘explosive’ flashes, two of which are reproduced here. As I was filming I caught the whole sequence. Could they be fireballs?
Paul Sparham, via email
Thanks for getting in touch, Paul. The bright flashes in your image look a lot like sunlight glinting off two satellites. – Ed.
Dark matters
Regarding the article ‘Pioneers of dark matter’ (May 2022), shouldn’t the scientific community resolve this matter? If the proposers cannot prove it exists and the opponents cannot ‘prove the negative’, that it does not exist, then there’s a stalemate.
Milgrom, who proposes the effect is a function of gravity at the edges of galaxies, should be accepted. That will bring an end to the speculation that dark matter exists. At least Milgrom has proof, using gravity, and this will surely add to our understanding of this phenomenon; even if measurement is impracticable due to distance.
Stuart Hunter, via email
Moon lighting
This may seem a silly question from a fully grown adult, but I’m struggling to explain to my three-year-old daughter, so here we go… why can we see a full Moon? If the Moon has to be on the other side of Earth to the Sun for us to see a full Moon, why doesn’t Earth’s shadow block out the light. And how does the Sun’s light reach the Moon with Earth in the way?
I’m hoping I’m not the only person to think this and hope, maybe, other readers must have thought this at some point.
Adam Rulewski, via email
That’s a great question Adam. We see a full Moon when the Sun, Earth and Moon are in a line because the Moon’s orbit is angled about 5° from being lined up with the ecliptic (Earth’s orbit of the Sun). At the distances involved, that 5° angle is enough to allow sunlight to pass Earth and reach the Moon. – Ed.
CORRECTIONS
• In the picture of M65 and M66 in ‘From city lights to deep space’ (April 2022 issue, page 30), the caption incorrectly said the two galaxies are approximately 35 lightyears apart. M65 and M66 are in fact 160,000 lightyears apart and around 35 million lightyears away.
• In the star chart of Coma Berenices in ‘From city lights to deep space’ (April 2022 issue, page 32), NGC 4564 should have been labelled NGC 4565.
• In the caption to the image of an astronaut collecting rock samples on the lunar surface in ‘Apollo 16’ (April 2022 issue, page 35), Charles Duke was incorrectly named as Charles Young.
• In the caption to the extravehicular activity map in ‘Apollo 16’ (April 2022 issue, page 37), Charles Duke was incorrectly named as George Duke.
Tweet
Peter Lewis @PeterLewis55 • Apr 21
Development of massive sunspots that have appeared since Easter Sunday (numbered AR2993-6). Inspired by @Avertedvision @ skyatnightmag @StormHour @ThePhotoHour @VirtualAstro
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WE ASKED: What is your favourite astronomy fact?
Carol Miller 1,300 Earths could fit into Jupiter. This fact blows my mind and it’s something I regularly tell others when pointing out Jupiter in the night sky.
Austin Monks The Moon is 400 times smaller than the Sun, but also 400 times closer to us, which makes them both appear equal in size in the sky (most of the time). This allows us to have stunning solar eclipses complete with the Sun’s corona.
Steven Johnson Venus’s day is longer than its year.
Mihai Saiph The further we look into deep space, the younger we see the Universe.
Debz Townsend Jupiter is the fastest spinning planet in the Solar System and it has rings!
Stephen Webber Saturn would float in the bath.
Alex James There are more stars in the Universe than grains of sand on Earth.
Martin Bailey The rocks in Saturn’s rings are so close together that you could walk on them like stepping stones.
anas.albounni • 15 Apr 2022
With the rise of the first day of Ramadan, 2 April, an early morning shot of the Milky Way from @eao_ae with my gear in the foreground. Nikon D810a, Nikon 12–24 2.8, 10 subs, 15″ each, ISO 6400, on a tripod, stacked in Sequator, processed in Photoshop. @bbcskyatnightmag
SOCIETY IN FOCUS
Swindon Stargazers was founded in 2009, the International Year of Astronomy, by Peter Struve, a descendant of the famous family of astronomers such as Friedrich Georg Wilhelm von Struve, who is best known for his study of double stars, and after whom many are named.
The club exists to promote the hobby of astronomy and we meet once a month in our local village hall, where speakers give talks on aspects of observational and scholarly astronomy.
The club conducts many outreach activities, such as working with uniformed groups on their astronomy badges, and with groups such as the National Trust at Avebury. We’ve also worked with Wiltshire Wildlife Trust at its Blakehill Farm Nature Reserve, Women’s Institutes, libraries and schools, and with Marlborough Town Council for the Marlborough Dark Skies Festival, where we have recently organised our ‘Stargazing on the common’ event.
Members also support a Swindon U3A Astronomy Group. The club has a number of telescopes that can be loaned to members, and practical astronomy is actively encouraged. Members also regularly attend star parties around the country.
The club is a member of the Federation of Astronomical Societies (FAS) and is run for the benefit of its members to support and encourage their interest in astronomy.
Robin Wilkey, Chair, Swindon Stargazers
SCOPE DOCTOR
Our equipment specialist, Steve Richards, cures your optical ailments and technical maladies
Email your queries to scopedoctor@skyatnightmagazine.com
I want to attach a motorised RA drive to my Sky-Watcher EQ5 mount, but will I still be able to use the manual fine-adjustment controls after the motor drive has been installed?
TONY GRETTON
The Sky-Watcher EQ5 is an equatorial mount with two large, knurled, plastic knobs to make fine adjustments to the RA (Right Ascension) and dec. (declination) axes by hand. The mount can be upgraded with either a single or dual axis motor drive and a choice of either a basic or more advanced hand controller, the latter including an ST4 interface for auto-guiding.
Installing the Sky-Watcher motor drives doesn’t remove the ability to adjust the pointing of the telescope manually with the fine control knobs, as the upgrade includes knurled knobs that control slipping clutches mounted on the original drive shaft. When the clutch knob is slackened off, the motor drive is disengaged and maunal control is enabled.
A rough pointing is carried out by loosening the main RA and dec. clutches and manually pushing the telescope to the correct position. Fine adjustment is made by re-tightening the main clutches and using the hand controller’s direction buttons to centre the chosen object in the field of view.
Steve’s top tip
What is a dew shield?
Dew shields are cylindrical extensions fitted to the front of refractors. They can be added to Schmidt-Cassegrains, by using a piece of camping mat cut to size and wrapped around the scope tube’s front. Dew shields stop stray light entering the light path from oblique angles and reduce the formation of dew.
Telescopes reach equilibrium with the ambient temperature through convection, but after that the glass elements continue to cool through radiation, causing dew. Trapping a pocket of air in front of the primary lens reduces the radiation rate and the dew shield restricts the direction in which it takes place.
Steve Richards is a keen astro imager and an astronomy equipment expert