Here’s a short article I wrote on Autumn Stargazing, printed in issue 55 of the Muir Matters magazine. Thanks to Jeffery Rodgers for formatting the piece and providing me with a free copy.
The Milky Way
With Moonless skies at the moment it’s a great time to view the Milky Way running from South to North and cutting through the zenith close to midnight. Look for the bright central regions close to the horizon near Sagittarius and up past the dark bands of dense galactic material around the constellations Cygnus.
Even if the weather’s looking patchy get out for that late night walk somewhere dark. You might be rewarded with tantalising glimpses during breaks in the cloud. It’s these excursions when expectations are low that I often find the most rewarding when the sky finally opens up.
“There’s something fascinating about our own home galaxy. Even if we still cannot look at it from above and gaze at the full span of its arms, the sideway view offers a quite a showdown.
To me the central part of the milky way is the most spectacular sight of the night sky. It’s something you can clearly see with the naked eye when you are away from city lights. It’s a sight that really brings your down to Earth and lets you wonder at how small we are, while comforting you in the thought that you are part of this Earth and the Universe.” – Adrien Mauduit
Increasing Astronomical Darkness
You might notice the nights seem to be pulling in quickly at the moment. This isn’t your imagination. We’re in a period of greater daylight change as we approach the Autumn equinox on September 22nd.
At the moment the Sun is setting around 20 mins earlier each week. Compare that to July when Sunset times were only changing by around 5 mins per week, and almost no noticable change over the summer solstice on June 21st.
Of course this is great news for stargazers, with astronomical twilight now kicking in around 9.50pm meaning your late night forays under clear skies will reveal increasing numbers of stars and fainter nebulae.
For seekers of dark skies this month’s new moon is September 9th so binoculars, cameras and telescopes at the ready.
Clear skies.
New Star Stories Events and Speakers
The winter Star Stories programme at Abriachan Forest is really coming together with loads of exciting talks and observing opportunities to look forward to in the months ahead. Booking links will be added as the Eventbrites go up:
12th October – Neolithic Stargazing – Dark sky observing, storytelling and talk on ancient stargazing from Stephen Mackintosh – EVENT SOLD OUT.
Eventbrite: https://www.eventbrite.co.uk/e/neolithic-stargazing-tickets…
16th November – Leonids Meteor Shower Special – With guest speaker Dr Anthony Luke, Lecturer of Natural and Applied Science at UHI, giving a talk on the chemistry of stars, meteors and comets. 60% of tickets already allocated.
Eventbrite: https://www.eventbrite.co.uk/e/stargazing-leonid-meteor-sho…
5th December – Evening with Professor Martin Hendry – A special guest talk from Martin Hendry, Professor of Gravitational Astrophysics and Cosmology at Glasgow University, entitled “Exploring the Dark Side of the Universe”
Eventbrite: https://www.eventbrite.co.uk/e/star-stories-with-martin-hendry-tickets-49979041659
21st December – Winter Solstice Special – Mark the shortest day under a full moon with an evening of moon and bright star observing and a talk on the winter solstice from astronomer Stephen Mackintosh.
Eventbrite: please check back
12th January – Audience with Dark Sky Man – Observing under a crescent Moon with guest talk from author of Stargazing For Dummies and On Tour Manager of the Glasgow Science Centre, Steve Owens.
Eventbrite: please check back
9th February – Dark sky observing and Photography special – With guest speaker Graham Bradshaw of Graham Bradshaw Photography. Graham is a local photographer who has taken some stunning landscape, aurora and night sky photos. Eventbrite: https://www.eventbrite.co.uk/e/star-stories-photography-special-tickets-49979762816
27th April – TBC
All evenings will include indoor and outdoor learning opportunities with Clelland, Suzann, Ronnie and the rest of the Abriachan team. Please check eventbrite links for full details. More events, details and ticket links will appear on my Facebook site here.
The Perseids 2018
The period between August 11th -13th will mark peak activity for the annual Perseid meteor shower. Like all annual meteor showers the Perseids occurs due to the Earth ploughing through the fine debris left behind by a short period comet, in this case Comet Swift-Tuttle. Rates of shooting stars could be as high as 60-70 per hour at peak although this figure is under the most favourable of conditions and you’ll likely see less.
This year’s Perseids looks set to be the best shower of the year due to favourable Moon conditions. A thin crescent Moon will set before the shower gets properly underway providing excellent sky conditions if you’re sufficiently away from urban lighting and (of course) have clear skies.
Even if you don’t see any shooting stars you can always look out for Saturn and Mars in the south, both setting between 2 – 4am in the morning, and appreciate the increasing number of stars popping into view as our subarctic skies gradually darken.
The radiant for the shower is within the constellation Perseus the hero, although you don’t need to look in this direction to see them. In fact some of the longest fireballs and streaks caught on camera will be picked up looking away from the radiant.
Due to the brightness of skies this far north you’ll want to wait for the Sun to dip as far below the horizon as possible to achieve the most favourable darkness, this means you’ll want to observe as late as possible, ideally close to or after midnight if you can.
Shooting stars and meteor showers are one and the same phenomena – fine lumps of material impacting the earth’s atmosphere about 40-60 miles overhead. These tiny pieces of debris are travelling so fast they superheat when entering the atmosphere and burn up rapidly. Occasionally a larger piece will impact resembling a spectacular fireball.
Remember, you don’t have to look directly at the radiant to see a meteor shower, this is just the area of space they’ll originate from.
Observing Meteor Showers
You don’t need any special equipment to view a meteor shower, in fact binoculars or telescopes will just narrow your field of view. Grab a deck chair or a warm blanket, prepare a hot drink, wrap up warm and lay out under the darkest conditions you can find. It’s an excellent activity to do alone or if you have children they’ll love an excuse to get outside for some after dark play.
Put away any lights or bright mobile phones and simply look up and wait. Remember it takes up to 30 minutes for your eyes to fully dark adapt and any exposure to bright lights will start the process all over again. If you need a light red touches are best for preserving your night vision.
Clear skies!
Mars Closest Approach to Earth until 2287
Today Mars is closer to Earth than it will be for the next 269 years!
The reason for this varying distance is the red planet’s elliptical orbit which alters the distance between the planets each time Earth overtakes Mars. The attached animation below should give you a feel for how this works.
This close proximity means Mars is particularly bright at the moment shining at magnitude -2.8, and will remain so for the next month and a half. In fact Mars is twice as bright as Jupiter at the moment and will be brighter than the gas giant until September 7th.
Weather permitting you can see Mars sitting low in the South after dark, burning like a brilliant red coal. Viewing surface details requires a telescope at a reasonable magnification, currently hampered by the planet wide dust storms raging on the surface of Mars.
Clear skies.
Total Lunar Eclipse
This Friday (the 27th of July) the Moon will rise into view in the south east around 9.30pm with an unusual red colour. This is due to a rare phenomena known as total lunar eclipse – when the Earth sits directly between the Moon and the Sun.
But why doesn’t the Moon darken if its light supply is cut off by the Earth, and why will it turn a red colour?
The best way to think about this is to imagine yourself standing on the surface of the Moon as the Earth slowly passes in front of the Sun.
As the disc of the Earth begins to occult the Sun it will start to darken until finally the whole of the Earth sits in front of the Sun. But as this takes place something amazing happens. The Earth’s atmosphere refracts the sunlight into an intense circle of vibrant sunset. It’s this ring of fire around the Earth that illuminates the Moon during totality, giving it an eerie red colour.
This far north between 9.30pm and 10.30pm it’ll still be pretty bright outside but the colour change should still be obvious to see. As the evening progresses the eclipse will become partial and will be almost over by midnight.
Totality for this lunar eclipse will be 103 minutes making it the longest in this century. As my animation below shows we won’t be able to witness the start of this eclipse, only its middle and end.
Times:
Peak Eclipse 9.21pm
Moonrise (at 57 deg north) 9.35pm
Total eclipse ends 10.13pm
Partial eclipse ends 11.19pm
Eclipse ends 12.28am
Clear skies and happy Moon watching!
