October 2023

The Milky Way

I always hope that around the time of a New Moon we can get to see the sparkling band of stars of the Milky Way stretching over our heads. The next New Moon is October 14th. Despite the fact that ancient civilisations did not have powerful telescopes they knew the Milky Way was special. It was considered a path, road or even a river between Heaven and Earth. In Peru, the Milky Way is thought to take water from the cosmic ocean and return it to us as rain. In Hebrew tradition, the river of light; in India the reflection of the Ganges. It is estimated that now one third of humanity can’t observe this spectacle for many reasons but mainly due to light pollution. So we are very lucky to be able to see it here in Embsay.

Often it can be mistaken for light cloud, but if you just point a pair of binoculars upwards you will see countless stars that form our home. Although we live in a disc of 100,000 million stars, as we look at it we are looking from inside and edge on. When we see the Milky Way we are looking into a big spiral (plate shaped), in the main when we look away from this band we are looking outwards into deep space. Of course there are other local stars that make up the ‘thickness’ of our galaxy and these are the ones we see elsewhere in the sky. Shaped like a catherine wheel we are positioned away from the centre in one of the arms that form a great spiral.

It is big! It would take 200,000 years (at the speed of light) to travel across our galaxy, and 1000 years to travel through its thickness. That is travelling nearly 3.5 BILLION YEARS using our current technology. Despite this enormous size, it can be faint to our eyes and our challenge this month is to try and photograph it.

Photo: Aezo

How to photograph the Milky Way.

Basic steps

The faintness of the Milky Way can be overcome by setting your camera (or phone) to a shutter speed of about 15 to 20 seconds. This will let enough light in for the faintness to stand out. But because you have done this, your camera will have to be very steady for that length of time. So either put it on a tripod or have a delay of a few seconds so that you can put it into position. Then pick a moonless, clear night. Set your camera to face anywhere along a NE or SW line across the sky or just straight upward.

Better pictures

A couple of other things will help a lot but are a bit technical. If you know how to make your camera more sensitive by adjusting the ISO, then set it between 3200 and 6400. Also, set your lens as wide as possible (f/2.8)

Even better pictures

Set the camera white balance to 4000k.

Some particular mobile phones do a terrific job at taking dark sky scenes, why not give it a go!

https://cameragroove.com/can-you-take-pictures-of-the-milky-way-with-an-iphone/

https://petapixel.com/2021/07/26/these-astrophotographs-were-all-shot-with-smartphones/

Photo: Outerspace Universe

Comet 103P Hartley

This peanut shaped lump of ice, carbon dioxide and methanol is about 1000m across. In 2010, as part of the Deep Impact Mission, a flyby took place and identified its very unique movement. It spins around one axis but tumbles around another. As it gets closer to the sun, the dry ice and gases heat up and burn off as a long tail across space - always facing away from the sun due to the solar wind blasting it outward.

This is its position on 14th October before sunrise - looking South East.

https://www.skyatnightmagazine.com/advice/comet-103p-hartley

A quick look at our night sky this month.

Looking North at 9pm on 14th October

Looking South at 9pm on 14th October

The planets this month

Mercury - best the first week of October early in the morning

Saturn - low in the East

Uranus - October 29th Can be found South of the Moon.

https://www.timeanddate.com/astronomy/night/@2648147

New Moon 14th October

Full Moon 28th October

Other points to note this month? A Partial Lunar Eclipse 28th October 21.15 pm where the Earth will cast a 12% shadow over the moon. https://www.timeanddate.com/eclipse/in/@7298251

My target to observe this month is the Elephant’s Trunk Nebula, almost directly above, a concentration of interstellar gas and dust. If I manage an image, I will include it in my next article!

Clear Skies

Milan Davidovic

September 2023

The Night Sky September 2023

After all those long days and short nights, it’s that time again to take advantage of our dark night sky here in Embsay. But first - a true story to whet your appetite!

On September 5th 1977, a space probe was launched as a once- in- a- lifetime chance to catch a special alignment of the planets and hitch a ride using their gravity to Jupiter, Saturn and its satellites. In 1979 it skimmed past Jupiter, then a year later, Saturn. Having completed its main mission, it headed off to outer space, briefly turning its camera back towards Earth to take this iconic picture (The pale blue dot) in 1990. At this point it was 3.7 billion miles from us. For me, this was as astounding as the discoveries it made….

…Here, in a single pixel, is everything you and I have ever known and all people who have lived and will live, against the vastness of space.

Photo: NASA 1990

Onward it journeyed, having accomplished its main aim and in 2012 it left the influence of our solar system into interstellar space. By coincidence, it was also the day (August 25th) that Neil Armstrong died. Incredibly, the Voyager 1 probe has 70 kilobytes of memory and most current smartphones have 200,000 time more memory. Its technology is that of the 70s but the yet it still continues onwards but when its energy is expired we will inevitably lose contact. It will travel through space indefinitely unless its path is blocked or it is intercepted. Currently, it is 14.7 billion miles away and is still receiving commands from mission control. On board is a treasure-trove of information relating to humankind imprinted on a golden disc.

What images and sounds would you have sent on this journey that will no doubt outlive our existence? https://voyager.jpl.nasa.gov/golden-record/

Find out more about the missions (there were 2 missions in quick succession) :

https://voyager.jpl.nasa.gov/mission/status/

https://www.msn.com/en-us/news/technology/where-are-nasas-voyager-1-and-2-probes-in-deep-space/ar-AA1eGrPL

The Voyager Mission was primarily created to visit the two main planets we can see this month.

Here are two sky charts for the 15th - hopefully a clear, moonless evening. The yellow curve is the path that the planets take as this month you should spot the biggest two; Jupiter and Saturn.

Looking North 15th September at 10pm

If you can find a dark place you may be able to spot the Milky Way arching across the sky from North East to South West. Look carefully and you will see Jupiter low in the East…… more about that shortly.

Looking South 15th September at 10pm

Saturn is low in the South with the Great Square of Pegasus half-way up in the sky due East.

Earth and Jupiter will soon be the closest to each other than at any other time of the year. Situated just above the Eastern horizon, they move slowly and higher throughout the night. Since the Voyager Mission we have discovered more and more about Jupiter. It is huge! Its mass is more than two and a half times that of all the other planets put together! It does have rings but they are too faint to see. Over time, an increasing number of moons have been discovered - currently standing at 92 moons! The largest 4 and the great red spot can be seen with a modest telescope or binoculars.

Photo Trevor O'Donoghue

Photo: Milan Davidovic. Embsay

Hubble Telescope Images.

https://lightsinthedark.com/2017/04/08/heres-hubbles-newest-knockout-portrait-of-jupiter/

Of course the James Web telescope does it even better!

https://science.nasa.gov/jupiter-webb-space-telescope

September 15th New Moon

September 22nd Mercury Greatest Elongation West

September 23rd Autumn Equinox. Night and day of equal length.

September 29th Full Moon

Clear Skies

Milan Davidovic

Our Dark Sky

In my final article for this season I would like to focus on something that perhaps we all take for granted…

Our Dark Sky

It is very easy to forget that we and wild species have evolved to operate in both daylight and night time. Artificial light removes a natural part of a time that wildlife uses to rest, migrate, hunt, hide and function during the day time. As humans we can close the curtains and turn off the lights inside our homes at will. Wildlife does not have such control and becomes vulnerable, having learnt to live and rely on the cover of darkness. Keeping our skies dark protects those natural ecosystems. Here in Embsay many people are lucky enough to gaze into a dark night sky. It is a gift, part of the character of where we live and something we must protect and value. Of course, light is necessary but stray light, overly intense, or misdirected, is not. It also impacts on our well-being, balance of sleep and wakening time. The increase of light at night decreases our melatonin production which results in sleep deprivation. The type of light has an impact too. High intensity light, which can be energy- efficient, emits more UV light that we can’t see but some wildlife can. Our LED street lights are pointed downward but are extremely intense and focused. These lights are rich on the blue wavelength which is now known to damage your retina. Finally, it uses energy which as we know is costly and in many cases is derived from using fossil fuels.

The night sky is a way in which we can connect with the wider universe and understand our place so to lose it is to lose something bigger than us.

So please think before you install an outside light. Is the light shining upward and just lighting the sky? Can it be shielded in some way? Does it need to be on? Can it come on just when something moves or just when you need it to? Keep your curtains closed and keep your light inside.

The Bortle Scale

This is a scale that measures the night sky’s brightness. 9 represents inner-city skies through to 1 being excellent. I believe that Embsay is currently Bortle 4/5 and currently lies in the suburban/rural category.

A rough test you can do during the summer months is to try to spot the Milky Way. Iif you can see it across the sky but it looks washed out and invisible at the horizon then we have a Bortle 5 or lighter sky. The more lights we point upward the closer to the left on the diagram we move. The more houses that are built (and associated lighting) the greater the erosion of our night sky. It is with some irony that the Yorkshire Dales National Park Dark Sky Reserve was granted in 2020 and a few years later is considering building housing developments in our village that will inevitably reduce our ability to have a dark sky.

The impact on our dark skies can be seen dramatically at www.lightpollutionmap.info .If you click on the link and search for Embsay then zoom in you will see how it has changed over recent years by adjusting the’ VIIRS’ in the overlay menu top right.

Clear Skies

Milan Davidovic