Fact or Fiction?

The Night Sky December 2019

Imagine being in a spacecraft launched in 1977. On board you have been asked to take a 90-minute recording of important sounds, speeches and music, together with 118 pictures of everyday life, in the hope that at some point in the future you would be able to describe and explain some of the wonders of your home planet. What would you choose? I wouldn’t know where to start!

The journey ahead would visit the outer solar system, but then you would have no real destination - just an endless discovery of new places further into space than you could imagine. Every day you would send messages back home to tell us what you had seen. Your next encounter would be in 80,000 years, which is our nearest star, and then past that and outward to infinitum. By then, perhaps, the spaceship itself would be the only relic left of the civilisation that had built it.

Science fiction, I hear you say. Well, not quite. Apart from the spacecraft being unmanned, it is absolutely true. Currently on their 41st year of travel, Voyager 1 and Voyager 2 have both broken away from our solar system and are over 13 billion miles away. They have exited the region of space that is affected by our sun and are now in interstellar space.

Amazingly, the spacecraft are sending measurements and observations back to us but sadly in about five years they will both run out of power. They will continue with their payload of information on our world to share with whoever may at some point in the future stumble across them in the vastness of space. It will take another 30,000 years to cover just 1 light year. (Recommend watching: Netflix- The Farthest. Recommended reading: Murmurs of Earth ISBN 0 340 24423 2)

Cassiopeia

The very familiar ‘W’ shape of the constellation of Cassiopeia is high in the sky this month. It is dancing around the North star opposite the equally recognisable partner The Plough (or Big Dipper). When you view Cassiopeia it is set against the Milky Way and a rich source of Deep Sky Objects. It also contains a supernova remnant and this is the strongest radio source in the sky outside our solar system, first discovered in 1947. The first light from the supernova is believed to have reached us 300 years ago. The pattern of Cassiopeia is nothing more than a line-of-sight effect. Each star that makes up the pattern has a vastly differing distance from us. For example, the star in the middle of the ‘W’ is 10 times further away than the star that makes the end of the ‘W’ shape.

It is easy to understand how the night sky, viewed from different places in space, would soon lose its familiar pattern. Indeed, given time, all stars making up constellations are changing their position in relation to each other. Therefore the patterns we have created will become slowly distorted and eventually unrecognisable.

Longest Night

This month contains the longest night (22nd December) - an astronomer’s dream. A personal winter favourite to look out for is the awesome Rosette Nebula. It is a huge circular nebula that is a popular target for astronomers. The image I have included is in monochrome but viewed in colour is a beautiful red rose- like flower.

Impressively it appears to be nearly three full-moons’ width in our night sky although its actual width would take 130 years to cross at the speed of light! It is just visible to the naked eye but its full glory is unlocked with a pair of binoculars or better still, a telescope. Its location in the sky is low in the south-east to the left of the very distinctive star of Betelgeuse in the top left corner of Orion.

Between 10th & 11th December the very bright Venus is visible in the south-west and passes Saturn after sunset.

Full Moon 12th December

New Moon 26th December

Don't look now!

The Night Sky November 2019

The Milky Way.

You could be mistaken into thinking that the Milky Way was just a long stretch of very hazy evening clouds. But when it is a clear night it is absolutely unmistakable. This month it wraps over the sky from east to west right overhead with the very faint smudge of the Andromeda Galaxy directly overhead. From Embsay, facing east, it seems to rise from the direction of Bolton Abbey with the familiar hour-glass figure of Orion to the right.

Looking over to the west you will see Cygnus (the Swan) superimposed on top of the Milky Way before it sinks below the horizon.

Unbelievably, it was Greek philosophers who hypothesised that the Milky Way may be made up of distant stars - but this was not proved until nearly 2000 years later when a telescope was used to study its composition. From our location at this time of year the centre of our galaxy is just below the horizon, looking towards the west. At its centre is a black hole named Sagittarius A . Recently, a pair of vast bubbles hundreds of light years across have been detected. These are speculated to have been formed by massive levels of energy bursts near the black hole. New research has also discovered an event called ‘Seyfert flares’, which blast out of cones of radiation through our galaxy and originate from a black hole.

Something not to see, directly!

This month sees a special event on 11th November. Before I describe it, there is a health warning! DO NOT OBSERVE THE SUN DIRECTLY, it will cause permanent damage to your eyes.

Between 12.35 pm and 4.30 pm (when the sun sets) the planet Mercury will pass in front of the Sun. As Mercury moves across the surface of the Sun the very small black disc of the planet will be silhouetted against the colossal brightness of our Sun. When this happens it demonstrates just how small the planet is and also how immensely big the Sun is in comparison. This is called a transit and will not happen again until 2032. Records show that the first observed transit was 7th November 1631 and much later Captain Cook saw a transit and used it to determine his latitude during his first voyage on the Endeavour in the Pacific. He will have had special solar filters to observe it safety. The only other safe way to observe for us is to project the image through a telescope or binoculars on to card.

Even then, the temptation to line up the telescope with your eye MUST be resisted. If you remember playing with a magnifying glass when you were younger and observed how a focused light beam starts a fire, don’t let this happen in the back of your eye. If you want to see it my recommendation is to see it online. I am sure the transit will be uploaded on to the internet and maybe images will be published in newspapers or web sites if you want to see it. If we have a clear day I’ll have a go and put any images on my site (see link below).

Planets and Moons.

Looking south west on 28th November just before 5pm, you will see the crescent moon low on the horizon. On the left of it is Venus, on the right Jupiter. These are the two brightest planets and this trio of objects should look spectacular! Our single moon seems to be rather lonely compared to the 79 moons of Jupiter. Saturn, however, holds the current record at 82, 20 new ones have just been discovered!

Full Moon 12th November

New Moon 26th November

False Dawn

The Night Sky October 2019

An often forgotten and rare phenomenon that occurs this month is the appearance of Zodiacal Light. If you are up early in the first half of this month, look towards the East over Bolton Abbey. You may be lucky enough to see a faint pyramid of glowing light. I’ll be on the hunt for it too as I have never seen it myself. It is our sun’s light reflecting off tiny particles or cosmic dust in space. Also known as a false dawn, it is a very eerie light that can only be seen in a dark country night sky such as ours.

It is best to catch it at the beginning of the month before the increasing phase of the Moon spoils the show.

The Full Moon on the 13th of this month is called the Hunter’s Moon. It is named after Herne the Hunter, who leads his dogs across the heavens as they yelp across the early winter sky. In reality, it will probably be the wild geese migrating from the likes of Embsay Reservoir to warmer climes.

Halley’s Comet.

As the month progresses and the moon fades, there will be a chance to see another light show in the form of a meteor shower caused by one of the most famous comets of all, Halley’s Comet. I remember watching Halley’s Comet in 1986. It wasn’t the most impressive of displays but historically it seems to turn up at key times. The first known observation was 239 BC, returning every 75 years and next projected to return in 2061. Currently, it is still heading outward into deep space from its last visit until November 2023. Then it will fall back towards the sun and fly past again. Some people have linked its appearance to the Star of Bethlehem, the defeat of Attila the Hun and it is depicted on the Bayeux Tapestry. Good news for William but clearly regarded as a bad omen for Harold! Each year the Earth passes through the route the comet has made countless times, bumping into the dust and remnants it has left as it repeatedly crosses our orbit. Sometimes the streaks that light up the sky are drowned out by moonlight, but not this year because in the early hours of 22nd and 23rd the moon will be well out of the way. The stream of debris is called the Orionid meteor shower. Look out just before dawn to get the best views. They will seem to originate from Betelgeuse, the top left-hand star of Orion.

Planet Feast

At the end of the month, looking South West in the early evening, you will be able to see Saturn, the crescent Moon, Jupiter and a very bright Venus on your right. Just popping above the horizon close to Venus is Mercury.

As if that wasn’t enough, Uranus will be visible with the naked eye, half-way up the sky in the South East. Uranus will come the closest to Earth on the 27th but is still quite faint. This is a great chance to spot five planets all at once.

The clocks go back an hour on October 27th at 2am as British Summer Time (BST) ends.