The night sky in January - and the 50th anniversary of the first person to land on the moon

It’s January, the beginning of another astronomical year, and although we are now in winter, the Earth is actually at its closest point to the Sun during the year. We will be starting the year with an eclipse of a Super Moon this month.

On January 3 , the Earth is at ‘Perihelion’ or closest point to the Sun, when it will be 91,403,554 miles (147,099,761km) away. That’s in contrast to six months from now when Earth reaches ‘Aphelion’, its most distant point, on July 4 when we will be 94,513,221 miles (152,104,285km) from the Sun.

In January in the northern hemisphere we experience winter, so it can seem counter intuitive to learn that the Earth is now at its closest to the Sun. However, the northern hemisphere is tilted away from the Sun in January, while the southern hemisphere, which is tilted towards the Sun, has summer. In six months’ time of course the situation will be reversed.

Now is the best time to start looking at the winter night sky. The nights can be very cold but to compensate it gets dark early in the evening, meaning there is more time to look and learn your way around the night sky. Our two main signposts, the Plough and Orion, can be easily found and used to navigate around the sky.

If you look north east you will see the Plough with its handle pointing towards the horizon. The two stars furthest from the handle of the Plough are, as always, pointing to the North Star. The ‘W’ of Cassiopeia is now very high in the North West and because of its position is becoming a letter ‘M’. If you look directly overhead you will see the bright yellow star Capella in the constellation of Auriga the Charioteer and just to the right and below Capella you will notice a faint but distinctive triangle of stars known the Haedi or Kids. ‘Capella’ means the she-goat and where the she-goat goes, the kids will follow, meaning they are always easy to find.

If you look to the south you cannot fail to see the splendid constellation of Orion the Hunter. Seven bright stars make up this constellation; four that form a large rectangle and inside this the three stars that form the belt of Orion. According to legend, Orion boasted that he could kill any living creature, but one day when he was boasting to a large crowd about all the animals he had killed he did not see a little Scorpion creeping up behind him. The Scorpion stung Orion on the ankle and killed him. The gods, however, had been so impressed with the boasting of Orion that he was placed in the sky forever, and so was the clever Scorpion. To make sure they could never meet again Orion was placed in the winter sky while the Scorpion was placed in the summer sky.

It will quickly be seen that six of the seven stars that form Orion are blue/white in colour, while one is distinctly red. The red star in the top left hand star of the rectangle is called Betelgeux or as some people like to call it, Beetlejuice! The colours of the stars tell astronomers which are the hottest. Stars that appear blue/white are much hotter than stars that are red. The blue stars are very young stars and can have surface temperatures of around 30,000 degrees centigrade, while the much older red stars have surface temperatures of only 3,000 degrees centigrade. Our Sun has a surface temperature of around 5,800 degrees centigrade and is, in stellar terms, rather middle aged.

Just below the stars of Orion’s Belt you will notice the fuzzy patch of the Orion Nebula. This is a stellar nursery: an area of space where as many as one thousand stars are actually being created out of a giant cloud of dust and gas at any moment.

If you use the belt stars and draw a line down and to the left you will arrive at Sirius the Dog Star; the brightest star in the sky in the constellation of Canis Major, the Great Dog. Using the belt stars and drawing a line up and to the right you will find the bright red star Aldebaran in the constellation of Taurus the Bull and if this line is continued you will reach a fuzzy or misty patch in the sky which is the Pleiades or Seven Sisters, a cluster of stars moving through space together. Although called the Seven Sisters I can usually only see five or six with the naked eye. People with much better eyesight than mine will see seven or more, but in fact there are hundreds of stars there.

Going back to Betelgeuse, a line drawn to the left and slightly curved will reach another bright star, Procyon, in the constellation of Canis Minor, the Little Dog. A line drawn from the middle star of the belt of Orion past Betelgeuse and curved slightly to the left will reach the two brightest stars in the constellation of Gemini the Twins; the stars Castor and Pollux.

By using Orion as a signpost it is possible to find the brightest stars in the winter sky and then to move around and find the fainter constellations and stars.

The Planets in January

This month we can see planets just after sunset and again just before sunrise. Look low to the south west after dark and you will see the familiar bright orange looking ‘star’ which is planet Mars. Mars has been in the evening sky since summer. However, it is the morning sky which is attracting attention at the moment because if you look to the east before sunrise you will see a bright white dot in the sky. This is Venus, which apart from the Sun and Moon is the brightest object we can see. While Venus had the morning sky to itself in December, it is joined this month by the biggest planet in the solar system, Jupiter, which can been seen towards the end of the month as another bright dot in the sky.

The other naked eye planets Mercury and Saturn are too close to the Sun to be seen this month.

Meteor Showers

Following the spectacular Geminid meteor shower last month we have the Quadrantid meteor shower on the night of January 3rd /4th, when around 40 meteors per hour can be seen. The Quadrantids do have one very important claim to fame, in that theirs is the only meteor shower named after a constellation that no longer exists. A meteor shower is named after the constellation from where all the meteors appear to come from, in this case the Mural Quadrant. In 1930 when the modern constellation boundaries were defined, the Mural Quadrant was discarded as were many other old constellations. As this meteor shower was known during the nineteenth century we still recognise the defunct constellation in its name.

Phases of the Moon for January

New Moon 6, First Quarter 14, Full Moon 21, Last quarter 27

The Full Moon in January is called the Wolf Moon. This is because of the howling of the wolves that could be heard in the forests in ancient times while they were struggling to find food. It also of course acted as a warning to the unwary, who might venture too deep into the forests, that the wolves were still there.

Eclipse of a Super Moon

On the morning of January 21, there will be an eclipse of the Moon. This is not just an ordinary eclipse of the Moon but an eclipse of a Super Moon. The Moon orbits the Earth in an ellipse or egg shaped orbit rather than a circle.

Eclipses of the Moon occur when the Sun, Earth and Moon are in a line and the Moon passes into the shadow cast by the Earth. Although the Moon orbits the Earth every month it does this at a slight angle which means that we do not get an eclipse every month. To try to explain: if you imagine a piece of paper with the Sun, Earth and Moon in a line, sometimes the Moon can be found above the shadow of the Earth and sometimes below.

The eclipse will happen early in the morning with totality beginning at 4.40 am, mid eclipse being at 5.12 am and totality ending at 5.43.

The Moon will appear to turn red in colour when the eclipse is occurring because although the Moon is in the shadow of the Earth, some light from the Sun will reach it as the light passes though the Earth’s atmosphere and is refracted, or bent, onto the surface of the Moon. The atmosphere blocks the blue part of the spectrum, only allowing the red light to pass through, thus explaining the red colour of the Moon. This is often referred to as a Blood Moon, or in this case a Super Blood Moon.

The 50th anniversary of the Apollo 11 Moon landing: a celebration of the Moon

Our Solar System began forming about 5 billion years ago when a large cloud of dust and gas collected together and a star, our Sun, was formed. There was plenty of material left over, and around 4.5 billion years ago, this material formed into the planets and the rest of the solar system.

Around 50 million years later when the Earth was still a ball of wibbly wobbly material and was much larger than it is today, an object named Theia, possibly about the size of Mars, crashed into the Earth and a lump of material was scooped out and formed into what today we call the Moon.

During the next 4.1 to 3.8 billion years the Moon, together with all the other planets in the solar system, experienced what astronomers call ‘the heavy bombardment period’, when large asteroids crashed into them.

After the heavy bombardment period eased off, between 3.8 to 1 billion years ago, there were many active volcanoes on the Moon. It was during this period that there was a kind of atmosphere around the Moon and water was one of many elements being formed. Readers may be aware that in 2008/9 astronomers discovered water ice deep inside craters at the poles on the Moon which is probably ice from this early period in its history.

It was during the last billion years that those spectacular ray type craters that can be seen on the Moon were formed, after the volcanoes became dormant and the surface of the Moon stopped being re-shaped.

The Moon we see would have appeared the same to the very first humans who looked up into the sky around 5 million years ago.

The next meeting of the Earby Astronomical Society will be on Friday January 25, at All Saints’ Church, Earby, from 7.30pm to 9pm. The speaker will be Martin Lunn MBE FRAS, Earby Astronomical Society, and the title of the talk will be ‘The Sun’.