24 April: The Night Sky

On this date in 1957, English astronomer Patrick Moore presented the first broadcast of The Sky at Night. 10 facts about the night sky.

1. Astronomers use a concept called the Celestial Sphere to map the night sky. This idea dates back to ancient times when people believed Earth sat in the middle of a huge hollow ball which rotated and that was what made the stars move. While we know now that it's not like that, it's still useful to help explain the positions of stars.
2. At the top of it, in its Northern Hemisphere, is the Pole Star, or Polaris. It's directly above the axis of the Earth's rotation and so all other stars appear to revolve around it. There is no equivalent in the Southern Hemisphere.
3. The oldest star map was discovered in a Chinese tomb dating back to 25BC. It was painted on the ceiling.
4. A night sky is never completely dark. Even when there is no Moon or you're far from any city lights it's still possible to see the silhouette of something against the night sky. There is light emanating from the stars but there's also something called airglow which is basically light from the Earth's atmosphere. This is why astronomers are so keen to launch telescopes into space to eliminate this from their observations.
5. There are three stages of twilight – civil twilight is when the sun is the time between sunset and the sun reaching 6 degrees below the horizon. Between 6 and 12 degrees below is called nautical twilight and astronomical twilight is when the sun is 12 -18 degrees below the horizon. After this the sky will be as dark as it ever gets.
6. Ancient maps of the night sky noted the patterns the stars made and often assigned some kind of image to groups of stars, usually something from the mythology of the time. These are constellations. While different cultures had different ones, since 1922, there has been an internationally accepted list of 88. By 1928 the International Astronomical Union had divided the celestial sphere into 88 areas corresponding to the constellations, with boundaries between them. The best known ones include the 12 zodiac signs, the Plough and Orion.
7. Within this list of 88 constellations 42 are animals, 29 are inanimate objects and 17 are people.
8. Some of the planets of the solar system are visible to the naked eye at night. The brightest of these is Venus, sometimes also referred to as the morning star or the evening star as it's often the only star you can see close to sunrise or sunset. Mercury, Mars, Jupiter and Saturn are also visible to the naked eye. The word planet comes from the Greek word for wanderer, because they were observed to move through the night sky a little each day.
9. A point of light travelling in a straight line across the night sky, taking a couple of minutes to cross, will be a man made satellite of some kind. If they appear to blink this probably means they are rotating bits of space junk.
10. A spiral arm of our galaxy, the Milky Way, is also visible in the night sky although in cities it's blocked out by light pollution. The Milky Way is more spectacular in the Southern hemisphere than in the northern one. It appears as a dim, glowing band which appears “milky” to the naked eye, hence the name. The word galaxy also derives from an ancient Greek word for Milk.

Obsidian's Ark

Teenage years bring no end of problems. Daniel Moran's include getting hold of computer games his parents don't think he should have; a full blown crush on the beautiful Suki from Zorostan; maintaining his status as a prefect and getting his homework done. He must also keep from his parents and sister the fact that he is a superhero with a sword from another world.

Trish wonders how to get science whizz Tom to notice her; how to persuade him that the best way to stand up to the school bully is to fight back. She doesn't want her friends, especially not Tom, to know she is a genetic variant with superpowers. Little does she know that Tom has secrets of his own.

Suki struggles to make friends at school when she cannot understand everyday cultural references, and they all suspect her of being a terrorist. She, too, has a secret, but is it what her classmates assume?

When Daniel stumbles upon a plot by an alliance of supervillains to plunge the world into war, he tries to alert the established superheroes, but none of them believe him. When the Prime Minister's only daughter, Yasmin Miller, is abducted, Daniel knows the villains' plan is underway. It seems humanity's only hope may be Daniel and the ragtag bunch of teenage superheroes he recruits. Can he pull together, not only his own team, but the older heroes as well, in a bid to save the Earth from a devastating war?

Available from:

Amazon

Amazon Kindle