This planet’s too COLD... but this one’s just RIGHT
If aliens exist they will be in a ‘Goldilocks’ zone, a part of the universe – like Earth – where everything aligns to allow life ...as explained in a book that will enthral every stargazer
Have you ever noticed the stars on the flag of Brazil? Even if you have, you’ve probably thought of them simply as random additions, there to give it some sparkle. Only if you’re a professional astronomer like Dr Maggie Aderin-Pocock will you know that there are 27 stars, representing Brazil’s 26 states and one federal district, and that they’re arranged exactly as they appeared in the sky on November 15, 1889, the day the country became a republic.
Dr Aderin-Pocock, who presents BBC4’s The Sky At Night, has written this comprehensive guide for those who, like her, look up at the twinkle of little stars and really do want to know what they are.
As a child her fascination was so great that one night at 3am she ended up locked out of her block of flats in London, having wanted to view the sky without the barrier of a window in the way. Thankfully she found a way back in without having to wake her father and incur his wrath.
The International Astronomical Union divides the sky into 88 constellations, and her book examines each in turn, describing its main stars, their composition, distance from Earth and so on. There’s a lot of detail, which is really aimed at those with a serious scientific interest.
That isn’t to say that the rest of us don’t learn things along the way. Blue-white stars, apparently, are the younger ones, while those that appear red are much older. Galileo Galilei made his first telescope in 1609, while Aderin-Pocock herself has worked on one with a reflecting mirror that’s 26ft across.
And there’s a useful reminder that, although several of the constellations have names taken from the zodiac, astrology (as opposed to astronomy) is complete nonsense. You might be tempted to read significance into the patterns formed by certain stars, but they only make those patterns because we’re viewing them from Earth. Change your perspective and those shapes will disappear.
There are some lovely stories about how stars were named. Many still bear shortened versions of the Arabic titles coined in medieval times by Islamic astronomers. For instance, the brightest star in Ursa Major (the Great Bear) is known as Dubhe, short for zahr ad-dubb al-akbar (‘the back of the bigger bear’), because that’s the part of the animal it represents.
Sirius, the brightest star in the sky after the Sun, appears in the hottest part of the summer, which is why the ancient Greeks gave it a name that means ‘scorching’. It’s also known as the dog star, because it forms part of the constellation Canis Major (the ‘Greater Dog’ in Latin) – and this in turn is why that part of the year came to be known as the ‘dog days’.
Then there’s the constellation known as the Air Pump, because the 18th Century French astronomer who discovered it named it after one of the latest scientific tools, ‘a little like if an astronomer now were to announce a constellation called “the 3D printer”.’
The Giraffe is also known by its Latin name of Camelopardalis. Some people think the word means ‘camel leopard’, and that the ancients believed a giraffe was a cross between those two animals. But that’s a mistake – ‘pardalis’ actually means ‘spotted’, and the ancients were simply saying that a giraffe looks like a spotted camel.
The constellation Apus means ‘bird of paradise’. This word dates from the specimens brought back from Papua New Guinea in 1522 by the crew of the Portuguese explorer Ferdinand Magellan. They removed the legs from the bodies, supposedly because they distracted people from the birds’ beautiful plumage – I’m struggling with the logic there, but never mind. As a result, Europeans believed that birds of paradise didn’t have legs in the first place, so named the species ‘apus’, Greek for ‘without feet’.
It isn’t just stars and constellations that need naming: planets do too. When a new one was discovered in 1930, an 11-year-old girl in Oxford called Venetia Burney suggested to the authorities that, as the other planets were named after gods from classical mythology, this one should be as well – and why not Pluto? They took her up on the suggestion. Even though Pluto has since been downgraded to a ‘dwarf planet’, I still love the story. Venetia sounds like an early Maggie Aderin-Pocock.
Of course, the first question many people ask about space is, ‘Might there be life out there?’ We don’t know, but we do have an interesting name for the areas of the universe where life has the greatest chance of existing: ‘Goldilocks zones’.
This is because they are at a distance from their nearest star that makes them neither too hot nor too cold for a planet to sustain water. This topic always reminds me of Arthur C. Clarke, the science fiction writer. He said that there were two possibilities – mankind is either alone in the universe, or it isn’t – and either way, it’s an incredible thought.
As always with books on this subject, the best bits are a reminder that space is bizarre. Some stars you see might not actually be there. That’s because it takes so long for their light to reach us that they might have exploded in the meantime.
The light from our nearest star, the Sun, takes eight minutes to reach us, but the light from the second nearest star, Proxima Centauri, takes four years. More distant stars are hundreds or even thousands of light years away. Saturn has rain made of liquid diamonds. So does Jupiter – and it also has a storm in its atmosphere that’s as big as Earth, called the Great Red Spot.
Finally, our Milky Way galaxy is due to collide with the Andromeda galaxy in 4.5billion years. But there’s so much space between adjacent stars that there probably won’t be many actual collisions. Phew.