What’s up in the sky next month?

26th April

Venus

The kings and queens of the solar system show themselves to best advantage in May.

Everyone likes a good story and astronomy is littered with the characters from good stories. The planets take their names from the mythology of a pre-scientific age and in May two of the brightest are prominent in the evening sky.

Venus dominates the evening sky. Throughout May half an hour after sunset you can see it as the brightest object hanging low above the horizon. Not exactly close at 200 million kilometres away from us but easily seen. Frequently called the evening star as it is the first object to be seen in the sky after sunset and long associated with the goddess of love and beauty, possibly as it is the brightest of all the planets. Of course we now know that if Venus should be associated with anything it should be a hellish inferno and not beauty. The Venusian climate would melt metal, the air pressure crushes with the force of kilometre deep water, it rains acid, snows metal and the entire place is covered in volcanoes. If there is one thing we can say for certain about the goddess of beauty it is that she was certainly misnamed.

At the same time that the queen of the planets sinks into the west the king of the planets rises in the east. An hour or two after sunset the brightest object hanging above the eastern horizon is Jupiter. Even further away at 700 million kilometres Jupiter is so bright and easily seen because it is huge. In legend Jupiter was the king of the Roman pantheon of gods and the planet has a suitably impressive set of facts to help it live up to that name.

Venus

Europa – A home for life around the king of the planets?
Credit: NASA, ESA, and G. Bacon (STScI)

Jupiter is the largest planet in the solar system. At 1,000 times larger than the Earth, it has 69 moons; a single storm on Jupiter has raged for 400 years and could swallow the whole of the planet Earth twice over with room to spare. By any measure this is a large planet! With even a small pair of binoculars you can look at Jupiter and see some of its moons and, over a few days, you can see them dancing around the planet as they travel around their parent planet; the same observations that Galileo made in 1610 and which displaced the Earth from the centre of the Universe.

So why are we interested in them? Venus could, billions of years ago, have been quite hospitable for life but natural global warming long put paid to any chance of that. Around Jupiter there are moons with oceans larger than any on Earth which could be host to life now. Studying them tells us a lot about us. Most space research has far more to do with learning about us even if we are looking up.

Jarvis Brand wrote this piece. He runs the planetarium for the Observatory Science Centre at Herstmonceux and can be contacted on planetarium@the-observatory.org, 01323 832731.

The Observatory Science Centre is open every day until 2nd December and in May will also be open on the 5th May for the Eta Aquarid meteor shower and the 18th May for “museums at night”.