Look again a year later and the same beauty is there for all to see. Save for the changing position of the planets and the Moon, the night sky returns reassuringly each year, an unchanging backdrop to our lives. But if you look more closely or watch a little longer, even with just your own eyes, you will see evidence all around that we live in a dynamic universe that is constantly changing.
Sometimes the evidence comes from events happening now — eruptions on the surface of our sun that give us periods of enhanced aurora activity, or showers of shooting stars that herald the passage of the Earth through a comet’s tail.
Sometimes the evidence is frozen in time, such as the craters on the Moon that were gouged out of the lunar surface in cataclysmic collisions eons ago, with sufficient violence to wipe out life on Earth if they happened here today. And sometimes the evidence is generated so infrequently that we might not experience it in our own lifetime, for example when a star ends its death in a violent explosion and lights up the night sky with the brightness of the full moon for weeks on end.
On the night of April 22 and the morning of April 23 the annual peak of the Lyrids meteor shower will occur. The shower is produced by dust particles from the tail of comet Thatcher, which was discovered in 1861, and the meteors themselves are the dust particles burning up harmlessly in the Earth’s atmosphere.
This year the Lyrids happen when the Moon is a mere crescent, so the skies should be dark and you should have a good chance of seeing up to 20 meteors per hour. The best time to observe is after midnight, when the meteors are brightest and the tails are longest. Expect to see the Lyrids anywhere in the sky.
If you do go out to watch the Lyrids, take a moment to be reminded that we live in a dynamic universe, and that we cannot take the safety of our home planet for granted. Our atmosphere protects us from the myriad of small rocks that assault us every day. But if you lived on Mars, for example, you would not be afforded the same level of atmospheric protection because Mars’ atmosphere has slowly leaked out into space over billions of years.
Even our atmosphere cannot protect us from the millions of icy comets and chunks of rock that are capable of penetrating it and doing some real damage — the phrase “dinosaur extinction” comes to mind.
Yet we are fortunate enough to live in an era when technology offers us, for the first time, the chance to protect ourselves from events which would otherwise be catastrophic. Advances in rocket technology and in our ability to “see” objects coming our way make this increasingly possible.
Discussions around climate change have, understandably, focused on emissions of greenhouse gases and how to control them. But if we really want to protect our climate we need to keep in mind that our universe is beautiful, but dynamic, and that the forces that originate from beyond our planet are capable of overwhelming anything we can generate on it.
DID YOU KNOW?
The giant planet Jupiter is closest to the Earth this year on April 7. It will also be at its brightest and will be visible throughout the night from around 9pm, rising towards the east.