A gamma ray burst close to Earth could be devastating. Disclosure statement Daniel Brown does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment. Nottingham Trent University provides bitcoin supernova star as a member of The Conversation UK. The Conversation UK receives funding from Hefce, Hefcw, SAGE, SFC, RCUK, The Nuffield Foundation, The Ogden Trust, The Royal Society, The Wellcome Trust, Esmée Fairbairn Foundation and The Alliance for Useful Evidence, as well as sixty five university members.
If you ask yourself what the biggest threat to human existence is you’d probably think of nuclear war, global warming or a large-scale pandemic disease. But assuming we can overcome such challenges, are we really safe? Living on our blue little planet seems safe until you are aware of what lurks in space. The following cosmic disasters are just a few ways humanity could be severely endangered or even wiped out. High energy solar flare Our sun is not as peaceful a star as one might initially think. It creates strong magnetic fields that generate impressive sun spots, sometimes many times larger than Earth. If kept in check by Earth’s magnetic field, this wind can cause beautiful northern and southern lights.
But when it becomes stronger, it can also influence radio communication or cause power outages. The most powerful magnetic solar storm documented hit Earth in 1859. The incident, called the Carrington Event, caused huge interference with rather small scale electronic equipment. Such events must have happened several times in the past, too, with humans surviving. But only in recent years have we become entirely dependent on electronic equipment.
The truth is we would suffer greatly if we underestimate the dangers of a possible Carrington or even more powerful event. Recent research has made us aware of the large host of space rocks in our solar system that could pose danger. We are at the starting point of envisaging and developing systems for protecting us against some of the smaller asteroids that could strike us. But against the bigger and rarer ones we are quite helpless. While they would not always destroy Earth or even make it uninhabitable, they could wipe out humanity by causing enormous tsunamis, fires and other natural disasters.
Expanding sun Where the previous cosmic dangers occur at the roll of a dice with a given probability, we know for certain that our sun will end its life in 7. But humanity will not experience these final stages. As the sun becomes older, it will become cooler and larger. By the time it becomes a stellar giant it will be big enough to engulf both Mercury and Venus. Earth might seem safe at this point, but the sun will also create an extremely strong solar wind that will slow down the Earth. As a result, in about 7.
These energy bursts are extremely powerful because they focus their energy into a narrow beam lasting no longer than seconds or minutes. Nearby supernovas Supernova explosions, which take place when a star has reached the end of its life, occur on average once or twice every 100 years in our Milky Way. Ia supernova in the NGC 4526 galaxy. So can we expect a nearby supernova anytime soon? Orion is just 460-650 light years away.
It could become a supernova now or in the next million years. This might lead to an increased chance of a huge comet hurtling to Earth. The sun itself follows a path through the Milky Way that takes us through more or less dense patches of interstellar gas. Currently we are within a less dense bubble created by a supernova. The end of humanity on Earth is a given.
But this is not something to make us crawl under a table. It is something that we cannot change, similar to our lives having a definite start and end. This is what defines us and makes us realise that the only thing we can do is make the most of our time on Earth. Especially when we know that Earth needs a careful balance to sustain humanity.
All the above scenarios harbour possible destruction, but in every instance they also offer beauty and wonder. In many cases, they produce what allowed us to be created. So rather than looking into the night sky and wondering what will kill us next, we should marvel at the depth of space, the wonders therein and the sublime nature of the universe. Explainer: what is interplanetary dust and can it spread the ingredients of life? Can Usain Bolt really make it as a footballer? Dragon Hall Debate: Should we feel sympathy for the devil? Stay informed and subscribe to our free daily newsletter and get the latest analysis and commentary directly in your inbox.