Earth asteroid collision: myths debunked by UCLan scientists

16 September 2015

Press Office

UCLan academics agree with NASA: there is no need to worry

Rumours have been sweeping the internet concerning an imminent asteroid strike expected between the 15 and 28 of September. The rumours have been so strong that NASA has issued a statement reassuring the general public that no such event is on the horizon. Here, two UCLan scientists, Professor Robert Walsh and Dr Sarita Robinson discuss why people are so attracted to the notion of the end of the world, they debunk myths, separate fact from fiction and conclude that mystic tales are no substitute for scientific fact.

Professor Robert Walsh, Executive Director of Research at the University of Central Lancashire:

1) How often do asteroids hit the planet? What is the biggest one ever recorded?

What you may not realise is that Earth is hit with about a hundred tons of extraterrestrial material every day! However, this debris is in the form of numerous small rocks, the majority of which burn up in the planet’s atmosphere. Those that make it through this fiery force field are then observed as meteors shooting across the sky; if they do reach the ground, we call them meteorites. However, given that over 70 percent of our planet is covered with water, many, many meteor landings go undetected.

Earth has experienced very destructive impacts in the past – just ask any dinosaur; oh wait, you can’t! The Earth-smashing asteroid in that case has been estimated to be around 10 km across. So we have to take the threat seriously.

In fact, in February 2013, a lorry-sized space rock exploded in the skies above Chelyabinsk, Siberia. Spectacularly caught on camera phones as it sped across the sky, the force of the resulting blast smashed windows, injuring hundreds of people. However, the result could be much more devastating if this sort of event was repeated above major centres of population like London, New York or Beijing.

2) Is it possible that NASA might not be able to spot an asteroid, something that could travel so fast we may miss it?

In short, no. The international astronomy community is taking seriously the slim threat of a devastating collision with an asteroid. In April 2015, an international conference organised by the European Space Agency brought together several scientific disciplines (including astronomers, physicists and engineers) to debate and role-play the possibilities around dealing with an Earth directed asteroid collision.

NASA indicates that if there was any object large enough to do the type of destruction in September indicated by claims across the blogs and web postings, we would have seen it by now.

NASA’s Near Earth Object office at the Jet Propulsion Laboratory is at the forefront of what is now a worldwide collaboration to watch the skies for any asteroids that could do harm to our planet. Their “Spaceguard” programme detects and tracks these objects as well as trying to determine their nature; such as understanding their mass or their composition.

There are dedicated observatories whose job it is to monitor the pin-pricks of light in the night sky. These pin-pricks might not be stars, they could be celestial travellers that might just want to pay us a visit. One such facility is Pan-STARRS (Panoramic Survey Telescope and Rapid Response System) in Hawaii that surveys the entire available sky several times each month.

The Sun observing satellite mission called SOHO (Solar and Heliospheric Observatory) has observed nearly 3000 sun-grazing comets in the last 20 years. Many of these comets pass so close to the Sun that they are vaporised within hours of discovery; but some are seen to sling shot around our closest star and escape a fiery death!

"What you may not realise is that Earth is hit with about a hundred tons of extraterrestrial material every day! However, this debris is in the form of numerous small rocks, the majority of which burn up in the planet’s atmosphere."

3) Have there been many accurate asteroid strike predictions?

In 1994, Jupiter, the largest planet in our astronomical neighbourhood, experienced an asteroid strike from Comet Shoemaker Levy 9 - this was the first time humankind had predicted and then observed such an event.

4) Where do asteroids come from and how fast do they travel?

Asteroids are the rocky crumbs left over after the formation of the planets in our Solar System. Most are found in an huge ring of space known as the asteroid belt - somewhere between the planets Mars and Jupiter and about two and a half times the distance from our Sun compared to the Sun-Earth distance.

However, some are found outside the main asteroid belt. Three groups (called Atens, Amors, and Apollos) are the ones we worry about here on Earth. These are known as near-Earth asteroids and they spiral around in the inner parts of the Solar System (in the neighborhood of our planet) and can sometimes cross the path of Earth and Mars.

According to the Earth Impact Effect Programme at Imperial College London, the typical impact velocities are 17 km/s for asteroids and 51 km/s for comets.

To give that some context:

• A comet could travel from Edinburgh to London in 10 seconds
• An asteroid could travel from Edinburgh to London in just over 30 seconds



5) Are we more likely to be killed by man-made satellites falling from the sky than a meteor strike?

I would direct you to this excellent image which shows the odds of dying by various means (!) in America in a single year. An asteroid strike is definitely the lowest by a long way!

6) Other points – how can we avoid a catastrophic comet?

There are several ways of trying to deflect an oncoming asteroid. The first is to try the “Hollywood approach” and simply blow it up! However, in spite of the possibly spectacular visuals that could result from “nuking it”, the shattered asteroid could merely become a swarm of slightly smaller and still very destructive space rocks heading towards our planet. Really, this would only be considered as a very, very last resort.

Another way would be to just give the asteroid a nudge, to change its path away from the Earth. Knocking it with some sort of impact could do this.

Orbiting around and landing on a comet may seem like the stuff of Star Trek. However this was actually achieved in 2014 by the European Space Agency’s Rosetta space craft which also sent a small lander called Philae down to the comet’s surface.

However, Rosetta took a decade to get to its comet destination. To deflect an asteroid it would need to be detected many years in advance and shoved or pulled many million of kilometres from Earth.


"People tend to think that apocalyptic beliefs are tied into religion and that the belief in the “end of world” is part and parcel of a spiritual theory."

Dr. Sarita Robinson, Senior Psychology Lecturer at the University of Central Lancashire:

1) Why are people so attracted to the idea of the end of the world?

People tend to think that apocalyptic beliefs are tied into religion and that the belief in the “end of world” is part and parcel of a spiritual theory. However this does not seem to be the case. You can have a lot of non-religious people who believe that the end of the world is coming, however, this can be due to a nuclear threat or other man-made technologies such as genetic manipulation.

Why people are attracted to these beliefs is an interesting question. One possibility is that in a world which is unpredictable it offers a sense of control. People can be concerned about the future and what to plan but without any information to base your plans on it can be difficult. If a charismatic leader tells you that the world is going to end on a specific date you can plan for the event. By having a date to plan for, you have taken away the uncertainty in your life. Not only that but you also have like-minded people to work with in a friendship group with a common purpose. For some (especially those who are religious) the end of the world might lead to a better world. A religious leader may well have offered a better life in the future.
The problem comes when the world does not end. It can be very difficult for people when they suddenly find that the world has not ended. They need to find a way to explain this such as their calculations being wrong.

2) Are there any previous examples of 'end of the world' notions that have started panic in Great Britain?

In 1938 in the US a radio station broadcast a version of HG Wells’ book War of the Worlds but the radio play purported to be a live broadcast of a real life event. This was in the days before you could check things on the internet and people trusted the radio for news. As a result thousands of people are reported to have fled their house to escape the Martian invasion.

Similar behaviours were seen in 1992 when the BBC broadcasted a drama called Ghostwatch, a ‘live broadcast’ documentary where some people believed that a real poltergeist had escaped and it was the end of times. People reported psychological problems in children after they had watched the show.

There have been very few ‘end of world’ notions that have led to real problems. Those who are religious tend to believe that they are going to a better place so they don’t really panic. In fact in most life-threatening situations (such as plane crashes and boats sinking) we rarely see panic. If the apocalypse did happen people might actually cope by denying that the events were taking place and just ignore them until it was no longer possible (at which point it would be too late!)

The only mild psychological upset I can think of is the Y2K (Millennium bug) predictions, but people did not panic. People tended to do what could be considered to be sensible actions such as storing food and not flying.

As mentioned, people don’t generally panic when faced with the possibility of major disasters. In fact people generally try and pretend that they are not going to occur. If you look at those who live on the San Andres fault line in California you would expect them to be prepared for the 'Big One' (major earthquake) but some people don’t have an earthquake kit etc.

3) Do you think there is a real provable link between phases of the moon and people's behaviour?

Some people believe that the full moon has a negative effect on human behaviour (the Transylvania hypothesis). However, no real evidence has been found.

One study of admissions to an emergency department found the full moon was associated with a significant increase in animal bites to humans. Other studies have noted a small rise in GP appointments in the six days following a full moon. However other studies have reported no links between the full moon and increased trauma/violence leading to hospital admissions and no increases in violence and aggression from residents in psychiatric units.

4) What kind of measures would you recommend to people who literally can't help themselves but believe the end of the world is nigh? Is there any way to prepare yourself psychologically if you can't get away from the idea that it will happen?

Believing that the end of world is nigh is not a bad thing if it does not interfere with your everyday life. As long as you do not sell your house and spend the money on a nice holiday or give it to a cult leader, preparing for the end of the world may not be a bad idea. We do not actively consider a whole range of risks in everyday life. For example we don't think about the consequences of a flu pandemic and most people don’t want to think about dying as it is psychologically uncomfortable. Most of us don’t prepare for disaster and don't carry out, what could be considered, sensible tasks of preparedness (such as keeping a blanket and a flask of coffee in the car in case we get stuck in the snow during the winter).

People who are distressed by end of world predictions should try and rationalise and challenge their negative thoughts.

5) What are the most bizarre fears you've heard of?

The fears that the Large Hadron Collider would destroy the world with black holes was quite odd.

6) Are there any cults or British peculiarities that you can talk about?

In 1910 it was thought that the Earth would pass through Halley's Comet’s tail and poison everything on Earth with cyanogen gas. Lots of people bought gas masks as well as other things like anti-comet pills and even anti-comet umbrellas.