When stargazing and science collide
Amateur astronomers are recording fireballs flying above the UK.
There are dozens of cameras all over Britain pointing straight up at the night sky.
Behind them, amateur astronomers are waiting and hoping to see moments of magic, and perhaps capture them on film.
One of these devices was a CCTV camera stationed on top of the Museum for two years.
It was scanning the darkness for shooting stars, and is just one of many similar cameras working together to document extraterrestrial activity.
They are looking for meteors, the term given to space debris including dust, ice or rocks entering Earth's atmosphere.
Behind the cameras is the UKMON network (United Kingdom Meteor Observation Network), a group of amateur astronomers documenting meteor activity over the UK.
The network's cameras detect a meteor's motion and record video clips, which are then analysed for basic information about the meteor. If a meteor is recorded from different locations around the country, astronomers can calculate its altitude, speed and orbit around the Sun.
The St Patrick's Day fireball
The Museum's camera is currently off, but there is a similar camera stationed at a school, as part of a Royal Society-funded outreach project.
Fireballs are bigger and brighter than your average meteor, which can often be quite small.
This one whizzed over the UK in the early hours of the morning and was picked up on eight cameras of the UKMON network, including one in Wilcot in Wiltshire, shown in the video below.
At its brightest, the light it gave off was comparable with the brightness of the full Moon, so it was also observed by the general public in the UK, the Netherlands, Belgium and France.
Ashley King, a Museum planetary scientist, says, 'Fireballs tend to have a burst of light at one end that causes a white-out on camera. The Museum camera mostly captured that white light.
'The fireball probably came from cometary material. Because it was picked up by eight different cameras, we could then work out its direction and speed, and even where in the solar system it came from.
'It's amazing to know that this is the kind of thing we can do really quickly with these CCTV cameras.'
What's so special about meteorites?
Out of around 60,000 known meteorites in the world, only about 30 have data associated to their orbit and location in the solar system.
Ashley says, 'We would love to know more about where meteorites come from. For instance, do they come from the asteroid belt (between Mars and Jupiter), or from beyond Jupiter?
'We probably have samples from beyond the orbit of Jupiter in our collections, but we don't know it.'
The cameras can also help scientists and astronomers predict where a meteorite will fall, sometimes allowing scientists to go searching for it.
Ashley says, 'Most meteorites we have are ones that people have found after they have fallen to Earth, usually in Antarctica or deserts, where they are easy to spot. They can sit there for many years, unaltered.
'If a meteorite falls in the UK, you will often struggle to find it. If they fall in forests or fields, you're in trouble. They look similar to many other rocks and are unlikely to be uncovered.'
The biggest and most famous UK meteorite is the one that fell in Barwell, near Leicester, on Christmas Eve 1965. It made such an entrance that it smashed cars and windows.
A fireball the size of a desk entered Earth's atmosphere, burning up on its way through. A chunk 'the size of a Christmas turkey' made it through as the rock exploded into pieces. Barwell was showered with rocks.
That time was the exception. It is predicted that more than 10 meteorites fall in the UK every year, but we only have 18 of them in collections. These cameras could help scientists to find a few more.
What is a meteorite?
- A meteoroid is a piece of matter (usually rock or metal) that travels through space.
- A meteor is the flash of light that we see on Earth when a meteroid enters Earth's atmosphere.
- A meteorite is the name given to meteoroids once they fall to Earth.