The rock from the birth of the Solar System
Can we learn all about the universe without leaving Earth? A meteorite that landed in a Gloucestershire driveway on Sunday has been hailed as a once-in-a-lifetime discovery.
It was like looking for a needle in a haystack. Thousands of people had reported a fireball in the sky on Sunday night, and a battery of special cameras had helped narrow down the area where fragments of the meteorite could have fallen. But it was still extremely vague – “Somewhere north of Cheltenham, over towards Stow-On-The-Wold” – and such fragments are usually the size of a sugar cube.
But this time the researchers got lucky: a man in the town of Winchcombe rang to say that he had found a pile of charred stone in his front drive. Dr Richard Greenwood of the Open University set off to investigate.
“I looked in this plastic bag he’d been told to put it in, and my legs went wobbly,” says Greenwood. “It was unbelievable. This is a very special meteorite.”
After hitting the Earth’s atmosphere at 30,000mph, most of the fireball had vapourised within six seconds. What remained was extraordinarily precious. Greenwood recognised it as being made of carbonaceous chondrite, a stony material that retains unaltered chemistry from the formation of the Solar System 4.5 billion years ago.
Of the 65,000 meteorites in collections around the world, barely 2% have had eyewitnesses to their fall – and of those, only 51 belong to this type.
Dr Ashley King of the Natural History Museum in London describes carbonaceous chondrites as “the left-over building blocks of our solar system. Many contain simple organics and amino acids; some of them contain minerals formed by water – so all the ingredients are there for understanding how you make a habitable planet such as the Earth.”
Sunday’s meteorite was the first to be retrieved in the UK since 1991, when a 10cm rock landed next to a man tending his onions in a Cambridgeshire garden. And the new one is in amazing condition. “It will have been affected by passage through the atmosphere,” says Dr Greenwood, “but it must be very close to pristine… It's as good as you will ever get collected here on Earth.”
The excitement did not stop there. The videos taken by the special cameras – operated by the UK Fireball Alliance – made it possible to work out where the meteorite came from. “In this case, the orbit was like an asteroid’s,” says Dr King. “This particular piece of asteroid spent most of its orbit between Mars and Jupiter, though sometimes got closer to the Sun than Earth is.”
“Basically, that's part of the Solar System we regard as like a deep freeze of material that’s 4.5 billion years old,” says Professor Sara Russell, also of the Natural History Museum.
“It hasn’t had a chance to change at all from pre-planetary time. It will give us an insight into what our solar system was like before the planets were there.”
Both NASA and Japan’s space agency have sent probes to bring back similar material from asteroids. But Dr Greenwood says that the Winchcombe meteorite will be almost as good a subject for study.
Can we learn all about the universe without leaving Earth?
Some say, yes. With finds like the meteorite, and such an extraordinary array of technology at our disposal – from UKFall’s fireball cameras to the Large Hadron Collider and the Hubble Telescope – we have already been able to unlock some of the greatest secrets of creation. As that technology becomes ever more sophisticated, there will be nothing of significance we will not be able to discover.
Others argue that since the universe is infinite, there will always be more for us to discover. A find like the meteorite is such a rarity that we cannot expect all the material we need for analysis to come to us, so we need to travel in search of it. A manned expedition to Mars would be able to collect far more information than the rover currently exploring it. The further we can go the better.
- Are things that happened in the distant past of less importance to us than recent history?
- If the universe is infinite, must the information contained in it be infinite too?
- Draw a map of the Solar System showing the region where the meteorite came from.
- Imagine that you are the man who found the Winchcombe meteorite. Write a diary entry recording what happened.
Some People Say...
“It is humanity’s destiny to explore the universe. When we start thinking and working on that cosmic level, we will transcend our… tribal natures.”Story Musgrave (1935 – ), American astronaut
What do you think?
Q & A
- What do we know?
- It is generally agreed that meteorite fragments must be handled with great care if they are to be of use to science. If you find one, you should photograph it on the spot and note its location using your phone GPS. Rather than touch it with your hands, you should pick it up in aluminium foil or a plastic bag. Above all, keep it away from magnets that could destroy some of its vital properties. Scientists hope more fragments, looking like small blackish stones, will be found near Winchcombe.
- What do we not know?
- One main area of debate is around where the volatile elements essential to life on Earth – such as hydrogen, water, carbon dioxide, nitrogen, ammonia and methane – came from. Scientists have long believed that they were brought on meteorites and comets from beyond Jupiter after the Earth was formed. But new research suggests that some of them may have been present in dust that bathed the planet while it was still taking shape.
- Special cameras
- The UK Fireball Alliance has over 30 cameras in the UK monitoring the sky for meteorites. Sunday’s meteorite was picked up by six, as far apart as Cardiff and Cambridge.
- A small piece of rock that has broken off an asteroid is known as a meteoroid. If it enters the Earth’s atmosphere, most of it will burn up; the rock that remains is a meteorite.
- Solar System
- The Sun and the objects whose movement it controls.
- Amino acids
- Organic compounds which form the basic constituents of proteins.
- Unspoilt. It derives from a Latin word meaning former or original.
- UK Fireball Alliance
- A team of people devoted to retrieving newly fallen meteorites, led by the staff of the Natural History Museum.
- Also known as minor planets or planetoids, asteroids are made up of rock and minerals. The majority of known ones orbit the Sun between Mars and Jupiter.
- The National Aeronautics and Space Administration, responsible for the US space programme.
- Turned into gas. It can apply to something which starts in either a solid or a liquid state.