The vision seems to show a large ball burning with green-blue light in the night sky.

Different colours are released when different elements burn. Yellows and reds are released when space-junk passes through the atmosphere. Greens and blues are telltale signs of iron and nickel, says Tucker.

Most space rocks are the left-overs of ancient failed protoplanets.

Stony chondrites, the more common type of meteor, come from the surface, while rarer metallic chunks come from the protoplanet’s core.

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And it was going fast. Space junk – such as old satellites and bits of rocket – typically orbits the Earth about 30,000 km/h. Meteors are a lot quicker, travelling at up to 100,000 km/h.

That accounts for the large explosion, despite the rock being relatively small.

“It is not as big as people might imagine – we’re not talking a car coming in,” says Brown. “But because it’s coming in at 30 kilometres a second, there’s a lot of energy being released as that thing slows down in the atmosphere.”

The bang was likely a sonic boom, the same as the loud crack heard from an accelerating jet fighter (or, on a smaller scale, a bullet being fired).

When an object travels quickly through the air, it pushes pressure waves in front of it – similar to a boat creating a bow wave. These waves move at the speed of sound. But if the asteroid is travelling faster than the speed of sound, it compresses these waves together, merging them together into a single powerful shockwave.

“That’s really important. That’s a sign it slowed down and probably broke apart – you only get that reverb and rattling from a fragmentation of a meteor,” says Tucker. Small meteors typically don’t produce sonic booms. “In this case, there is a good chance there could be meteors on the ground from this one.”

Was there any danger to human life? Will we be able to find bits today?

The meteor was so small the risk it posed to human life was tiny, the astronomers said. By the time it had reached cloud-level, most of the rock’s energy would have been expended. It would take an extremely unlucky direct hit to cause harm.

“There’s not going to be huge craters. These things lose most of their energy when they break up. They are pretty much falling at free-fall speed, and they are relatively small,” says Tucker.

There may be debris and pieces of meteorite, although at this stage it is not clear exactly where they may have landed.

Preliminary estimates from the Desert Fireball Network, which has several cameras trying to track meteorites above Victoria, suggest it may have landed somewhere west of Castlemaine and Bendigo.

“It’s a big meteor. We think there’s probably [a] very high chances there’s meteor on the ground,” says Professor Andy Tomkins, who runs the network in Victoria. His team plans to send scientists searching for fragments on Monday afternoon.

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If you want to go searching, look for small rocks that appear different to others in the area.

The outside will be covered in “fusion crust”: a smooth, black surface left over after the meteorite’s surface melted in the atmosphere. There will also be characteristic dimples, like those on a golf-ball, caused by the molten crust being reshaped by the air as the meteor fell. It is likely magnetic, and will feel deceptively heavy in the hand.

Dermot Henry, head of sciences at the Museums Victoria Research Institute, said the museum would be happy to take a look at any maybe-meteorites people turned up. “They are scientifically valuable. This is the cheapest form of space exploration: the rocks come to us.”

Where does it come from? And what’s the difference between an asteroid, a meteorite and a meteor anyway?

The nomenclature changes as the rock enters Earth’s atmosphere. In space it is called an asteroid. Once it hits the atmosphere, it becomes a meteor, and if it reaches the surface we can call it a meteorite.

Asteroids are the left-over building bricks of our solar system, which began life as a dust cloud orbiting the sun.

But not every planetoid can become a planet. Some crash into each other, scattering their hard inner cores into space.

Those lumps – asteroids – are often found in our solar system’s asteroid belt between Mars and Jupiter. “In there, there are collisions going on – one asteroid smashes into another, and both tumble about in space, change their orbit, and one day land on earth,” says Henry.

The meteor should serve as a reminder of our place in the ever-changing, always under-construction solar system, said Brown. “We’re seeing left-overs. It’s part of the broader solar system, coming very close to home.”