ArabiaWeather – In 2015, David Hall was excavating in Maryborough Provincial Park near Melbourne, Australia. Carrying out a metal detector, he discovered something unusual – a very heavy red rock resting in some yellow clay.
The Maryborough meteorite. (Museums Victoria)
He took it home and tried everything to open it, and confirmed that there was a nugget of gold inside the rock – after all, Maryborough Park is located in the Goldfields, where the Australian gold rush reached its peak in the 19th century.
To break down his find, Hall used a rock saw, an angle grinder, a drill, and even doused the object in acid. However, even a heavy hammer couldn’t create a crack. That’s because what he was trying so hard to open wasn’t a solid block of gold.
As he discovered years later, it was a rare meteorite.
Dermot Henry, a geologist at the Melbourne Museum, told the Sydney Morning Herald in 2019: “He had a chiseled, winked look.”
“This is formed when they pass through the atmosphere, melt outside, and are sculpted by the atmosphere.”
Hall was unable to open the “rock,” but remained fascinated, taking the nugget to the Melbourne Museum to identify it. “I’ve looked at a lot of rocks that people think are meteorites,” Henry told Channel 10 News. In fact, after 37 years of working at the museum and examining thousands of rocks, Henry said only two of the offerings turned out to be real meteorites.
This was one of the two.
The Maryborough meteorite, with a slab cut from the mass. (Melbourne Museum)
“If you saw a rock like this on the ground, and you picked it up, it shouldn’t be that heavy,” Bill Birch, a geologist at the Melbourne Museum, explained to the Sydney Morning Herald. The researchers published a scientific paper describing the 4.6 billion-year-old meteorite, which they named Maryborough after the town near where it was found.
It weighs 17 kilograms (37.5 pounds), and after using a diamond saw to cut a small slice, researchers discovered that its composition contains a high percentage of iron, making it an ordinary H5 chondrite.
Once opened, you can also see tiny crystalline droplets of metallic minerals throughout it, called chondrules.
“Meteorites provide the cheapest form of space exploration,” Henry said. “They transport us back in time, providing clues about the age, composition and chemistry of our solar system (including Earth).” Some of them offer a glimpse into the deep interior of our planet. In some meteorites, there is “stardust” older than our solar system, which shows us how stars form and evolve to form the elements of the periodic table.
“Other rare meteorites contain organic molecules such as amino acids, which are the building blocks of life.”
A slab cut from the Maryborough meteorite. (Birch et al., PRSV, 2019)
Although researchers don’t yet know where the meteorite came from or how long it spent on Earth, they do have some guesses.
Our solar system was a pile of dust and chondrite rocks. Eventually gravity pulled much of this material together to form planets, but the remains mostly ended up in a massive asteroid belt.
Henry said: “This particular meteorite most likely comes out of the asteroid belt between Mars and Jupiter, and it was pushed out of there due to some asteroids colliding with each other, and then one day it collided with Earth.”
Carbon dating suggests that the meteorite was on Earth between 100 and 1,000 years ago, and there were a number of sightings of the meteorite between 1889 and 1951 that could correspond to its arrival on our planet.
Researchers believe that the Maryborough meteorite is much rarer than gold, which makes it more valuable to science. It is one of only 17 meteorites ever recorded in the Australian state of Victoria, and is the second largest chondrite mass, after a massive 55-kilogram specimen identified in 2003.
“This is only the 17th meteorite found in Victoria, while thousands of gold nuggets have been found,” Henry said.
“Given the chain of events, it is arguably astronomical that it was discovered at all.” It’s not even the first meteorite that takes a few years to reach the museum.
In a particularly astonishing story covered by ScienceAlert in 2018, a space rock took 80 years, two owners, and a stint as a doorstop before it was finally revealed for what it is. Now might be as good a time as any to check your backyard for rocks. Heavy and hard to break – you may be sitting on a metaphorical goldmine.
Source: sciencealert
