A team of scientists say they found pieces of opal in a meteorite called EET 83309 in Antarctica during an announcement on June 27 at the National Astronomy Meeting in Nottingham, England. Opal is a crystal that contains water, hence this discovery shows that meteorites brought water ice on asteroid when our solar system was still young.
“The pieces of opal we have found are either broken fragments or they are replacing other minerals,” says lead researcher Downes, a professor at Birkbeck College London. “Our evidence shows that the opal formed before the meteorite was blasted off from the surface of the parent asteroid and sent into space, eventually to land on Earth in Antarctica.”
Opal is made of silica with 30 percent water in its structure. It is a popular stone used in jewelry.
The team believes that the meteorite was exposed to the sun’s radiation before it broke off from the asteroid. This radiation is also called solar wind, which hits an asteroid’s unprotected surface all the time.
Further analysis reveals that EET 83309 contains pieces of other kinds of meteorite, which demonstrates that the asteroid where it came from experienced many impacts. One of these impacts brought water ice, aiding opal to form.
Based on various methods used, the researchers concluded that the precious stone was not formed many years after the meteorite fell in the Antarctic ice. They realized that it actually came from space.
The used an instrument at Open University called NanoSims. Their NanoSims instrument revealed that the meteorite’s opal interacted with a little water in the Antarctic. However, the opal’s isotopes, also known as different forms of the same element, are similar to the other minerals of the meteorite, proving that the stone was already present in the meteorite.
“This is more evidence that meteorites and asteroids can carry large amounts of water ice,” points out Downes. “Although we rightly worry about the consequences of the impact of large asteroid, billions of years ago they may have brought the water to the Earth and helped it become the world teeming with life that we live in today.”