Of the thousands of meteorites found on Earth, about 188 have been confirmed to be from Mars. How did they get here? Over the tumultuous history of our Solar System, asteroids have smashed into Mars with such force, the debris was blasted off the planet and then drifted through space, eventually entering Earth’s atmosphere, and surviving the journey to the ground.
Astronomers once thought it was a complex process, with only the most powerful impacts capable of throwing rocks from Mars into space. But new research shows that it takes much less pressure than previously believed, which means there could be more chunks of Mars floating in space and on their way to Earth.
On Earth, geologists study rocks to help better understand the history of our planet. In contrast, planetary geologists study meteorites to help better understand the history of our solar system. While these space rocks put on quite the spectacle when they enter our atmosphere at high speeds, they also offer insights into both the formation and evolution of the solar system and the planetary bodies that encompass it. But what happens as a meteorite traverses our thick atmosphere and lands on the Earth? Does it stay in its pristine condition for scientists to study? How quickly should we contain the meteorite before the many geological processes that make up our planet contaminate the specimen? How does this contamination affect how the meteorite is studied?
In a recent study published in Science, a team of researchers at Imperial College London examined 18 meteorites containing the volatile element zinc to help determine their origin, as it has been long hypothesized that Earth’s volatiles materials, including water, were derived from asteroids closer to our home planet. However, their results potentially indicate a much different origin story.
In a recent study published in Sciences Advances, an international team of scientists led by the Technical University of Munich examined the Martian meteorite Tissint, which fell near the village of Tissint, Morocco, on July 18, 2011, with pieces of the meteorite found as far as approximately 50 kilometers (30 miles) from the village. What makes Tissint intriguing is the presence of a “huge organic diversity”, as noted in the study, which could help scientists better understand if life ever existed on Mars, and even the geologic history of Earth, as well.
Our modern telescopes are more powerful than their predecessors, and our research is more focused than ever. We keep discovering new things about the Solar System and finding answers to long-standing questions. But one of the big questions we still don’t have an answer for is: ‘How did life on Earth begin?’
Humanity is getting better a planetary defense. At least from external threats from outer space. As long as they’re just dumb rocks that follow the laws of physics. And a group of extraordinary humans proved it last week when the planetary defense community jumped into action to accurately track and predict exactly where a relatively small meteor would fall on November 19th.
In a recent study published in the Proceedings of the National Academy of Sciences, an international team of researchers led by Monash University in Australia have verified the existence of a rare hexagonal structure of diamond called lonsdaleite, within ureilite meteorites from the inside of a dwarf planet that formed approximately 4.5 billion years ago.
Lonsdaleite is named after Dame Kathleen Lonsdale, a famous British pioneering crystallographer responsible for developing several X-ray methods for studying crystal structures, and was the first woman elected as a Fellow to the Royal Society in 1945. This study holds the potential for further unlocking the secrets of the formation of our solar system, and was conducted with collaboration from RMIT University, the Australian Synchrotron and Plymouth University, and CSIRO.
Piecing together the history of the Solar System from the traces left behind isn’t easy. Bit by bit, however, we’re working it out. This month, new research examining the composition of lunar meteorites offers compelling evidence that the Moon and the Earth were formed from the same material, perhaps in the aftermath of a cataclysmic collision some 4.5 billion years ago.
For nearly 30 years Geoff Notkin has traveled the world in search of meteorites, those ancient relics from outer space that have fallen to Earth. He shared his adventures on the Science Channel series “Meteorite Men,” and through lectures and appearances across almost every continent, he has sparked interest in space science and exploration. He has been a devoted meteorite hunter and collector, amassing a large collection. But now, after much deliberation, Notkin has decided to auction off some of his personal meteorite collection, as well as other personal items.
Of course, our first question was, why? Is he leaving the field of meteorite hunting?
Earth formed over 4.5 billion years ago via accretion. Earth’s building blocks were chunks of rock of varying sizes. From dust to planetesimals and everything in between. Many of those chunks of rock were carbonaceous meteorites, which scientists think came from asteroids in the outer reaches of the main asteroid belt.
But some evidence doesn’t line up well behind that conclusion. A new study says that some of the Earth-forming meteorites came from much further out in the Solar System.