- 3091 - ASTEROID - near miss and a perfect hit? One of the larger stones that hit was about 5 centimeters long. Its crust is the remainder of the surface that got heated as the meteorite came through the atmosphere. “Winchcombe meteorite” may look a bit like a broken barbecue briquette, but to scientists, it is absolutely beautiful.
------------------ 3091 - ASTEROID - near miss and a perfect hit?
- Astronomers will get a valuable opportunity to observe a space rock up close as asteroid 2001 FO32 swoops past our home planet on March 21, but the rock won't come closer than 1,250,000 miles
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- The path of the asteroid 2001 FO32, which will fly safely by Earth on March 21, 2021.
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- Astronomers know the orbital path of 2001 FO32 around the sun very accurately, since it was discovered 20 years ago and has been tracked ever since.
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- The asteroid, which is estimated to be 1,300 feet to 2,230 feet wide, will zoom past us at a whopping 77,000 mph, which is faster than most asteroids travel near Earth. Its unusual speed is due to its elongated and highly inclined orbit around the sun.
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- As the rock nears the inner solar system, it picks up speed before whipping back around toward deep space before turning back towards the sun, orbiting once every 810 days.
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- The rock is deemed a "potentially hazardous asteroid. Using ground-based radar and telescopes, tracking their movement is crucial in case they get close enough to Earth to pose an impact risk.
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- While the asteroid orbits the sun once about every 2.25 years, 2001 FO32 won't come this close to our planet again until 2052, when it will pass by at 1.75 million miles.
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- Although the upcoming "close" pass doesn't pose a risk for those of us living on planet Earth, the flyby does provide an opportunity for astronomers to get a good look at 2001 FO32.
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- The proximity will allow astronomers to better observe the asteroid's size and brightness and give them a better idea of its composition, essentially doing "geology with a telescope.
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- Now, while professional astronomers are planning their observations for the flyby with telescopes like NASA's Infrared Telescope Facility (IRTF) in Hawaii, "amateur astronomers in the Southern Hemisphere and at low northern latitudes should be able to see this asteroid using moderate-size telescopes with apertures of at least 8 inches in the nights leading up to closest approach, but they will probably need star charts to find it.
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- Meanwhile earlier this year as people in the UK were settling down to watch the late evening news on February 28, 2021, a fresh news story, quite literally, appeared in the night sky.
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- A large and very bright fireball was seen over southern England and northern France at 21:54 GMT. It was recorded by many doorbell webcams, so it was a very well-observed fireball. More importantly, it was also captured by the automated cameras of the UK “Meteor Observation Network” and similar networks.
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- Working with colleagues in France and Australia, the meteor-watchers worked out the fireball’s trajectory and determined where the meteorite pieces could be located, just north of Cheltenham in the UK. Based on their calculations, specialists in meteorites at the Natural History Museum in London, made an appeal on local TV and radio stations for information about any unusual black rocks seen to have fallen from the sky.
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- Among the photographs they received, there was one that caught their attention: a small mound of dust and pebbles on a driveway in the small village of Winchcombe. King asked Open University researcher Richard Greenwood (who lived closest) to check out the sample.
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- Greenwood was overwhelmed to find that not only was it a meteorite, it was a very rare species.
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- Over the following four days, specialist researchers from several UK institutions formed teams to systematically search the countryside surrounding Winchcombe. The results of their labors are several stones weighing around 500g, plus a lot of dust and fragments. The specimens are now at the Natural History Museum.
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- Meteorites are divided into two main groups: primitive and processed. The primitive ones come from the solar nebula that gave birth to the Solar System, preserving the composition of this original material. In contrast, processed samples have been altered by heat. They are from larger bodies and contain information about planetary surfaces and interiors.
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- Meteorite piece weighing about 4g. The stones that fell over Winchcombe are from the former group. They are of a sub-category, known as carbonaceous chondrites – the most pristine (or unchanged) of all meteorites, carrying records of the earliest stages of Solar System history. They are rich in organic compounds, the molecules that form the building blocks of life. They also contain tiny specs of dust from stars that have died and are older than the Sun.
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- Some of the newfound rocks are almost completely black and featureless, while others are dark grey with irregular, pale patches. Clearly, it is a complex meteorite, possibly one that has come from the surface of an asteroid where several different bits of asteroid have got mixed up during collisions.
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- And here is where things become a little ironic: scientists are currently collecting samples from two asteroids in space. About five grams of material collected by the Japanese Hayabusa2 mission from asteroid Ryugu arrived safely in December 2020.
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- Nasa’s OSIRIS-Rex mission is on its return trip from asteroid Bennu carrying around 200g of material that will arrive in September 2023. These missions cost a lot of money, but could help unveil the secrets of the origins of life and the Solar System.
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- And then just out of nowhere, almost 500g of rock from an asteroid, that is possibly very similar to Ryugu and Bennu, falls over part of England.
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- Meteoriticists in the UK will now analyze the material, practically on a grain-by-grain basis. Things must happen in a sequence. There are time-sensitive measurements that have to be carried out within the first month or so of a fresh fall.
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- Meteorites are not radioactive. They don’t emit harmful radiation, but they do contain elements that are unstable and fall apart. And if we can measure the amounts of the elements that decay very quickly, then we can get valuable information.
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- We must also take a good look at the organic compounds in the meteorite – there is always in danger of contamination from Earth. So the quicker we can analyze its organics, the better.
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- The more we can understand about these materials in meteorites, the more we can piece together the chemistry that led to life on Earth. This can give an idea of how widespread that chemistry might be. or have been, in the Solar System, and even the universe.
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- Searching for a meteorite in a small village and its surrounding fields is not usually hazardous and requires little in the way of risk assessment: ask permission of the owners to access their land, observe the country code, remember to close gates and don’t tread in anything soft. But in the time of a pandemic, everything changes.
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- The UK government currently forbids citizens from traveling far from home, unless the travel is essential. Was it essential for a group of meteoriticists to travel to Winchcombe? Yes, it was. Each had completed fieldwork risk assessments and received permission to travel from their institutions. They were scrupulous about wearing masks and keeping a
2 meter distance when talking to locals.
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- One of the larger stones was about 5 centimeters long. Its crust is the remainder of the surface that got heated as the meteorite came through the atmosphere.
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- “Winchcombe meteorite” may look a bit like a broken barbecue briquette, but to scientists, it is absolutely beautiful.
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March 13, 2021 ASTEROID - near miss and a perfect hit? 3091
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