00:00Have you ever wondered what an impact crater looks like from space?
00:06Craters are inevitably part of being a rocky planet.
00:09They occur on every planetary body in our solar system, no matter the size.
00:15By studying impact craters and the meteorites that cause them, we can learn more about the
00:19processes and geology that shape our entire solar system.
00:24Over the past two decades, ESA has tracked and analysed asteroids that travel close to
00:28Earth.
00:29ESA's FlyEye telescopes will survey the sky for these near-Earth objects, using a
00:35unique compound eye design to capture wide-field images.
00:39This will enhance the detection of potentially hazardous asteroids.
00:42ESA's HERA spacecraft, launching later this year, will closely explore asteroids and improve
00:48our understanding of these celestial bodies.
00:51This will help us better prepare for potential future asteroid deflection efforts.
00:56Today, for Asteroid Day, we're counting down some of our favourite impact craters
01:00here on Earth, captured by satellites.
01:0410.
01:06Nordlinger Ries
01:08Formed around 15 million years ago, Germany's Ries crater didn't become apparent until
01:12the 1960s.
01:14Prior to that time, many geologists had suspected that the crater had been formed by volcanic
01:19activity.
01:20The crater's rim can be seen as a semicircle.
01:23The medieval town of Nordlingen was built in its depression.
01:27The impact led to the creation of over 70,000 tonnes of microscopic diamonds.
01:32The stone buildings of the town were constructed almost entirely with diamond-encrusted rock.
01:389.
01:39Oaxes Crater
01:41The Oaxes Impact Crater is located in northwest Algeria, close to the border with Morocco.
01:47Around 3.5 km across, the crater was created when a meteor hit Earth less than 70 million
01:53years ago, when dinosaurs still roamed the planet.
01:57Originally called Tindolf, the crater is now heavily eroded.
02:01Despite this, its circular shape still remains evident due to the exposure of ancient sedimentary
02:06rock layers, which create ridgelines that run roughly northwest to southeast.
02:128.
02:13Tinouma Crater
02:15Deep within the Sahara Desert lies one of the best-preserved craters on Earth.
02:19It was long debated whether the Tinouma Crater was formed by a volcano or meteorite.
02:25Scattered rocks around the crater created the impression of an ancient volcano.
02:29But a closer examination of the structure revealed the crater's hardened lava was
02:33actually rock that had melted by a meteorite impact.
02:37Tinouma Crater is almost 2 km wide.
02:40The rims rise over 100 m high above the base.
02:43But the bottom of the crater is covered with a thick layer of sediments.
02:47The crater sits in a vast plain of rocks that are so ancient, they were deposited hundreds
02:51of millions of years before the first dinosaurs walked Earth.
02:56Even though it resides in ancient rock, Tinouma is much younger, ranging in age between 10,000
03:02and 30,000 years old.
03:057.
03:06Gosses Bluff
03:08The Gosses Bluff Crater in the Northern Territory of Australia was most likely formed a
03:13hundred and forty million years ago by the impact of a large comet or meteorite slamming
03:18into Earth.
03:19It is one of the most studied of the Australian impact craters.
03:23Australia is a very good place to observe and study impact craters.
03:27Because of the dry climate, the craters haven't weathered away, nor are they hidden by dense
03:31vegetation.
03:326.
03:33Silian Ring
03:35Around 400 million years ago, an asteroid slammed into the land that is now south-central
03:41Sweden.
03:42Its impact left quite a mark.
03:44After millions of years of erosion, the scar it left is still recognisable, especially
03:49from above.
03:50Measuring more than 50 kilometres across, the Silian Ring is the largest known impact
03:55crater in Europe.
03:56It is surrounded by a depression, which today is partially filled with water.
04:015.
04:02Rotterdam
04:05The Rotterdam Impact Crater is found in the Namib Desert in southwest Namibia.
04:10According to geologists, the crater was formed by a meteorite around the size of a large
04:14vehicle that collided with Earth around 5 million years ago.
04:18The crater is around 2.5 kilometres wide and is around 130 metres deep.
04:24It is clearly visible in contrast with the Russ Red Dunes, with its rims rising over
04:2950 metres above the surrounding plain.
04:324.
04:33Manicouagan Crater
04:35In southeast Quebec lies one of the world's oldest impact craters.
04:39The Manicouagan Crater was formed 214 million years ago when an asteroid 5 kilometres wide
04:46struck what is now Canada.
04:48Its concentric structure results from the shock waves transmitted by the impact.
04:53The structure is around 100 kilometres across, with its 70-kilometre diameter ring its most
04:58prominent feature.
04:593.
05:00Shoemaker Crater
05:03Formerly known as Teague Ring, the Shoemaker Impact Crater is located in Western Australia
05:09and was named after Eugene Shoemaker, a planetary geologist and pioneer in impact crater studies.
05:15The almost circular shape of the Shoemaker Impact Site is around 30 kilometres in diameter
05:21and is defined by concentric rings formed in the sedimentary rocks, seen in dark brown.
05:27The precise age of the impact is unknown, but estimated to be around 1.6 billion years old.
05:332.
05:34Ayuranga Crater
05:36The Ayuranga Crater in northern Chad is one of the best preserved impact structures in
05:40the world.
05:41It was thought to be created by a meteorite impact around 340 million years ago, based
05:46on the age of sedimentary rocks deformed by the impact.
05:49The central highland, or peak of the crater, is surrounded by a sand-filled ring, which
05:55is also surrounded by another ring of rock.
05:58The linear rock ridges that run diagonally are yardangs, and are formed by wind erosion.
06:04Here we can clearly see how the wind blows from northeast to southwest.
06:081.
06:09Meteor Crater
06:10The Meteor Crater, also known as Barringer Crater, is located in the desert of northern
06:16Arizona.
06:17It's around 1,200 metres in diameter and 180 metres deep, surrounded by a rim of smashed
06:23and jumbled rocks, some the size of small houses.
06:28One of its main features is its squared-off outline, believed to be caused by cracks in
06:32the strata at the impact site.
06:35Discovered in 1891, the crater's age has been variously estimated to be around 50,000
06:40years old.
06:41The crater is a site of active research.
06:43It is well-preserved, making it an excellent place to learn about the process of impact
06:48cratering.
06:50Thanks for watching.
06:51Let us know in the comments below which impact craters you'd like to see from space.
06:55Until the next time!
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