The effects of ancient asteroid impacts on Earth are still evident from the variety of impact craters across our planet. And from the Chelyabinsk event back in 2013, where an asteroid exploded in the air above a Russian town, we know how devastating an “airburst” event can be.
Now, researchers in Antarctica have discovered evidence of a strange intermediate-type event – a combination of an impact and an airburst. The event was so devastating, its effects are still apparent even though it took place 430,000 years ago.
Continue reading “100-meter Asteroid Created a Strange Impact Event in Antarctica 430,000 Years Ago”
Telescopes have captured meteoroids hitting the Moon and several spacecraft imaged Comet Shoemaker–Levy 9 smacking into Jupiter in 1994. But impacts as they happen on another rocky world have never been observed.
However, the MESSENGER (MErcury Surface, Space ENvironment, GEochemistry and Ranging) mission may have seen an impact take place back in 2013. In looking at archival data from the mission, scientists found evidence of a meteoroid impact on Mercury. While this data isn’t a ‘no-doubt’ photo of the event, it does tell scientists more about impacts and how they affect Mercury’s wispy-thin atmosphere.
Continue reading “MESSENGER Saw a Meteoroid Strike Mercury”
Here’s something we don’t see very often: an Earth-grazing meteoroid.
On September 22, 2020, a small space rock skipped through Earth’s atmosphere and bounced back into space. The meteoroid was spotted by the by a camera from the Global Meteor Network, seen in the skies above Northern Germany and the Netherlands. It came in as low as 91 km (56 miles) in altitude – far below any orbiting satellites – before it skipping back into space.
Continue reading “Video Shows a Meteoroid Skipping off Earth’s Atmosphere”
In a year of devastating wildfires, destructive derechos, early and active hurricanes, widespread social unrest, contentious politics and more — all amid an unprecedented global pandemic — it might seem fitting that ‘asteroid impact’ would be added to the 2020 bingo card.
Continue reading “Completely Harmless Asteroid Almost Certainly Won’t Hit Earth Just Before the US Election”
It’s no secret that planet Earth is occasionally greeted by rocks from space that either explode in our atmosphere or impact on the surface. In addition, our planet regularly experiences meteor showers whenever its orbit causes it to pass through clouds of debris in the Solar System. However, it has also been determined that Earth is regularly bombarded by objects that are small enough to go unnoticed – about 1 mm or so in size.
According to a new study by Harvard astronomers Amir Siraj and Prof. Abraham Loeb, it is possible that Earth’s atmosphere is bombarded by larger meteors – 1 mm to 10 cm (0.04 to 4 inches) – that are extremely fast. These meteors, they argue, could be the result of nearby supernovae that cause particles to be accelerated to sub-relativistic or even relativistic speeds – several thousand times the speed of sound to a fraction of the speed of light.
Continue reading “There Could be Meteors Traveling at a Fraction of the Speed of Light When They Hit the Atmosphere”
From the study of meteorite fragments that have fallen to Earth, scientists have confirmed that bacteria can not only survive the harsh conditions of space but can transport biological material between planets. Because of how common meteorite impacts were when life emerged on Earth (ca. 4 billion years ago), scientists have been pondering whether they may have delivered the necessary ingredients for life to thrive.
In a recent study, an international team led by astrobiologist Tetyana Milojevic from the University of Vienna examined a specific type of ancient bacteria that are known to thrive on extraterrestrial meteorites. By examining a meteorite that contained traces of this bacteria, the team determined that these bacteria prefer to feed on meteors – a find which could provide insight into how life emerged on Earth.
Continue reading “A Microorganism With a Taste for Meteorites Could Help us Understand the Formation of Life on Earth”
When ‘Oumuamua crossed Earth’s orbit on October 19th, 2017, it became the first interstellar object to ever be observed by humans. These and subsequent observations – rather than dispelling the mystery of ‘Oumuamua’s true nature – only deepened it. While the debate raged about whether it was an asteroid or a comet, with some even suggesting it could be an extra-terrestrial solar sail.
In the end, all that could be said definitively was that ‘Oumuamua was an interstellar object the likes of which astronomers had never before seen. In their most recent study on the subject, Harvard astronomers Amir Siraj and Abraham Loeb argue that such objects may have impacted on the lunar surface over the course of billions of years, which could provide an opportunity to study these objects more closely.
Continue reading “By Continuously Watching the Moon, we Could Detect Interstellar Meteorites”
In 2008, scientists from Oxford and Aberdeen University made a startling discovery in the northwest of Scotland. Near the village of Ullapool, which sits on the coast opposite the Outer Hebrides, they found a debris deposit created by an ancient meteor impact dated to 1.2 billion years ago. The thickness and extent of the debris suggested that the meteor measured 1 km (0.62 mi) in diameter and took place near to the coast.
Until recently, the precise location of the impact remained a mystery to scientists. But in a paper that recently appeared in the Journal of the Geological Society , a team of British researchers concluded that the crater is located about 15 to 20 km (~9 to 12.5 mi) west of the Scottish coastline in the Minch Basin, where it is buried beneath both water and younger layers of rock.
Continue reading “1.2 billion years ago, a 1-km asteroid smashed into Scotland”
When ‘Oumuamua was first detected on October 19th, 2017, astronomers were understandably confused about the nature of this strange object. Initially thought to be an interstellar comet, it was then designated as an interstellar asteroid. But when it picked up velocity as it departed our Solar System (a very comet-like thing to do), scientists could only scratch their heads and wonder.
After much consideration, Shmuel Bialy and Professor Abraham Loeb of the Harvard-Smithsonian Center for Astrophysics (CfA) proposed that ‘Oumuamua could in fact be an artificial object (possibly an alien probe). In a more recent study, Amir Siraj and Prof. Loeb identified another (and much smaller) potential interstellar object, which they claim could be regularly colliding with Earth.
Continue reading “Astronomers Think a Meteor Came from Outside the Solar System”
When a meteor strike the Earth’s atmosphere, a magnificent (and potentially deadly) explosion is often the result. The term for this is “fireball” (or bolide), which is used to describe exceptionally bright meteor explosions that are bright enough to be seen over a very wide area. A well-known example of this is the Chelyabinsk meteor, a superbolide that exploded in the skies over a small Russian town in February of 2013.
On December 18th, 2018, another fireball appeared in the skies over Russia that exploded at an altitude of about 26 km (16 mi) above the Bering Sea. The resulting debris was observed by instruments aboard the NASA Terra Earth Observation System (EOS) satellite, which captured images of the remnants of the large meteor a few minutes after it exploded.
Continue reading “Satellites Watched a Huge Fireball Explode Above the Bering Sea Late Last Year”