A meteorite crater found in almost every continent of the world could treat any traveler to a Mars-like panorama with its desolate, sometimes arid, rock-strewn environment. Yet the arresting enormity of the familiar curved-in contour on land is more terrifying than they appear.
Scientists unearthed an ancient crater in southern Alberta, Canada, which is alleged to have formed 70 million years ago from a very powerful impact caused by asteroid debris the size of an apartment block.
While Earth has its own barrier against the meteorites that stray in its proximity in the form of atmosphere, some cosmic rocks are too huge to be slowed down, eventually piercing through the planet's first line of defense and striking the surface at soaring velocities of 12 to 20 kilometers per second.
The newfound crater eight kilometers wide, though it showed "no obvious morphological expression at surface," is so massive the so-called blast could completely wipe out Calgary, the most populous city of Alberta and home to a million inhabitants.
"An impact of this magnitude would kill everything for quite a distance," said Doug Schmitt of the University of Alberta, who is also the Canada research chair in Rock Physics. "Something of that size, throwing that much debris in the air, potentially would have global consequences; there could have been ramifications for decades."
However, Schmitt and his fellow researchers from the University of Alberta and Alberta Geological Survey (AGS) made it clear that they have yet to conclude whether the crater was indeed due to a "hypervelocity meteorite impact" because most of the evidence, such as the "roots" of the crater, were either eroded or buried by time and glaciers.
Found near Bow City, a hamlet in Alberta, the crater was traced with hints of strong seismic and geological evidence in the crater and was mapped via downhole geophysical well logs, which helped the researchers reach an estimated calculation that the crater's depth could have reached 1.6 to 2.4 kilometers in its early formation.
Meteorite impacts found on Earth are classified into two types, namely the simple and the complex craters. Both craters are bowl-shaped but the complex ones encompass a distinct raised central peak. Viewed from above, complex craters would look like a ring with a dot in the middle. The crater in Alberta is classified as a complex crater.
Geologist Paul Glombick was the first to discover the crater while drafting a geological map of the area for the AGS in 2009.
Our planet traverses through a midst of celestial debris and it is no stranger to meteorite impacts. A total of 44 impacts have been confirmed, says Planetary and Space Science Center. The largest known crater found so far is in South Africa.
Dubbed as the "Vredeford Dome," the crater, though not very well-preserved, measures a whopping 300 kilometers across and has lately been declared as a World Heritage Site.
The team's discovery can be found in the Meteoritics & Planetary Science journal.