As Earth’s climate continues to warm, some scientists are looking at doing more than simply reducing humanity’s outpouring of greenhouse gases into the atmosphere by devising ways to actively cool the planet back to temperatures that our civilization is comfortable with. One of the proposed techniques would be to spray massive amounts of sulphur dioxide into the atmosphere to create a cloud layer that would reflect a portion of the Sun’s rays back into space, emulating the cooling effect that the gases from a large volcanic eruption would have.
Two new studies have added new evidence to the theory that a major airburst from a meteor or comet occurred over North America, ushering in a 1,400-year cooling period called the Younger Dryas that occurred between the Pleistocene and the Holocene eras. The Younger Dryas saw the extinction of most of the large land mammals across North America, and also the end of the Clovis People, a Paleo-Indian culture. A charred layer of soil, found at roughly 50 Clovis sites across the continent, suggest a massive wildfire that raged continent-wide, possibly caused by such a massive meteor strike.
Discovered in September of 1999, asteroid 101955 Bennu is a 500-meter (1,640 foot) asteroid that crosses Earth’s orbit once every six years. Because it has been observed for 17 years, astronomers have been able to plot its orbit very accurately, and have found that it will make a series of extremely close passes to the Earth between 2169 and 2199, but they calculate that the chance of an impact is only 1-in-2,700.
Unfortunately, this possibility of an impact has fueled the circulation of a great deal of misinformation on the internet, with most articles illustrating a civilization-ending impact to take place in 2135, with the equivalent energy of 3 billion tons of TNT — but this figure appears to be grossly erroneous.
Unknown Country has been keeping a keen eye on the skies just recently, and with good cause: following the revelation last week that the Earth had narrowly escaped serious damage from 26 very sizeable asteroids over the past few years, another lucky escape was reported over the weekend.