Every so often, the fossil record indicates, ecological catastrophes wipe huge numbers of species off the face of Earth. These huge disasters occur approximately every 26 million to 30 million years—nearly the similar interval at which our solar system travels through the plane of the Milky Way. Placing two and two together, some scientists have suggested that layer of dust and gas in the galactic plane might interrupt the tracks of far-flung comets and initiate planet-smacking impacts. A recent study proposes an additional culprit may cause those huge disasters: dark matter. Some of Earth’s historical mass extinctions have been triggered by the impacts of extraterrestrial stuffs, for example the asteroid that hit near Mexico’s Yucatán Peninsula and caused the extinction of the dinosaurs nearly 66 million years ago. Others have happened throughout stretched periods of geological disturbance that comprise region-smothering volcanic eruptions. Both types of disasters appear to happen on a cycle of about 30 million years, notes Michael Rampino, a geoscientist at New York University in New York City. Michael Rampino says “It’s always been a mystery as to how extraterrestrial impacts could cause these long-lived geological effects,” But unseen dark matter, he suggests, could cause both extraterrestrial impacts and geological disturbances in one fell swoop.
Researchers still don’t have any idea what dark precisely matter is, but its gravitational effect on other objects in space displays that there’s lots of it out there. Scientists estimate that in the plane of the galaxy, each square light-year holds nearly one solar mass of dark matter. Resembling to the clouds of dust and gas that astronomers can perceive, clouds of dark matter may be disturbing the courses of unfriendly comets, triggering them to fall into the inner solar system where they can impact Earth. As the solar system travels through this supposed cloud of particles blocking the galactic plane, some get stuck by Earth’s gravity, Rampino proposes. These particles circle Earth’s core and ultimately fall to the center of the Earth, where they interact with ordinary matter or one another, discharging energy that gets converted into heat.
As the solar system to cross the galactic plane, interfaces with dark matter might increase the temperature of Earth’s core by hundreds of degrees Celsius, Rampino stated online in the Monthly Notices of the RoyalAstronomical Society. Then, over millions of years, that heat might be carried to Earth’s exterior via huge plumes of hot tough rock that, in turn, make volcanic hot spots or gradually rip apart lands—probably changing global climate or constructing gigantic swaths of the planet so unfriendly that millions of species decease.
The notion that dark matter might cause both extraterrestrial impacts and geological disruptions “is fascinating,” says Dennis Kent, a geophysicist at the Lamont-Doherty Earth Observatory in New York. He says “One of those sources of environmental disruption might be tolerable,” but together they might pack a one-two blow that is way too much for several ecosystems to tolerate. Certainly, he adds, some slightly huge impacts that weren’t escorted by extensive geological destruction—for instance an object that crashed into what is now the Chesapeake Bay approximately 35 million years ago, leaving a now-buried crater—don’t appear to have produced noteworthy ecological harm.