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.
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| SERGE BRUNIER/ESO |
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.
