Scientists hoping to detect dark matter deep in a former South Dakota gold mine have taken the last major step before flipping the switch on their delicate experiment and say they may be ready to begin collecting data as early as February.
What's regarded as the world's most sensitive dark matter detector was lowered earlier last month into a 70,000-gallon water tank nearly a mile beneath the Earth's surface, shrouding it in enough insulation to hopefully isolate dark matter from the cosmic radiation that makes it impossible to detect above ground.
And if all goes as planned, the data that begins flowing could answer age-old questions about the universe and its origins, scientists said.
What's the deal with dark matter?
Scientists know dark matter exists by its gravitational pull, but unlike regular matter and antimatter, it's so far been undetectable. Regular matter accounts for about 4 percent of the universe's mass, and dark matter makes up about 25 percent. The rest is dark energy, which is also a mystery.
What's the history of this experiment?
The search in South Dakota began in 2003 after the Homestake Gold Mine in the Black Hills' Lead, S.D., shuttered for good. Scientists called dibs on the site, and in July, after years of fundraising and planning, the Large Underground Xenon experiment detector moved into the Sanford Underground Research Facility, 4,850 feet below the earth's surface.
Carefully submerging the delicate detector into its final home – a water-filled vat that's 20 feet tall and 25 feet in diameter – took more than two months, a graduate student said
Keeping the water and xenon pristine will help remove what scientists called “fake sources” – or stuff that they have seen before, such as radiation, that could serve as false alarms in their efforts to detect dark matter.
Once the data start to flow, it'll take a month or two before the detector is sensitive enough to claim the “most-sensitive” title.