Scientists believe a dark matter “storm” is making its way past the Sun and could be detected here on Earth.
The study, conducted by Ciaran O’Hare of the University of Zaragoza in Spain, was published in Physical Review D and looked at the S1 stream, a cluster of neighbouring stars travelling in the same direction. According to APS Physics, these are “believed to be the remnants of a dwarf galaxy that was eaten by the Milky Way billions of years ago.”
The ESA’s Gaia spacecraft, which is mapping a billion stars in our galaxy, discovered the S1 stream of 30,000 stars last year. In our galaxy, some 30 such streams have been discovered, each one the result of a previous collision.
S1 is particularly intriguing because it is currently “blowing” by us at approximately 500 kilometres (310 miles) per second. According to the experts, this could have an impact on the dark matter surrounding us.
“Current detectors probing for weakly interacting massive particles (WIMPs), a widely discussed form of dark matter, are unlikely to see any effect from S1,” the statement said, “but future WIMP detectors may.”
All galaxies are assumed to have originated within a vast halo of dark matter, which is invisible to us and does not interact with normal matter. However, the researchers discovered that approximately 10 billion solar masses of dark matter originating in the initial dwarf galaxy was migrating down S1.
A star stream passing past our Sun is depicted. Jon Lomberg/NASA/C. O’Hare
“As the S1 stream ‘hits the Solar System slap in the face’, the authors write, its counter-rotating structure will dramatically increase the amount of dark matter appearing to come from the same patch of sky as the standard dark matter wind,” reports Cosmos Magazine.
“Indeed, it should generate a ring-like structure around this wind, which directed dark matter detectors… may easily detect in the future.”
ScienceAlert also reported that axions, theorised particles 500 million times lighter than an electron that could represent dark matter, could be detected in the stream. “[T]hese ultralight particles, which humans cannot see, could be transformed to visible photons in the presence of a strong magnetic field,” they said.
Despite repeated efforts, no direct discovery of dark matter has ever been made. However, this “storm” may present an exciting opportunity to do so.