Dark Matter

A team has made some intriguing discoveries in the outer regions of the Milky Way. Astronomers mapped the fringes of the sparse halo that envelops our home galaxy, and found the wake of a dwarf galaxy on an eventual collision course with the Milky Way.

Scientists may be able to detect the presence of dark matter by searching for anomalous heat signatures from distant alien worlds. Dark matter is an enigmatic, invisible substance that is thought to make up around 80 percent of the universe’s mass.

There’s invisible, undetectable stuff all around us, and we call it dark matter. There’s plenty of evidence that this stuff is very real, but what exactly is dark matter? How do we know it’s there? And how are scientists looking for it?

With elusive dark matter continuing to evade detection, scientists are having to search in stranger and stranger places. In a new study, physicists at MIT have studied the spins of black holes for signs of drag from dark matter slowing them down.

Dark matter makes up the majority of matter in the universe, but it’s strangely shy about making its presence known. Now physicists have designed a new test to search for signs of two candidate particles, using the quirky world of quantum technology.

The expansion of the universe is accelerating, and current models call the driving force dark energy. But perhaps this placeholder doesn’t exist – a new study has found that dark matter could produce the same effect if it had some form of magnetism.

Astronomers have discovered the aftermath of a cosmic hit-and-run in our own neighborhood. While studying the closest star cluster to the Sun, ESA scientists realized it may have been disrupted by a huge lump of invisible mass, possibly dark matter.

In January scientists reported the detection of very low-frequency gravitational waves. Now astrophysicists have investigated two possible sources – the universe cooling down after the Big Bang, and a field of particles that could be dark matter.

Last year gravitational waves were detected from a massive black hole collision. But now astrophysicists propose a new explanation: a collision of two boson stars – hypothetical, invisible objects that could help untangle the mystery of dark matter.

Astronomers have detected a strange signal coming from neutron stars that could be a new elementary particle. An unexplained excess of X-rays hints at axions, hypothetical “ghost” particles that could solve several long-standing physics puzzles.

Dark matter should outnumber regular matter five to one, yet it remains frustratingly elusive. But there might be ways to spot it, and now astronomers have scanned neutron stars for telltale signals of a proposed dark matter particle called an axion.

Dark matter is currently the most widely accepted hypothesis for explaining some of the weirdness we see in the cosmos. But now astronomers have discovered evidence in over 150 galaxies for a long-standing alternative model of “modified gravity.”