Category Astronomy/Space

The Milky Way is surrounded by dozens of dwarf galaxies that are thought to be relics of the very first galaxies in the universe. Among the most primitive of these galactic fossils is Tucana II—an ultrafaint dwarf galaxy that is about 50 kiloparsecs, or 163,000 light years, from Earth.

Now MIT astrophysicists have detected stars at the edge of Tucana II, in a configuration that is surprisingly far from its center but nevertheless caught up in the tiny galaxy’s gravitational pull. This is the first evidence that Tucana II hosts an extended dark matter halo—a region of gravitationally bound matter that the researchers calculated to be three to five times more massive than scientists had estimated...

At some point between 300 million and 1 billion years ago, a large cosmic object smashed into the planet Venus, leaving a crater more than 170 miles in diameter. A team of Brown University researchers has used that ancient impact scar to explore the possibility that Venus once had Earth-like plate tectonics.

For a study published in Nature Astronomy, the researchers used computer models to recreate the impact that carved out Mead crater, Venus’s largest impact basin. Mead is surrounded by two clifflike faults — rocky ripples frozen in time after the basin-forming impact...

Scientists have calculated the mass range for Dark Matter – and it’s tighter than the science world thought. Their findings – due to be published in Physics Letters B in March – radically narrow the range of potential masses for Dark Matter particles, and help to focus the search for future Dark Matter-hunters. The University of Sussex researchers used the established fact that gravity acts on Dark Matter just as it acts on the visible universe to work out the lower and upper limits of Dark Matter’s mass.

The results show that Dark Matter cannot be either ‘ultra-light’ or ‘super-heavy’, as some have theorised, unless an as-yet undiscovered force also acts upon it.

The team used the assumption that the only force acting on Dark Matter is gravity, an...

A lot is known about galaxies. We know, for instance, that the stars within them are shaped from a blend of old star dust and molecules suspended in gas. What remains a mystery, however, is the process that leads to these simple elements being pulled together to form a new star.

But now an international team of scientists, including astrophysicists from the University of Bath in the UK and the National Astronomical Observatory (OAN) in Madrid, Spain have taken a significant step towards understanding how a galaxy’s gaseous content becomes organised into a new generation of stars.

Their findings have import...