Two Unusual Galaxies Shake Up the Dark Matter Debate, Again

Astronomers have found two galaxies that appear devoid of dark matter, which they argue is in fact strong evidence of the elusive particle's existence.

When it comes to the nature of dark matter, astronomers are still largely, well, in the dark. The existence of this mysterious substance was hypothesized more than 40 years ago to explain discrepancies between the calculations of how galaxies ought to behave, based on their mass, and what was actually

Decade long study sheds light on “killer” galactic mergers

Two merging galaxies known as Arp 302, also called VV 340

Images taken by NASA's Spitzer Space Telescope are providing insight into the phenomenon of "killer" galaxies that, when they merge, shut down star formation within the new united galaxies. The collision and mixing of a pair of galaxies under the right (or wrong) conditions can disrupt the processes that allow

Ghostly Galaxies Hint at Dark Matter Breakthrough

The bizarre galaxy NGC 1052-DF2, a diffuse collection of stars, gas and dust that is apparently devoid of dark matter.

Much as a ripple in a pond reveals a thrown stone, the existence of the mysterious stuff known as dark matter is inferred via its wider cosmic influence. Astronomers cannot see it directly, but its gravity sculpts the birth, shape and movement of galaxies. This makes a discovery from last

Oddball Galaxy Puts Dark Matter Theory to the Test

Dark Matter

A small, faint galaxy residing some 65 million light-years away has been threatening to upend scientists’ entire paradigm of dark matter—the supposedly ubiquitous particles thought to pervade the universe like a hidden cosmic skeleton. All galaxies should be surrounded by a more massive cloud of dark matter, the thinking goes,

Einstein’s Greatest Theory Validated on a Galactic Scale

Einstein’s theory

Three years ago astrophysicist Tom Collett set out to test a theory. Not just any theory, but one that sets scientists’ expectations for how the universe operates at large: Einstein’s general relativity. First published in 1915, the theory mathematically describes how gravity emerges from the fundamental geometry of space and

Trio of infant planets discovered around newborn star

Two independent teams of astronomers have uncovered convincing evidence that three young planets are in orbit around an infant star known as HD 163296. Using a new planet-finding strategy, the astronomers identified three discrete disturbances in a young star’s gas-filled disk: the strongest evidence yet that newly formed planets are

Exoplanets could easily survive in double- and triple-star systems


Over 3,700 exoplanets have been found lurking around our universe, and although each has its own unique set of characteristics, the vast majority have one thing in common: they orbit a single star. Researchers once believed that it would be near impossible for planets to survive outside of single-star systems,

Could alien life exist in parallel universes?


It’s one thing to look for life elsewhere in the universe. But why stop there? What about life in all those parallel universes that theoretical physicists like to talk about? A recent paper in the Monthly Notices of the Royal Astronomical Society suggests that some of that real estate might

Andromeda and Milky Way Galaxies Are Already Touching

Andromeda Collides Milky Way

The merger of the Milky Way and Andromeda galaxy won’t happen for another 4 billion years, but the recent discovery of a massive halo of hot gas around Andromeda may mean our galaxies are already touching. The Andromeda Galaxy is the largest member of a ragtag collection of some 54 galaxies, including the Milky