Delta_V

...a Yale-led team measured the internal motions of a faint, diffuse galaxy called NGC 1052-DF9 and found its stars moving too slowly to hide a normal dark matter halo. The galaxy joins two earlier oddballs, DF2 and DF4, and all three lie along the same narrow line of galaxies in the NGC 1052 field...

A few years ago the same group noticed that DF2 and DF4 were not alone. About a dozen faint galaxies in the field fall along a remarkably tight, straight trail, and follow-up work showed their velocities increase steadily along its length...

That geometry points to a specific and dramatic origin. In one leading idea, two gas-rich galaxies slammed into each other at high speed long ago. The dark matter of each passed straight through, because dark matter barely interacts with anything, while the ordinary gas piled up, shocked and compressed, and later collapsed into a string of small galaxies made almost entirely of normal matter...

...The finding is that DF9’s motion is consistent with its stars alone and inconsistent with a full dark matter halo. That is not the same as proving the halo is exactly zero. A modest amount of dark matter still fits inside the error bars; a normal amount does not...

The deeper reason astronomers care is almost the opposite of what the headline suggests. Finding galaxies without dark matter is, oddly, some of the better evidence that dark matter is real. If gravity simply behaved differently in faint galaxies, as some alternative theories propose, then every galaxy of a given size should show the same anomaly. Instead a few galaxies, all apparently born in the same collision, stand out from thousands of ordinary ones. Dark matter that can be left behind in a crash is dark matter that exists as a substance, not as a quirk of the equations...

...After a long, challenging cruise phase with nine planetary flybys (one by Earth, two by Venus and six by Mercury), BepiColombo finally closed this chapter last Monday by permanently switching off its SEP thrusters...

Without any other source of propulsion, BepiColombo will follow a “ballistic” or free-falling trajectory as it initiates its first key arrival manoeuvre – MTM separation – on 3 September 2026.

After the MTM is ejected, the remaining spacecraft composite (MPO-Mio-MOSIF) will continue its planetary approach using MPO’s chemical propulsion system. This system will adjust the spacecraft’s trajectory ahead of the critical Mercury orbit insertion manoeuvre on 21 November, then guide it into Mio’s deployment orbit in early December before finally lowering MPO into its science orbit by March 2027...

In 2025, astronomers reported one of the largest rotating structures ever found: a cosmic filament some 50 million light-years long, holding close to 300 galaxies, with many of them turning in step with the filament as a whole. The coordinated motion is difficult to reconcile with the way galaxies are thought to acquire their spin...

Galaxies are thought to get their spin early, through what is called tidal torque: as matter collapses under gravity, the uneven pull of its surroundings sets it turning. On that picture, a galaxy’s spin is shaped mostly by its own local patch of the universe, and there is no obvious reason for hundreds of galaxies, spread across tens of millions of light-years, to share a single coordinated rotation tied to the filament around them...

The question underneath is an old one, which is where galaxies get their angular momentum. This filament has not answered it, but it has handed the problem a large and awkward new clue.

...In May 2026, a team of researchers reported evidence for primordial black holes (PBHs) by spotting a short-lived flicker of light from a star in the Large Magellanic Cloud. They monitored millions of stars in this galaxy using DECam. They spotted one star that briefly brightened for less than an hour. They interpreted this as a gravitational microlensing event. Microlensing occurs when a tiny object passes in front of a star and its gravity briefly bends and magnifies the star's light like a lens.

Because the brightening was so short, they calculated the "lens" causing it must have had about the mass of the moon. This one-time, nonrepeating signal was interpreted as a microlensing event caused by a primordial black hole nicknamed "Phoebe."...

In this new study, Udalski and Mr.óz present an independent analysis of the same public DECam data, plus extra observations from 2020 and 2021 that the previous paper didn't include.

They found that the star brightened at least three separate times over the years—one of which was previously interpreted as a microlensing event. In addition, its average brightness also changed over time...

"This is not the first time that a variable star has been mistaken for a short-timescale microlensing event in high-cadence time-series observations of limited duration," the researchers note. Short-term monitoring lasting some days, they explain, simply isn't enough to tell the difference. Distinguishing a genuine one-time gravitational event from a star's natural flickering requires months or years of monitoring.

...In 2013, a team of anthropologists led by Lee Berger unearthed the remains of more than 20 small-bodied hominins (ancient relatives of humans), all 335,000 to 236,000 years old, from the Rising Star Cave System in South Africa. Excavations at Rising Star have sparked debate about whether these little hominins had all ended up in the caves by tragic accident, or whether they’d been carefully placed there by other members of their enigmatic species, dubbed Homo naledi.

Now there’s a plot twist that may speak to how the remains got there: All of the hominins in Rising Star are female, at least according to the proteins in their dental enamel...

There’s an ongoing debate about Neanderthal art and abstract thought despite a growing pile of evidence. And that sort of debate rises in intensity when the early hominins in question have brains as relatively small as Homo naledi’s, which is about the size of a chimpanzee’s.

“There is a divide in the field between those that think that humans evolved from cultural species that were before us, and those that believe that culture originated with modern humans,” says Hawks, “so they resist any claims of culture earlier unless they have some sort of extraordinary evidence.”...

“This is our first contact with a—and I think it’s important to repeat this—a non-human species. Their brains are not human brains,” says Berger. And he’s deeply concerned about how humanity navigates that first contact.

...no other hominin species, meaning none of the Australopithecines and not even Homo erectus, have presented us with such clear evidence that they tended to their dead and etched art or symbols on the cave walls nearby. In other words, Homo naledi might have thought and felt in ways that we have to recognize as on a level with our own cognition...

...He hopes the protein study will prompt anthropologists and Homo sapiens in general to seriously think about the ethics of digging up the graves of an intelligent and cultured but non-human species.

“It certainly will mean we have to stop digging hominins like dinosaurs,”...

...The discovery expands how motors and actuation systems can be designed. Most electromagnetic motors today depend on magnets and copper coils. This new approach can create motion without magnets or rare earth metals, which could be valuable in a world where material resources are limited.

The design could also be lighter and simpler. Since the rotating component can be made from resin instead of metal, devices may become lighter and faster to respond. That could help in robotics, compact machines, and precision systems.

Because the motor does not depend on magnetic fields, it may also work well in places where magnetic noise causes problems, including medical equipment and data storage devices...

The discovery of all five nucleobases on Ryugu strengthens the idea that life’s molecular ingredients formed in space before reaching Earth.

A new study reports that samples from the asteroid Ryugu contain all five fundamental nucleobases, the molecular “letters” of life.

Tiny asteroid grains can preserve chemical clues about the ingredients that may have helped life emerge on Earth. The Ryugu material was returned from space in 2020 by the Japan Aerospace Exploration Agency’s (JAXA) Hayabusa2 mission.

In 2023, an international research team reported finding uracil, one of the nucleobases, in the Ryugu samples. Now, a study published on March 16, 2026, in Nature Astronomy by Japanese scientists has confirmed that all five nucleobases are present in the pristine asteroid material.

The finding suggests that these life related ingredients may have been common across the young Solar System...

On a flat dry lakebed in Death Valley National Park, heavy rocks sit at the end of long grooves they have plowed across the mud. The trails run for tens of meters, some bending in sharp turns or doubling back, yet no one had ever watched a rock actually move. For more than sixty years the question of how they travel sat unanswered, the subject of guesses that ranged from hurricane-strength winds to floating sheets of ice.

In 2014 a research team published the first direct scientific observation of the rocks in motion, and the mechanism turned out to be far gentler than the leading theories. The stones glide when a thin sheet of ice, only three to six millimeters thick, covers a shallow winter pond, starts to melt in the late morning sun, and breaks into floating panels that a light wind nudges across the water. The ice shoves the rocks along at a walking pace of a few meters per minute...

Malaysian scientists have discovered a new species of parasitic fungus in Borneo's jungles that preys on "zombie fungi" known to infect insects before subjecting them to a gruesome death...

The Lebanese Armed Forces on Monday urged people displaced from the south of the country by Israeli military operations there not to return to their homes and await further instructions, following Sunday's announcement of a memorandum of understanding that could bring an end to the U.S.-Israeli war with Iran.

"In light of recent developments in the region and with news circulating about reaching a ceasefire, the Army Command emphasizes the need for residents to postpone their return to the southern border villages and towns, and to adhere to the instructions of the deployed military units, in order to protect their safety from the danger of Israeli violations and attacks,"...

Israeli Defense Minister Israel Katz on Monday said that the Israel Defense Forces will not withdraw from areas it has seized in southern Lebanon, Syria and the Gaza Strip regardless of a deal with Iran.

Qcells has begun manufacturing solar cells at its new facility in Cartersville, Georgia, bringing the company closer to operating what it says is the United States’ first and only fully vertically integrated solar manufacturing factory.

The company announced that the plant is now producing solar cells and expects all production lines to reach full capacity by the third quarter of 2026. Once fully operational, the facility will manufacture ingots, wafers, cells, and solar modules under one roof.

The start of cell production marks a significant milestone for domestic solar manufacturing, as most solar panels installed in the US still rely on imported components. Qcells said the Cartersville site will become the largest operating solar cell factory in US history...

Images from EarthCam showed numbers on the lawn since at least Wednesday afternoon, with the number eight appearing most clearly as browned grass. It's not clear what caused the grass to brown.