More stories

  • in

    A gas clump in the Milky Way’s neighborhood might be a ‘dark galaxy’

    A potential dark galaxy — one made primarily of dark matter — may have been spotted in the local universe.

    Dark galaxies are theoretical, starless systems whose discovery could help astronomers better understand galaxy formation. The new candidate was found within a large, fast-moving cloud of gas first seen in the 1960s. High-resolution observations of the cloud, reported April 18 in Science Advances, revealed a compact clump of gas that might be a dark galaxy. More

  • in

    A claimed hint of alien life whips up spirited debate

    You may have already seen the headlines: Signs of life have reportedly been discovered on an alien world. 

    A team of astronomers led by Nikku Madhusudhan of the University of Cambridge used the James Webb Space Telescope to search for interesting molecules in the atmosphere of a planet outside our solar system called K2 18b. The team now says they’ve found molecules that, on Earth, are associated with life, in an abundance that is hard to explain otherwise. More

  • in

    A NASA rover finally found Mars’ missing carbon

    The carbon that once warmed Mars’ atmosphere has been locked in its rusty rocks for millennia. 

    That’s the story revealed by a hidden cache of carbon-bearing minerals unearthed by NASA’s Curiosity rover along its route up a Martian mountain. The finding is the first evidence of a carbon cycle on the Red Planet, but also suggests that Mars lost its life-friendly climate because that carbon cycle was slow, researchers report in the April 18 Science. More

  • in

    Yes, there really is a black hole on the loose in Sagittarius

    For the first time, astronomers have confirmed the existence of a lone black hole — one with no star orbiting it.

    It’s “the only one so far,” says Kailash Sahu, an astronomer at the Space Telescope Science Institute in Baltimore.

    In 2022, Sahu and his colleagues discovered the dark object coursing through the constellation Sagittarius. A second team disputed the claim, saying the body might instead be a neutron star. New observations from the Hubble Space Telescope now confirm that the object’s mass is so large that it must be a black hole, Sahu’s team reports in the April 20 Astrophysical Journal. More

  • in

    Ancient computer’s gears may not have been able to turn

    A piece of the Antikythera mechanismLOUISA GOULIAMAKI/AFP/Getty Images
    The Antikythera mechanism, a mysterious ancient Greek device that is often called the world’s first computer, may not have functioned at all, according to a simulation of its workings. But researchers say we can’t be sure of this since the machine is so badly damaged.
    Since the mechanism was discovered in 1901, in a shipwreck thought to date to around 60 BC, researchers have struggled to work out exactly why it was built. X-ray scans and digital reconstructions show that it was originally a 30-centimetre box containing interlinked systems… More

  • in

    Iron Age site was a purple dye factory for centuries

    Stone tools with purple dye residue found at Tel Shiqmona in IsraelMaria Bukin/Shalvi et al., 2025, PLoS One, CC-BY 4.0
    For centuries, a coastal settlement in modern-day Israel was home to the industrial-scale production from marine snails of a purple dye that was one of the ancient world’s most precious commodities.
    Known as Tyrian purple, it was especially sought after to colour woollen textiles and was highly prized by the wealthy and powerful in Iron Age Mediterranean societies. But until now the direct evidence of any sites of large-scale production has been sparse.
    Advertisement
    From 1100 BC to about 900 BC, Tel Shiqmona was a small Phoenician fishing village where purple dye was produced on a small scale. Then, as the Kingdom of Israel began to expand, the site was transformed “from a fishing village to a fortified purple dye production centre”, says Golan Shalvi at the University of Chicago.
    During archaeological work at the site, Shalvi and his colleagues found the remains of dye-stained vats used to process the substance, each of which could have held up to 350 litres of liquid. Altogether 176 artefacts related to purple dye production were recovered, including 135 purple-stained items.
    The dye is harvested from sea snails in the Muricidae family, which secrete mucus to defend themselves and kill prey. “The secretion is initially a slightly greenish fluid, which oxidises upon exposure to air and gradually turns purple,” says Shalvi. “However, in order to transform it into an actual dye — one that chemically bonds with textiles — it must be processed into a solution through a complex series of chemical steps.”
    The researchers claim Tel Shiqmona is the only site in the world where there is clear evidence for large-scale manufacture of purple dye in a specialised facility for so long.
    However, there are no historical records that tie the site to the dye and little is known about the actual process that was used to manufacture it, says Shalvi.

    After the Kingdom of Israel fell around 720 BC, the scale of dye production wound down until the Assyrians took over the site and ramped the process up yet again. Around 600 BC, when the Babylonians conquered the region, dye production at Tel Shiqmona was abandoned.
    “It was an industrial site throughout most of the Iron Age, without monumental architecture or any particular beauty or elegance,” says Shalvi. “I imagine it as a very smelly place — especially to a modern nose — since the production process emitted a terrible odour. I picture wool fleeces dyed in various shades drying outside and inside the buildings, which may have given the site a purplish-reddish-blue hue.”
    Purple dye has fascinated people all over the world, he says, and it has been the subject of extensive research. “Its association with elite classes and religious rituals gave it immense cultural, symbolic and economic significance far beyond its function as a mere colour.”

    Topics:archaeology More

  • in

    Drought may have sped the demise of Rapa Nui sculpture culture

    Moai on Rapa Nui, also known as Easter IslandAll Canada Photos / Alamy Stock Photo
    A newly identified drought on the Pacific island of Rapa Nui, also known as Easter Island, could have spurred islanders to invest fewer resources in building their legendary stone monuments. But some archaeologists dispute this interpretation.
    The island of Rapa Nui has become central to a cautionary tale of disaster caused by unsustainable use of resources. The standard narrative is that the arrival of the first Polynesians on the tiny island in the 1200s led to rapid deforestation, in part to support the… More

  • in

    Bronze naval ram from Roman battle recreated using ancient techniques

    A ship’s ram found near Sicily that had been used in the Punic warsPeter Horree/Alamy
    Ancient Greek and Roman warships were equipped with bronze rams to smash and sink enemy vessels – and a team of archaeologists has just recreated one. They plan to test the weapon on replica warships to assess how effective the rams were during naval battles.
    “This research can help us understand the evolution of major warships, from the fleets of Alexander the Great’s successors to the vessels that secured Rome’s naval dominance,” says Stephen DeCasien at Dalian University of Technology in China,… More