MI weekly selection #566
Black holes account for only small fraction of dark matter
Contradicting earlier theories, massive black holes are made of a small percentage of dark matter. A team used gravitational microlensing to monitor nearly 80 million stars over 20 years, finding only 13 microlensing events, which indicates that other factors could explain the gravitational waves found by gravitational wave detectors.
Full Story: Earth
How do these butterflies fly nonstop over the Atlantic?
Painted lady butterflies traveled more than 4,200 kilometers nonstop across the Atlantic Ocean from West Africa to French Guiana, which points to wind conditions, specifically the Saharan Air Layer, that help in long-distance migrations. The research, published in Nature Communications, used weather data, genetic analysis, including sequencing the DNA of pollen grains on the butterflies, and isotopic studies to confirm the journey.
Full Story: Smithsonian
Drone images reflect impact of coral bleaching
Researchers who used drones to measure the damage from a mass bleaching event on Lizard Island’s North Point Reef in Australia found that nearly all the bleached corals are dead, raising concerns about the Great Barrier Reef’s overall health. The researchers explain how they used drone images of the corals and compared them to images taken in March.
Full Story: The Conversation
Marsquakes could lead to finding water on Mars
Researchers developed a method that could potentially reveal water deep below the Martian surface by analyzing electromagnetic signals generated by seismic waves passing through aquifers. “The scientific community has theories that Mars used to have oceans and that, over the course of its history, all that water went away,” said Nolan Roth, lead author of the study. “But there is evidence that some water is trapped somewhere in the subsurface.”
Full Story: Space Daily
Could a “sauna” keep frogs from dying of deadly disease?
Green and golden bell frogs in Sydney, Australia, are benefiting from “frog saunas” — low-cost structures made from bricks and plastic tarp — to combat the deadly chytrid fungus. The saunas help these declining species of frogs recover from infections and build immunity, according to a study published in Nature.
Full Story: Popular Science