SPACE.com: Comets shed material along their orbits. When Earth’s orbit takes our planet through those debris-strewn paths, terrestrial observers see meteor showers in the night sky. On 16 October, automatic sky-watching cameras captured two meteorlike fireballs streaking across the sky. No big meteor showers usually occur on that day, so it came as a surprise that an analysis of the fireballs’ trajectory pointed suggestively to comet Hartley 2 as the source. Unlike comet Tempel-Tuttle, which spawns the famous Leonid meteor shower in November, comet Hartley 2 is thought to be too small to beget meteors. The case remains open.
The finding that the Saturnian moon may host layers of icy slush instead of a global ocean could change how planetary scientists think about other icy moons as well.
Modeling the shapes of tree branches, neurons, and blood vessels is a thorny problem, but researchers have just discovered that much of the math has already been done.
January 29, 2026 12:52 PM
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