This Week in Science – The Kickass Science Podcast · Dr. Kirsten Sanford Science Media

Tilting at Tumbleweeds

·1 hr 12 min·7 clips

NASA found ribose and glucose on asteroid Bennu, suggesting life's building blocks existed in early solar system.

Dr. Kiki hosts a solo episode of This Week in Science, episode 1041, recorded December 10, 2025, working through a collection of science stories she selected that week. The opening segment covers three papers published simultaneously in Nature Geoscience and Nature Astronomy analyzing pristine samples from asteroid Bennu returned by NASA's OSIRIS-REx spacecraft. Researchers, including scientists at NASA's Johnson Space Center, found ribose and glucose — the first discovery of a six-carbon glucose ring from any extraterrestrial source. They also identified a previously unseen polymer substance described as a chaotic, sticky, gum-like material with chemical groups similar to polyurethane on Earth, dubbed an informal 'space plastic.' The Bennu samples also contained all five nucleobases and phosphates previously reported. The significance: all molecular ingredients for DNA and RNA are present on Bennu, strongly supporting the hypothesis that life's chemical building blocks arrived on early Earth via asteroid impacts. The glucose finding is particularly exciting because glucose is the primary energy currency of biochemistry. In the dinosaur segment, researchers used scanning electron microscopy to examine fossilized skin from juvenile diplodocid dinosaurs from the Morrison Formation in Montana. They found two distinct types of fossilized melanosome structures in the epidermal layers — one oblong and one flat, platelet-like. By comparing the dimensions of these structures to melanosomes in living organisms with known coloration, the researchers concluded the juvenile diplodocids likely had speckled, multi-toned skin with browns, grays, and light-dark patterning rather than uniform solid color. Dr. Kiki connects the findings enthusiastically, with humor and tangents typical of the show's live-stream format. The audience is science enthusiasts and curious listeners who enjoy accessible, conversational science coverage.

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