Anna and Avery cover LandSpace becoming the first Chinese commercial company to land an orbital-class rocket booster — a big step for the country's private space sector. Plus: astronomers find a "mega-Earth" 23 times more massive than our planet that shouldn't be able to exist, a star weaving impossibly close to our galaxy's supermassive black hole that could reveal its spin within a decade, and new JWST data showing the early universe's galaxies were hiding roughly four times more mass than we thought. Full show notes: Today's episode — S05E172, Thursday August 20, 2026: Main story: China's private spaceflight sector sticks the landing. On August 19, Chinese commercial launch company LandSpace successfully recovered the first stage of its Zhuque-3 (ZQ-3) rocket after liftoff from the Dongfeng Commercial Space Innovation Pilot Zone in northwestern China — the first time any Chinese commercial company has landed an orbital-class booster. The 76.6-metre, stainless-steel, methane-fueled rocket (taller than a Falcon 9) touched down on four legs roughly 390km downrange in Gansu Province about eight minutes after liftoff, running on a single Tianque-12 engine. It's ZQ-3's second flight — the first, in December 2025, reached orbit but couldn't stick the recovery. The landing puts LandSpace among a very small club of companies with proven booster-reuse technology and marks, in the company's words, a shift "toward the engineering application phase of reusability." A "mega-Earth" that shouldn't be this dense. Astronomers led by Max Kroft (University of Wisconsin–Madison) have identified GJ 523b, a rocky exoplanet 23.5 times more massive than Earth but only 2.5 times its width — extraordinarily dense for its size. Standard planet-formation models say a planet this massive, orbiting its star every 17.75 days in a system just 170 million years old, should have pulled in a thick hydrogen-helium envelope; instead it's stayed almost entirely rocky. Found by TESS and confirmed with the WIYN 3.5-metre telescope at Kitt Peak; submitted to The Astronomical Journal, not yet peer-reviewed. The star that could reveal a black hole's spin. A newly identified star, S301, is orbiting our galaxy's central supermassive black hole, Sagittarius A*, closer and faster than any star found before it — passing within 12 astronomical units at roughly 25,000 kilometres per second and completing a full orbit in just 8.7 years. Led by K. Abd El Dayem (Paris Observatory) with Nobel laureate Reinhard Genzel's group, researchers expect to use S301's orbit to directly measure the black hole's spin within a decade — a first for any supermassive black hole, and a real-world test of Einstein's general relativity. JWST finds the early universe's galaxies were hiding their mass. A team led by Chloe Cheng (Leiden University), using JWST's NIRSpec instrument alongside data from the VLT's LEGA-C survey, found that ancient "quiescent" galaxies contain far more faint, low-mass stars than previously accounted for — potentially raising their true mass estimates by a factor of four. The hidden stars had simply been outshone by brighter ones in the same galaxies. Published in Nature Astronomy; the finding deepens existing tension with current galaxy-formation models. Tonight's sky: the Moon is about 56% illuminated and well-placed for lunar observing — look along the sunrise terminator for the crater Theophilus and its dramatic, shadowed walls. Venus is still blazing at magnitude -4.1 low in the western sky after sunset, and Saturn continues its predawn "moon parade" in the south-southeast for early risers. Links & sources: -
Spaceflight Now — LandSpace becomes first commercial Chinese company to land an orbital-class booster -
