Episode Details

This weekend's Astronomy Daily wraps up the biggest stories from across the cosmos, starting with two completely fresh discoveries — a 1976 ocean rock that's turned out to hold atomic-scale proof of an ancient neutron star collision, and a record-breaking rocket launch from Europe's Ariane 6. Then we wind back through the week for our four biggest headlines: a new crew for Artemis III, JWST's salty 'Pink Planet' discovery, an update on the daring Swift Observatory rescue mission, and China's Tianwen-2 closing in on its target asteroid.   Story 1: A Kilonova's Fingerprint, Found in a 1976 Ocean Rock •       A rock sample dredged from the Pacific seafloor in 1976 has been found to contain a few hundred atoms of plutonium radioisotopes. •       The plutonium originated from a kilonova — a collision between two neutron stars — that occurred over 100 million years ago. •       Stellar debris from the merger settled to Earth and was slowly incorporated into a ferromanganese crust on the ocean floor. •       Isotope ratios provide the strongest physical clues yet to what created the elements and roughly when the merger occurred. •       Study published 18 June 2026.   Story 2: Ariane 6 Smashes Its Own Heaviest-Payload Record •       On 17 June 2026, an Ariane 64 rocket launched 36 Amazon Leo satellites from French Guiana (mission VA269 / LE-03). •       First flight of new P160C solid boosters — about a metre longer than the previous P120C, holding up to 156 tonnes of propellant each. •       Boosters deliver roughly a 10% performance increase, raising Ariane 64's LEO capacity to approximately 22 tonnes. •       The mission broke the 13-year record for heaviest payload ever launched by an Ariane rocket, previously held by the 2013 ATV 'Albert Einstein' resupply flight. •       Eighth Ariane 6 launch overall; 100th Amazon Leo satellite deployed by Arianespace.   Story 3: Artemis III Crew Revealed •       NASA announced the Artemis III crew on 9 June 2026 at Johnson Space Center: Commander Randy Bresnik, Pilot Luca Parmitano (ESA), and Mission Specialists Frank Rubio and Andre Douglas, with Bob Hines as backup. •       The Artemis II crew (Wiseman, Glover, Koch, Hansen) symbolically passed their lunar baton to the new crew. •       Artemis III is a two-week test flight in low Earth orbit to test docking procedures between Orion and commercial landers from SpaceX and Blue Origin. •       Targeted for launch as early as late 2027, ahead of a planned lunar surface landing in 2028. •       Will be Andre Douglas's first spaceflight.   Story 4: JWST Cracks the 'Pink Planet' Mystery •       JWST has confirmed salt clouds in the atmosphere of GJ504b, the 'Pink Planet,' located 57 light-years away. •       First direct evidence of salt clouds on a cold substellar companion object, a phenomenon theorised 15 years ago. •       At approximately 550°F, GJ504b is the coldest companion object ever directly imaged. •       Its true nature remains uncertain — it may be a giant planet or a brown dwarf. •       Research led by a Northwestern University team.   Story 5: The Swift Rescue Mission Heads for the Pacific •       NASA's Neil Gehrels Swift Observatory (orbiting since 2004) faces premature reentry due to orbital decay accelerated by recent solar activity. •       Katalyst Space Technologies' LINK robotic servicing spacecraft will attempt to grapple and boost Swift to a safer ~600km orbit. •       LINK launches on a Northrop Grumman Pegasus XL rocket, carried by Stargazer, the last flying Lockheed L-1011 TriStar. •       Stargazer departed NASA Wallops Flight Facility on 18 June 2026, en route to Kwajalein Atoll via California and Hawai'i. •       Launch targeted for 27 June 2026; if successful, it will be the first capture of an unprepared US government satellite by a commercial vehicle.   Story 6: Tianwen-2 Closes In on Kamo'oalewa •       China's Tianwen-2 spacecraft, launched May 2025, completed orbital insertion at near-Earth asteroid Kamo'oa