The forefront of planetary exploration at the LPSC (Lunar and Planetary Science Conference) - including reports on the latest research results from the asteroid Ryugu and Bennu samples
The 55th Lunar and Planetary Science Conference was held from March 11-15 in The Woodlands, a suburb of Houston, Texas, USA. This was the first Lunar and Planetary Science Conference since NASA's OSIRIS-REx asteroid probe returned the Bennu sample to Earth, and related sessions were well attended with standing room only.
In the session on the Ryugu samples returned by JAXA’s Hayabusa2 mission (Analysis of Ryugu Samples and Aqueous Processes on Chondrite Bodies), for example, the results of the analysis of the infrared reflection spectra from the infrared microscope ‘MicrOmega’, used by JAXA Curation for the initial description of the Ryugu samples, showed that the particles collected at the first touchdown had more extensive variations in space weathering than those collected at the second touchdown, which were collected close to the artificial impact crater that had ejected sub-surface material across the second touchdown site.
In addition, a detailed analysis of the Ryugu sample allocated to research teams around the globe through the international call for Announcement of Opportunity (AO) reported that evidence of iodine-129, an extinct nuclide that was present in the primitive Solar System, was detected by xenon isotope analysis, indicating its age to be 9 million years after the formation of CAI, the oldest solid material in the Solar System.
The session on the results of the asteroid Bennu sample analysis (Special Session: To Bennu and Back) reported that, although the Bennu sample is mineralogically and chemically similar to the primitive CI chondrite meteorites like the Ryugu sample, it is more organic-rich and for some reason contains more magnesium phosphate minerals and more anhydrous silicate minerals. Further detailed comparative studies are expected in the future.
In addition to Hayabusa2 and OSIRIS-REx, a number of asteroid missions were discussed, including DART, which crashed a probe into the moon of the asteroid Didymos, its observation mission Hera, and Lucy, which aims to eventually rendezvous with an asteroid in Jupiter's Trojan group (the first flyby target object in the asteroid belt, the asteroid Dinkinesh, whose moon is actually a contact binary like the asteroid Itokawa!).
Other than missions related to asteroids, the Smart Lander for Investigating Moon (SLIM), which became the first Japanese mission to soft land on the Moon this year, Artemis, which will be launched next year, the VIPER probe and other lunar missions, the progress of sample collection by the NASA Mars rover Perseverance, and the Europa Clipper mission to search for signs of life on Jupiter's icy moon Europa, which is scheduled for launch this year, and many other satellite and planetary missions that JAXA is also involved with were reported, giving the audience a first-hand experience of the forefront of planetary exploration during the five days.
