Keeping up with Icarus for April 2026 (vol. 448):
Sakatani, N. Kameda, S. Kitsunai, K. et al. Boulder motions on asteroid Ryugu induced by thruster gas disturbance by Hayabusa2 Art 116916 .2025.116916
Dewsnap, L. Campbell-Brown, M. Meteor luminous efficiencies from simultaneous multi-frequency radar and high-resolution optical observations Art 116926 .2025.116926
Tsirvouils, G. Granvik, M. Schirner, L. et al. Instantaneous thermally-driven erosion can explain dearth of dark near-Sun asteroids Art 116942 .2026.116942
The OSIRIS-REx craft, with no sampler head, will attempt a ‘soil’ experiment at Apophis using its thrusters. The way Apophis’ regolith responds to the disturbance will tell us of its particle properties. OREx will attempt this, after serendipitously doing so at Bennu, and after Haya2 did so at Ryugu. Sakatani et al. now write of the Ryugu results.
Meteors can be seen on camera; they can also be counted with meteor radars. Unfortunately, the two don’t always jibe with each other, and I don’t just mean daytime meteors. Dewsnap et al. attempt to square the two observations.
We have an outer Asteroid Belt dominated by carbonaceous chondrite bodies (C-type, plus others). We have an inner Belt dominated by stonier objects (S-type bodies). And then a trickle of objects got scattered inward, forming the Mars crossers and NEOs. But the scattered bodies are not a random, unbiased sample of the Belt: S-types lead. Is this a scattering effect? Tsirvouils et al. say no: conditions in the inner Solar System (like the Sun) are decimating the C-type NEOs.