The extremotolerant desert moss Syntrichia caninervis is a promising pioneer plant for colonizing extraterrestrial environments.

Many plans to establish human settlements on other planets focus on adapting crops to growth in controlled environments. However, these settlements will also require pioneer plants that can grow in the soils and harsh conditions found in extraterrestrial environments, such as those on Mars. Here, we report the extraordinary environmental resilience of Syntrichia caninervis, a desert moss that thrives in various extreme environments. S. caninervis has remarkable desiccation tolerance; even after losing >98% of its cellular water content, it can recover photosynthetic and physiological activities within seconds after rehydration. Intact plants can tolerate ultra-low temperatures and regenerate even after being stored in a freezer at -80°C for 5 years or in liquid nitrogen for 1 month. S. caninervis also has super-resistance to gamma irradiation and can survive and maintain vitality in simulated Mars conditions; i.e., when simultaneously exposed to an anoxic atmosphere, extreme desiccation, low temperatures, and intense UV radiation. Our study shows that S. caninervis is among the most stress tolerant organisms. This work provides fundamental insights into the multi-stress tolerance of the desert moss S. caninervis, a promising candidate pioneer plant for colonizing extraterrestrial environments, laying the foundation for building biologically sustainable human habitats beyond Earth.

Directly imaging excited state-resolved transient structures of water induced by valence and inner-shell ionisation.

Real-time imaging of transient structure of the electronic excited state is fundamentally critical to understand and control ultrafast molecular dynamics. The ejection of electrons from the inner-shell and valence level can lead to the population of different excited states, which trigger manifold ultrafast relaxation processes, however, the accurate imaging of such electronic state-dependent structural evolutions is still lacking. Here, by developing the laser-induced electron recollision-assisted Coulomb explosion imaging approach and molecular dynamics simulations, snapshots of the vibrational wave-packets of the excited (A) and ground states (X) of D2O+ are captured simultaneously with sub-10 picometre and few-femtosecond precision. We visualise that θDOD and ROD are significantly increased by around 50∘ and 10 pm, respectively, within approximately 8 fs after initial ionisation for the A state, and the ROD further extends 9 pm within 2 fs along the ground state of the dication in the present condition. Moreover, the ROD can stretch more than 50 pm within 5 fs along autoionisation state of dication. The accuracies of the results are limited by the simulations. These results provide comprehensive structural information for studying the fascinating molecular dynamics of water, and pave the way towards to make a movie of excited state-resolved ultrafast molecular dynamics and light-induced chemical reaction.