Directed Panspermia Using Interstellar Comets.

It may be that habitable planets are common but life is rare. If future advances in telescopes increasingly suggest this is so, humankind might feel motivated to seed lifeless planets with resilient terrestrial organisms or synthetic forms designed to thrive on the target planet. A useful mechanism for achieving this goal at a relatively low cost is to use interstellar comets transiting the Solar System to convey microbial cargoes toward nearby planetary systems, where they could disseminate the inoculum via their dust trails.

Amazonian terrestrial water balance inferred from satellite-observed water vapor isotopes.

Atmospheric humidity and soil moisture in the Amazon forest are tightly coupled to the region's water balance, or the difference between two moisture fluxes, evapotranspiration minus precipitation (ET-P). However, large and poorly characterized uncertainties in both fluxes, and in their difference, make it challenging to evaluate spatiotemporal variations of water balance and its dependence on ET or P. Here, we show that satellite observations of the HDO/HO ratio of water vapor are sensitive to spatiotemporal variations of ET-P over the Amazon.

Progress on the Starshot laser propulsion system.

The Breakthrough Starshot research program envisions a laser-propelled sail that will probe our neighboring stars within a human lifetime. Starshot spacecraft weigh no more than a few grams and are accelerated by photon momentum transfer with a beam generated by a kilometer-scale, ground-based 100 GW coherent phased-array laser. We describe some of the major challenges for the laser and early exploratory efforts to overcome them.

Control of western corn rootworm via RNAi traits in maize: lethal and sublethal effects of Sec23 dsRNA.

Background: RNA interference (RNAi) triggered by maize plants expressing RNA hairpins against specific western corn rootworm (WCR) transcripts have proven to be effective at controlling this pest. To provide robust crop protection, mRNA transcripts targeted by double-stranded RNA must be sensitive to knockdown and encode essential proteins.

Results: Using WCR adult feeding assays, we identified Sec23 as a highly lethal RNAi target.