The study of multiscale pickup ion phase-mixing in the lunar plasma wake with a hybrid model is the main subject of our investigation in this paper. Photoionization and charge exchange of protons with the lunar exosphere are the ionization processes included in our model. The computational model includes the self-consistent dynamics of the light (H+ or H-2(+) and He+), and heavy (Na+) pickup ions. The electrons are considered as a fluid. The lunar interior is considered as a weakly conducting body. In this paper we considered for the first time the cumulative effect of heavy neutrals in the lunar exosphere (e.g., Al, Ar), an effect which was simulated with one species of Na+ but with a tenfold increase in total production rates. We find that various species produce various types of plasma tail in the lunar plasma wake. Specifically, Na+ and He pickup ions form a cycloid-like tail, whereas the H+ or H-2(+) pickup ions form a tail with a high density core and saw-like periodic structures in the flank region. The length of these structures varies from 1.5 R-M to 3.3 R-M depending on the value of gyroradius for H+ or H-2(+) pickup ions. The light pickup ions produce more symmetrical jump in the density and magnetic field at the Mach cone which is mainly controlled by the conductivity of the interior, an effect previously unappreciated. Although other pickup ion species had little effect on the nature of the interaction of the Moon with the solar wind, the global structure of the lunar tail in these simulations appeared quite different when the H-2(+) production rate was high.

Measurements of gaseous (NO, NOy, SO2, HONO) and ice particle concentrations in young contrails in primary and secondary wakes of aircraft of different sizes (B737, A319, A340, A380) are used to investigate ice particle formation behind aircraft. The gas concentrations are largest in the primary wake and decrease with increasing altitude in the secondary wake, as expected for passive trace gases and aircraft-dependent dilution. In contrast, the measured ice particle concentrations were found larger in the secondary wake than in the primary wake. The contrails contain more ice particles than expected for previous black carbon (soot) estimates. The ice concentrations may result from soot-induced ice nucleation for a soot number emission index of 10(15) kg(-1). For a doubled ice particle concentration in young contrails, a contrail cirrus model computes about 60% increases of global radiative forcing by contrail cirrus because of simultaneous increases in optical depth, age, and cover.

NASA's two spacecraft ARTEMIS mission will address both heliospheric and planetary research questions, first while in orbit about the Earth with the Moon and subsequently while in orbit about the Moon. Heliospheric topics include the structure of the Earth's magnetotail; reconnection, particle acceleration, and turbulence in the Earth's magnetosphere, at the bow shock, and in the solar wind; and the formation and structure of the lunar wake. Planetary topics include the lunar exosphere and its relationship to the composition of the lunar surface, the effects of electric fields on dust in the exosphere, internal structure of the Moon, and the lunar crustal magnetic field. This paper describes the expected contributions of ARTEMIS to these baseline scientific objectives.