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A Quarter Century of Wind Spacecraft Discoveries

Verscharen, Daniel; Hurley, Kevin; Wicks, Robert T. +11 more

The Wind spacecraft, launched on November 1, 1994, is a critical element in NASA's Heliophysics System Observatory (HSO) - a fleet of spacecraft created to understand the dynamics of the Sun-Earth system. The combination of its longevity (>25 years in service), its diverse complement of instrumentation, and high resolution and accurate measurem…

Impacts of Ionospheric Ions on Magnetic Reconnection and Earth's Magnetosphere Dynamics

Lavraud, B.; André, M.; Kistler, L. M. +13 more

Ionospheric ions (mainly H⁺, He⁺, and O⁺) escape from the ionosphere and populate the Earth's magnetosphere. Their thermal energies are usually low when they first escape the ionosphere, typically a few electron volt to tens of electron volt, but they are energized in their journey through the magnetosphere. The io…

Polar Vortices in Planetary Atmospheres

Teanby, Nicholas A.; Mitchell, Dann M.; Seviour, William J. M. +4 more

Among the great diversity of atmospheric circulation patterns observed throughout the solar system, polar vortices stand out as a nearly ubiquitous planetary-scale phenomenon. In recent years, there have been significant advances in the observation of planetary polar vortices, culminating in the fascinating discovery of Jupiter's polar vortex clus…

Are Slope Streaks Indicative of Global-Scale Aqueous Processes on Contemporary Mars?

Zorzano, María-Paz; Bhardwaj, Anshuman; Sam, Lydia +1 more

Slope streaks are prevalent and intriguing dark albedo surface features on contemporary Mars. Slope streaks are readily observed in the equatorial and subequatorial dusty regolith regions with low thermal inertia. They gradually fade over decadal timescales. The proposed mechanisms for their formation vary widely based on several physicochemical a…

Current Systems in the Earth's Magnetosphere

Dubyagin, S.; Liemohn, M. W.; Ganushkina, N. Yu.

Dusty Plasma Effects in Comets: Expectations for Rosetta

Mendis, D. A.; Horányi, M.

Despite their small masses, comets have played an extraordinary role in enhancing our understanding of cosmic physics. It was the calculation of comet Halley's orbit and the successful prediction of its return in 1758 that firmly established the correctness of Newton's law of universal gravitation. It was the morphology of the dusty tails of comet…

The Martian Atmospheric Boundary Layer

Spiga, A.; Vázquez, L.; Määttänen, A. +10 more

The planetary boundary layer (PBL) represents the part of the atmosphere that is strongly influenced by the presence of the underlying surface and mediates the key interactions between the atmosphere and the surface. On Mars, this represents the lowest 10 km of the atmosphere during the daytime. This portion of the atmosphere is extremely importan…

Mars ionosphere: A review of experimental results and modeling studies

Kallio, E.; Haider, S. A.; Mahajan, K. K.

In this paper we review results from atmospheric and ionospheric experiments on the early planetary missions like the Mariners, Mars, and Viking 1 and 2 Orbiters/Landers. We then discuss the new results obtained from the two latest missions, namely, the Mars Global Surveyor (MGS) and Mars Express (MEX). The MGS had three ionospheric and atmospheri…

Solar Influences on Climate

Beer, J.; Lockwood, M.; Gray, L. J. +12 more

Understanding the influence of solar variability on the Earth's climate requires knowledge of solar variability, solar-terrestrial interactions, and the mechanisms determining the response of the Earth's climate system. We provide a summary of our current understanding in each of these three areas. Observations and mechanisms for the Sun's variabi…

How unprecedented a solar minimum?

Luhmann, J. G.; Russell, C. T.; Jian, L. K.

The end of the current solar minimum is at least 2 years late, and indicators of solar and geomagnetic activity are approaching or are at their historical lows. We examine current indicators to determine how unprecedented this solar cycle might be, comment on possible earlier analogs to the current situation, and discuss attempts to predict future…