Results 21 to 30 of about 2,988 (164)

Seasonal and Local Time Variation in the Observed Peak of the Meteor Altitude Distributions by Meteor Radars

Journal of Geophysical Research: Atmospheres, Volume 129, Issue 21, 16 November 2024.
Abstract Meteoroids of sub‐milligram sizes burn up high in the Earth's atmosphere and cause streaks of plasma trails detectable by meteor radars. The altitude at which these trails, or meteors, form depends on a number of factors including atmospheric density and the astronomical source populations from which these meteoroids originate.
E. C. M. Dawkins, D. Janches, G. Stober, J. D. Carrillo‐Sánchez, R. S. Lieberman, C. Jacobi, T. Moffat‐Griffin, N. J. Mitchell, N. Cobbett, P. P. Batista, V. F. Andrioli, R. A. Buriti, D. J. Murphy, J. Kero, N. Gulbrandsen, M. Tsutsumi, A. Kozlovsky, M. Lester, J.‐H. Kim, C. Lee, A. Liu, B. Fuller, D. O’Connor, S. E. Palo, M. J. Taylor, J. Marino, N. Rainville   +26 more
wiley   +1 more source

Waves and Instabilities in Saturn's Magnetosheath: 2. Dispersion Relation Analysis

Journal of Geophysical Research: Space Physics, Volume 129, Issue 10, October 2024.
Abstract The WHAMP (Rönnmark, 1982, https://inis.iaea.org/search/search.aspx?orig_q=RN:14744092) and LEOPARD (Astfalk & Jenko, 2017, https://doi.org/10.1002/2016ja023522) dispersion relation solvers were used to evaluate the growth rate and scale size for mirror mode (MM) and ion cyclotron (IC) instabilities under plasma conditions resembling Saturn's ...
I. Cheng, N. Achilleos, X. Blanco‐Cano, C. Bertucci, P. Guio   +4 more
wiley   +1 more source

Atmospheric collection of extraterrestrial dust at the Earth's surface in the mid‐Pacific

Meteoritics &Planetary Science, Volume 59, Issue 10, Page 2789-2817, October 2024.
Abstract The Kwajalein micrometeorite collection utilized high volume air samplers fitted with polycarbonate membrane filters to capture particles directly from the atmosphere at the Earth's surface. This initial study focused on identifying cosmic spherule‐like particles, conservatively categorizing them into four groups based on bulk compositional ...
Penelope J. Wozniakiewicz, Luke S. Alesbrook, John P. Bradley, Hope A. Ishii, Mark C. Price, Michael. E. Zolensky, Donald E. Brownlee, Matthias van Ginneken, Matthew J. Genge   +8 more
wiley   +1 more source

Explaining the Evolution of Ion Velocity Distributions at a Low Activity Comet

Journal of Geophysical Research: Space Physics, Volume 129, Issue 9, September 2024.
Abstract At a low activity comet the plasma is distributed in an asymmetric way. The hybrid simulation code Amitis is used to look at the spatial evolution of ion velocity distribution functions (VDFs), from the upstream solar wind (SW) to within the comet magnetosphere where the SW is heavily mass‐loaded by the cometary plasma.
A. Moeslinger, H. Gunell, H. Nilsson, S. Fatemi, G. Stenberg Wieser   +4 more
wiley   +1 more source

Not So Fast: A New Catalog of Meteor Persistent Trains

Journal of Geophysical Research: Space Physics, Volume 129, Issue 7, July 2024.
Abstract This paper presents the results of a nearly 2‐year long campaign to detect and analyze meteor persistent trains (PTs)—self‐emitting phenomena which can linger up to an hour after their parent meteor. The modern understanding of PTs has been primarily developed from the Leonid storms at the turn of the century; our goal was to assess the ...
L. E. Cordonnier, K. S. Obenberger, J. M. Holmes, G. B. Taylor, D. Vida   +4 more
wiley   +1 more source

Commonsense morality and contact with value

Philosophy and Phenomenological Research, Volume 109, Issue 1, Page 410-430, July 2024.
Abstract There seem to be many kinds of moral duties. We should keep our promises; we should pay our debts of gratitude; we should compensate those we've wronged; we should avoid doing or intending harm; we should help those in need. These constitute, some worry, an unconnected heap of duties: the realm of commonsense morality is a disorganized mess ...
Adam Lovett, Stefan Riedener
wiley   +1 more source

Pioneer Venus Orbiter Observations of Solar Wind Driven Magnetosonic Waves Interacting With the Dayside Venusian Ionosphere

Geophysical Research Letters, Volume 51, Issue 12, 28 June 2024.
Abstract We use in situ plasma observations made by the Pioneer Venus Orbiter spacecraft to show for the first time that magnetosonic waves can couple the solar wind to the upper ionosphere and deposit energy there. The waves are generated upstream of Venus, are advected into the shock and propagate across the draped magnetic field, through the ...
C. M. Fowler, S. Ledvina, C. C. Chaston, M. Persson, R. Ramstad, J. Luhmann   +5 more
wiley   +1 more source

Comet Halley returns: A teachers' guide 1985-1986 [PDF]

This booklet has been put together as an aid for teachers in elementary and secondary schools. It is divided into two distinct parts. The first part is a brief tutorial which introduces some of the most important concepts about comets, including their ...
Bondurant, R. L., Chapman, R. D.
core   +1 more source

Comet Halley’s outburst [PDF]

Monthly Notices of the Royal Astronomical Society, 1991
It is suggested that the outburst suffered by Comet Halley (1986 III) in early 1991 February, was caused by the ejection from the nucleus of 1.4 × 10 13 g of dust, this being about 0.02 per cent of the cometary mass. The energy required was in the range 2 × 10 19 to 2 × 10 23 erg.
openaire   +1 more source

Designing dual-plate meteoroid shields: A new analysis [PDF]

Physics governing ultrahigh velocity impacts onto dual-plate meteor armor is discussed. Meteoroid shield design methodologies are considered: failure mechanisms, qualitative features of effective meteoroid shield designs, evaluating/processing meteoroid ...
Bamford, R., Chen, R., Swift, H. F.
core   +1 more source