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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS1977

Microstructure of a magnetotail fireball

We use high time resolution data from the magnetometer, LEPEDEA and plasma wave analyzer on IMP-7 to examine the microstructure of a long-duration magnetotail fireball event observed during an extended quiet period on November 9, 1972. We demonstrate that the magnetic field is turbulent with fluctuation time scales down to several seconds. These findings suggest that the magnetic merging process may be a highly turbulent one, possibly associated with a form of the tearing mode instability.

Coroniti, F. V.↗
NASA NTRS1978

Prairie Network fireballs. I - General information and orbits

Methods for obtaining and processing photographs of bright meteors in the United States in the period from 1963 to 1975 are briefly described. Orbital elements and other characteristics are given for 334 bright persistent and long Prairie Network fireballs. The accuracy of the data presented is evaluated.

Mccrosky, R. E.↗
NASA NTRS1981

A fireball in Jupiter's atmosphere

One fireball was photographed during two encounters with Jupiter. Its total luminosity was 120,000 0 mag s (at standard range 100 km). If the luminous efficiency proposed by Cook et al. (1981) for slip flow of a meteoroid in its own vapors is employed, an estimated mass of 11 kg is obtained. A rough absolute magnitude is -12.5. If it is noted that the search was conducted for a total of 223 s during two exposures, a number density near Jupiter of 10 to the -28th/cu cm is estimated for masses of meteoroids of 3 kg and greater. This value is about a factor of six smaller than a rough upper limit reached from an extrapolation from terrestrial observations of meteors and comets.

Cook, A. F.↗
NASA NTRS1992

Relativistic fireballs - Energy conversion and time-scales

The expansion energy of a relativistic fireball can be reconverted into radiation when it interacts with an external medium. For expansion with Lorentz factors greater than or approximately equal to 1000 into a typical galactic environment, the corresponding time-scale in the frame of the observer is of the order of seconds. This mechanism would operate in any cosmological scenario of gamma-ray bursts involving initial energies of order a percent of a stellar rest mass, and implies photon energies and time-scales compatible with those observed in gamma-ray bursts.

Rees, M. J.↗
NASA NTRS2011

The NASA Fireball Network All-Sky Cameras

The construction of small, inexpensive all-sky cameras designed specifically for the NASA Fireball Network is described. The use of off-the-shelf electronics, optics, and plumbing materials results in a robust and easy to duplicate design. Engineering challenges such as weather-proofing and thermal control and their mitigation are described. Field-of-view and gain adjustments to assure uniformity across the network will also be detailed.

Suggs, Rob M.↗
NASA NTRS1997

Temperature, Size and Energy of the Shoemaker-Levy 9 G-Impact Fireball

The fortunate position of the Galileo spacecraft provided us with a unique opportunity to directly observe the Shoemaker-Levy 9 impacts as they occurred on the far side of Jupiter, and we present observations of the G fireball obtained by the Near Infrared Mapping Spectrometer (NIMS).

Comets↗
NASA NTRSDate not supplied

Seven Years of Bright Meteor Data from the NASA All Sky Fireball Network

The NASA All Sky Fireball Network is a network consisting of 18 all-sky meteor cameras across the continental US. We present a data release of 33,660 bright meteors collected between 2013 and 2019. The released data consists of trajectory, orbit, radiant, shower association, and brightness. We discuss the camera hardware and software used to make the observations, the characteristics of the data, and known error sources. The camera hardware consists of Watec 902H2 Ultimate CCD cameras with a fish-eye lens giving an all-sky field of view. The data is complete until an absolute meteor magnitude of approximately -4, but meteors down to a magnitude of -1 are routinely observed. The cameras are spread across the continental United States in five subnetworks, with each network consisting of two to five cameras. The cameras report to a central server where the data is processed each morning. The network is modeled after the University of Western Ontario’s Southern Ontario Meteor Network. The cameras are running All-sky and Guided Real-time Detection (ASGARD) meteor detection software and analysis pipeline.

Aaron Kingery↗
NASA NTRS1975

Mass of the grazing fireball of August 1972

It is noted that the mass of the August 1972 meteoroid has been estimated to be of the order of one billion grams, based on the magnitude of its near-IR and visible radiation. In the present letter, published velocities and altitudes are analyzed from the viewpoint of momentum considerations. It is shown that the meteoroid mass was about 1000 times smaller than that deduced from the luminosity data.

Caulk, H. M.↗