Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 0273-1177
    Keywords: Gamma ray bursts ; archival searches ; optical transients ; plate collections ; plate photometry
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Earth, moon and planets 68 (1995), S. 107-126 
    ISSN: 1573-0794
    Keywords: interplanetary bodies ; large meteoroids ; fireballs ; atmospheric flight: models ; observations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Problems of hypervelocity interaction of large bodies with the Earth's atmosphere has attracted more attention during last few years. Several new concepts of dynamical explosive fragmentation of strong interplanetary bodies at extremely low heights under dynamic pressures of hundreds of Mdyn/cm2 were published. Comparison of these theoretical models with precise observations has not yet been done, because data on atmospheric penetration of large bodies are not available. Single body theory with sudden gross-fragmentation was successfully applied to photographic observations of fireballs. The largest bodies observed have sizes up to several meters. The highest dynamic pressure acting on these observed bodies reached slightly over 100 Mdyn/cm2. All these photographed fireballs follow theoretical concepts of motion of either the single-body or the single-body with gross-fragmentation under dynamic pressures in the range from 1 to 12 Mdyn/cm2. When this theory has been applied to photographic observations, typical standard deviation of the distance flown in the trajectory has been found in a range of 10 to 30 m for one observed distance corresponding also to the geometrical precision of the observations. This model can explain all good observations of atmospheric trajectories of meteoroids up to initial sizes of several meters with high precision. Also the three photographed and one videorecorded meteorite falls fit to this concept completely. The most important phenomenon of atmospheric motion of meteoroids up to several meters in size is the ablation with final stage of hot vapor from ablated material. Spectral records of meteoroids up to several meters in size, down to a height of 16 km and for various velocities show overwhelming radiation of rather low excited metalic atoms (several eV; temperatures 3000 to 5000 K) in the pass-band of visible light. Radiation from high excited atoms of either atmospheric or ablational origin forms only an insignificant part of visible radiation. Contrary to this regime, theories of very large bodies contain ablation mostly in the form of explosive fragmentation. Ablation at higher heights is negligible. This absence of “classical” ablation and fragmentation at low dynamic pressures for large bodies (contrary to observations of smaller bodies) brings the body to lower heights without too much change of size and makes thus the dynamic pressure much higher than in reality. In any case the change of body dynamics and radiation going from sizes of several meters (observed regime) to sizes of several tens of meters (hypothetical regime) may be crucial for our understanding of dynamics and radiation of large body penetration through the low atmosphere to the Earth's surface. Observations of atmospheric trajectory of these bodies with sufficiently high precision are extremely needed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 367 (1994), S. 624-626 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Objects responsible for bright fireballs occupy the low-mass (l-106kg) end of the asteroid size spectrum. Several recent studies2'3'4 have considered the fragmentation of large meteor-oids during atmospheric flight, but comparison of these models with observational data has not been possible. Up to ...
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1573-0794
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract A general overview of the events surrounding the fall of the Peekskill meteorite is presented.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Earth, moon and planets 68 (1995), S. 563-572 
    ISSN: 1573-0794
    Keywords: detonating bolide ; satellites: detection ; energy ; mass ; orbit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract On February 1, 1994, a large meteoroid impacted over the Pacific Ocean at 2.6° N, 164.1° E. The impact was observed by space based IR sensors operated by the US Department of Defense and by visible wavelength sensors operated by the US Department of Energy. During entry the object broke into several pieces, one of which detonated at 34 km and another at 21 km altitude. The entry velocity of the object is estimated to be 24–25 km/sec. Based on the visible wavelength data, the integrated intensity of the radiated energy of the fireball was approximately 1.3 × 1013 joules. Assuming a 6000 K black body and a 30% efficiency for the conversion of the kinetic energy of the body into visible light, we estimate the mass of the body to be between 1.6×105 kg and 4.4×106 kg, and to have a diameter of between 4.4 and 13.5 meters. The object entered at a 45° angle, traveling on a heading of approximately 300°, i.e. from the southeast to the northwest. Calculations using a gross-fragmentation model indicate that the body was most likely a stony object larger than 10 m with an Apollo orbit prior to impact.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1572-9672
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...