4 research outputs found
NASA's Meteoroid Environments Office's Response to Three Significant Bolide Events Over North America
Being the only U.S. Government entity charged with monitoring the meteor environment, the Meteoroid Environment Office has deployed a network of all sky and wide field meteor cameras, along with the appropriate software tools to quickly analyze data from these systems. However, the coverage of this network is still quite limited, forcing the incorporation of data from other cameras posted to the internet in analyzing many of the fireballs reported by the public and media. A procedure has been developed that determines the analysis process for a given fireball event based on the types and amount of data available. The differences between these analysis process will be explained and outlined by looking at three bolide events, all of which were large enough to produce meteorites. The first example is an ideal event - a bright meteor that occurred over NASA's All Sky Camera Network on August 2, 2014. With clear video of the event from various angles, a high-accuracy trajectory, beginning and end heights, orbit and approximate brightness/size of the event are able to be found very quickly using custom software. The bolide had the potential to have dropped meteorites, so dark flight analysis and modeling was performed, allowing potential fall locations to be mapped as a function of meteorite mass. The second case study was a bright bolide that occurred November 3, 2014 over West Virginia. This was just north of the NASA southeastern all-sky network, and just south of the Ohio-Pennsylvania network. This case study showcases the MEO's ability to use social media and various internet sources to locate videos of the event from obscure sources (including the Washington Monument) for anything that will permit a determination of a basic trajectory and fireball light curve The third case study will highlight the ability to use doppler weather radar in helping locate meteorites, which enable a definitive classification of the impactor. The input data and analysis steps differ for each case study, but the goals remain the same - a trajectory, orbit, and mass estimate for the bolide within hours of the event, and, for events with a high probability of producing meteorites, a location of the strewn field within a day
The 2012 Lyrids from Non-traditional Observing Platforms
The NASA Meteoroid Environment Office (MEO) observed meteors during the Lyrid meteor shower peak on 22 April 2012 from three different observing platforms: the ground, a helium-filled balloon, and from the International Space Station (ISS). Even though the Lyrids are not noted for spectacular rates, the combination of New Moon and a favorable viewing geometry from ISS presented a unique opportunity to simultaneously image shower meteors from above the atmosphere and below it. In the end, however, no meteors were observed simultaneously, and it was impossible to identify Lyrids with 100% confidence among the 155 meteors observed from ISS and the 31 observed from the balloon. Still, this exercise proved successful in that meteors could be observed from a simple and inexpensive balloon-based payload and from less-than-optimal cameras on ISS
Computing optical meteor flux using Global Meteor Network data
Meteor showers and their outbursts are the dominant source of meteoroid
impact risk to spacecraft on short time scales. Meteor shower prediction models
depend on historical observations to produce accurate forecasts. However, the
current lack of quality and persistent world-wide monitoring at optical
meteoroid sizes has left some recent major outbursts poorly observed. A novel
method of computing meteor shower flux is developed and applied to Global
Meteor Network data. The method is verified against previously published
observations of the Perseids and the Geminids. The complete mathematical and
algorithmic details of computing meteor shower fluxes from video observations
are described. As an example application of our approach, the flux measurements
of the 2021 Perseid outburst, the 2020-2022 Quadrantids, and 2020-2021 Geminids
are presented. The flux of the 2021 Perseids reached similar levels to the
1991-1994 and 2016 outbursts (ZHR 280). The flux of the Quadrantids
shows high year-to-year variability in the core of the stream while the longer
lasting background activity is less variable, consistent with an age difference
between the two components. The Geminids show a double peak in flux near the
time of peak.Comment: Accepted for publication in MNRAS, 18 pages, 15 figure