Meteor Showers as Indicators of Cometary Nature of Near Earth Asteroids (NEAs) and Physical Properties of Meteoroids
Tech Area / Field
- SAT-AST/Astronomy/Space, Aircraft and Surface Transportation
- SAT-SAF/Space Safety/Space, Aircraft and Surface Transportation
8 Project completed
Senior Project Manager
Ryzhova T B
Institute of Astrophysics, Tajikistan, Dushanbe
- Astronomical Institute, Czechia, Ondrejov\nQueen Mary, University of London, UK, London
Project summaryMeteoroid streams, producing meteor showers when to be intersected by the Earth, are formed as a result of the disintegration of cometary nuclei. The existence of observed meteor showers associated with some of Near- Earth Asteroids (NEAs) is one of the few criterion that such asteroids have a cometary origin, i.e. they are extinct cometary nuclei. The existence of asteroids identifiable with extinct or dormant comets (2060 Chiron, 4015 Willson-Harrington, 1986 TF Parker-Hartley) confirm the cometary origin for some NEAs.
Investigation of NEA-meteor showers association is important not only for confirmation or denial of NEA cometary origins, but also for the receipt of important information about NEA sources – comets from outer regions of the Solar system and real asteroids from the main belt.
The scientific goals of the proposed project are:
- Identify Near-Earth Asteroids that may be of cometary origin;
- Find new meteor showers and meteoroid streams genetically related with NEAs;
- Identifying new interrelation between the small bodies of the Solar system;
- Determine the physical properties of meteoroids on the base of photographic observations of meteors.
These goals may be attained by the project participants through the investigation of the NEAs orbital evolution using the methods of celestial mechanics and the determination the NEAs' theoretical radiants, i.e. conditions for the possible collision of the bodies or their fragments with the Earth. Moreover, it is necessary to use all available observational data on meteor showers and inpidual meteors, which have to be compiled as a database for computer reduction. The completion of the project will allow identifications of extinct cometary nuclei among Near-Earth Asteroids and find new meteor showers and new interrelations between minor bodies of the Solar system. It will also illustrate the types of orbital evolution that NEAs can follow, the Earth-crossing class of NEAs and conditions for the possible encounter of NEAs’ fragments with the Earth.
The investigation of meteoroids’ physical parameters is of great interest for understanding of the physical features of meteoroids’ parent bodies (i.e. Near-Earth Objects), that is important both scientifically and because asteroids and comets represent a long-term danger for the biosphere and the human species since they can cross the Earth’s orbit. The density relates to important physical characteristics of meteoroids. Using physical theory of meteors, which takes into account the fragmentation of meteoroids in the atmosphere, on the basis of the results of double-station photographic observations of meteors, the densities and, possibly, porosity of meteoroids belonging to different streams and sporadic background will be determined.
The accomplishment of project tasks will:
a) Reveal the NEAs, which are the parent bodies of meteoroid streams and so of meteor showers. In other words to identify whether the asteroid is of cometary origin or is an extinct cometary nucleus;
b) Show new interrelations between asteroids, comets, meteoroid streams and meteor showers;
c) Identify previously unknown meteor showers from the data bases of inpidual meteors observed by different methods;
d) Demonstrate different types of orbital evolution of asteroids and the multiplicity of intersections of their orbits with the Earth’s orbit;
e) Determine the densities of meteoroids on the basis of photographic observations of meteors and of modern physical theory of meteors;
f) Carry out one-and-a-half-year double-station photographic observations of fireballs during the periods of activity of the main meteor showers;
g) Formulate recommendations for future investigation of NEAs and meteor matter.
Results of the planned investigation are important for taking into account the asteroidal – meteoroidal danger for space apparatus (vehicles). Competence of project team in the specified area is high. Developed methods and some preliminary results of investigation on the subject of proposed project are published in the leading international scientific journals (see, e.g. Babadzhanov P.B.1998, Celest. Mechanics & Dynam. Astron. 69, 221-234; A&A 2001, 373, 329-335; A&A 2002, 384, 317-321; and A&A 2003, 397, 319-323) and are well recognized.
Proposed project considerably supports the basic researches in Tajikistan, directed to the study of meteoroidal conditions in the near-Earth space, and promotes still more integration of scientist of Tajikistan into the international scientific community.
Consistent with the scope of activities of the project proposal, role of foreign collaborators consists in the following: a) information exchange in the course of project implementation; b) provide comments to the technical reports (semi-annual, annual, final), submitted by the project participants to the ISTC; c) meetings at conferences and direct visits; and d) possible joint papers for publication in scientific journals.