Possible origin of Theia, the Moon-forming impactor with Earth
- Autor(en)
- Rudolf Dvorak, Birgit Loibnegger, Thomas Maindl
- Abstrakt
Background: The problem of the formation of the Moon is still not explained satisfactorily. While it is a generally accepted scenario that the last giant impact on Earth between some 50 to 100 million years after the starting of the formation of the terrestrial planets formed our natural satellite, there are still many open questions like the isotopic composition, which is identical for these two bodies. In our investigation, we will not deal with these problems of chemical composition but rather undertake a purely dynamical study to find out the probability of a Mars-sized body (Theia) to collide with the Earth after the formation of the Earth-like planets. Materials and Methods: We assume an additional massive body between Venus and Earth, respectively Earth and Mars, which formed there at the same time as the other terrestrial planets. We have undertaken massive n-body integrations of such a planetary system with four inner planets (we excluded Mercury but assumed one additional body as mentioned before) and the gas giants Jupiter and Saturn. For the present positions of the planets, we have undertaken the integrations for 100 Myrs to be able to check for stable orbits of Theia for or up to tens of millions of years. Results: We find a probable origin of the Earth impactor at a semi-major axis of 1:16 AU < aTheia < 1:195 AU; a Theia inside the orbit of Earth suffers from collisions on much shorter time scales. Conclusion: We can provide a statistical estimation of the collision velocities as well as the collision angles, which will then serve as the basis for further investigation with detailed smooth(ed) particle hydrodynamics computations.
- Organisation(en)
- Institut für Astrophysik
- Journal
- Astronomische Nachrichten
- Band
- 338
- Seiten
- 366 - 374
- Anzahl der Seiten
- 9
- ISSN
- 0004-6337
- DOI
- https://doi.org/10.1002/asna.201613209
- Publikationsdatum
- 05-2017
- Peer-reviewed
- Ja
- ÖFOS 2012
- 103003 Astronomie, 103004 Astrophysik
- Schlagwörter
- ASJC Scopus Sachgebiete
- Astronomy and Astrophysics, Space and Planetary Science
- Link zum Portal
- https://ucrisportal.univie.ac.at/de/publications/628d5cc4-e17a-408b-a92c-cd7d582e3335