The Production of Terrestrial Meteorites – Moon Accretion and Lithopanspermia
Martin Beech,
Mark Comte,
Ian Coulson
Issue:
Volume 7, Issue 1, March 2019
Pages:
1-9
Received:
9 May 2019
Accepted:
12 June 2019
Published:
1 July 2019
Abstract: The conditions under which terrestrial, impact-derived ejecta can be launched into cis-lunar space is studied. A numerical code is developed in order to follow the ablation and deceleration conditions of material ejected from the Earth’s surface and outwards through the atmosphere. The deceleration filtering-effect imposed by Earth’s atmosphere results in multi-meter-sized, 5 to 20 meters across, fragments escaping into cis-lunar space being favored. Smaller fragments tend to be more rapidly decelerated than larger ones and are re-accreted by the Earth. The conditions under which Earth-ejected material might impact upon the Moon is additionally considered. It is found that for encounter speeds smaller than some 7 km/s, terrestrial meteorites might be expected to survive upon impact (that is they will not undergo shock melting) when encountering the Moon’s regolith. It is argued that terrestrial meteorites may well survive, with identifiable features (fusion crust and mineralogy), for long periods of time within the lunar regolith (a result recently vindicated through the discovery of terrestrial material – launched during the late heavy bombardment – contained within a lunar impact breccia #14321, collected during the Apollo 14 Moon landing mission). Further to this, the important role that terrestrial meteorites must have played in transporting microbial life to other potentially habitable locations within the solar system is discussed.
Abstract: The conditions under which terrestrial, impact-derived ejecta can be launched into cis-lunar space is studied. A numerical code is developed in order to follow the ablation and deceleration conditions of material ejected from the Earth’s surface and outwards through the atmosphere. The deceleration filtering-effect imposed by Earth’s atmosphere res...
Show More
Coronal Mass Ejections, Solar Cycles and Magnetic Poles Reversal
Issue:
Volume 7, Issue 1, March 2019
Pages:
10-17
Received:
19 June 2019
Accepted:
12 July 2019
Published:
26 July 2019
Abstract: The magnitude of the measured geomagnetic index increases when the Coronal Mass Ejections occur on the Sun's surface. The abrupt increase in the geomagnetic index has seriously impacted the accuracy in the forecast of the activity of the next solar cycle. A method is proposed to filter the effect from the Coronal Mass Ejections. The correlation between the geomagnetic index and the activity of the subsequent solar cycle is found to have drastically improved with the proposed scheme. A strong correlation between the maximum amplitude RN of a solar cycle N and its pre-cycle coronal mass ejections adjusted monthly geomagnetic activity index has been qualitatively determined, as illustrated by an impressive correlation coefficient of 0.91+0.09-0.12, with its statistical significance estimated at 4.3 σ. The corrected data have significantly improved the correlation between the observed variables from their original un-corrected case of 0.63 ± 0.23. Our result indicates that the upcoming solar cycle, estimated at R25 = 147 ± 30, would be stronger than the current waning solar cycle 24. In a related calculation, the magnetic poles reversals occurring in the solar cycles 21 and 22 are reproduced numerically from Maxwell's electromagnetic equations.
Abstract: The magnitude of the measured geomagnetic index increases when the Coronal Mass Ejections occur on the Sun's surface. The abrupt increase in the geomagnetic index has seriously impacted the accuracy in the forecast of the activity of the next solar cycle. A method is proposed to filter the effect from the Coronal Mass Ejections. The correlation bet...
Show More
