Explosions of small Spacewatch objects in the Earth's atmosphere
Article Abstract:
The probability and estimated velocity of collisions between the Earth and Spacewatch objects measuring 50 m with kinetic energy lower than 10 megatonnes were measured using Opik's equation. The Opik equation accounts for the Earth's orbital eccentricity but do not apply for other earth-crossing objects whose inclinations are too low. Results indicate that asteroids or comets with energy levels less than 2 megatonnes do not pose any hazards to the earth, except for rare iron objects. The study concludes that the high level of earth-crossing objects observed by Spacewatch do not represent potential terrestrial hazards.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1993
User Contributions:
Comment about this article or add new information about this topic:
Life beyond Mars
Article Abstract:
Reports and results from astronomical studies support the premise that extraterrestrial life in Mars or beyond is possible. The reports on life possibility on Mars fail to show substantial evidence and depend on speculation. The studies conducted at Capri regarding the formation of extraterrestrial organics and the Drake equation on star formation and the evolution of life support speculations on extraterrestrial life.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1996
User Contributions:
Comment about this article or add new information about this topic:
Energy for microbial life on Europe: A radiation-driven ecosystem on Jupiter's moon is not beyond the bounds of possibility
Article Abstract:
It is shown that disequilibrium chemistry in the ocean's ice cover, fuelled by changed particles accelerated in Jupiter's magnetosphere, could produce sufficient organic and oxidant molecules to fuel a substantial European biosphere. A particular radiation-drive ecosystem is plausible, based on current knowledge of Europa.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2000
User Contributions:
Comment about this article or add new information about this topic:
- Abstracts: Experience-dependent representation of visual categories in parietal cortex. An awakening
- Abstracts: Morphogenesis of shapes and surface patterns in mesoporous silica. Lamellar aluminophosphates with surface patterns that mimic diatom and radiolarian microskeletons
- Abstracts: Energy implications of future stabilization of atmospheric CO2 content. Deriving global climate sensitivity from palaeoclimate reconstructions
- Abstracts: Effects of human disturbance on success of artificial duck nests. Effects of backpack and implanted radiotransmitters on captive blue-winged teal
- Abstracts: Wintering waterbird use of two aquatic plant habitats in a southern reservoir. Frequency of nest box maintenance: effects on wood duck nesting in South Carolina