Washington, April 3 ANI | 7 months ago

Researchers have revealed that the centimeter-sized fragments and smaller particles that make up the regolith - the layer of loose, unconsolidated rock and dust - of small asteroids is formed by temperature cycling that breaks down rock in a process called thermal fatigue.


Previous studies suggested that the regolith of asteroids one kilometer wide and smaller was made from material falling to the surface after impacts and from boulders that were pulverized by micrometeoroid impacts.

Recent laboratory experiments and impact modeling conducted by a team of researchers from Observatoire de la Cote d'Azur, Hopkins Extreme Materials Institute at Johns Hopkins University, Institut Superieur de l'Aeronautique et de l'Espace and Southwest Research Institute (SwRI) have shown that the debris from large impacts reaches escape velocities and breaks free from the gravitational pull of these asteroids, indicating this mechanism is not the dominant process for regolith creation.

The team's research showed that thermal fragmentation, which is induced by mechanical stresses caused by temperature variations of the rapidly spinning asteroid's short night and day, is the process primarily responsible for breaking up rocks larger than a few centimeters on asteroids.
Model extrapolation of these experiments also showed that thermal fragmentation caused rocks to break down an order of magnitude faster than from micrometeoroid impacts, particularly at distances of 1 astronomical unit (about 93 million miles) with the speed of breakdown slowing at distances further from the Sun.

The paper has been published in Nature Advance Online Publication.

(Posted on 03-04-2014)

Share This Page:


Post your comments


Information on States of India:

Andaman Nicobar | Andhra Pradesh | Arunachal Pradesh | Assam | Bihar | Chandigarh | Chhattisgarh | Dadar Nagar Haveli | Daman Diu | Delhi | Goa | Gujarat | Haryana | Himachal Pradesh | Jammu Kashmir | Jharkhand | Karnataka | Kerala | Lakshadweep | Madhya Pradesh | Maharashtra | Manipur | Meghalaya | Mizoram | Nagaland | Orissa | Pondicherry | Punjab | Rajasthan | Sikkim | Tamil Nadu | Tripura | Uttar Pradesh | Uttaranchal | West Bengal

INDIA REGIONAL MAPS:

Andhra Pradesh Travel Map | Bihar Travel Map | Goa Travel Map | Gujarat Travel Map | Haryana Travel Map | Himachal Pradesh Map | Karnataka Travel Map | Kerala Travel Map | Maharashtra Travel Map | Punjab Travel Map | Rajasthan Travel Map | Sikkim Travel Map | Tamil Nadu Travel Map | Uttar Pradesh Travel Map | West Bengal Travel Map |

KERALA TRAVEL MAPS:

Alappuzha | Ernakulam | Idukki | Kannur | Kasaragod | Kollam | Kottayam | Kozhikode | Malappuram | Palakkad | Pathanamthitta | Thiruvananthapuram | Thrissur | Wayanad |

TRAVEL MAPS OF INDIA:

Airports of India | Districts of India | India Pilgrim Centers | Tourism Map of India | National Highways in India | India Railway Routes |

INDIA CITY MAPS:

Ahmadabad | Bangalore | Chennai | Coimbatore | Delhi | Hyderabad/Secunderabad | Kochi | Kolkata | Mumbai | Pondicherry | Pune | Surat |