Editor's Summary
19 January 2006
Gathering comet dust
Earth is continually bombarded by interplanetary dust particles up to a millimetre in diameter, released from asteroids and comets by collision or fragmentation. The fact that the particles are rich in helium-3 means that they can be identified in the geological record. New measurements of 3He in seafloor sediments, together with numerical modelling, point to a single Solar System event as virtually the only source of interplanetary dust accreting to the Earth for a period of 1.5 million years in the late Miocene. The event was probably the destruction by collision of a 150-km-diameter asteroid some 8 million years ago, the same collision that produced the Veritas family of asteroids. Intriguingly, the climax of this bout of dust accretion coincides with modest cooling during the Miocene, although a causal link between the two phenomena remains a matter for speculation.
Letter: A late Miocene dust shower from the break-up of an asteroid in the main belt
Kenneth A. Farley, David Vokrouhlický, William F. Bottke & David Nesvorný
doi:10.1038/nature04391
First paragraph | Full Text | PDF (192K) | Supplementary information
