Iron in the night sky RSS

04 May 2011

Odin measurements show meteor remnants

Measurements with the Optical Spectrograph and Infrared Imager System (OSIRIS) on-board the Swedish Odin spacecraft has shown what are probably remnants from meteors burning up in the upper atmosphere. The Earth’s night airglow is produced in this region, a faint light generated by chemical reactions, studied already in 1869 by A. J. Ångström.

Since iron is abundant in meteorites it was expected that light emitted from iron oxide (FeO) would be found in the Earth’s night airglow. But so far only spectral signatures from atomic and molecular oxygen, hydroxyl radicals, sodium and nitrogen dioxide could be identified.

With these known sources removed from OSIRIS data coming from 75 to105 kmaltitude a broad orange emission band about 600 nm remains. Comparisons to published iron oxide laboratory spectra give excellent agreement. The iron oxide can be excited through interactions of iron with ozone.

For details see the article published in 2010 by Evans, W. F. J., R. L. Gattinger, T. G. Slanger, D. V. Saran, D. A. Degenstein, and E. J. Llewellyn in Geophysical Research Letters 37, page L22105

Iron oxide was already detected in 2000  in meteor’s persistent remnants as published by P. Jenniskens and co-workers

A nice time time-lapse video of the 2009 Leonid meteor shower showing this type of persistent smog

For more information

contact Urban Frisk, SSC, tel +46 8 627 62 71


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