Infrared heating of Comet Halleys atmosphere

✍ Scribed by M. L. Marconi; D. A. Mendis

• Publisher: Springer Netherlands
• Year: 1986
• Tongue: English
• Weight: 456 KB
• Volume: 36
• Category: Article
• ISSN: 1573-0794
• DOI: 10.1007/bf00055162

✦ Synopsis

The warm circumnuclear dust in the inner cometary coma reradiates in the IR in the wavelength range of the ground state rotational band of the dominant atmospheric molecule, HzO. However, the interaction of this radiation with Hz0 has hitherto not been taken into account in cometary atmospheric models. Here we have extended our earlier two-phase, multifluid model of the dusty atmosphere by including this effect. Although this IR radiation initially pumps the rotational levels of HzO, frequent intermolecular collisions in the inner coma transfer this energy from rotational modes to translational modes. As a result the temperature in the innermost coma no longer decreases to about 10 K, as predicted by the earlier models, but reaches a minimum of only about 120 K.