Planetary Astronomy Late-morning Seminar for 2017-04-24

Series: Planetary Astronomy Late-morning Seminar
Date: Monday 24-Apr-2017
Time: 11:15-12:15
Location: CSS 1250
Speaker: Michael Kelley (UMD)
Title: Cometary Orbital Trends with Spitzer

Cometary activity, i.e., the mass-loss process, is driven by the sublimation of volatiles. The three most abundant volatiles are water, carbon dioxide, and carbon monoxide, and each plays a different role in cometary activity. By observing the distribution and abundances of these gases in the coma, we can obtain a better understanding of their contributions to activity and the evolution of comets. The water, CO2, and CO coma distributions have been studied in spacecraft missions to comets 9P/Tempel 1, 103P/Hartley 2, and 67P/Churyumov-Gerasimenko. These data exhibit a variety of coma asymmetries, apparently caused by surface heterogeneities and/or thermal history. In order to connect the detailed observations from comet missions to the whole comet population, a better understanding of the role of water and CO2 in cometary activity is needed. To that end, we initiated a long-term survey of comets we call Cometary Orbital Trends. In this survey, we aim to measure water, CO2, and dust in a set of ~20 comets over year timescales. In this talk, I will present our survey and first results, including the aphelion activity of comet 2P/Encke, and the dust-to-CO2 ratio of the comet population.

For further information contact PALS coordinator Dr. Matthew Knight at or (301)-405-2629.


Special accommodations for individuals with disabilities can be made by calling (301) 405-3001. It would be appreciated if we are notified at least one week in advance.


Directions and information about parking can be found here.

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