National Radio Astronomy Observatory | ALMA | 2014 Aug 11
An international team of scientists using the Atacama Large Millimeter / submillimeter Array (ALMA) has made incredible 3D images of the ghostly atmospheres surrounding comets ISON and Lemmon. These new observations provided important insights into how and where comets forge new chemicals, including intriguing organic compounds.Click to play embedded YouTube video.
Comets contain some of the oldest and most pristine materials in our Solar System. Understanding their unique chemistry could reveal much about the birth of our planet and the origin of organic compounds that are the building blocks of life. ALMA's high-resolution observations provided a tantalizing 3D perspective of the distribution of the molecules within these two cometary atmospheres, or comas.
“We achieved truly first-of-a-kind mapping of important molecules that help us understand the nature of comets,” said team leader Martin Cordiner, a Catholic University of America astrochemist working at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
The critical 3D component of the ALMA observations was made by combining high-resolution, two-dimensional images of the comets with high-resolution spectra obtained from three important organic molecules – hydrogen cyanide (HCN), hydrogen isocyanide (HNC), and formaldehyde (H2CO). These spectra were taken at every point in each image. They identified not only the molecules present but also their velocities, which provided the third dimension, indicating the depths of the cometary atmospheres. ...
NASA’s 3-D Study of Comets Reveals Chemical Factory at Work
NASA | Goddard Space Flight Center | 2014 Aug 11
Mapping the Release of Volatiles in the Inner Comae of Comets C/2012 F6 (Lemmon)
and C/2012 S1 (ISON) Using the Atacama Large Millimeter/Submillimeter Array - M. A. Cordiner et al
- Astrophysical Journal Letters 792(1) L2 (2014 Sept 11) DOI: 10.1088/2041-8205/792/1/L2