Comets have long fascinated humans and the earliest appearance of Halley’s Comet was made in 240 BC by a Chinese historian who called it a broom star. Though it was viewed by Romans and Babylonians its best depiction was made in Bayeux Tapestry that commemorated conquest of England by Normans in 1066 and was regarded as a symbol of doom. But now we know that comets are just clumps of rock dirt, ice and dust and little has changed about them in the 4.6 billion years of our existence as they are the most primitive heavenly bodies that can be studied by scientists.
NASA’s James Webb Space Telescope which is scheduled to be launched in 2021 will observe different types of comets in infrared light that is not visible to human eyes. This will increase our knowledge about comets and scientists also will have better insight about what the solar system was like billions of years ago. These comet studies will be carried out by Webb’s Guaranteed Time Observations program of solar system that is led by Heidi Hammel, selected by NASA as an Interdisciplinary Scientist in 2002. She is also the EVP of Association of Universities for Research in Astronomy (AURA) at Washington.
Hammel’s new program will demonstrate the capabilities of the Webb for tracking targets on the move and looking at bright objects within the solar system. Hammel stated that the Webb is being used to keep an eye on comets because it has powerful capabilities in both near and mid-infrared. The wavelengths of light are very powerful for studies of comets as they allow users to study chemical structure of dust and gas that move out of the nucleus of comets. As the molecules of this gas and dust absorb dark infrared light wavelengths they can analyze this light to determine which chemicals exist in this area.