In 1986, the European spacecraft Giotto became one of the first spacecraft ever to encounter and photograph the nucleus of a comet, passing and imaging Halley's nucleus as it receded from the sun. Data from Giotto's camera were used to generate this enhanced image of the potato shaped nucleus that measures roughly 15 km across. Some surface features on the darkHalley Multicolor Camera Team, Giotto Project, ESA
Artist’s rendering of the Spitzer Space Telescope in space.
Credit: NASANASA
Stardust was the first spacecraft to return a cometary sample and extraterrestrial material from outside the orbit of the moon to Earth.NASA
A recent report in the Philosophical Transactions of the Royal Society A discusses the diversity of primitive refractory grains in cometary dust. Comet dust is a primitive remnant of the Solar System’s earliest days, and can teach scientists about how our solar system formed and evolved. Studies of cometary particles have been made possible with micrometeorites recovered from Antarctica, samples of interplanetary dust particles (IDPs) and chondritic porous (CP) IDPs from missions like NASA’s Stardust mission and the European Rosetta mission, and remote sensing with telescopes like Spitzer.
Interplanetary Dust Particle (IDP) collected by NASA's Stardust spacecraft.Image credit: NASA.
These primitive, extraterrestrial objects shed light on the primordial composition of the protoplanetary disk from which our solar system was built. There is a diverse range of structures found in cometary dust particles, and they reflect the materials present in the region of the protoplanetary disc where the comets themselves took shape. The particles can also provide information about the assortment of materials available during the formation of the Earth, and that may have been present on the early Earth when life first originated.
The article was presented in a special issue of the Philosophical Transactions of the Royal Society A, themed ‘Cometary science after Rosetta’. The report was performed by researchers supported in part through NASA’s Emerging Worlds Program and the Laboratory Analysis of Returned Samples (LARS) Program. NASA Astrobiology provides resources for these and other Research and Analysis programs within the NASA Science Mission Directorate (SMD) that solicit proposals relevant to astrobiology research.