the trans-Neptunian region and “nearly isotropic comets” (NICs) from the Oort
cloud, the latter including both long period and high inclination short period comets
of the Halley type (Levison 1996). The third reservoir is the main asteroid belt,
which has recently been recognised to contain a significant population of icy bodies,
including the so-called “Main Belt Comets” (MBCs), whose relatively circular orbits
stay within the belt (Jewitt et al. 2015; Snodgrass et al. 2017). Cross-comet calibration of the measurements identifying differences in these objects would clearly be
worthwhile.
The next mission to a comet is likely to be the European Space Agency’s Comet
Interceptor, recently selected for launch in 2029, which is designed to make a fast
fly-by of a dynamically new comet or, if luck is on one’s side, an interstellar visitor.
The idea here is that the spacecraft waits at a parking position until a dynamically
new comet or an interstellar asteroid is detected on its way to the inner Solar System.
The spacecraft leaves its parking position and performs a fast fly-by to study the
surface and innermost coma of the object. This mission will address questions of
diversity between reservoirs but it is unlikely to constrain the physico-chemical
structure of the nucleus and inner coma that we have just discussed.
We can summarize these issues by referring to a table of possible future missions
and their goals (Table 8.1) taking in account the fact that spacecraft missions are
limited in terms of financial, technical, and programmatic resources. One can see that
no one mission can address all of these outstanding questions so that some form of
selection or trade-off would be necessary. On the other hand, this shows that there is
plenty of scope for designing and implementing our next foray into the world of the
comet.
8 Future Investigations of Comets
443
cloud, the latter including both long period and high inclination short period comets
of the Halley type (Levison 1996). The third reservoir is the main asteroid belt,
which has recently been recognised to contain a significant population of icy bodies,
including the so-called “Main Belt Comets” (MBCs), whose relatively circular orbits
stay within the belt (Jewitt et al. 2015; Snodgrass et al. 2017). Cross-comet calibration of the measurements identifying differences in these objects would clearly be
worthwhile.
The next mission to a comet is likely to be the European Space Agency’s Comet
Interceptor, recently selected for launch in 2029, which is designed to make a fast
fly-by of a dynamically new comet or, if luck is on one’s side, an interstellar visitor.
The idea here is that the spacecraft waits at a parking position until a dynamically
new comet or an interstellar asteroid is detected on its way to the inner Solar System.
The spacecraft leaves its parking position and performs a fast fly-by to study the
surface and innermost coma of the object. This mission will address questions of
diversity between reservoirs but it is unlikely to constrain the physico-chemical
structure of the nucleus and inner coma that we have just discussed.
We can summarize these issues by referring to a table of possible future missions
and their goals (Table 8.1) taking in account the fact that spacecraft missions are
limited in terms of financial, technical, and programmatic resources. One can see that
no one mission can address all of these outstanding questions so that some form of
selection or trade-off would be necessary. On the other hand, this shows that there is
plenty of scope for designing and implementing our next foray into the world of the
comet.
8 Future Investigations of Comets
443