KNOWING where comets were born is crucial for astronomers hoping to
understand how the Solar System formed. Now Hideyo Kawakita and colleagues at
the Gunma Astronomical Observatory in Japan have found a way to glean this
information using ground-based telescopes.
Kawakita’s team analysed light from a comet to determine the crystalline
structure of the frozen ammonia it contains. From this they were able to work
out the thermal history of the comet, including how far away from the Sun it
formed.
That in turn helps astronomers establish where the first clumps of matter
began to emerge from the gas and…
