309
creates streams of dust, gas, and
plasma hundreds of millions of
miles long. The material in the tail
is lost from the comet forever. 67P
had only been close to the sun a
handful of times in its existence.
That meant it was still “fresh” with
its primordial composition intact.
All aboard
Rosetta was launched by an Ariane
5 rocket from ESA’s space center
in French Guiana. The spacecraft
weighed just under 3 tons, with
a central body about as large
as a small van. A folded solar
array unfurled to provide 690 sq ft
(64 m^2 ) of photovoltaic cells, which
would power the craft throughout
the mission.
Most of Rosetta’s instruments
were designed to study the comet
while in orbit. They included various
spectroscopes and microwave
radars for studying the composition
of the comet surface and the dust
and gases that would be released
when 67P neared the sun and
began to heat up. One of the most
important instruments on board
was CONSERT (Comet Nucleus
Sounding Experiment by Radiowave
Transmission), which would blast
a beam of radio waves through the
comet to find out what lay inside.
CONSERT would operate with the
help of the lander Philae. Once on
See also: The Oort cloud 206 ■ The composition of comets 207 ■ Investigating craters 212 ■
Exploring beyond Neptune 286–87 ■ Studying Pluto 314–17
THE TRIUMPH OF TECHNOLOGY
the surface, Philae would pick up
signals from CONSERT, sent out
while Rosetta was orbiting on
the far side. Philae was equipped
with solar panels and rechargeable
batteries and was designed to
work on the comet’s surface in
order to analyze its chemistry.
Both the names Rosetta and
Philae referred to ancient Egyptian
artifacts. The Rosetta Stone
has a carved inscription in three
languages: Hieroglyphs, Demotic
Egyptian, and ancient Greek. ❯❯
To find out,
we need to land
on a comet.
Comets are the
leftovers from the
formation of
the planets.
First indications
are that Earth’s water and
organic chemicals did not
come from comets.
Earth’s water and the
chemicals needed for
life may have come
from comets.
An artist’s impression shows
Rosetta releasing the Philae lander
above comet 67P. The lander bounced
on landing, flying up from one lobe of
the comet to land again on the other.
We didn’t just land once—
maybe we landed twice!
Stephan Ulamec
Philae landing manager