Cassini-Huygens, the joint NASA/ESA/ASI space mission has successfully
made a close encounter with Saturn’s moon, Titan. This was confirmed
in the early hours of this morning as the first information and pictures
were beamed back via NASA’s Deep Space Network tracking station in
Madrid, Spain. As anticipated, the spacecraft came within 1,200
kilometres (750 miles) of Titan’s surface.

The first images can be found at
http://saturn.jpl.nasa.gov/news/events/titana/index.cfm

At the time, Cassini was about 1.3 billion kilometres (826 million
miles) from Earth. Numerous images, perhaps as many as 500, were taken
by the visible light camera and were being transmitted back to Earth. It
takes 1 hour and 14 minutes for the images to travel from the spacecraft
to Earth. The downlink of data will continue through the night into the
early morning hours. Cassini project engineers will continue to keep a
close watch on a rainstorm in Spain, which may interrupt the flow of data
from the spacecraft.

Professor Carl Murray from Queen Mary, University of London, a member
of the Cassini Imaging Science Subsystem team, has been taking a look at
the first images,

“Titan’s veil has been lifted yet again and we have been treated to a
spectacular array of images from this bizarre moon. The return of this
data from such a peculiar and distant world is another remarkable
success for Cassini. When the images are combined with data from the
other instruments on Cassini we will have a much more complete
understanding of what the Huygens probe can expect when it lands in
January.”

The flyby was by far the closest any spacecraft has ever come to Titan,
the largest moon of Saturn, perpetually drenched in a thick blanket of
smog. Titan is a prime target of the Cassini-Huygens mission because it
is the only moon in our solar system with an atmosphere. It is a cosmic
time capsule that offers a look back in time to see what Earth might
have been like before the appearance of life.

Mark Leese, is a member of the Huygens team at the Open University, who
are involved in the Science Surface Package (SSP) and the Huygens
Atmospheric Instrument (HASI).

“The Open University Huygens team are looking forward to what these images
and other data may tell us about the surface of Titan, in anticipation of
the Huygens mission on January 14th 2005. Then we hope that the UK built
Surface Science Package will send back the first measurements from the
surface of Titan.”

He adds, “The combination of images, spectrometer measurements and
RADAR data from this close flyby should help to prepare us for the
mission ahead. In addition, Cassini’s measurements of the atmosphere
should confirm that the Titan atmosphere model used to design the
probe entry system is correct.”

The Huygens probe, built and operated by the European Space Agency, is
attached to Cassini; its release is planned on Christmas Day. It will
descend through Titan’s opaque atmosphere on January 14, 2005, to
collect data and touch down on the surface.

UK scientists are playing significant roles in the Cassini Huygens
mission with involvement in 6 of the 12 instruments onboard the Cassini
orbiter and 2 of the 6 instruments on the Huygens probe. The UK has the
lead role in the magnetometer instrument on Cassini (Imperial College)
and the Surface Science Package on Huygens (Open University).

Notes to Editors

Press Contacts
Peter Barratt – PPARC Press Office
Tel: 01793 442025. Email: peter.barratt@pparc.ac.uk
Mobile: 0787 9602899

Gill Ormrod – PPARC Press Office
Tel: 01793 442012. Email: gill.ormrod@pparc.ac.uk
Mobile: 0781 801 3509

Science Contacts

Professor Carl Murray, Queen Mary, University of London – Co-I on the
Imaging Science Subsystem (Cassini)
Office: 0207 8825456
Email: c.d.murray@qmul.ac.uk

Professor John Zarnecki, Open University – PI on the Science Surface
Package (Huygens) and Co-I on the Huygens Atmospheric Instrument.
Available on mobile this week.
Office : 01908 659599 Mobile: 07769 943883. Email:
J.C.Zarnecki@open.ac.uk

Mark Leese, Open University – Science Surface Package (Huygens) and
Huygens Atmospheric Instrument team.
Tel: 01908 652561. Email: m.r.leese@open.ac.uk

Professor Michele Dougherty, Imperial College – PI on the Magnetometer
instrument (Cassini)
Contact through Abigail Smith, Imperial Press Office. Tel: 020 7594
6701 or 07761 799089.
Email abigail.smith@imperial.ac.uk. Email:
m.dougherty@imperial.ac.uk

Cassini Electron Spectrometer (CAPS-ELS)
Dr Andrew Coates, Mullard Space Science Laboratory, UCL
Tel: 01483 204145. Email: ajc@mssl.ucl.ac.uk
Mobile: 07788 448318

Dr Ingo Mueller-Wodarg, Imperial College (Titan science, Cassini
science, INMS team)
Tel: 020 75947674. Mobile: 07973 271816. Email:
i.mueller-wodarg@imperial.ac.uk

For full list of UK contacts see previously issued media note at
http://www.pparc.ac.uk/Nw/titan_flyby.asp

Further NASA briefings and coverage

For details of the NASA TV coverage of the flyby and results see:
http://www.nasa.gov/multimedia/nasatv/MM_NTV_Breaking.html

UK Science and Industrial Involvement

UK scientists are playing significant roles in the Cassini Huygens
mission with involvement in 6 of the 12 instruments onboard the Cassini
orbiter and 2 of the 6 instruments on the Huygens probe. The UK has the
lead role in the magnetometer instrument on Cassini (Imperial College)
and the Surface Science Package on Huygens (Open University).

UK industry had developed many of the key systems for the Huygens probe,
including the flight software (LogicaCMG) and parachutes (Martin Baker).
These mission critical systems need to perform reliably in some of the
most challenging and remote environments ever attempted by a man made
object. For examples, the Huygens probe will hit the atmosphere of Titan
at 6 km/sec. LogicaCMG’s software onboard the probe will be responsible
for
deploying the parachutes, separating the front and back shield with
precise timings to achieve the required descent profile; reducing the
velocity of Huygens before commencing the science experiments, and
managing communications back to Cassini.

Titan Background

Titan is a highly complex world and is closer to a terrestrial planet
than a moon typical of the outer planetary systems. Titan was first seen
by Dutch astronomer Christiaan Huygens (after which the ESA probe is
named) in 1655.

Not only is Titan the largest of Saturn’s satellites, it is also
larger than the planets Mercury and Pluto, and is the second largest
satellite in the solar system (Jupiter’s Ganymede being larger). It is
the only satellite in the solar system with appreciable atmosphere,
composed mostly of Nitrogen, but also contains aerosols and
hydrocarbons, including methane and ethane. Titan’s atmosphere was
first confirmed in 1944 when Gerard Kuiper confirmed the presence of
gaseous methane with spectroscopy.

Titan’s peak surface temperature is about 95 K (-178 degrees C) and
surface pressure is 1.6 Earth atmospheres. At this temperature and
pressure, many simple chemicals that are present in abundance (methane,
ethane, water, ammonia) provide materials in solid, liquid and gaseous
form which may interact to create exotic features on the surface.
Precipitation, flowing liquids, lakes and eruptions are all possible.

Titan orbits Saturn at a distance of just over 20 Saturn radii
(1,222,000 km/759,000 miles) which is far enough to carry the moon in
and out of Saturn’s magnetosphere. Very little is known about
Titan’s interior structure, including whether it has its own
magnetic field.

Titan’s surface has been difficult to study, as it is veiled by a
dense hydrocarbon haze that forms in the dense stratosphere as methane
is destroyed by sunlight. From the data collected so far, dark features
can be seen crossing the equatorial region of Titan, with a large bright
region near longitude 90 degrees now named Xanadu, and possibly a large
crater in the northern hemisphere.

The Cassini-Huygens mission is a cooperative project of NASA, the
European Space Agency and the Italian Space Agency. The Jet Propulsion
Laboratory, a division of the California Institute of Technology in
Pasadena, manages the Cassini-Huygens mission for NASA’s Science Mission
Directorate, Washington, D.C. The Cassini orbiter and its two onboard
cameras were designed, developed and assembled at JPL.

The Particle Physics and Astronomy Research Council (PPARC) is the
UK’s strategic science investment agency. It funds research,
education and public understanding in four broad areas of science –
particle physics, astronomy, cosmology and space science.

PPARC is government funded and provides research grants and
studentships to scientists in British universities, gives researchers
access to world-class facilities and funds the UK membership of
international bodies such as the European Organisation for Nuclear
Research, CERN, the European Space Agency and the European Southern
Observatory. It also contributes money for the UK telescopes overseas on
La Palma, Hawaii, Australia and in Chile, the UK Astronomy Technology
Centre at the Royal Observatory, Edinburgh and the MERLIN/VLBI National
Facility.