Crunch, squelch or splash? Titan still offers all possibilities for the Huygens probe landing
The prospect of the Huygens probe landing on a hard, soft or liquid
surface when it lands on Titan next January still remain following
further analysis of data taken during the Cassini mother ship’s
closest encounter with Saturn’s largest moon during its fly-by on
26th October.
Commenting on the latest data results and implications for the
Huygens probe Mark Leese of the Open University, Programme Manager for
Science Surface Package [SSP] instruments that will unravel the mysteries
of Titan said: “It’s interesting that all of the possible landing
scenarios that we envisaged – a hard crunch onto ice, a softer squelch
into solid organics or a splash-down on a liquid hydrocarbon lake – still
seem to exist on Titan.”
Leese added, “A first look at the measurements of Titan’s atmosphere
during the fly-by suggest that the “Atmosphere Model” we developed and
used to design the Huygens probe is valid and all looks good for the
probe release on Christmas day and descent to the surface on 14th
January 2005.”
Further analysis of Titan’s upper atmosphere, the thermosphere, has
revealed a strange brew as Dr Ingo Mueller-Wodarg of Imperial College
London explained,” Our instrument, the Ion Neutral Mass Spectrometer
(INMS), made in-situ measurements of atmospheric gases in Titan’s upper
atmosphere and found a potent cocktail of nitrogen and methane, stirred
up with signatures of hydrogen and other hydrocarbons. We are now
working on a ‘Weather Report’ for the Huygens landing in January”.
Commenting on the surface characteristics of Titan Professor John
Zarnecki of the Open University, lead scientist for the Huygens SSP
said: “The recent results from the fly-by have started to show us a very
diverse and complicated surface. Titan is geologically active but hasn’t
yet given up all of its secrets. Combining the visible images with
infrared and RADAR data from this and future fly-bys should help to
clarify the picture – but the arrival of the Huygens probe in January
will perhaps be the key to unlock these mysteries.”
Professor Carl Murray, of the Imaging Science System [ISS] team from
Queen Mary, University of London also commented on the surface
features: “The images of the Huygens’ landing site returned by the cameras
show a diverse range of features. We see bright and dark areas roughly
aligned in an east-west direction. These are similar to wind streaks seen
on Mars and may indicate that material on Titan has been deposited by
the effects of wind blowing across the landscape. All indications suggest
that we are in for a real treat in January when the Huygens probe reaches
Titan’s surface and returns the first in situ data from this alien world.”
UK scientists and technologists are amongst an international team
continuing to analyse the latest data received from the NASA/ESA/ASI
Cassini Huygens mission after the spacecraft made its close fly-by of
Titan last week. The data has provided a wealth of information about
Saturn’s largest moon, which will not only assist the European Space
Agency’s Huygens team in advance of the probe landing on Titan in
January 2005 but will also increase our understanding of the relationship
between Titan and its parent planet Saturn.
Professor Michele Dougherty from Imperial College is lead scientist on
the Cassini Magnetometer, which is studying the interaction between
the plasma in Saturn’s magnetosphere and the atmosphere and ionosphere
of Titan. “We have been able to model the Magnetometer data very well
from the Titan flyby. There does not seem to be an internal magnetic field
at Titan from the observations we obtained during this flyby, but we will
have a much better idea about this when we have a further flyby in
December which is on a very similar trajectory. All we can say at this
point is that if there is a magnetic field generated in the interior of
Titan, then it is very small”
Dr Andrew Coates from University College London’s Mullard Space
Science Laboratory, a Co-Investigator on the Cassini Electron
Spectrometer team, said: “We received some remarkable new information
about Titan’s plasma environment within the context of Saturn’s
fascinating magnetosphere. Unexpectedly, it looks like we can directly use
features of the electron results to understand what Titan’s upper
atmosphere is made of, supplementing the ion measurements from companion
sensors on other instruments. Our electron results contain tell-tale
fingerprints of photoelectrons and Auger electrons which we will use for
this. Also, the total picture shows how important electrons, raining down
on Titan’s upper atmosphere, are in helping the feeble sunlight drive the
complex chemistry in Titan’s upper atmosphere.”
Nick Shave, Space Business Manager at UK IT company LogicaCMG said “The
amazing imagery and radar results recently received from Cassini of
Titan’s surface is providing important early information and creating
real excitement in the industrial community. UK industry’s critical
contributions to Cassini-Huygens via the LogicaCMG Huygens flight
software and other systems, such as the parachutes by Martin Baker, will
enable even more spectacular science that could help unlock some of the
secrets of life on Earth.”
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.
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
LogicaCMG – Contact: Nick Shave, Space & Satcoms Operations Manager,
LogicaCMG. Email: Nick.Shave@logicacmg.com. LogicaCMG PR – Alex
Rowley.
Tel: 0207 4197331. Email: Alex@bbpr.com
For full list of UK contacts see previously issued media note at
http://www.pparc.ac.uk/Nw/titan_flyby.asp
Further information and latest images
http://saturn.jpl.nasa.gov/home/index.cfm
ISS imaging team website: http://ciclops.org
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.
