What Lies Beneath by Deirdre Kelleghan Published December 2004 in Realta

On Christmas Eve when you are cozy in your bed either wondering what you will get for Christmas or if the turkey you have will be big enough for your guests, way above your house, way above the sky, way above the atmosphere in fact over 1 billion miles above this planet Earth, a wonderful event will be happening!

This event is the release of the Huygens probe by the robot ship Cassini Huygens. The Huygens probe will then have a three-week journey to the surface of one of the most unusual moons in our solar system – the incredibly unique Titan.

A robot ship the size of a 30-seater bus built jointly by NASA, The European Space Agency and The Italian Space Agency. This spacecraft blasted off from Cape Canaveral Florida in October 1997 over seven years ago. This is the biggest spaceship ever launched from Earth and every day since Cassini left our planet it has been traveling an average speed of 54,000 miles an hour. Cassini –Huygens is a spacecraft on a mission to explore the planet Saturn and the many moons of this giant world. Titan is Saturn’s largest moon and is particularly targeted for study. To put 1997 in context that was the year that princess Diana died, Gianni Versace was killed, Comet Hale- Bopp was visible in our skies and the movie Titanic was on our screens.

The Huygens probe is detachable from Cassini and is managed by the European Space Agency, and even though it is only about 8 feet in diameter it is packed with instruments to measure all it can in the atmosphere of the strangely beautiful moon Titan.

The atmosphere on Titan is so thick that visible light cannot escape from it. This moons dry cold atmosphere causes a 300km thick layer of orangey smog to build up around it. Titan is singularly unique as it is the only moon in our solar system that has an atmosphere.

On January 14 2005 the 8 foot wide Huygens probe protected by a heat shield will drop down and literally parachute into this unknown alien moon. The probe will take hundreds of photographs and sample the atmosphere and take stock of the physical and chemical components of this moon and will beam the data to the orbiting Cassini hopefully before its power runs out. The probe has enough power for only 3½ hours work, the uploaded data received by Cassini will then be sent to Earth via the Deep Space Network i.e. 3 massive communication dishes based in California, Madrid and Australia

Image courtesy of BBC

VENT TUBE WORMS LIVING WITHOUT THE SUN

Found deep on the ocean floor near hydrothermal vents. This extreme environment with no sunlight, high pressures, and a cocktail of chemicals that would kill most forms of life is a comfortable home for these creatures, so perhaps similar forms of life are capable of existing in the sun starved surface of Titan. These and many more questions may be answered in just a few weeks.

If this mission is a success, I think it will be a major achievement for NASA and the ESA and I hope it will encourage people to read more about the many space exploration missions that are under way and are in the pipeline for the very near future.

So sleep well on Christmas Eve and do take a look in the sky in the direction of Saturn and be amazed at what is happening so far above your house, many miles out in space so very very far from our living planet Earth. Check out www.heavansabove.com for the location of the planet Saturn.

SATURN KEY FACTS

• Diameter 74,975 miles

• Density 0.69 g/cm³

• Length of Day 10hr 40mins

• Length of Year 29.42 Earth Years

• Rings 7

• Known Moons 33

• Composition of Atmosphere Hydrogen

Helium Methane Ammonia and other hydrocarbons.

TITAN KEY FACTS

• Distance to Saturn 759,200 miles

• Diameter 3,199 miles

• Density 1.82 g/cm³

• Surface Temp - 181 ^o C

• Surface Pressure 1.5 bars (1½ at sea level on Earth)

• Composition of Atmosphere Nitrogen Methane and other hydrocarbons.