The Cassini-Huygens Mission to Titan, Alien Abductions and UFOs

19 December 2004
Presented by Chris Smith


This week Professor John Zarnecki, from the Open University, joins us to discuss the Cassini-Huygens mission to Titan, Saturns largest moon, and Ministry of Defence (MOD) official Nick Pope, who headed the governments UFO desk for 3 years, talks about UFOs and listens to your close encounters of the third kind.

In this episode

- Cassini-huygens Mission To Titan, Saturn's Largest Moon

The Naked Scientists spoke to Prof. John Zarnecki

Cassini-huygens Mission To Titan, Saturn's Largest Moon
with Prof. John Zarnecki

Joining us from mission control at the Jet Propulsion Lab in Pasadena, California, principal investigator on the Huygens probe, Professor John Zarnecki, talks about the events that will take place on Christmas Day, and on January 14 2005, to provide us with our first glimpse of the surface of Saturn's largest moon, Titan.

John - My beloved space probe Huygens, which has been riding piggy-back with the Cassini spacecraft for the last seven years, is currently in orbit around Saturn. In a few days time, Huygens will be released from Cassini to make its final plunge towards Titan.

Chris - Of the 30 or so moons around Saturn, why choose Titan?

John - Not only is Titan the largest, but it is also a bit of an odd ball. It is the only planetary satellite in the solar system that has an atmosphere, and its atmosphere is thicker than Earth's. It is composed of a very complex mixture of gases, including a range of hydrocarbons. This makes it similar to Earth's very early atmosphere, which was immensely important as it probably provided the conditions from which life formed. Earth's atmosphere today is very different, but Titan's atmosphere seems to have got caught in a deep freeze, as the moon is extremely cold. Titan is therefore important because it is like going back to an early Earth.

Chris - What will happen when the probe is released?

John - Cassini will dispatch the probe on Christmas day by releasing a number of bolts. From there, three springs will gently push the probe away. Huygens will touch the upper atmosphere of Titan on the 14th January, where it will start to decelerate due to atmospheric friction. A dish-shaped shield on the front of the probe will act as protection against the intense heat. Closer to the ground, three parachutes will be released in succession to allow a gentle two and a half hour decent to the surface. We then have two hours, whilst Cassini is in touch with Huygens, before it moves out of reach on in its orbit. This gives us a total mission time of four hours. Despite seeming a very short time for a seven year journey, our data will be unique and should provide some fascinating information.

Chris - How do you protect the probe from high temperatures, and how do you test it before sending it into space?

John - When Huygens enters the atmosphere, it will encounter temperatures around 15000°C over a period of two minutes. It is a huge challenge to provide sufficient thermal protection for the instruments during this time. Once through the upper atmosphere, Huygens faces the opposite problem: a surface temperature of minus 180°C. The probe is kitted out with tiny on-board heaters, thermal insulation for the equipment, and sensors and wires that lose very little energy as heat. All these instruments are tested by dunking them in a vat of liquid nitrogen, which has a temperature comparable to Titan. Some of these instruments failed during initial testing, which meant we had to go back to the drawing board. But by the time we sent Huygens to Saturn, we had tested everything we could think of. It's now in the lap of the gods...

Cartoon of a flying saucer

- Why have a Government UFO Desk?

The Naked Scientists spoke to Nick Pope, Ministry of Defence

Why have a Government UFO Desk?
with Nick Pope, Ministry of Defence

Nick - The MOD have been in the business of looking at UFOs since the 1950s. The government's UFO project was set up by Sir Henry Tizzard, a radar expert and scientific hero from the Second World War. After the war, he said that the government could not and should not dismiss strange readings without a scientific reason. The committee was amusingly named The Flying Saucer Working Party, and spent time studying a range of phenomena.

Chris - Looking back in history, how long have people been claiming to see UFOs?

Nick - Biblical writings and other ancient texts talk about various sightings, showing that people have always seen strange things. As far as modern UFOs are concerned, it all started in 1947 with a pilot named Kenneth Arnold. He saw a number of delta-shaped craft. When the press asked him how the objects moved, he said they looked like a saucer would if you skipped it over water. This is how the name flying saucer came about.

Chris - Why didn't people see flying saucers before the advent of planes?

Nick - We don't really know that people didn't see flying objects centuries ago because the sightings might not have been recorded. It wasn't a time when people had access to the media, so information from many people has been forgotten.

Kat - Are you a believer?

Nick - I do want to believe. I think there is some intriguing evidence but not necessarily complete proof.

Kat - How much of peoples' descriptions are based on science fiction films?

Nick - That's an interesting question, because many people dismiss those who have seen UFOs as people who watch too much Star Trek. However, when making Sci-Fi films and programmes, the producers of the series read a lot of literature on the subject, which has come directly from people who have seen UFOs. Movies on the big screen take images and information from accounts of sightings, not the other way round.

Chris - What is your most memorable experience from the UFO desk?

Nick - There was a case in 1993 where I went into work and the phones were ringing off the hook. There had been a massive wave of sightings of a diamond-shaped metallic craft flying slowly and low to the ground. It was observed by one witness as firing a narrow beam of light towards the horizon while emitting a low frequency hum. Having been flying slowly the entire time, it suddenly shot off into the horizon. During the day it had even flown directly over two military bases. The sighting is still unexplained to this day. The government will have the odd secret craft, but at the end of the day, we know where we trail our own bits of kit.

Kat - Where do these crafts come from? Nick - To be honest, we're as much in the dark as anyone else. When people get together, we just brainstorm.

Catherine - Is there a particular part of the world with UFO hot spots?

Nick - There are some parts of the world with more sightings, but this could be related to there being more people to see them. It also depends on whether the country has a media network predisposed to reporting it. Examples of hot spots are the United States in general, and in this country, Suffolk, which has been a hotspot ever since the Rendlesham sightings of the 1980s. Rendlesham is Britain's version of Roswell. Over several nights in December 1980, numerous United States air force personnel saw a UFO: not just lights but a proper metallic craft. Some people got close enough to touch it and said they saw a metal hull with hieroglyphic - type writing on it. The craft even left evidence of its being there. The following morning, there were indentations on the floor of a clearing in the shape of a perfect equilateral triangle. A Geiger counter taken to the scene showed that radiation readings were ten times normal levels; readings that were later verified by MOD intelligence staff. As radiation levels were normal outside the marks in the triangle, it is clear that the radiation came from whatever it was that landed there.

Chris - Do photos of UFOs usually come out?

Nick - Yes. When I was at the MOD, I was sent stack loads of photos and videos. If I still worked there, I imagine I would probably get even more due to the development of digital cameras and camera phones. Some people claim their photos don't come out because their equipment froze up. There have been incidences of this phenomena reported by the military when encountering unknown objects on radar.

Chris - What do you do when you receive a UFO report?

Nick - Every night, I would have in front of me a whole range of information, including plane flight paths, the position of particularly bright satellites and the occurrence of any meteor showers. I would usually take the UFO report and try and correlate it with any of this information.

Kat - Are most UFO sightings at night?

Nick - They are, but the daylight sightings are much more interesting, especially if there is a photo.

Chris - What do we know about Area 51?

Nick - It does actually exist and is part of the vast Nellis Air Force Base. Where the truth and the conspiracy theorists diverge is what is actually there. Aerospace experts say they are testing advanced prototype aircraft. Conspiracy theorists say this is where the Roswell aircraft is kept. Others say that Area 51 is where aliens and American scientists work hand in hand to develop spacecraft. Personally I'm not sure about that one! Some conspiracy theorists go off the deep end! The notion of a conspiracy arose as a response to the actions of the US army; the first people to mention the Roswell in a press release. They said that having seen the flying discs, they had managed to capture one after it had crashed at a nearby farm. A few days later they released another statement saying it had all been a mistake and the discs had really been weather balloons. People picked up on this and suspected the military of covering up spacecraft and aliens.

- What was this bright object I saw in the sky?

On night when I was in Italy on holiday, a bright light appeared. I turned around and saw a big round thing and it was so close it looked...

What was this bright object I saw in the sky?

(Nick) This is a fascinating account. What is particularly spectacular about your sighting is that you can describe the craft well. Most of the cases we see are vague, or just blurry lights.

- Are there any substances on other planets that can be used for energy?

Are there any substances on other planets that can be used for energy?

Are there any substances on other planets that can be used for energy?

There are billions of suns out there (which look like tiny stars from earth), some of which are like our sun. They have powerful chemical reactions going on in them just like our sun. Planets can be gassy, rocky and watery, substances very much like those on earth. As John Zernecki said earlier, the atmosphere on Titan has lots of hydrocarbons in it. These are the same things that can be used as fuel in your car. So in answer to your question, there are definitely raw materials on other planets to make fuel from.

- Why would aliens navigate space safely only to crash land on Earth?

I've always wondered why these supposed aliens with their amazing spaceships get all the way to Earth and then crash land in America...

Why would aliens navigate space safely only to crash land on Earth?

(Nick) Aside from the Roswell incident, there haven't been that many landings in America. I'd also like to add that advanced technology is not always particularly safe. Even though our planes are much better than in the days of the Wright brothers, we still manage to crash!

- I often see lights in the sky when I'm driving. Are they aeroplanes or are they UFOs?

I often see lights in the sky when I'm driving. Are they aeroplanes or are they UFOs?

I often see lights in the sky when I'm driving. Are they aeroplanes or are they UFOs?

(Nick) Statistically, 85-90% are usually explained by normal things such as planes, weather balloons or satellites. Driving is also a difficult situation in which to make an accurate judgement: not only is the car moving, but you are also seeing the lights through glass, which can lead to distortion.

- Did I see a UFO?

I was out in the garden in the early 1990s and saw a light in the distance. It then came closer and closer and got bigger and bigger. It ...

Did I see a UFO?

(Nick) This is the type of movement often reported about UFOs. It's a very common feature. It is also interesting that it happened in the early 1990s, as these were years with many sightings.

- Was this silver disc I saw in the sky a UFO?

What was the object I saw while gardening?

Was this silver disc I saw in the sky a UFO?



(Nick) I've seen several reports and photos of disc-like objects. Most of them are described as looking like a metallic frisbee. This is a fascinating encounter.



- If Santa were real, would it be possible to make reindeer fly?

If Santa were real, would it be possible to make reindeer fly?

If Santa were real, would it be possible to make reindeer fly?

Yes, put wings on it or put it in an aeroplane!

- What was the light that shot over us in a park at night?

My wife and I were walking through a park in the evening. Suddenly, a light shot across, hovered over us and then shot away at a speed yo...

What was the light that shot over us in a park at night?

(Nick) This is fascinating because this is the fourth call this evening in which the craft was silent and showed amazing flexibility in movement. The lack of sound is quite common, and a low frequency hum is also often described.


Add a comment