The brightest spot on Saturn's moon Titan has been seen brightening and growing, suggesting it might be an active volcano, a controversial analysis of images from the Cassini spacecraft suggests. If so, it would be the first indication of current volcanic activity on the giant moon.

Scientists are interested in whether Titan is volcanically active because volcanoes could help supply the large amount of methane seen in its atmosphere. The methane is quickly broken down by sunlight, so it must be getting replenished in some way.

Cassini's Visual and Infrared Mapping Spectrometer (VIMS) revealed a bright spot 400 kilometres across on Titan during its first flyby of the moon in July 2004 (see Titan's bright spot revealed by Cassini).

The spot - the brightest on the moon - lies southeast of a much larger, bright region called Xanadu. At the time of its discovery, Cassini scientists thought the spot might be a cloud or a patch of fog but also suggested it might be the site of volcanic activity.

Follow-up observations have shown it gets brighter and grows, only to dim and shrink again. For example, the spot had brightened to twice its discovery level in March 2005 but had returned to its original level by November 2005. In December, it brightened again, gradually dimming since then.

Successive eruptions

It also appears to grow during its outbursts, increasing in area from 70,000 square kilometres to about double that size.

Now, Cassini team member Robert Nelson of the Jet Propulsion Laboratory in Pasadena, US, suggests the spot is the site of a volcano - and the brightening episodes are eruptions.

The spot is not likely to be a cloud, because these tend to break up within hours or days and have distinctive colours that do not match the spot, Nelson says.

It is also not likely to be a patch of ground fog, since Cassini measures dramatic changes in the spectrum of the spot's light during the brightening events, he says.

"As of today, we should add Titan to the group of objects that exhibit volcanism," he says. "We have seen active volcanism."

Just an illusion?

Karl Mitchell, also of JPL, says this is the best evidence so far of ongoing volcanic activity. "I wouldn't say that I am 100% convinced, but [Nelson] has put together a compelling case," he told New Scientist.

But Robert Brown, the leader of the Cassini VIMS team and a researcher at the University of Arizona in Tucson, US, says the apparent variations of the spot are likely just an illusion caused by the haze in Titan's atmosphere. This haze varies over time and is difficult to account for in observations.

"There is no conclusive evidence of any currently active volcanoes on Titan right now," Brown told New Scientist. "There's not even tantalising evidence."

Jason Barnes of the University of Arizona in Tucson, US, agrees. Volcanic activity could conceivably happen when a mixture of liquid water and ammonia comes from underground to the surface, he says.

Stable temperature

But its temperature would be at least 170 K (-103°C), and no extra heat has been observed in conjunction with the spot, which has a temperature of about 94 K (-179°C), just like the rest of the moon. "If there were a jump of even 10 or 20 K it would have been very evident," he told New Scientist.

David Stevenson of the California Institute of Technology in Pasadena, US, suggests the brightening events could instead be the result of methane buried just beneath the surface getting heated and spurting above ground.

He says figuring out what type of material is causing the brightness variations could shed light on what is causing the events. "Identifying the composition is crucial," he says.

Cassini has found geological evidence of volcanoes elsewhere on Titan, but no other signs of current activity (see Slushy volcanoes might support life on Titan).

Nelson presented his study of the spot last week at a meeting of the American Astronomical Society's Division for Planetary Sciences in Pasadena, California, US.

Word is that he is not in great shape, but hopefully he has come through post-op recovery fine. I will update this information, as soon as I can.

Needless to say, Keel is well-known for his many books and articles on a variety of topics, most especially in recent years, of course, Mothman.

More later...

A pair of Massey University scientists went to the house and failed to hear it.

Dr Tom Moir and Dr Alam Kakhrul say hearing a hum is common worldwide, and they have dubbed it the 'Unidentified Acoustic Phenomena'.

Dr Moir says there are two possible explanations for the noise.

He says it could be a very low frequency sound that only certain people can hear.

Or it could be that microwaves in the atmosphere trigger a hum-like sound in the heads of some people.

The research continues.

Race 'ironed out'

But in the nearer future, humans will evolve in 1,000 years into giants between 6ft and 7ft tall, he predicts, while life-spans will have extended to 120 years, Dr Curry claims.

Physical appearance, driven by indicators of health, youth and fertility, will improve, he says, while men will exhibit symmetrical facial features, look athletic, and have squarer jaws, deeper voices and bigger penises.

Women, on the other hand, will develop lighter, smooth, hairless skin, large clear eyes, pert breasts, glossy hair, and even features, he adds. Racial differences will be ironed out by interbreeding, producing a uniform race of coffee-coloured people.

However, Dr Curry warns, in 10,000 years time humans may have paid a genetic price for relying on technology.

Spoiled by gadgets designed to meet their every need, they could come to resemble domesticated animals.

Receding chins

Social skills, such as communicating and interacting with others, could be lost, along with emotions such as love, sympathy, trust and respect. People would become less able to care for others, or perform in teams.

Physically, they would start to appear more juvenile. Chins would recede, as a result of having to chew less on processed food.

There could also be health problems caused by reliance on medicine, resulting in weak immune systems. Preventing deaths would also help to preserve the genetic defects that cause cancer.

Further into the future, sexual selection - being choosy about one's partner - was likely to create more and more genetic inequality, said Dr Curry.

The logical outcome would be two sub-species, "gracile" and "robust" humans similar to the Eloi and Morlocks foretold by HG Wells in his 1895 novel The Time Machine.

"While science and technology have the potential to create an ideal habitat for humanity over the next millennium, there is a possibility of a monumental genetic hangover over the subsequent millennia due to an over-reliance on technology reducing our natural capacity to resist disease, or our evolved ability to get along with each other, said Dr Curry.

He carried out the report for men's satellite TV channel Bravo.

"I feel offended because my efforts did not attract much attention," the 46-year-old said. "Only local media wrote about it."

He then hopped into a waiting car and drove away by himself.

Doctors who examined Vartanyan said he lost 51 pounds during the ordeal, dropping to 158 pounds.

A spokeswoman, Lybov Kobzar, told reporters that Vartanyan drank about 0.8 gallons of water a day. To pass the time, he watched TV, listened to the radio, and talked on his cell phone. As the weather in the northern Russian city turned colder, he got an electric heater.

Beginning his attempt on Aug. 27, Vartanyan said he was inspired by a similar effort by stuntman and illusionist David Blaine, who fasted for 44 days in 2003 while suspended in an acrylic box over the Thames River in London.

Vartanyan said he planned on submitting documentation of his efforts to the Guinness Book of World Records.

"Diet stuff doesn't satisfy hunger like conventional food, because hunger is linked to certain texture and taste sensations. If you don't get them, you don't feel satisfied -- you don't have the feeling 'I've had enough, I'm full'."

He said people also ate more because they felt they had "done something healthy" by having diet products.

"Then they tend to consume just as much, if not more, than before," he said.

"There is little research to show that these foods have great benefit for long-term weight control.

"Long-term weight control is about eating good, healthy, nutritious foods, combined with a positive lifestyle, which includes keeping fit."

He said people focused on calories instead of nutrition.

Rather than diet food, people should eat healthier, with fewer processed grains and more "super foods" such as beans, nuts, vegetables and omega-3 oils, Prof Dingle said.

Instead of diet or soft drinks, people should drink water, which was healthier.

"Parents give their kids two cans a night and then they complain they can't sleep," he said.

The Aspartame Information Center website says scientific evidence overwhelmingly shows aspartame is safe and not associated with adverse health effects.