In the second of our new series of monthly columns, ANDREW DUNN takes a look at developments in science and technology in our region and the wider world

Malham Cove in the Yorkshire Dales is more than four times older than was thought. Scientists believed the massive, limestone, cave-riddled cliff - carved by glaciers and waterfalls - was formed during the last ice age which ended about 14,000 years ago. But Leeds University earth scientist and keen cave diver Phillip Murphy has discovered evidence that dates it back at least 50,000 years.

He collected a stalactite from an underwater cave. Stalactites are formed by dripping water, so it cannot have been made when the caves were flooded, or ice-bound. Yet it turned out to be about 26,000 years old.

It now seems the valley below the cove was gouged out during an earlier ice age by a glacier, which drained the caves. Then came a warmer period between glaciations, and the stalactite grew. During the last ice age another glacier brought down silt blocking the caves, and when the ice melted the caves flooded again. So the caves - and the cove - must predate all that activity.

New IVF hope

Biologists at the University of York, with doctors at Leeds General Infirmary, have developed a revolutionary way to spot which 'test-tube' embryos are most likely to do well in in-vitro fertilization treatment. In IVF, fertilization of the would-be mother's eggs takes place artificially, outside the body. ('In-vitro' means 'in glass'.) Failure rates are high. One problem is choosing which of the tiny embryos to implant into the womb. At present, they're chosen by eye under a microscope, but it is difficult to predict which ones will do best.

Professor Henry Leese and his colleagues put candidate embryos in a culture of special nutrients two days after fertilization and watch what happens. Professor Leese says, "We've found a marked difference between the embryos which develop successfully in culture and those which do not. The healthy embryos have a 'quieter' metabolism".

The new method doesn't harm the embryos, but it does help to select high-quality embryos to replace into the womb, increasing success rates and greatly reducing the risks of multiple births. The scientists hope the test will be available in clinics in two or three years' time.

Satellite speed police

Cars set automatically to obey speed limits are to be tried out soon in Leeds. Transport researchers at Leeds University have developed equipment which uses global positioning satellites to track the cars, and knows the speed limits for every road. Some cars display a warning to the driver if the car is going too fast, while others govern the car's speed, although the driver can over-ride that by pushing a button. Keeping to speed limits could cut serious accidents by nearly half.

Growing in space

Four York University physics students have won a competition to have their experiment carried out in space. It's the second time for these high-flyers; they ran experiments in zero gravity on a parabolic flight last summer. The snag is that this time they must raise the money to pay costs, which could exceed £10,000.

The team comprises two BSc students, Tony Wilkinson and Jon Howe, and two postgraduates, Neil Melville and David Waterman. The new experiment will take place aboard a Russian satellite, and will develop the ideas they took on the July flight.

"The experiment will examine proteins that have never been grown in space before including the human growth hormone," says Tony. They hope to find out more about the proteins themselves and how the lack of gravity affects their crystal structure.

The competition was run by the European Space Agency as part of its drive to promote space science for young people.

Dance of the planets

You still have a fortnight to enjoy the most spectacular alignment of the planets seen in decades. For the last few weeks the five planets visible to the naked eye - Mercury, Venus, Mars, Jupiter and Saturn - have been dancing around each other, and often the moon, in one small patch of sky. Look west, towards sunset, as twilight gathers. The dance culminates on June 3 with a breathtakingly close pairing of Venus and Jupiter, the two brightest planets.

It's all an illusion. The planets are still hundreds of millions of kilometres apart. But every so often their different orbits bring them to the same side of the sun at the same time.

Such events are relatively rare, cosmologically speaking. They happen roughly every twenty years, but the last widely visible bunching was in February 1940, and the next good one will be in 2060.

So grab your chance now: look west on the next clear night.

Updated: 10:51 Tuesday, May 21, 2002