A possible problem could occur on this historic transition in time - a geomagnetic storm.

While it is geomagnetic storms that give rise to the beautiful Northern lights, they can also pose a serious threat for commercial and military satellite operators, power companies, astronauts, and they can even shorten the life of oil pipelines in Alaska by increasing pipeline corrosion.

Geomagnetism is the study of the Earth's magnetic field. The field can undergo large and rapid fluctuations due to the interaction of charged particles ejected by the Sun that collide with the geomagnetic field. These disturbances are known as "geomagnetic storms," and can cause power blackouts, disruptions in communications, satellite failures, and other hazardous effects. These solar ejections, traveling at more than a million miles an hour, are associated with sunspots, whose number increase and decrease over an 11-year cycle. The number of geomagnetic storms therefore increases and decreases in concert with that cycle. The next peak in sunspot activity is expected to occur in early 2000 - perhaps just in time for, or a little after, the arrival of the New Year.

The last great magnetic storm occurred exactly 11 years ago this coming March 13 at 3 a.m. EST. That storm caused the collapse of the Hydro-Quebec power system in Canada, leaving about 6 million people without power. If the storm had struck a few hours later than it did, the blackout would likely have been much worse because of the heavier power consumption during daytime hours.

Magnetic storms are not rare, but great storms like this are.

"During the sunspot maximum we are going through now, smaller storms can occur rather frequently - even several times a week. Though it is unlikely that a really large storm will hit just as the New Year arrives, it could happen, and if it does, the results might complicate the situation with Y2K," said Don Herzog, a geophysicist with the U.S. Geological Survey (USGS) said last Tuesday .

The usually staid state media in Shanghai carried reports yesterday that an unidentified flying object had been sighted in the city.

In a front-page story, with colour photographs of an object resembling a meteor, the Wenhui Daily said the UFO was spotted over western Shanghai on Thursday afternoon.

The paper said one of its reporters dashed to the 43rd floor of a building after receiving a call from a reader about the sighting. The reporter claimed he saw an illuminated object which remained stationary in the sky for about 10 minutes before it disappeared.

Two Shanghai television channels broadcast footage of an object darting through the sky with a flaming orange tail, saying nearly 100 people saw it.

A former researcher at the Shanghai Observatory, Professor Jiang Xiaoyuan, was among the witnesses but he could not offer any explanation.

The UFO hovered over Shanghai for 1.5 hours, reports said. The city's aviation bureau and Hongqiao airport said their radar did not detect anything.

The Shanghai Daily also reported the incident in a story headlined "UFO darts across the city's skyline".

A British astronomer may have discovered a new and bizarre planet orbiting the Sun, 1,000 times further away than the most distant known planet.

Currently, Pluto is the furthermost planet that circles our Sun. But the new planet would be 30,000 times more distant from the Sun than the Earth, putting it a significant fraction of the distance to the nearest star.

What is more, it seems that the new planet cannot be a true member of our Sun's family of planets. It may be a planet that was born elsewhere, and roamed throughout the galaxy only to be captured on the outskirts of our own planetary system.

The controversial suggestion that there is another planet in deep space comes from Dr John Murray, of the UK's Open University. For several years, he has been studying the peculiar motions of so-called long-period comets.

Comets deflected

Comets - flying mountains of rock and ice - are thought to come from the cold and dark outer reaches of the Solar System, far beyond the planets in a region called the Oort cloud.

They spend millions of years in the Oort cloud, until they are deflected into an orbit that takes them into the inner Solar System where we can see them.

By analysing the orbits of 13 of these comets, Dr Murray has detected the tell-tale signs of a single massive object that deflected all of them into their current orbits.

"Although I have only analysed 13 comets in detail," he told BBC News Online, "the effect is pretty conclusive. I have calculated that there is only about a one in 1,700 chance that it is due to chance."

In a research paper to be published next week in the Monthly Notices of the Royal Astronomical Society, he suggests that the so-far unseen planet is several times bigger than the largest known planet in our Solar System, Jupiter.

Being so far from the Sun - three thousand billion miles - it would take almost six million years to orbit it.

"This would explain why it has not been found," explained Dr Murray to BBC News Online. "It would be faint and moving very slowly."

REPORTS OF CURIOUS FLASHES and fleeting clouds on the Moon may not be figments of wild imaginations, astronomers say. A new look at observations by the American satellite Clementine show that a small area on the Moon's surface darkened and reddened in April 1994. Why this happened remains a mystery.

For hundreds of years, people have reported seeing flashes, short-lived clouds and other brief changes on the Moon's surface. But astronomers have never been able to confirm the sightings. "The events were observed on many occasions, but most astronomers don't believe in them," says Bonnie Buratti of NASA's Jet Propulsion Laboratory in Pasadena, California.

On 23 April 1994, around a hundred amateur astronomers reported seeing a possible darkening of the Moon, lasting 40 minutes, near the edge of the bright lunar crater Aristarchus. At the same time, the US Department of Defense's Clementine satellite was mapping the lunar surface.

Intrigued by the amateur reports, Buratti's team has taken a close look at the Clementine data to see if the satellite also recorded the event. Sure enough, they found that the crater looked different before and after the amateur reports. "After the event, it looks redder," says Buratti, who announced the findings at a meeting of the American Astronomical Society in Padua, Italy, last week.

A burst of solar flare activity around the millennium could wreak more havoc on satellite systems and power grids than the Y2K problem, Reuters quoted a senior British Y2K planner as saying. A surge of solar flares or solar storms that can shut down power grids and burn out satellites was expected to peak in late 1999 and early 2000, a conference for Y2K planners was told. The last peak in the 11-year cycle of solar flares was in March 1989, when surge of atmospheric magnetic activity shut down the Hydro-Quebec power grid in Canada, leaving 6 million people without power for days.

A sneak preview of how solar flare activity could paralyze communications came in May last year when it is believed solar flare activity knocked out the Galaxy 4 satellite over the United States. For three days' chaos ensued as 40 million pagers stopped working, television and data broadcasts were disrupted, and many credit card transactions were blocked. The satellite's operator, PanAmSat, had to ask users to redirect their antennas to other satellites. The outage caused havoc in the U.S. medical system because many doctors relied on their pagers to be alerted about patients.

This next solar flare peak is expected to have a much heavier impact on communications satellites than in 1989, because so many more satellites have been put in place and are used more widely for mobile phones, the global positioning system (GPS), and as a route for the Internet.

Lloyd's, Britain's leading insurance market, is turning to astrology amid fears that a planetary conjunction in 2000 could force huge payouts. Some underwriters believe the phenomenon could herald a spate of worldwide natural disasters.

The conjunction, in which Mercury, Venus, Mars, Jupiter and Saturn will line up with the sun and moon, is predicted to generate a collective gravitational pull that could initiate earthquakes, tidal waves and volcanic eruptions. The alignment, which will happen in early May 2000, has long been a source of dire predictions among astrologers but has never been taken seriously elsewhere until now.

Last week, however, it emerged that D. P. Mann, one of the biggest non-marine syndicates at Lloyd's, has formed a millennium group to study such threats.

Conjunctions involving two or three bodies are relatively common but the last one to involve six was 6,000 years ago.

Dr. Julian Salt said there was fossil evidence that the last such conjunction had prompted earthquakes, volcanic eruptions and tidal waves. He said: "There is a real possibility that the collective force of these planets acting on the Earth's outer crust will cause it to slip. It could produce mile-high waves, hurricane-like winds and volcanic explosions worldwide."

Such disasters would come at the same time as problems caused by the millennium bug--the design flaw in computer chips that is predicted to cause global malfunctions in 2000 and is already causing concern to insurers.

Planetary conjunctions have been linked with disasters and other globally important events for centuries by astrologers. One of the most significant is said to be that of Jupiter, Saturn, Uranus and Neptune--which has happened only seven times in 3,500 years.

The last, in 1812, was followed by "the year of no summer" in which the northern hemisphere suffered freezing temperatures for months, destroying harvests and causing widespread famine. In 1962 a conjunction of five planets coincided with a huge earthquake that rocked the Middle East, killing 20,000 people in Iran. In Europe flooding killed more than 600 people.