When they near the Sun they throw off a tail of heated dust and gas that in some cases is visible during the day.Spacecraft have already landed on asteroids, the rocky leftovers from the formation of the solar system Comets are different; little is known about their origins. They might be formed in other parts of the galaxy and travel between stars. Some scientists think comets provided the water for the Earth's oceans when the planet was forming. Others suggest that they could even carry life or the building blocks of life.Though the Rosetta will not test for signs of life - because that was not considered when it was being designed more than a decade ago - it will analyse the chemicals in the nucleus of the comet But first it will have to find the nucleus. Since the start of the week, the Leeds United fan has sold 9.5 million shares.Although there has been much talk of various consortia working on a deal to buy the debt-ridden, relegation-threatened club, it is difficult to see how a takeover can deliver any value to Leeds shareholders.

The gases and dust thrown off comets as they near the Sun occupy huge volumes of space, but the nucleus - composed, scientists believe, principally of ice - is comparatively tiny.Dr Ian Wright, of the Open University, who has worked on the lander system for the project, put the challenge in perspective: if a comet was the size of London, including the M25, then finding the nucleus was like "landing on a 12-inch ruler perched on Nelson's head in Trafalgar Square".The nucleus of Comet CG is about 1.3 miles (two kilometres) in radius, roughly the size of Heathrow airport, while the lander is about the size of a large washing machine.Even if the Rosetta locates the nucleus, the mission scientists are still unsure how solid it will be. At present, Easier's most appealing asset is its £5.4m cash pile, which compares with a market capitalisation of just £4.8m at yesterday's close.Leeds United dropped 0.38p to 2.87p as the Greek shipping tycoon Andreas Dracopoulos continued to sell down his stake in the stricken Premiership club. He sold 3 million shares at 3.12p, leaving him with a 1.3 per cent holding of 4.6 million shares. He now owns 80 million Innovation Group shares through his ICE SAS investment vehicle, which accounts for 18.4 per cent of the company.The move seems to mirror exactly Mr Bonnier's stake-building in Regus last year. He initially built up a large position through a contract-for-difference arrangement with Cantor Fitzgerald and then moved to buy the underlying stock in the office space provider. Buying into a company via a contract for difference allows an investor to greatly leverage his capital. So one can get exposure to £1m of shares in a company with significantly less in the way of hard cash.Austin Reed jumped 7p to 150p as Dawnay, Day disclosed a 4.4 per cent holding in the group.

Market professionals reckon the mini-investment house is likely to try to prompt a bid for the out-of-favour retailer. Easier, the cash shell, was unchanged at 19.5p as the company's management team indicated that it intended to take the company into the property investment businesses. According to the talk, the group is considering a move on its rival Synstar, up 3.5p to 75p. Arbuthnot Securities noted that operationally there is much in the way of synergy between the two companies. With net funds of £46m, Computacenter certainly has the firepower to complete such a deal, should it wish, says Arbuthnot.Carphone Warehouse pegged at 136.25p as Geoffroy Roux de Bezieux, a director, disclosed the sale of 500,000 shares at 135p, netting him £675,000. Bulls were back in control of the FTSE 100 yesterday as news that Standard Life had finally completed the disposal of £7.5bn worth of equities set the blue-chip index soaring 72.7 points to 4,515.6.

After the disposal he retains a holding of 12 million shares or 1.4 per cent.Meanwhile at easyJet, down 8p to 354p, the founder and former chairman Stelios Haji-Ioannou sold down his holding. The Greek tycoon netted £14m as he cut his holding in the no-frills airline from 17.5 to 16.5 per cent and said he would use the cash to fund the development of his other business interests, which include easyHotel and easyCruise.Innovation Group, down 0.25p to 38.25p, saw the dot entrepreneur Robert Bonnier actually purchase the underlying shares he controlled in the software group via his contract-for-difference agreement with the broker Cantor Fitzgerald. Credit Suisse First Boston urged its clients not to read too much into this. According to the Swiss broker, the setback at QuickBooks is specific to that product and should not be taken as meaning that things are not going well for Sage's Peachtree business in the US.William Hill put on 22.75p to 466.5p thanks to UBS, which upgraded its rating on the bookmaker to "buy" from "neutral". UBS named William Hill as its top pick in the UK gaming sector and raised its price target on the stock from 470p to 545p Dimension Data was not so fortunate.