It seems to have gone forever this 2010 Formula One world championship. It is the longest in the sport's history - 19 races, 17 of them now consigned to the history books. But it's going to end in a flash.

Usually there are two weeks between grands prix, but these last two races will be run on successive weekends - in Sao Paulo, Brazil, this Sunday (early Monday, Australian time), and Abu Dhabi, capital of the United Arab Emirates, the next.

Therefore there are a lot of kilometres for Australia's Mark Webber to cover, in the air and on racetacks, in these next 12 days.

But Webber will know soon enough whether he's world champion.

Despite his crash at the inaugural Korean GP nine days ago, he has good reason to be confident for Brazil. The Red Bull RB6 car remains the sport's pacesetter, and Webber won at the Interlagos circuit last year.

But the Ferrari rival he now has to overhaul, Fernando Alonso, has good form there too - he clinched world titles at Interlagos in 2005 and '06 when driving for Renault.

Interlagos is nestled beside a ghetto, its facilities are well short of F1's normal pristine standards, but - with its undulations and anti-clockwise direction of racing - it is one of the best on the calendar with a passionate crowd.

Alonso, 11 points ahead of Webber and the craftiest racer in the field, could seal his third title there.

If Alonso wins, and collects 25 points, Webber needs to finish at least fourth, worth 12 points, for the title fight to go on to Abu Dhabi.

Lewis Hamilton, McLaren's 2008 champion, trails Alonso by 21 points and needs to finish at least seventh if Alonso is victorious at Interlagos.

Sebastian Vettel, the young German who is Webber's teammate and dominated the Korean race until his Renault engine exploded, is out of title contention if he finishes behind Alonso.

Reigning champion Jenson Button, who sealed his title with the then Brawn team in Brazil a year ago, retains only a mathematical chance of retaining that crown with McLaren this season. He needs a miracle - or lightning to strike Alonso, Webber, Hamilton and Vettel at both remaining races.

Rain, at least, is always on the cards at Interlagos. And, as the Korean GP emphasised, once it finally got going, water makes F1 racing so much better. It ought to be compulsory, even if artificially induced.

If Alonso becomes a triple champion, either in Brazil or Abu Dhabi, in some eyes there will be a question of the legitimacy of that success.

Remember that at the German GP, at Hockenheim on July 25, Ferrari's other driver, Brazilian Felipe Massa, was leading but dutifully acceded to radio instructions from the team to let the following Alonso overtake him.

The victory that ensued for Alonso gives him seven points more than critics believe he should have - 231 rather than 224, which would be just four more than Webber.

Max Mosley, the controversial former head of world motorsport, is one who believes that Alonso should have been stripped of those seven points on top of the US$100,000 fine Ferrari incurred for employing "team orders".

"If by chance Alonso were to win the championship with a margin less than seven points I would say it would devalue the championship," said Mosley, who recently was speculated to be plotting a comeback to the presidency of the Federation Internationale de l'Automobile (FIA) but has denied any desire to oust Frenchman Jean Todt, the former Ferrari team principal he endorsed as his successor a year ago.

F1 ringmaster Bernie Ecclestone is an admirer of Alonso's driving skill but would prefer a more extrovert world champion.

Vettel, still only 23 but already the winner of eight GPs (three of them this year), was his pre-season tip and remains his preference, but he'd be happy with Webber too.

Either way he would get his greatest wish of the moment - a new world champion that would make five in the field for next season's 20-race series.

Michael Schumacher, Alonso, Hamilton and Button already have 11 titles between them - Schumacher seven of them.

While the great German's comeback from a three-year retirement has been a huge letdown, F1's switch from Bridgestone to Pirelli tyres next year may suit Schumacher and his Mercedes team better.

Webber has faded from the favoritism he had for this season's title before his Korean blemish.

Sir Jack Brabham - Australia's F1 champion in 1959, '60 and '66 - has been a strong believer in Webber throughout his often difficult career but fears he's blown the best chance he was ever going to have.

Alan Jones - Australia's only other F1 champion, in 1980, and not such a fan of his younger countryman, although he has come to admire his grit - was a steward at Korea's drenched Yeongam track when Webber ignominiously spun and crashed into a safety wall.

All the main contenders this season have used the eight engines allowed without incurring a 10-place grid penalty if they need a ninth. Alonso's engines are the most used.

Webber has one which has done only 242km, including many gentle laps behind the safety car in Korea, and which, provided there is no hidden damage from that crash, should have another 1750km in it - more than enough for the 600km of the Brazilian and Abu Dhabi races.

Perhaps the worst that can happen to Webber now is that he goes to the final race still a chance of becoming champion with Vettel out of contention but in a position to win that last race.

Unlike Ferrari, Red Bull Racing declares it is not into "team orders" - that each of its drivers should always race to win and not crash into each other, as they did so infamously in Turkey on May 30.

As unpalatable as manipulated race results are to many, it would be cruel for Webber to miss out on being a world champion if a teammate without that chance this season did nothing to assist him.

In light of the enmity between Webber and Vettel, that appears a possibility. In such a situation, the constructors' world championship that is almost certain for Red Bull Racing would be little consolation instead of having the world champion driver.

And, in the mix, there's still that crafty Alonso - and perhaps Hamilton - to overcome.