What did we learn today? Not a lot, but as Tom Clarkson said, we effectively have a two-day grand prix weekend. We've also got a new qualifying format to look forward to, so things are sure to be interesting either way tomorrow.

Here's Andrew Benson's report and I'll see you tomorrow at 02:30 GMT.

Cheerio!

We asked you to vote on who you think will be Lewis Hamilton's biggest threat this season, and 55% of you said it will be Sebastian Vettel.

Not many backed Nico Rosberg, who took 24% of the votes.

As is the way, Albert Park is bathed in sunshine now that the chequered flag has fallen.

The interchangeable weather meant it was a bit of a write off today, but there was an air of familiarity with how things panned out for the two Mercedes drivers.

Lewis Hamilton spent much of second practice relaxing, before popping out for a solitary timed lap and immediately put himself at the top of the timesheet. In contrast, Nico Rosberg crashed out of the session.

How will that affect their mentality going into the weekend, if at all?

1) Hamilton 2) Hulkenberg 3) Raikkonen 4)  Ricciardo 5) Sainz 6) Alonso 7) Button 8) Vettel 9) Perez 10) Kvyat

11) Gutierrez 12) Wehrlein 13) Grosjean 14) Haryanto 15) Rosberg 

No time: Magnussen, Palmer, Massa, Bottas, Ericsson, Nasr, Verstappen

Tom Clarkson
BBC Radio 5 live pit-lane reporter in Melbourne

"In a way I have always been an advocate of two-day GP weekends and that is effectively what we have got now."

Kimi Raikkonen is on a very determined walk down the pitlane. Not quite sure where he is off to but wherever it is, he wants to get there quickly. That's his session over.

In fact, the session is over for everyone as the chequered flag is waved.

Felipe Massa and Valtteri Bottas have left it late before deciding to get involved, probably because of the weather. Five minutes of practice remains and the two Williams cars head out for their first few laps of the session.

How are the McLarens getting on?

Fernando Alonso is sixth fastest with 1:39.895 while Jenson Button is P7, one tenth off his team-mates fastest time. 

Meanwhile, the rookies are racking up the mileage. Rio Haryanto has completed 22 laps, with Pascal Wehrlein just on his 21st of the session.

Poor Jennie Gow is copping the worst of the weather. 

While Jack Nicholls and Tom Clarkson are basking in glorious sunshine in the BBC comms box, it is raining on the pitlane, where Jennie is stood. 

Strange, strange weather.

Damp patches are still catching out one or two of the drivers. Sergio Perez had a brief trundle onto the grass, before Esteban Gutierrez locks up and is straight into the gravel at Turn 1.

Meanwhile, Nico Hulkenberg has moved to within four tenths of a second of timesheet topping Lewis Hamilton.

Up to the top of the timesheet Lewis Hamilton goes. 

The world champion is leisurely swinging the Mercedes round the circuit and is straight into P2 with his first timed effort, going six tenths of a second quicker than Kimi Raikkonen with 1:38.841.