Ahead of today's opening practice session their temperature is 27 degrees C, while the track temperature is 42 degrees.

In many way, this is the most pointless session of the year, for being that qualify and the race are held as day turns to night, this session, being held at 13:00 (local time) will in no way represent the conditions of those that follow.

On the other hand, it gives teams the opportunity to try new parts for 2018 and give reserve drivers a run. Also, with an eye on next week's test, and next season, it will allow teams to try the Halo device once again. After all, other than this session, and the two days next week, the drivers don't get an opportunity to run their cars in anger again until late February.

Talking of reserve drivers, George Russel is in Esteban Ocon's Force India for this session, while Antonio Giovinazzi is in Kevin Magnussen's Haas.

As we await the start of the session, Bottas' car appears to be sporting the farmyard gate, such is the size of the sensor device fitted to the Mercedes.

The lights go green and Hartley leads the way, followed by Hulkenberg, Ericsson, Grosjean and Bottas.

While Bottas could yet leapfrog Vettel for second in the championship and Raikkonen could pip Ricciardo for fourth, the main interest this weekend is the battle for sixth in the team standings between Toro Rosso, Renault and Haas.

Raikkonen is another early riser, the Ferrari sporting a very interesting sensor device at the rear of the car as the Maranello outfit checks out diffuser data.

Old MacDonald - sorry - Bottas posts the first time of the weekend, the Finn stopping the clock, indeed almost knocking it off the wall with that sensor - at 44.180. Teammate Hamilton, with no such device attached, posts 41.664.

Bottas subsequently improves to 43.060.

Six minutes into the session and all bar Stroll have made an appearance.

Ericsson and Giovinazzi are running the Halo.

While Bottas gets down to 42.922, Hamilton can only manage 41.659. The Finn is on the supersofts while his teammate is on softs.

As Stroll finally emerges from his garage most other drivers have opted to 'sit this one out', leaving the Mercedes duo an almost empty track.

Stroll complains that his right mirror is a little bit too high. Though he admits he can make do for this session.

Did we hear that right? "Funky driving for the first lap please," Alonso is instructed.

Despite his mirror issues, Stroll posts 43.414 and Russell 52.844. The Briton, the fourth driver to post a time, subsequently improves to 44.392.

Hulkenberg is advised that his tyre temperatures and pressures are "on the low side".

Twenty minutes in and Hartley becomes the fifth driver to post a time (47.137).

Bottas begins his 12th lap of the session.

A flurry of activity sees Ricciardo, straight on to the ultras, go second (41.581), while Massa, Hulkenberg, Gasly and Grosjean post their first times of the weekend.

Back on track, but without that weird device at the back, Raikkonen goes quickest in S2 and S3, finally crossing the line at 40.638. The Finn is on the ultras.

Ricciardo leapfrogs Hamilton with a 40.968 to go second. His Red Bull teammate, on supers, posts 42.172 to go 5th, 1.534s off the pace.

Despite a significant lock-up, Massa improves to fourth (41.723) on ultras.

Vettel posts 41.930 to go sixth on the ultras.

Half-an-hour in and Alonso, Vandoorne and Perez are the only drivers still to post times.

Quickest in all three sectors sees Raikkonen raise the bar with a 39.841.

As Ricciardo runs wide in the final corner, clearly struggling for grip, Perez posts 41.441 to go fifth, thereby demoting the Red Bull driver to sixth. However, the Australian responds with a 40.968 to go third.

"I don't have any feeling with the steering wheel," complains Verstappen, "it feels really bad."

"Struggling bad with the rear, entries and exits," reveals Hartley, "also at high speed". And that's before he hears he's got another grid penalty after his team changed his MGU-H.

A 40.192 sees Vettel go second, thereby meaning that Ferrari is 1-2, though the weekend is still in its infancy.

As we reach the stage at which drivers have to hand back their extra set of tyres, which usually means a lull in the action, as has become the norm at recent races, the Mercedes duo head out to take advantage of the empty track.

With the tarmac to themselves, the Silver Arrows go first and second, Hamilton posting 39.126 and Bottas 39.741. Both are on the ultras, the Briton now 0.715s clear of Raikkonen.

At half-time, it's: Hamilton, Bottas, Raikkonen, Vettel, Verstappen, Perez, Ricciardo, Vandoorne, Massa and Hulkenberg.

Alonso has yet to post a time, though he has completed 8 laps. His crew have completed four setup changes and five runs thus far, according to the team.

Despite the fact that conditions will be entirely different, drivers now begin their longer runs.

That said, Grosjean improves from 14th to 9th as he makes the switch to ultrasofts.

Posting PBs in all three sectors, Massa improves to 7th with a 40.723.

Clearly out to impress Williams - or anyone who's watching - Wehrlein is up to 12th in the Sauber.

As Hulkenberg spins at T14, Verstappen, now on ultras, goes second, 0.28s off Hamilton's pace, having been quickest in S3.

The Renault duo and Stroll are the only drivers yet to try the ultrasofts.

Now it's Giovinazzi's turn to have a spin, the Italian getting it a*** about t** after carrying too much speed into T17.

Shortly after Giovinazzi's moment in T17, Russell runs wide there also. The Briton is advised that it was the cross wind that caught him out.

With 23 minutes remaining, Alonso finally posts a time and it's good enough for 6th (40.522).

Though he leapfrogs his teammate with a 39.757 to take fourth, Vettel, still 0.631s off Hamilton's pace, is not happy with the handling of his car.

Stroll runs wide in T1, the Canadian, currently 20th, still to try the ultras. That said, the Williams driver subsequently pits and switches to the purple-banded rubber.

Having previously been asked for a "funky" lap, Alonso is now told to "stop normally".

From out of nowhere Vettel produces a 39.006 while a mistake in T17 means Raikkonen can only manage fourth (39.518).

"And that's the session done for Carlos," reveals Renault. "Planned engine change for his car ahead of FP2; which takes time!"

Grosjean spins at T19, the Haas going backwards into the barrier but not outwardly incurring much damage. "Check the rear wing," he warns his team before pitting.

Bottas is coming out for a late run with the Halo.

The session ends, Vettel is quickest, ahead of Hamilton, Verstappen, Raikkonen, Bottas, Perez, Alonso, Vandoorne, Massa and Ricciardo.

Russell is eleventh, ahead of Grosjean, Stroll, Gasly, Sainz, Wehrlein, Hulkenberg, Giovinazzi, Ericsson and Hartley.

Check out our Friday gallery from Yas Island, here.