Thanks all for tuning in, for what has been an extraordinary day for space and science history. We've enjoyed all your comments but for now that's it from Jonathan Webb, external and Melissa Hogenboom, external on the BBC Science team. Thanks also to our social media colleagues, external.

There will be a full media briefing at 13:00 GMT on Thursday and there will be more comment, analysis and updates on the BBC News science pages.

We leave you with the remarkable "farewell" image of Philae as it dropped away from the orbiting Rosetta craft, towards an uncertain but exciting future.

Image source, ESA/Rosetta/MPS

The lengthy list of credits indicates just how many people's hard work went into the history-making voyage that culminated in today's events.

Congratulations to them all.

tweets, external: That's right.... I have a bounce in my step. #YouWouldToo #HarpoonGate

From the web comic xkcd, external:

Image source, XKCD

Stephan Ulamec went on to explain that the early data suggests Philae may have lifted and turned slightly after touching down for the first time.

There was a signal suggestive of turning - which stopped after two hours.

"Maybe today, we didn't even just land once - maybe we landed twice," he told the room, to laughter and applause.

"We will know a lot more tomorrow."

Image source, Esa

Philae lander manager, Stephan Ulamec, says: "It's complicated to land on a comet it's also complicated to understand what has happened during this landing.

"What we know is we touched down, we landed at the comet at the time when you all saw us cheering and when it was announced. We had a very clear signal there, we received data from the landing - housekeeping and science data - that's the good news."

Then he told us the bad news. The anchoring harpoons did not fire, and so they are not anchoring the lander to the surface.

"We still do not fully understand what has happened."

Jean-Jacques Dordain, Director-General of Esa, said that Philae's radio link and power are functioning.

"When you have radio and power, you collect data."

The live stream has begun for the final press briefing - watch using the "live coverage" tab above.

And here's an update from the Open University's Prof Monica Grady, speaking moments ago on BBC News:

"There is data in the can, we have to wait for it to be transmitted. We will know by midday tomorrow how much data we've got."

Any minute now... The final briefing of a day when history was made.

tweets:, external Ptolemy on board @Philae2014 has data from a mass spectrometer safely down on the ground; exciting to have chemistry from a comet! #cometlanding

A mass spectrometer is a device which uses the mass of atoms to understand their chemical composition.

You could pass the time with this remarkable 3D tool that shows you exactly where Rosetta is, and how it got there - courtesy of the European Space Agency themselves:

http://sci.esa.int/where_is_rosetta/, external

The briefing has now been postponed until 19:00 GMT - Esa suggests you fetch a glass of wine before settling down to see the latest data from comet 67P, 300 million miles away.

Watch a moment of pure joy in our "key video" tab above: excitement and tears from the Open University's Prof Monica Grady.

"It's landed - I've waited years for this", she says, as she hugs our very own science editor David Shukman.

This illustration shows the many instruments on Philae - including Rolis (centre right) which has already sent us an postcard, external of the looming comet surface.

Image source, ESA/ATG medialab

The Sky at Night team tweets, external that they are hoping to see surface images at the imminent briefing.

They are not alone!

Esa TV will run a live briefing in five minutes' time (18:30 GMT).

Watch using the "live coverage" tab above.

John Grunsfeld, astronaut and associate administrator for Nasa's Science Mission Directorate says:

"This achievement represents a breakthrough moment in the exploration of our solar system and a milestone for international cooperation. We are proud to be a part of this historic day and look forward to receiving valuable data from the three Nasa instruments on board Rosetta that will map the comet's nucleus and examine it for signs of water.

"Small bodies in our solar system like comets and asteroids help us understand how the solar system formed, and provide opportunities to advance exploration.

"It's a great day for space exploration."

A new video is now up on our key videos tab above, with Esa project scientist Dr Matt Taylor. You may remember him from his tattoos, or have seen his name trending on Twitter earlier today...

He says people have invested their entire lives on the mission.

"I can't put words to it - it was beautiful".

Rebecca Morelle
Science Correspondent, BBC News

Rebecca tweets, external: Team investigating what no harpoons and unexpected telemetry means - awaiting surface picture to see what's happened #CometLanding #Rosetta

To clarify, that is the first image taken by Philae's camera ROLIS as it dropped towards its target landing site on the comet.

Emily is among many planetary scientists who are extremely excited, external to see it.

ROLIS is positioned on Philae's "balcony" pointed downward. It should now be about 31cm from the comet's surface.

tweets, external: This is a ROLIS image of the comet!!! Right on target!!!!!

Image source, ESA