2002 NT7 is closest at 16.50 today, UTC time. It will be 61 million kilometers away and they know the distance exactly to within 127 kilometers, and the time of the flyby accurate to the nearest minute. It is no risk to Earth.

It is already well above our orbit though, it crossed the orbit of Earth several days ago on the 8th. And 61 million kilometers is further away than Mars at its closest. It is not very close.

Earth's orbit in blue, 2002 NT7 in white.

More details here

It actually crossed our orbit already on the 8th. It is already moving upwards away from our orbit. Earth is catching up on it from behind and is closest on the 13th at 61 million kilometers. That's further away than Mars at its closest, and much further away than Venus at its closest.

The red top tabloids and other sensationalist press and YouTube videos are going wild about this, in many different languages too. It is my most often asked question at present from scared people, whether their lives are at risk because of this asteroid. It doesn't matter if they say it or write it in Russian, Spanish, or whatever language it is, or enlist the services of clairvoyants or astrologers to pronounce about it - it is still utter nonsense.

For any of you who haven't seen it, here is a stereo image of Ultima Thule, alternating between two images which help if you don’t have 3D Anaglyph glasses. The interesting thing about it is that there is no sign that the two lobes are more than slightly squashed by touching each other. They seem to have formed like this, in a gentle process, as separate objects that gradually grew by gravitational attraction of smaller pieces. Then eventually, the system lost energy probably due to influence of some third moon, and as they came together gently touched each other.

There are many sensationalist stories today about this research. But they were looking at the past history of this volcano. Not the present. It is not ready to collapse right now and is closely monitored. Likely to be centuries to millennia before a collapse if one is possible at all - it may have ended that phase too. A normal eruption would be devastating for local people and it is closely monitored. It probably did not make the Neanderthals extinct but the 2–4C global temperature reduction for a couple of years might have helped modern humans to get an edge over the Neanderthals at a critical time in the past.

Example stories to debunk:

This may be a welcome change from the climate change discussion which got a bit heated over the weekend. The Talanoa climate change story telling dialogs. They have been going on all day, in seven simultaneous sessions, today, 11th December 2018. The stories have been archived and you can rewatch them via Skype

Talanoa is a traditional word used in Fiji and across the Pacific to reflect a process of inclusive, participatory and transparent dialogue. The purpose of Talanoa is to share stories, build empathy and to make wise decisions for the collective good. The process of Talanoa involves the sharing of ideas, skills and experience through storytelling.

This is running as a scary story in the news today. I’m asked if it means we are all going to die. No, it does not. That was a 10 °C rise and we are headed towards 3.6 °C at maximum with the Paris pledges already. With the Paris agreement if they continue to ramp up the pledges they should get within 2 °C, many countries have already got to that point in their pledges and a fair number to within 1.5 °C. Others, especially China and Russia, face huge challenges but are rising to them especially China. We aren’t currently headed for anything like 10 °C.