The two satellites involved are:<p>OPS 6182 (10820, 1978-042A): <a href="https://www.n2yo.com/satellite/?s=10820" rel="nofollow">https://www.n2yo.com/satellite/?s=10820</a><p>SL-8 R/B (12443, 1981-041B): <a href="https://www.n2yo.com/satellite/?s=12443" rel="nofollow">https://www.n2yo.com/satellite/?s=12443</a><p>They are on head-on course. With a probability of about 80 percent they will miss each other. With a probability of more than 20 percent they will impact at a speed of more than 50000 km/h in an altitude of 780 km.<p>The two objects are not important (an old Russian rocket piece and an old US weather satellite).<p>But upon impact, the objects will create a large cloud of debris, that might collide with more objects, in the worst case in a chain reaction.<p>The danger is not falling debris, but that they will produce more damage in their orbit, maybe hitting more essential space equipment in the future.<p>No need to hide in a bunker.
Missed? <a href="https://twitter.com/EU_SST/status/1380601898164744199" rel="nofollow">https://twitter.com/EU_SST/status/1380601898164744199</a><p>> UPDATE: #EUSST’s network of sensors has only detected a single object or echo at passes over three radars after close approach. Most likely, the collision between SL-8 R/B and OPS 6182 did not take place. We will continue observing the objects to confirm this assessment.
Leolabs is tracking as well. Their data suggests a slightly lower but >2% chance of collision<p><a href="https://twitter.com/LeoLabs_Space/status/1380549507390259203" rel="nofollow">https://twitter.com/LeoLabs_Space/status/1380549507390259203</a>
You can watch a map of both here!<p><a href="https://www.n2yo.com/?s=12443|10820" rel="nofollow">https://www.n2yo.com/?s=12443|10820</a>
Tangent: I went to find UTC, and they've redesigned time.gov, it looks great on my desktop.<p><a href="https://time.gov/" rel="nofollow">https://time.gov/</a>
For anybody interested, they missed:<p><a href="https://www.n2yo.com/?s=12443|10820" rel="nofollow">https://www.n2yo.com/?s=12443|10820</a><p>(Link further in thread.)
In summary, a rocket body and an old weather satellite want to have a nice big hug. At high speed. Producing a cloud of 4 million fragments. 400 of which will bigger than 20cm.<p>Except that they'll probably miss (by about 10m). Probably.<p>Really interesting how much of this is statistical probabilities, and how much we can model about this. Right down to particle sizes.<p>And yet, I still have so many questions. Mostly involving the maths from <a href="https://what-if.xkcd.com/13/" rel="nofollow">https://what-if.xkcd.com/13/</a> and whether we could push either of them out of the way...
Here's the text without having to execute arbitrary code from twitter.<p>---<p>Update: according to #EUSST's latest estimates using data from its surveillance radars, the close approach between #space objects SL-8 R/B & OPS 6182 expected by tomorrow will have a miss distance under 10m and a Scaled Probability of Collision over 20%! +updates to follow soon<p>See the below plot for the conjunction plane at Time of Close Approach (TCA) #EUSST #spacedebris #space<p><a href="https://pbs.twimg.com/media/EycvaPZWQAMXjV2?format=png&name=large" rel="nofollow">https://pbs.twimg.com/media/EycvaPZWQAMXjV2?format=png&name=...</a><p>Update: #EUSST simulations indicate that the potential collision between the two #space objects would generate more than 4 million fragments. This plot shows the Delta-V distribution of the whole cloud of fragments #spacedebris<p><a href="https://pbs.twimg.com/media/EyhGxpjXMAE-pmM?format=jpg&name=small" rel="nofollow">https://pbs.twimg.com/media/EyhGxpjXMAE-pmM?format=jpg&name=...</a><p>More than 400 of the fragments generated by the potential collision would be larger than 20cm. Gabbard diagram shows the extent of orbital regimes that these simulated fragments would reach. #EUSST continues monitoring the probability of collision. Stay tuned for more updates.<p><a href="https://pbs.twimg.com/media/EyhQ_InWYAI5V5a?format=jpg&name=small" rel="nofollow">https://pbs.twimg.com/media/EyhQ_InWYAI5V5a?format=jpg&name=...</a><p>Latest update: according to #EUSST the close approach between #space objects SL-8 R/B and OPS 6182 remains stable in geometry and in Scaled Probability of Collision. Miss distance would be ~21m and Scaled PoC over 20%. This should be the last estimate until TCA.<p><a href="https://pbs.twimg.com/media/EyiBCnsXEAAgrCu?format=jpg&name=small" rel="nofollow">https://pbs.twimg.com/media/EyiBCnsXEAAgrCu?format=jpg&name=...</a>
it's 2021 now. They have presumably been tracking the orbits of there large objects for years now. Yes this is literally rocket science, but this collision is only a few hours away. Why can't they do better then a vague 20%?