OneGuyFromBarlick

Excellent achievement.

Unworthy thought - but I can't help wondering why they need such a large number of staff in the control room.There must have been a couple of hundred easily. The process is a quarter of a million miles away, and it's mainly under the control of a computer - what do they all actually do?

Participate in a landmark event David.....
I am so glad they achieved a soft landing. Particularly as it overshadows Russia's attempt to pip them at the post.....

I've copied this from an email we received today from the Society for Popular Astronomy. I'm posting it on OG because it shows the scale of plans for Low Earth Orbit satellites and emphasises why astronomers and others are so worried about the issue....

You may be aware of the growing threat to amateur astronomy posed by the surge in the number of satellites placed in low Earth orbit (LEO). Most of the satellites *should* be fainter than naked eye brightness but they still pose a problem to telescopic observations, astrophotography, spectroscopy and radio astronomy.

According to the Union of Concerned Scientists’ satellite database <https://www.ucsusa.org/resources/satellite-database>, up to the end of 2022 there were 6,718 functioning satellites in Earth orbit of which 5,938 were in LEO and over 80% of those were launched in just the past 3 years. There are proposals for an estimated 250,000 satellites to be launched into LEO over the next decade. This represents about a 40-fold increase over the current number.

Jonathan McDowell maintains a list of planned constellations on *Jonathan's Space Pages <https://planet4589.org/space/con/conlist.html>* where, up to 22-Aug-2023, he shows a maximum total of 543,811 LEO satellites from 18 different planned constellations. He doesn’t give a timescale but, if all are launched as planned, this would eventually represent a more than 90-fold increase over the current number!

The FAS is organising a survey to investigate the effect that these satellites have had on amateur astronomy observations. The survey will run until midnight on 22nd September 2023 after which the results will be collated and analysed and presented at *IAU Symposium 385 Astronomy and Satellite Constellations: Pathways Forward* (2nd– 6th October 2023, La Palma, Canary Islands, Spain). The recommendations from that symposium will be used to advise the international bodies that make policy on the operation of satellites and the sustainable use of space

In the wider scheme of things - and speaking in very broad terms - is it possible that such a number of communication satellites will do more good for the world than a few elite scientists taking photos of places which are light years away?

Discuss.

Advocatus Diaboli

Not just a few elite scientists but a world of both professional and amateur astronomers and physicists. And who's going to be in control of the 500,000 satelites? We don't seem able to control air traffic, never mind space traffic.

I wonder if anyone has laid plans for what happens to the satellites when they reach the end of their useful lives?
Surely they won't simply leave it to chance whether they burn up on re-entry or not.....

A few with a sense of responsibility are planning to recover them and there are some folk who hope to make a business of `catching' them for scrap (modern day Steptoe & Son!) but I bet many will just want to leave them to die. There should be international agreement that all those who launch them should take on responsibility for dealing with them at the end of their working life. But I can't see Russia or North Korea signing up to it - and perhaps the US if Trump gets back in the White House.

A good proportion of the objects such as the Starlink devices are "cube" satellites. They are quite small 6-9" cubes. As such not much chance of these surviving re-entry at end of life.

I'll believe it when I see it!
`UK expected to re-join Horizon science scheme' BBC

"According to sources in Brussels, there has been movement in EU-UK talks."
I agree Peter. How often have we seen the above and then been disappointed yet again.... It must be a nightmare for the people who have to arrange funding and staffing the projects.....

This short video is worth watching - simple, educational and entertaining!
`Three minutes to the centre of the Earth' BBC

That video was very interesting Tize, and it creates a lot of questions. One being ‘How do they know that it’s 6000 degrees at the very core?’
Probably best not to answer in a detailed way ( = me), haha.

Good question. Obviously they can't use any direct temperature measuring instrument but they can work out such things indirectly from lots of other data such as knowing the composition of the core from bits that work their way to the surface, the calculated pressure from the physical properties, way seismic ways travel through it, the amount of radioactivity and so on. There's a lot that's already known and each time you find out a bit more you can apply it to all that you already know.

Cathy, It's not just you! I don't understand these things either.....

Ah “bits that make their way to the surface “
I can see it now. Thanks Tize
Our planet amazes us every day .

I heard about THIS for the first time this morning. The human cell atlas.
Mission To create comprehensive reference maps of all human cells—the fundamental units of life—as a basis for both understanding human health and diagnosing, monitoring, and treating disease.

This article has a good up to date diagram of the path of deep ocean currents around the world...
`Deep-diving robots checking for climate collapse in our oceans' LINK

No link embedded Peter.
It's a subject that worries me when it's brought to my notice. It's such a fundamental mechanism in our weather and so massive, and yet we damage and alter it and don't seem to care.....
It's the nature of these things to be quiescent for decades or even millennia but then to reach a tipping point. If that happens with deep ocean currents it will be really serious.

Thanks for pointing out the omission. I've added the link.

This shows just how negligent the Israeli military and government were in missing preparations for the attack on 7 October...
`How Hamas built a force to attack Israel on 7 October' BBC

I saw the report as well Peter and it beggars belief that they didn't know about it. I am convinced that they may well have known about the threat but let it happen as a fait accompli for an invasion of Gaza. The Israeli government has already said that they are going to take over administration of the strip when they have finished levelling it. No mention from them either that the attack was multi factional and not just the military wing of Hamas. Some of the hostages apparently are held by other groups. Interesting also that the bulk of the Palestinians that they are releasing from jail are children who get thrown into prison for throwing stones.

Ian, I thought the Netanyahu government had said they would take over responsibility for security and not administration.....

Fairly sure the quote I heard said administration, time will tell when they have slaughtered a few more thousand. What is left in lots of areas will only be fit for the bulldozer and once cleared if they are in charge what is to stop expansion with more kibbutz or claiming the area as Israeli territory?

There's been very little mention of the Thai workers who were abducted along with the Israelis on 7th October. I learnt of them from a Times article at the start of the crisis. The citrus and avocado farms depend on them and the the workers need the money to send home to their families. The Thai government seemed to ignore the pleas of the families to help them. Of course, nobody is mentioning that Thailand is the favourite holiday destination of Israelis.