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About Listy

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  1. Vikram lander found - most definitely not in a single piece!
  2. Somebody tried: There is no piece of technology, no matter how old or simple, that can't be made worse by sticking bluetooth on it and connecting it up to the internet!
  3. Saw the Starlink-2 train pass almost directly overhead tonight. Was able to see about 30 of the 60 satellites during the ~10 minute pass - the sun had only recently set so the sky was still quite bright. Most satellites that I saw were spread out with 20-30 second gaps between each one that I could see, but there were a few clumps of 3-4 close together still. Most seem to be slowly spinning/tumbling at the moment, with brightness varying from invisible/very dim to fairly bright (4-5 reached Sirius level bright) over about a 10-20 second period.
  4. The big challenge for Starlink if it really does want to expand beyond serving rural westerners, is that mobile internet in the developing world (in Asia at least, which is by far the most affluent and populous 'developing' region) is already pretty fast, almost ubiquitous, and insanely cheap (cents per gigabyte cheap). Plus, you don't need to buy and carry a special base station around with you. The idea that there are billions of people just waiting to get online in the developing world but can't because there's no phone line nearby doesn't reflect today's reality - everywhere in the world, most people almost certainly live within the range of a phone tower these days. Today it's much more likely that people who remain offline either see no need for the internet, or they can share a phone with a family member who does have internet, or its simply unaffordable - in which case, they won't be able to afford Starlink either. Telecommunication companies outside the west also tend to be fairly young and a lot more dynamic than the dinosaurs we are used to - much like a certain upstart rocket company that's popular around here in fact . Certainly in Asia, if Starlink comes close to being competitive, those companies wont just sit still - they'll respond by dropping prices even more, and rolling out thousands of new phone towers faster than Elon can chuck satellites in the sky. If that happens it will be a win for consumers, but it might not be a win for Starlink.
  5. I wonder how far south the typical catch zone will be for a sun synchronous launch? If there's no boost back involved then somewhere in the southern ocean roughly between Wellington & Christchurch? Mahia peninsula is already on the fringe of the roaring 40's, and a number of Rocketlab launches have experienced weather delays so far. The chopper pilots will be earning their pay trying to catch a spent rocket in a 50 knot westerly.
  6. If a lunar base is ever established, it also sounds like NASA & SpaceX would both be keen to get a better handle on how best to stop everything nearby (habitats, rovers, equipment, astronauts etc) from being turned into a sieve every time a rocket lands or takes off nearby and starts flinging dirt around at 3km/s in an environment where there's no air to slow the debris down. " The exhaust of the Shuttle’s solid rocket boosters pulled several thousand bricks from the wall of the launch pad’s flame trench, slammed them into each other, creating many thousands of fragments, and blew them as far as a kilometer from the pad."
  7. The Keck Observatory was built around the same time as Hubble (mid-80's) & probably represented the pinnacle of ground based observatories at the time. It's got a bigger mirror (10m vs 2.4m), cost a lot less to build (~$200m versus $4.7billion) & costs less to operate per year ($15m versus $100m) than Hubble. So based on cost alone, ground telescopes will be around for a while yet. There are generally no do overs in space when something goes wrong (hello Hitomi X-Ray telescope), so new technology and techniques will continue to be honed on the ground too, before being tried in space (Hubble is a happy exception to the no do overs rule). There's a lot of unique & exciting things that can be done with telescopes in space (eg you could set up some truly huge interferometry arrays) though, so it's likely that more and more of the flagship scale observatories will become space based in the coming decades.
  8. The claim seems to date to a paper published in Science in 2012: Next-Generation Digital Information Storage in DNA From the methods : "Theoretical DNA density was calculated by using 2 bits per nucleotide of single stranded DNA. The molecular weight of DNA we used was based on an average of 330.95 g/mol/nucleotide of anhydrous weight for the sodium salt of an ATGC balanced library. This results in a weight density of 1 bit per 2.75 x 10-22 g, and thus 4.5 x 10-20 bytes per gram. Of course, practical maximums would be several orders of magnitude less dense depending the types of redundancy, barcoding, and encoding schemes desired." The 215 petabytes / gram figure is certainly much closer to the realistic 'practical maximum' the authors mention & it's still a huge number! DNA can be encapsulated in silica for long term error free storage (1 week at +70 degrees C & estimated to be ~2000 years at +10C, or up to 1 million years at -20C). 1 million years is about the age of the oldest fossil remains where DNA fragments have been successfully extracted & sequenced as well, so it would seem that on Earth at least for very long term storage controlling temperature & the chemistry of the surrounding environment is more important than worrying about radiation damage. In deep space maintaining your DNA data bank at an ultra cold temperature might be fairly easy & radiation might become a much bigger concern.
  9. This is a question that has a lot of relevance right now - for example when the Square Kilometer Array telescope in Australia & South Africa starts operating it will generate & store about an exabyte of processed data per day. There are more than 250,000 radio telescopes in the array & each one will generate 160 Gbits of raw, unprocessed data per second - which I think works out to be about 400 exabytes of raw data per day in total before processing. For data storage density nature currently has us well beaten - 1 gram of perfectly encoded DNA could theoretically store 455 exabytes of data, if you could keep it in a state that was both stable & somehow readable.
  10. It's in the early access / pre-print section for now, which may require a subscription to access, but the link is below. I imagine it will be published with the next issue of PNAS in a few days. "A seismically induced onshore surge deposit at the KPg boundary, North Dakota"; Robert A. DePalma et al. I had a quick read - it sounds like a remarkably well preserved site & likely captures the immediate aftermath of the Chicxulub impact (eg there are a couple of impressive looking CT scans of a fish gill fossil full of tiny glassy spherules, that might be impact ejecta) but I'm no paleontologist so I'll leave any further interpretation to the experts.
  11. They are not specifically meant to be impactors, but a pair of 75kg tungsten blocks (cruise stage mass balances) were detached from the cruise stage & impacted on the surface during EDL. Similar tungsten blocks were released when Curiosity landed & the impact site later was imaged by HiRise, allowing for some science to be done (mainly impact size/morphology related), so I expect the same will be done with the InSight debris field.
  12. This excellent close up footage quite clearly shows little puffs of gas coming from the fairings at around 1:50. (The whole video is quite spectacular!)
  13. The NIH didn't publish that article about copyrighting DNA - It's just hosted on pubMed, which is the NIH / National Library of Medicine's gigantic database of almost everything ever published in biomedical journals worldwide since the dawn of time - even silly, whimsical letters to the editor, like this particular piece was. The letter is 15 years old & mostly a tongue in cheek commentary about mp3 file sharing services like Napster etc. It was written at a time when a DNA sequence potentially had some monetary value, because sequencing was hard, and slow and expensive. The author noted that natural sequences of DNA cannot be easily patented and cannot be copyrighted (a 'natural' DNA sequence is not a work of authorship) and so whimsically (the author was quite clear about that) proposed that by converting DNA sequences into mp3 files, the owner of a DNA sequence could charge a fee for other users for the right to 'listen' (decode) to that DNA sequence, and thus get rewarded for going to the effort of sequencing the DNA in the first place. Today, DNA sequencing is fairly cheap & quick, so trying to own or protect a natural DNA sequence like this today is pointless.