Path: ...!local-3.nntp.ord.giganews.com!Xl.tags.giganews.com!local-1.nntp.ord.giganews.com!nntp.supernews.com!news.supernews.com.POSTED!not-for-mail NNTP-Posting-Date: Fri, 28 Jun 2024 18:03:21 +0000 From: john larkin Newsgroups: sci.electronics.design Subject: Re: Expedition to Europa Date: Fri, 28 Jun 2024 11:03:22 -0700 Message-ID: <0lut7jda7nlm266pbt0r28rdalupatjs0t@4ax.com> References: <63br7jpf7le468rnljlfhaol4432dt70lq@4ax.com> User-Agent: ForteAgent/8.00.32.1272 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Lines: 62 X-Trace: sv3-fQMLexqJ6UtTHswCWiJRAomUyc7RimXeDCn/t+xzbYkamIjJnyZ3t8xm18mVw/jYYGqSAagBZQEYy0L!YLVk7B7sRH9qZAqFojgo50l+iM5s3M7k4iucH/PrMKmb41GSCLcMm1B14qb6d4xQ66CiRwMq8GXv!O4nkkA== X-Complaints-To: www.supernews.com/docs/abuse.html X-DMCA-Complaints-To: www.supernews.com/docs/dmca.html X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.40 Bytes: 4060 On Fri, 28 Jun 2024 20:01:20 +0200, Jeroen Belleman wrote: >On 6/28/24 09:01, Jeff Layman wrote: >> On 28/06/2024 02:41, john larkin wrote: >>> On Fri, 28 Jun 2024 03:22:04 +0200, "Carlos E.R." >>> wrote: >>> >>>> On 2024-06-27 20:39, Joe Gwinn wrote: >>>>> >>>>> Excerpted from Aviation Week, June 3-16 2024, page 38: >>>>> >>>>> Located more than five times farther away from the Sun than Earth, >>>>> Europa seems an unlikely place to look for life. Surface temperatures >>>>> on the ice-shrouded moon of Jupiter average |-260F, and radiation >>>>> levels are high enough to kill a human being in one day. >>>> >>>> Being that far from the sun, where comes that radiation from? >>> >>> Our sun is friendly. The universe is deadly. >>> >>> It's a miracle that Earth is shielded. >> >> Indeed. It's a point often ignored by exoplanet life-seekers. It's one >> thing to find suitable conditions which might create life, it's another >> thing entirely to find conditions which could sustain life. Take this >> very recent review on Gliese 12 b: >> >> >> Note this comment: >> "..."Although we don't yet know whether it possesses an atmosphere, >> we've been thinking of it as an exo-Venus, with similar size and energy >> received from its star as our planetary neighbour in the solar system." >> >> An important factor in retaining an atmosphere is the storminess of its >> star. Red dwarfs tend to be magnetically active, resulting in frequent, >> powerful X-ray flares. >> >> However, analyses by both teams conclude that Gliese 12 shows no signs >> of such extreme behaviour, raising hopes that Gliese 12 b's atmosphere >> may still be intact." >> >> So a red dwarf tends to have frequent powerful x-ray flares, yet the >> only comment is that there were no signs of this extreme behaviour. >> Firstly, how can it be "extreme" if it's frequent, and how long have >> they been observing this star anyway? Secondly, did nobody consider what >> an x-ray flare would do to any life which might have formed on the >> planet? Never mind the planet's surface temperature and presence - or >> not - of an atmosphere. A blast of x-rays and probably other radiation >> isn't exactly know for its life-sustaining properties. >> >> And that's even supposing a red dwarf would be capable of providing >> "suitable" radiation levels capable of supporting an earth-like planet >> in the first place. See: >> >> > >Oh well. Earth has a toxic, oxidizing atmosphere, with free oxygen and >worse, ozone. And yet life thrives. Earth wants to burn down most of the stuff that we build.