Posts by markmccaughrean@mastodon.social
(DIR) Post #B2kIi1xZg3aHGn3f4i by markmccaughrean@mastodon.social
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On this day, forty years ago: 28 January 1986.I was working on my astronomy PhD in the terminal room at the Royal Observatory Edinburgh.Someone came in & told us the awful news. After so many launches & astronauts, we’d grown blasé & didn’t pay much attention anymore.That changed in 73 seconds on that cold day & we learned again that space is hard. I still remember their names:Onizuka, Smith, McAuliffe, Scobee, Jarvis, Resnick, & McNair. Ad astra, STS-51L Challenger crew ✨#space
(DIR) Post #B4EGWZsfPTnndIUFiC by markmccaughrean@mastodon.social
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Coming up soon: the 40th anniversary of the ESA Giotto probe’s flyby of Comet 1P/Halley, with closest approach at 00:03:02 UTC on 14 March 1986.Giotto flew within 596 km of the comet at a relative velocity of ~250,000 km/h, so it was all over quickly, but remarkable views of the 14.5 km long dark icy monster were had.Albeit not this composite made later by Nick Thomas on the Giotto team. What happened as images streamed back to live TV is another story 😬✌️ Who remembers that night?
(DIR) Post #B4vnCD0sNCDZCeUya8 by markmccaughrean@mastodon.social
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You'll likely catch this image a million times in your various feeds: Earth as seen by Reid Wiseman from Artemis II en-route to the Moon.My first thought? That's *really* noisy 🧐But then I realised – it's the *nightside* of Earth, illuminated by the almost full Moon, not the Sun 🌕The bright limb at lower-right is where the dayside starts, & the fact that you can see aurorae, airglow, & cities in Europe, Africa, & S & N America also gives the game away. Cool.#Photography #Artemis
(DIR) Post #B4vnCDZcI20UwOkijQ by markmccaughrean@mastodon.social
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Two planets for the price of one 🙂This screenshot from Celestia is pretty close to the orientation of the #Artemis II picture taken of Earth's nightside.The stars in the background line up pretty well, & as @Nina_cried suspected, the bright object to the lower-left of Earth is Venus 👍And as the original shot suggests, the Sun is behind Earth, slightly to the lower-right of centre, hence the bright dayside limb there. #Space
(DIR) Post #B4vnCDy4p5ZaAGCFrE by markmccaughrean@mastodon.social
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I tried getting Astrometry.net to solve for the starfield first, but it failed (perhaps not surprisingly given the stupid big planet in the way).So I went into Celestia, set the time to a reasonable guess for when the Artemis picture might've been taken (I ended up at 00:30 UTC last night), played with the orientation, & bingo – everything lines up.Not completely perfect, but good enough for government work.
(DIR) Post #B4vnCEbQSn348IbgBs by markmccaughrean@mastodon.social
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Ha – I promise I didn't check before fiddling in Celestia, but I see that the EXIF information in the original Artemis JPG says it was taken at 00:27:39, presumably UTC.And putting that time into Celestia, I get a sub-latitude of -2.8º, a sub-longitude of -13.9º, and a distance of ~10,000km from the surface of Earth.Which is niche information unless you're a planetary aurora specialist like Jonathan Nichols, who asked 🙂
(DIR) Post #B51b8Tnvy77ZcWeyzA by markmccaughrean@mastodon.social
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Hive mind: I'm a bit confused about the claim that tonight's #Artemis II lunar flyby will be the first time humans have seen the far side illuminated. The claim is that the all Apollo landings took place on the nearside when the Moon was full, so the far side was dark.That can't be entirely true: Apollo 8 saw some of the far side, as did all other Apollo flights. And the Moon is ~80% waning gibbous tonight from Earth, so only ~20% of the far side is illuminated today.What am I missing?
(DIR) Post #B52pnMqyJHekS3Qpv6 by markmccaughrean@mastodon.social
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Good morning from Heidelberg 👋As I'm due to to do a few radio interviews about the #Artemis II mission today, this picture seems like a good way to start 🤷♂️Taken at 07:15 CEST as the gibbous Moon set over the Königstuhl as seen from Ziegelhausen 🌖Question: are Artemis II & its four astronauts also in the picture? 🧐#Photography 📷#Heidelberg 🏰#Astronomy 🔭#Germany 🇩🇪#Space ✨
(DIR) Post #B52pnNnomUjBOYxpdw by markmccaughrean@mastodon.social
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Bonus picture, taken 15 minutes earlier, when the sun had just risen, the sky was a bit darker, & the contrast of the Moon against it a bit stronger. Not such a great composition though, but hey, these pictures were taken from my balcony, so the perspective was fixed.
(DIR) Post #B59nJn2HYnBfAKD66S by markmccaughrean@mastodon.social
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#OTD one year ago, I started photographing the many insects, spiders, & other wee beasties in our garden & some nearby locations. By New Year's Eve, I'd recorded 195 different species – not bad 🙇♂️This year, I started on New Year's Day, & have already reached 90+.OK, many overlaps, but many new species too. Even better 🙂🤷♂️#Heidelberg 🏰#Photography 📷️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️#BugOfTheDay 🐞#MacroPhotography 🔬#InsectsOfMastodon 🪰#BackGardenEntomology 🪲
(DIR) Post #B59nJnGSi4WtsIqQCm by markmccaughrean@mastodon.social
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Today's additions are from the forest atop the Königstuhl around @mpi_astro, at around 570m elevation, taken with my phone. And the first is a small weevil spotted on top of a cut tree trunk. Deceased unfortunately, but that meant I could photo the underside too 😬It's a Clay-Coloured Weevil (Otiorhynchus singularis; 🇩🇪 Brauner Lappenrüssler). #Heidelberg 🏰#Photography 📷️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️#BugOfTheDay 🐞#MacroPhotography 🔬#InsectsOfMastodon 🪰#BackGardenEntomology 🪲
(DIR) Post #B59nJnUdrLs8aHTkJ6 by markmccaughrean@mastodon.social
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Second is a group of isopods, who seemed a little shocked by being revealed to the world when I pulled a piece of wood off a rotting tree trunk.Probably Common Shiny Woodlice (Oniscus asellus; 🇩🇪 Mauerassel), but possibly Ratzeburg's Woodlouse Trachelipus ratzeburgii). #Heidelberg 🏰#Photography 📷️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️#BugOfTheDay 🐞#MacroPhotography 🔬#IsopodsOfMastodon #BackGardenEntomology 🪲
(DIR) Post #B59nJnhP5u53DrRwCO by markmccaughrean@mastodon.social
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And third, I spotted a small pile of dirt surrounding a hole amid the leaves in the forest, & sat down next to it to see if its owner would turn up.Sure enough, there was a bee inside & it popped its head up a few times, but never exited.Not sure of the species – presumably a mining bee of some kind. The white hairy face might help with an ID. #Heidelberg 🏰#Photography 📷️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️️#BugOfTheDay 🐞#MacroPhotography 🔬#InsectsOfMastodon 🪰#BackGardenEntomology 🪲