2025-12-28 00:51 UTC
@wikipedia To be fair, it doesn’t move much compared to the “fixed” stars, at least on human timescales.
Replies (2)
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@MichaelPorter@ottawa.place 2025-12-28 01:01
@aprilfollies @wikipedia He was also *this* close to discovering Uranus when he was observing Jupiter in 1609/1610. Just a smidge to the west…
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@soaproot@sfba.social 2025-12-29 06:25
@aprilfollies @wikipedia I think the techniques he was using (comparing its position to nearby stars/planets) would be sensitive enough. As far as I can tell from https://www.ph.unimelb.edu.au/~dnj/AP-June-2009-Galileo-Neptune.pdf (section "Galileo’s Observations of Neptune"), anyway.