I'm typing this on my lunch break at work so this'll be short, but this week I learned that Halley's comet will reach aphelion, the farthest point in its orbit from the Sun, at 3 PM HST (when this post goes out). At that point it'll be momentarily traveling at its slowest speed (relative to the Sun), a mere 0.91 km/s, or 2,035 mph. After that, it begins the long accelerating fall back in towards the inner Solar System. And yes, aphelion is only a "half-birthday" if you count its "birthday" as being perihelion, but it's as good a time as any and makes for a catchy title, so I went with it.
Halley's comet (or 1P/Halley to give it its official designation, the "P" meaning "periodic" and the "1" meaning it's the first to be recognized as such) is currently far too faint to be observed from Earth with even the largest telescopes, having last been imaged twenty years ago in 2003. (It might be possible to observe with the Hubble or JWST, but no one is looking – there wouldn't be much to learn from it.) Presumably that means it'll take about another twenty years to be imaged again, so look forward to that sometime around 2043, unless the ELT decides to try for it earlier or something.
Having been born three years after its most recent perihelion in 1986 I've never seen Halley's comet myself, but this is a nice reminder that it's still out there, and on its way back in again. Hopefully I'll get to see it at its next perihelion in July 2061! A hui hou!
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