Closer Up Again
Jan. 31st, 2019 06:48 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
krpalmerNot that long after the first halfway detailed image of Ultima Thule was radioed back to Earth from New Horizons, I went looking at the “raw images” available on the mission’s main site to notice some of them looked blank. Remembering comments seen that it isn’t easy to look in precisely the right direction close up to catch an object in a camera when very little of its orbit has been observed, I could keep wondering if the picture we had would be the best we’d get.
Several days ago, though, a better picture did arrive in the low-powered downlink, and when it was colourised as an Astronomy Picture of the Day I got to thinking. The conjoined blobs that had looked “dented” before were now showing some small craters, and after wondering (aware a layman’s speculation on scientific topics might be a bit off) if relative velocities are low that far from the sun and the less cratered plains on Pluto “might not mean as much as you thought they did” compared to the lunar highlands, Callisto, and the midsized moons of Saturn I did think of closeups of rocky rather than icy asteroids and the way the moon smooths out close up, gardened by really small impacts. The featured photograph all these thoughts came from was taken “seven minutes before closest approach,” but using the less telescopic camera on New Horizons, so I can at least wonder if there might be a better picture yet.
Several days ago, though, a better picture did arrive in the low-powered downlink, and when it was colourised as an Astronomy Picture of the Day I got to thinking. The conjoined blobs that had looked “dented” before were now showing some small craters, and after wondering (aware a layman’s speculation on scientific topics might be a bit off) if relative velocities are low that far from the sun and the less cratered plains on Pluto “might not mean as much as you thought they did” compared to the lunar highlands, Callisto, and the midsized moons of Saturn I did think of closeups of rocky rather than icy asteroids and the way the moon smooths out close up, gardened by really small impacts. The featured photograph all these thoughts came from was taken “seven minutes before closest approach,” but using the less telescopic camera on New Horizons, so I can at least wonder if there might be a better picture yet.