NASA says Jupiter is at its closest in 59 years

rod

Oct 22, 2019
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In June 2019, Jupiter was close, and I was able to resolve Ganymede and Io as small round moons or disk shape using my telescopes. The June 2019 issue of Sky & Telescope documented this for small scope users. Looks like some of the Galilean moons should be visible as small moons, not just points of light this opposition too.

On 12-June-2019 my log notes. [Observed 2100-0100 EDT. This was the double shadow transit of Io and Ganymede tonight...June Sky & Telescope shows Io began transit at 2222 EDT on 11-Jun-19 or 0222 UT on 12-Jun-19 and ended transit 0433 UT or 0033 EDT. I watched Io tonight with Ganymede approach Jupiter starting at 2150 EDT. Both moons approached Jupiter’s limb like two fighter jets flying in close formation and at 200x, Ganymede was obvious small disk shape, resolved, especially near Jupiter’s limb, Io too. It was very cool to see this event using the XT10i and 90-mm refractor...Both shadows were visible as the moons moved across the face of Jupiter, Ganymede’s shadow larger and easier to see than Io but both distinct...]
 
Feb 8, 2020
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The article states Jupiter will be around 367 million miles from Earth, but this is at opposition. that implies Jupiter can be as close as around 181 million miles at closest approach. So, when does THAT happen?
 
Nov 19, 2021
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Opposition means Jupiter is opposite the Sun from us. This is as close as we get to Jupiter. When Jupiter and the Sun are together it is "conjunction" and we add 180 some million miles to the 367 to get 547 million miles or thereabouts.
 
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rod

Oct 22, 2019
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I did get out my telescope last night and viewed a Ganymede transit at Jupiter.

Observed 2130-2345 EDT 20-Sep-2022/0130 UT-0345 UT 21-Sep-2022. Ganymede transit and shadow transit observed this evening using Orion Sirius 25-mm plossl at 40x, TeleVue 9-mm Nagler at 111x, and 9-mm with TeleVue 1.8x Barlow lens for 200x using 90-mm refractor. I used #58 Green and #12 Yellow filters. Ganymede black shadow difficult to see at 40x. 111x and 200x views no problem, especially using #58 Green filter. Numerous cloud bands visible, shading in north polar region and in south polar region. Near 2315 EDT or 0315 UT, I could see Ganymede and its shadow approaching Jupiter's limb. The shadow ~ 2 arcsecond or larger angular size and Ganymede ~ 1.7/1.8 arcsecond size. At 200x, Ganymede approaching the limb of Jupiter at egress looked like a small round moon. While I did not see all the Ganymede transit and shadow transit this evening, I did enjoy observing a great deal of the show. According to Sky & Telescope tool for Jupiter moons, Ganymede shadow transit began 0010 UT, Ganymede transit began 0058 UT and the entire show ended 0328 UT when Ganymede moved away from Jupiter’s disk (egress). Before I finished observing, I enjoyed some 40x observations of M45 (Pleiades) rising in Taurus with true FOV ~ 1.3-degrees. An enjoyable evening watching Ganymede move across Jupiter and its black shadow. Ganymede appeared as a small moon near the limb of Jupiter, not just a point of light. During the transit there were times I could see Ganymede against the disk of Jupiter along with its black shadow, especially as Ganymede approached closer to egress and Jupiter’s limb. My 10-inch Newtonian does a great job here, the images are brighter with more detail. However, the 90-mm refractor telescope easier to setup and bring in when done. Skies clear with temperature 17C.

So, folks, as Jupiter and Earth get closer, small telescopes at 200x or so can show some of the Galilean moons as small moons.
 

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