Mars will pass only about half a degree south of Jupiter on Sunday May 29.
See the end note about enlarging illustrations.
In sky scenes like this, arrows through the moving bodies show their motion from 2 days before to 2 days later, in relation to the starry background.
Our scene is close to the instant of the conjunction, which, though it doesn’t matter greatly, is about 11 Universal Time, which is 4 or more hours earlier by clocks on American shifted-daylight summer time.
Mars overtakes Jupiter on the inside about each 2.14 years, slightly longer than Mars’s synodic period of 2.13 years, because by the time Mars comes around to the same part of the orbit Jupiter has slightly moved on. But this is an average, and the intervals are irregular because if the times when the planets appear to go into retrograde motion as seen from Earth. The conjunctions come 4, 5, or 6 times in a decade. Here is the tale of the 2020s.
……………….separation magnitudes elongation
……………………UT Mars Jup. longitude
2020 Mar 20 12 -0.708 0.9 -2.1 -67 293
2022 May 29 10 -0.582 0.7 -2.2 -65 3
2024 Aug 14 15 0.307 0.8 -2.2 -66 77
2026 Nov 16 6 1.195 0.7 -2.1 -88 146
2029 Jul 19 17 -1.632 0.6 -2.0 82 199
These are the conjunctions in longitude, that is, in relation to the ecliptic, rather than in right ascension (relative to the equator) or the appulses (moments when the planets appear closest to each other). There would be little difference for those other two kinds of conjunction, but the movement of planets in relation to the ecliptic is liable to be more regular, and early astronomers, and astrologers, preferred to think in these terms.
Separation, elongation (angular distance from the Sun), and longitude (distance around the sky from the vernal equinox) are in degrees. Negative separation means that Mars is south of Jupiter. Negative elongation means in the morning sky.
So, all are at good elongations (high away from the Sun) but for one in the evening sky we have to wait till 2029. The 2024 conjunction will be closer than the 2022 one. Mars is always several magnitudes dimmer than Jupiter, even though so much nearer to us.
Stretched month
The conjunction in right ascension is nearer to Universal Time 11 than 10.
You gotta be careful how you touch the keyboard, especially when you’re typing numbers, especially these finical numbers.
In my post on May 25, I stated that this conjunction “will” come on “May 11.” That was the hour, not the day, and, in time, I inserted “29.” Yet, in the worry and flurry of corrections, I omitted in another place to delete “11.” So the post proclaimed that the event would happen on May 2911. That was corrected, though not in time, depending how soon you opened your email.
May 32 would be June 1, yes? And May 42 would be June 11 (I’m already near the limit of my mental arithmetic). So what is May 2911?
__________
ILLUSTRATIONS in these posts are made with precision but have to be inserted in another format. You may be able to enlarge them on your monitor. One way: right-click, and choose “View image” or “Open image in new tab”, then enlarge. Or choose “Copy image”, then put it on your desktop, then open it. On an iPad or phone, use the finger gesture that enlarges (spreading with two fingers, or tapping and dragging with three fingers). Other methods have been suggested, such as dragging the image to the desktop and opening it in other ways.
Sometimes I make improvements or corrections to a post after publishing it. If you click on the title, rather than on ‘Read more’, I think you are sure to see the latest version. Or you can click ‘Refresh’ to get the latest version.
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Guy, thank you for the table of information regarding Jupiter and Mars conjunctions in the 2020’s. It’s interesting to see that the elongations are in the morning sky up until 2026, and then in 2029 they begin to be in the evening sky. That is connected to the fact that in 2027, Mars and Jupiter will come to near-simultaneous oppositions in Leo, much like they did in 1980. There is a rough pattern of mutual oppositions of Mars and Jupiter that occur about 47 years apart. I made some diagrams of the 1980, 2027, and 2074/2076 mutual oppositions of the two and posted them to my site:
http://www.starvergnuegen.com/plan_charts/plan_align_index.html
We can see that by 2074, the Jupiter opposition comes about 2 weeks before Mars’, and so two years later the Jupiter opposition comes about 10 days earlier. According to my planetarium software, over the course of about 1,000 years of these events, the great majority of these mutual oppositions occur in the Cancer / Leo / Virgo direction, where both are near aphelion.
April 20, 2030
Jupiter and Mars were a glorious sight at dawn this morning, side by side just over a degree apart — close enough for the color contrast to be quite dramatic. Equally dramatic was the fact that the sky was mostly covered by dense stratus clouds, except, remarkably, for the parade of planets stretching from the Moon and Venus, through Jupiter and Mars, to Saturn.