Mars-Jupiter triple conjunction & Venus transits Jupiter in 2123

A triple conjunction is an astronomical event, where two planets or a planet and a star meet each other three times in a short period: 
(1) Triple conjunctions between two exterior/superior planets - both in opposition   (Sun - Earth - Exterior Planet A - Exterior Planet B): Triple conjunctions between the bright exterior planets are very rare: the last triple conjunctions between Mars and Jupiter occurred in 1789-1790, in 1836-1837 and in 1979-1980. The next events of this kind will be again in 2123.
(2) Triple conjunctions of inferior planets with exterior planets or stars - exterior planet in conjunction & inferior planet in inferior conjunction. (Exterior Planet - Sun - Inferior Planet - Earth).  "If Mars is in conjunction with the Sun, there is often a triple conjunction between Mars and Mercury or between Mars and Venus."  wiki 
(3) Triple conjunctions between Mercury and Venus (Sun - Mercury - Venus - Earth) - both in inferior conjunction.  This event is much rarer? 

Mars-Jupiter triple conjunction in right ascension between 1800 and 2100

So the one in 2123 may also last for only 4-5 months.  But will it be in the 1st half of the year?  Yes:  1/16  -  3/4  -  6/3

Side Note: Possible Explanations of the Star of Bethlehem

Note: The last column "occultation" is set to 1 when occultation of the two planets is visible from somewhere on Earth, and 0 when occultation is not visible.  Why? Mars & Jupiter are exterior planets so should be easy to observe. "These are the most interesting triple conjunctions, because all three conjunctions can be seen very easily, because of the great elongation of the planets or stars involved. "  wiki
? - something doubt:  Venus transits Jupiter - Venus's planet angular radius is 5.1 (too small, not about 10?) & Jupiter's planet angular radius is 60.4 (too large, not about 30?).  wiki

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合 (天體位置) (conjunction)

http://zh.wikipedia.org/wiki/%E5%90%88_(%E5%A4%A9%E9%AB%94%E4%BD%8D%E7%BD%AE)

合是位置天文學的一個名詞，它的意義是從一個選定的特定天體 (通常是地球) 觀察到二個天體在天空上的位置彼此非常靠近。

Transits and occults are very close distance conjunctions.

http://en.wikipedia.org/wiki/22nd_century

              2123: Triple conjunction of Mars–Jupiter.  (when are 1st, 2nd & 3rd conjunction?)
      June 9, 2123: Long-duration lunar eclipse of approximately 106.1 minutes.[13]
September 14, 2123: At 15:28 UTC, Venus transits Jupiter.

6/5-6/2012 (Tue-Wed)

金星凌日 - 最近的一對金星凌日事件是2004年6月8日和2012年6月5-6日。之前的一對是1874年12月和1882年12月，而在2012年之後，下一對的金星凌日会發生在2117年和2125年的12月。

Mutual planetary transits and occultations

The next time this will happen (as seen from Earth) will be on 22 November 2065 at about 12:43 UTC, when Venus near superior conjunction (with an angular diameter of 10.6") will transit in front of Jupiter (with an angular diameter of 30.9"); however, this will take place only 8° west of the Sun, and will therefore not be visible to the unaided/unprotected eye.

There are only 18 mutual planetary transits and occultations as seen from Earth between 1700 and 2200. Note the long break of events between 1818 and 2065.

• 19 Sep 1702 – Jupiter occults Neptune
• 20 Jul 1705 – Mercury transits Jupiter
• 14 Jul 1708 – Mercury occults Uranus
• 4 Oct 1708 – Mercury transits Jupiter
• 28 May 1737 – Venus occults Mercury
• 29 Aug 1771 – Venus transits Saturn
• 21 Jul 1793 – Mercury occults Uranus
• 9 Dec 1808 – Mercury transits Saturn
• 3 Jan 1818 – Venus transits Jupiter
• 22 Nov 2065 – Venus transits Jupiter
• 15 Jul 2067 – Mercury occults Neptune
• 11 Aug 2079 – Mercury occults Mars
• 27 Oct 2088 – Mercury transits Jupiter
• 7 Apr 2094 – Mercury transits Jupiter
• 21 Aug 2104 – Venus occults Neptune
• 14 Sep 2123 – Venus transits Jupiter
• 29 Jul 2126 – Mercury occults Mars
• 3 Dec 2133 – Venus occults Mercury

src  myFic

The unusually long gap in mutual occultations (in fact it is a transit) during our time spans nearly 250 years from 1818 and the next one is in 2065.  Both of these occultations are Jupiter-Venus events and the most spectacular type.

What of the next one in 2065 which a few young people have a chance of seeing?  This will be an (partial) occultation of Jupiter by Venus but it is only 8^o from the Sun and will be essentially unobservable. It surely would have been a beautiful occultation with two bright planets covering each other. Similar occultations occurred between these two planets in 1570 and 1818 which surely would have been noticed by observers but no historical records have surfaced yet. There is one more predicted in 2123 and will take place at an elongation of 16^o from the Sun.

^[1]The smaller the elongation, the closer to Sun so it is more difficult to be observed by unaided/unprotected eyes.
^[2]At superior conjunction, Venus looks smaller, only one third of the diameters of Jupiter.  At inferior conjunction, Venus looks much larger, nearly as big as Jupiter.

All the other Venus occultations of Jupiter have similar restrictions

• 1570 best location S45^o W50^o (in the South Atlantic off Argentina - Spanish colonists?)
• 2123 best location N30^o W150^o (Pacific Ocean between NA and Hawaii) although N60^o in Alaska would be Ok.

src    GMT vs. UTC