When will be the next time the 4 naked-eye outer planets line up?

[longtry]

Hi there,

I'd love to know when Mars, Jupiter, Saturn and Uranus will line up on the sky next. Is it visible in the evening? That is, before 11PM.

That's pretty much all. But if you're extra kind, I'd like to know when the 3 brighter ones of them line up as well. Oh, and when all 5 outer planets do it?

Thank you!

[neufer]

I'd love to know when Mars, Jupiter, Saturn and Uranus will line up on the sky next. Is it visible in the evening? That is, before 11PM.

That's pretty much all. But if you're extra kind, I'd like to know when the 3 brighter ones of them line up as well. Oh, and when all 5 outer planets do it?

You need to define what you mean exactly by "line up on the sky."

E.g., there will be a neat conjunction of planets Jupiter & Saturn at the end of 2020.

<<A great conjunction is a conjunction of the planets Jupiter and Saturn. The last great conjunction took place on May 31, 2000, while the next one will be in late December 2020. Great conjunctions take place regularly, every 18–20 years, as a result of the combined ~12-year orbital period of Jupiter around the Sun, and Saturn's ~30-year orbital period. The 2000 conjunction fell within mere weeks after both had passed conjunction with the Sun, and it was very difficult to observe without visual aid because the two planets rose only 30–45 minutes before sunrise, depending upon the location of the observer.

Great conjunctions have attracted considerable attention as celestial omens. There has been some speculation,[by whom?] for example, that the so-called "Star of Bethlehem" was a great conjunction that occurred c. 7 BCE. During the late Middle Ages and the Renaissance, great conjunctions were a topic broached by most astronomers of the period up to the times of Tycho Brahe and Kepler, by scholastic thinkers as Roger Bacon or Pierre d'Ailly, and they are mentioned in popular and literary writing by authors such as Dante or Shakespeare. This interest is traced back in Europe to the translations from Arabian sources, most notably Albumasar's book on conjunction.

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Great conjunction Date   Time(UTC) 	Separation 	Elongation 	Zodiac sign
	
17 July 1802 		22:57:00 	39' South 	40.6° East 	Virgo
19 June 1821 		16:56:57 	1°10' North 	63.3° West 	Aries
26 January 1842 	06:16:53 	32' South 	27.1° West 	Capricorn
21 October 1861 	12:27:02 	48' South 	39.7° West 	Virgo
18 April 1881 		13:35:59 	1°13' North 	3.1° East 	Taurus
28 November 1901 	16:37:33 	26' South 	38.2° East 	Capricorn
10 September 1921 	04:13:03 	57' South 	9.7° East 	Virgo
August 8, 1940 		01:13:20 	1°11' North 	90.9° West 	Taurus
20 October 1940 	04:42:14 	1°14' North 	164.0° West 	Taurus
15 February 1941 	06:36:25 	1°17' North 	72.9° East 	Taurus
19 February 1961 	00:07:18 	14' South 	34.9° West 	Capricorn
31 December 1980 	21:17:24 	1°03' South 	90.9° West 	Libra
March 4, 1981 		19:14:36 	1°03' South 	155.9° West 	Libra
24 July 1981 		04:13:35 	1°06' South 	63.8° East 	Libra
28 May 2000 		15:56:27 	1°09' North 	14.9° West 	Taurus

21 December 2020 	18:37:31 	6' South 	30.1° East 	Aquarius

According to financial astrologer Daniel T. Ferrera, whenever a great conjunction occurs during an election or inauguration year, the president is likely to die in office. Careful analysis shows that, although it remained correct from 1840 to 1960, this rule started to “lose its power” after 1980. However, even though those presidents did not die in office, they still came close in each case:

• Presidents who were elected around a great conjunction

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Election Year 	 	Died in office?   Date of Death/Incident 	 Detail of Incident

1840 	William Henry Harrison 	Yes 	4 April 1841 		Pneumonia
1860 	Abraham Lincoln 	Yes 	15 April 1865 		Assassination
1880 	James A. Garfield 	Yes 	19 September 1881 	Assassination
1900 	William McKinley 	Yes 	14 September 1901 	Assassination
1920 	Warren G. Harding 	Yes 	2 August 1923 		Heart attack
1940 	Franklin D. Roosevelt 	Yes 	12 April 1945 		Cerebral haemorrhage
1960 	John F. Kennedy 	Yes 	22 November 1963 	Assassination
1980 	Ronald Reagan 		No 	30 March 1981 		Shot but survived.
2000 	George W. Bush 		No 	10 May 2005 		Thrown a live grenade which did not detonate.

[longtry]

Yes, what I meant is conjunction. This fancy word sometimes slips from my mind because I'm not very good at English, so pardon me

I do know about the 2020 conjunction, seeing it at theplanetstoday.com. It seems like Mars will join the fray, but all this partying will take place late in the night, near sunrise. That's why I added the 'before 11PM' part in the original question.

I think it'd be cool to record the 4 brighter planets' retrograde dance with normal equipment, as I'm a newbie "astronomer".

[Nitpicker]

The Great Conjunction of 2020 will be visible just after sunset on Dec 21, low on the western horizon. Both planets will be well past their annual oppositions with Earth and Sun, and well past their annual periods of retrograde motion.

But this is a fun web page to play with:
https://www.heavens-above.com/planets.aspx

[neufer]

I'd love to know when Mars, Jupiter, Saturn and Uranus will line up on the sky next. Is it visible in the evening? That is, before 11PM.

That's pretty much all. But if you're extra kind, I'd like to know when the 3 brighter ones of them line up as well. Oh, and when all 5 outer planets do it?

You need to define what you mean exactly by "line up on the sky."

E.g., there will be a neat conjunction of planets Jupiter & Saturn at the end of 2020.

Yes, what I meant is conjunction. This fancy word sometimes slips from my mind because I'm not very good at English, so pardon me

I do know about the 2020 conjunction, seeing it at theplanetstoday.com. It seems like Mars will join the fray, but all this partying will take place late in the night, near sunrise. That's why I added the 'before 11PM' part in the original question.

I think it'd be cool to record the 4 brighter planets' retrograde dance with normal equipment, as I'm a newbie "astronomer".

• Well, from May 11 to Sep 29 in 2020 you can watch Jupiter & Saturn retrograde
  dance together (against the background stars) while staying ~6 degrees apart.

[longtry]

My original question is when will the conjunction of the 4 naked-eye outer planets be. While the 2020 'great' conj is quite anticipated, as evidenced by the answers, it doesn't involve all 4.

[Nitpicker]

It depends on what tolerance one applies to the definition of a conjunction, but I don't think the four planets from Mars to Uranus will line up that closely in our lifetimes. And to be visible nicely in the evening would require Earth to be more or less in line as well.

[Chris Peterson]

It depends on what tolerance one applies to the definition of a conjunction, but I don't think the four planets from Mars to Uranus will line up that closely in our lifetimes. And to be visible nicely in the evening would require Earth to be more or less in line as well.

Taking Uranus off the table might help. It is a naked eye planet only in the most technical sense- invisible except under ideal conditions to a skilled observer with excellent vision who knows exactly where to look. There's a reason it was never detected as a planet despite thousands of years of people studying the sky. Planetary conjunctions are fun because they are pretty; Uranus adds nothing to the visual experience.

[neufer]

It depends on what tolerance one applies to the definition of a conjunction, but I don't think the four planets from Mars to Uranus will line up that closely in our lifetimes. And to be visible nicely in the evening would require Earth to be more or less in line as well.

Taking Uranus off the table might help. It is a naked eye planet only in the most technical sense- invisible except under ideal conditions to a skilled observer with excellent vision who knows exactly where to look. There's a reason it was never detected as a planet despite thousands of years of people studying the sky. Planetary conjunctions are fun because they are pretty; Uranus adds nothing to the visual experience.

OTOH, on Nov. 19, 2020, (just after sunset) you can take a telescope out and observe all the outer planets within 120º of Azimuth... including a close clustering of the Moon, Saturn, Jupiter & Pluto.

[Chris Peterson]

It depends on what tolerance one applies to the definition of a conjunction, but I don't think the four planets from Mars to Uranus will line up that closely in our lifetimes. And to be visible nicely in the evening would require Earth to be more or less in line as well.

Taking Uranus off the table might help. It is a naked eye planet only in the most technical sense- invisible except under ideal conditions to a skilled observer with excellent vision who knows exactly where to look. There's a reason it was never detected as a planet despite thousands of years of people studying the sky. Planetary conjunctions are fun because they are pretty; Uranus adds nothing to the visual experience.

OTOH, on Nov. 19, 2020, (just after sunset) you can take a telescope out and observe all the outer planets within 120º of Azimuth... including a close clustering of the Moon, Saturn, Jupiter & Pluto.

Sure, but that's a different exercise, more akin to a Messier marathon. Nothing wrong with it, of course, but it isn't at all the same as an impressive naked eye conjunction.

[longtry]

Thank you for your prediction, nitpicker and your explanation, Chris. Makes a lot of sense. It's hard to even find a decent watching spot nowadays, let alone 'optimal'. Let's promote my secondary question "When will Mars, Jupiter & Saturn make a conjunction?" up to be the primary. The extra is, when will they do it before 11.30PM?

neufer's suggestion is pretty interesting, though again I'm more aligned with Chris' argument of it being more like a Messier marathon. I will still remember that date though

[Nitpicker]

Conjunctions in RA:
2040-08-18 Mars-Jupiter (just after sunset)
2040-09-01 Mars-Saturn (just after sunset)
2040-11-05 Jupiter-Saturn (just before sunrise)

But the pick of the bunch might be:
2040-09-08 Mercury-Venus-Moon-Mars-Jupiter-Saturn (all within about 10 degrees, just after sunset, very low in the West).

[longtry]

2040 then I'm wondering when will Mars, Jupiter & Saturn get into positions of both conjunction and opposition? To record something like the 20-12-2001 APOD, I think a night sky is more favorable than a twilight, Venus-belt-low scene like in 2040. Because it will take many days, right?

[Nitpicker]

2080, November to December are the next closest I can find to your ever changing criteria. I won't be alive by then, so I've started to lose interest.

These won't be close enough to opposition to see them all looping together. Each planet has a different retrograde period, increasing with distance out from Earth. The time span is typically months each year, not days.

[longtry]

Thanks, I see. So even though they're in conjunction, they won't necessarily 'dance' together. Seems like a pas de trois is nigh impossible to record, since just like in our world, it's not that common.
Also, don't lose faith in the medical progress! Technology can prolong our lifespan dramatically, we just don't know when that leap will be.

[Nitpicker]

Not impossible, just too rare for most of the current generations of humans, perhaps. Some future generations might be luckier in this respect.

And I don't think I'm that keen on living so long. Another thirty or forty years will be plenty for me, thanks.