B Has there ever been a planet-planet eclipse (i.e., observed from Earth)?

[swampwiz]

The upcoming conjunction of Jupiter & Saturn has got me thinking. I wonder if it has ever been observed (and hopefully photographed) of one planet's disc even partially taking over another's. I have seen a photo of Saturn doing this with the Moon, but I don't think I've ever seen one of a pair of planets.

 

[snorkack]

The upcoming conjunction of Jupiter & Saturn has got me thinking. I wonder if it has ever been observed (and hopefully photographed) of one planet's disc even partially taking over another's. I have seen a photo of Saturn doing this with the Moon, but I don't think I've ever seen one of a pair of planets.

If you ever see any, it´ s fake.
Last mutual planetary transit was 3rd of Janury, 1818, Venus over Jupiter. Before invention of photography.
In 18th and 19th century, the transits were (between the visible planets):

1. 1705 Mercury over Jupiter
2. 1708 Mercury over Jupiter
3. 1737 Venus over Mercury
4. 1771 Venus over Saturn
5. 1808 Mercury over Saturn.
6. 1818 Venus over Jupiter

Next transit is in 2065. This century´ s transits are:

1. 2065 Venus over Jupiter
2. 2079 Mercury over Mars
3. 2088 Mercury over Jupiter
4. 2094 Mercury over Jupiter

That´ s it, the 10 between 1700 and 2100.

 

[swampwiz]

Doesn't it seem odd that we happen to be in a big lull?

Do you have the dates to go along with the year? I'll "watch" it via Stellarium.

 

[snorkack]

Some more details:
https://www.bogan.ca/astro/occultations/occltlst.htm

 

[swampwiz]

https://www.bogan.ca/astro/occultations/2bcocclt.htm

The Star of Bethlehem?

I wonder if astronomers of that time had noticed this conjunction, or perhaps even had predicted it beforehand.

 

[Vanadium 50]

Doesn't it seem odd that we happen to be in a big lull?

It's aliens I tell's ya!

It is difficult or impossible to determine after-the-fact probabilites, but the probability of a gap at least this large is about 2%.

 

[sophiecentaur]

Doesn't it seem odd that we happen to be in a big lull?

"Odd"? It's a cotton pickin' nuisance from my point of view.

 

[DaveC426913]

Follow-up question:

Is the parallax caused by different observing locations on Earth sufficient to result in different occultations?

eg: would simultaneous observations from Northern and Southern locations result in noticeably different images?

 

[phyzguy]

Follow-up question:

Is the parallax caused by different observing locations on Earth sufficient to result in different occultations?

eg: would simultaneous observations from Northern and Southern locations result in noticeably different images?

Definitely. These events are only visible over part of the Earth's surface. For example the site linked in Post #5 has a map of the 2079 event. I'm not sure exactly how to interpret the map, but I think the gray region is where it will be visible.

 

[Ibix]

I'm not sure exactly how to interpret the map, but I think the gray region is where it will be visible.

I think that black means you are on the wrong side of the planet. The blue shades tell you the overlap when you are on the right side. The flare near the edge of the black bit is where you need to be to actually see it - while the Sun is still below the horizon. Everywhere outside that flare, you could see if you observed in a wavelength where the sky isn't bright.

That matches up with the commentary that says you need to be near 50°E to see it.

 

[DaveC426913]

The blue gradient is interesting. It's shown getting lighter and then at full eclipse it's shown darker.

That might not mean anything, but I find it reminiscent of the overlapping shadows of two tree branches. The combined shadow is actually lighter at the centre than next to the centre, like this:
4 4 3 2 1 2 1 2 3 4 4

I wish I could find a pic to show this.

Likewise, the brightness of near occultation will be brighter than full occultation.

 

[swampwiz]

Definitely. These events are only visible over part of the Earth's surface. For example the site linked in Post #5 has a map of the 2079 event. I'm not sure exactly how to interpret the map, but I think the gray region is where it will be visible.
View attachment 273186

Rats. If I am at my same location, I'll have to travel over 1K miles at age 113 to see this!

 

[SpaceJacob]

Well, I was born at the wrong time. I don't think I'll live until 2065 to see the Venus-Jupiter eclipse, although I adore stargazing, and I'd like to see this event. And even if I can live so long, I'll hardly be able to travel somewhere. It's disappointing.

 

[pinball1970]

Rats. If I am at my same location, I'll have to travel over 1K miles at age 113 to see this!

Im ok in the UK if I am reading this correctly. A whipper snapper at only 98 too!

 

[hutchphd]

Likewise, the brightness of near occultation will be brighter than full occultation.

Maybe this is caused by diffraction at the edges (like an Airy disk). If I get the chance I'll run the numbers.

 

[sophiecentaur]

There’s such a lot of space, compared planet cross section. A lunar eclipse is very frequent because the sizes and distances are favorable. Otoh, planet on planet has to be rare.
The percentage of exoplanets we can actually be aware of must be tiny, on the basis of observed occlusions.
The best chance of seeing such events is when Jupiter’s moons go across the face. That happens very frequently and is visible with a good home telescope.

 

[DaveC426913]

Maybe this is caused by diffraction at the edges (like an Airy disk). If I get the chance I'll run the numbers.

It's caused by the fact that a double disc is brighter than a single disc - more area.

There's a weird phenomena you can witness outside under a tree. If you spot two branches in alignment with the sun (so that one branch eclipses the other) the shadow will be complex. Instead of one shadow trough, it will have two, with a low peak between them.

 

[Thecla]

If you count minor planets, Ceres and Vesta, it might increase the number of eclipse events