Comments and questions about the
APOD on the main view screen.
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Beyond
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by Beyond » Sun Mar 18, 2012 5:29 am
oops!
![Embarassed :oops:](./images/smilies/icon_redface.gif)
She dropped one. I hope it didn't break, it might throw the solar system out of whack.
![Mr. Green :mrgreen:](./images/smilies/icon_mrgreen.gif)
And that 'space cat' sure has a l--o--n--g tail.
To find the Truth, you must go Beyond.
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orin stepanek
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by orin stepanek » Sun Mar 18, 2012 12:43 pm
Simply marvelous!
![Very Happy :D](./images/smilies/icon_biggrin.gif)
Orin
Smile today; tomorrow's another day!
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dodecadroid
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by dodecadroid » Sun Mar 18, 2012 1:21 pm
Please fix the caption. The next Venus/Jupiter conjunction is May 2013 not May 2012.
The current text:
> Although this conjunction is drawing to a close, another conjunction between Venus and Jupiter will occur next May.
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owlice
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by owlice » Sun Mar 18, 2012 1:47 pm
Next May = May next year
This May = May this year
I think the explanation is okay as it is, but I'll pass your comment along.
A closed mouth gathers no foot.
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Some dude
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by Some dude » Sun Mar 18, 2012 3:53 pm
I've been watching Jupiter & Venus for some months now, and have a question...
If the two planets are on the same orbital plane, why is a conjunction not a single point in the sky?
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APODFORIST
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by APODFORIST » Sun Mar 18, 2012 4:59 pm
owlice wrote:Next May = May next year
This May = May this year
I think the explanation is okay as it is, but I'll pass your comment along.
Sorry, but this is not correct.
This month is March, so you can say "this March". Only in a May you can say "this May".
Next mean the next May from today - which is May 2012.
PS: Same with days: Next Wednesday is the following Wednesday (not Wednesday one week later)
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neufer
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by neufer » Sun Mar 18, 2012 7:36 pm
APODFORIST wrote:owlice wrote:
Next May = May next year
This May = May this year
I think the explanation is okay as it is, but I'll pass your comment along.
Sorry, but this is not correct.
This month is March, so you can say "this March". Only in a May you can say "this May".
Next mean the next May from today - which is May 2012.
PS: Same with days: Next Wednesday is the following Wednesday (not Wednesday one week later)
http://wiki.answers.com/Q/Is_next_weekend_this_coming_weekend_or_weekend_after_next wrote:
<<The weekend of the week you are currently in is this weekend, Next weekend would refer to the week after that.
Then of course it depends on who you are talking to:
- If you came up to me on monday and said lets do something next weekend, I would assume you mean the very next weekend.
If you said the same thing on friday I would then assume you mean the weekend after this coming weekend.
That is why I end up saying things like two weekends from now, or the weekend after this. Unless you know how the other person thinks you can not be sure so clarify.>>
Art Neuendorffer
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Chris Peterson
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by Chris Peterson » Sun Mar 18, 2012 8:06 pm
APODFORIST wrote:owlice wrote:Next May = May next year
This May = May this year
I think the explanation is okay as it is, but I'll pass your comment along.
Sorry, but this is not correct.
This month is March, so you can say "this March". Only in a May you can say "this May".
Next mean the next May from today - which is May 2012.
PS: Same with days: Next Wednesday is the following Wednesday (not Wednesday one week later)
Perhaps English isn't your native language. Because the explanation given IS correct. In ordinary usage, "this" refers to the next occurrence in a larger cycle: this May is the next occurring May in this year; this Wednesday is the next occurring Wednesday this week. "Next" would be taken as May of 2013 or the Wednesday after next (given today is Sunday). It may not be entirely logical, but it's the way people say things. The APOD caption is perfectly correct.
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Sandstone
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by Sandstone » Sun Mar 18, 2012 8:40 pm
Some dude wrote:I've been watching Jupiter & Venus for some months now, and have a question...
If the two planets are on the same orbital plane, why is a conjunction not a single point in the sky?
The planets' orbits are close to being in the same plane, but not exactly.
Using earth's orbit to define the plane (ecliptic), Venus's orbit tilts at 3.39 degrees to that plane, and Jupiter's orbit tilts at 1.31 degrees to that plane.
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Sandstone
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by Sandstone » Sun Mar 18, 2012 9:14 pm
Beyond wrote: And that 'space cat' sure has a l--o--n--g tail.
I puzzled over this for quite a while, but finally got it. For those who need help:
In the APOD description, click on the link to "humorous pose"
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geckzilla
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by geckzilla » Sun Mar 18, 2012 9:23 pm
Whether the usage is correct or not, it is rather confusing. A simple change from "next May" to "next year in May" would alleviate the confusion.
Just call me "geck" because "zilla" is like a last name.
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Chris Peterson
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by Chris Peterson » Sun Mar 18, 2012 9:33 pm
geckzilla wrote:Whether the usage is correct or not, it is rather confusing. A simple change from "next May" to "next year in May" would alleviate the confusion.
Even better is just to provide a date, May 28, 2013. Which, BTW, will be a very nice conjunction, indeed, with Jupiter and Venus only 1° apart, and only 3° from Mercury. This conjunction will be close to the Sun (as you'd expect, since it involves Mercury), so it will be low on the horizon right after sunset. We can expect some interesting photo opportunities, quite different from those provided by the current conjunction.
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rstevenson
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by rstevenson » Sun Mar 18, 2012 9:54 pm
Chris Peterson wrote:... In ordinary usage, "this" refers to the next occurrence in a larger cycle: this May is the next occurring May in this year; this Wednesday is the next occurring Wednesday this week. "Next" would be taken as May of 2013 or the Wednesday after next (given today is Sunday). It may not be entirely logical, but it's the way people say things. ...
If only it were that simple -- which would require there being only one people to says things this way. There are many variations of English in use in the world. Here in Canada we get a lot of cross-cultural fertilization from US English and British English mixed in with our own unique variation on the theme. So subtleties like this are not at all well defined or clear or obvious.
If I said "next Monday" on Monday or any subsequent weekday this week, most everyone around here would know I meant the next Monday that occurs. But if I said it on Saturday I would have to elaborate as to whether I meant in two days time or in nine days time. No one could be sure otherwise. So if today I say "next May" there would be no doubt at all (around here) that I meant May 2012, but the closer it gets to May 2012 the less clear my meaning would become and the greater the requirement for some clarification.
That's "the way people say things" around
here.
Rob
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neufer
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by neufer » Mon Mar 19, 2012 2:24 am
Sandstone wrote:Some dude wrote:
I've been watching Jupiter & Venus for some months now, and have a question...
If the two planets are on the same orbital plane, why is a conjunction not a single point in the sky?
The planets' orbits are close to being in the same plane, but not exactly.
Using earth's orbit to define the plane (ecliptic), Venus's orbit tilts at 3.39 degrees to that plane,
and Jupiter's orbit tilts at 1.31 degrees to that plane.
http://en.wikipedia.org/wiki/Astronomical_transit wrote:
<<In rare cases, one planet can transit in front of another. 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. When the nearer object has a larger angular diameter than the farther object, thus covering it completely, the event is not a transit but an occultation. Before transiting Jupiter, Venus will occult Jupiter's moon Ganymede at around 11:24 UTC as seen from some southernmost parts of Earth. Parallax will cause actual observed times to vary by a few minutes, depending on the precise location of the observer.
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
The 1737 event was observed by John Bevis at Greenwich Observatory – it is the only detailed account of a mutual planetary occultation. A transit of Mars across Jupiter on 12 Sep 1170 was observed by the monk Gervase at Canterbury, and by Chinese astronomers. In addition, an occultation of Mars by Venus was observed by Michael Maestlin at Heidelberg on 3 October 1590.>>
http://transit.savage-garden.org/en/mutual.html wrote:
<<A total of 471 mutual planetary transit/occultation events occur in the time interval 5000 BC - 10000 AD. This makes an average frequency of one event in 32 years. However, these events are irregularly distributed in time. For instance, the shortest period of time between two consecutive mutual planetary events is a little over than 9 days. The transit of Venus in front of Saturn on 06 Mar 5199 is followed by a transit of Venus in front of Jupiter on 15 March 5199.
The longest period lacking of any mutual events is more than 90 538 days (almost 248 years) and we are currently living in that gap between 03 Jan 1818 and 22 Nov 2065, on both occasions Venus is transiting Jupiter.
For a planet to take part more frequently in mutual events two factors are decisive: fast apparent motion and large apparent diameter. The following table shows number of mutual events every planet takes part in:
The following table shows occurrence of mutual planetary events pairs (5000 BC - 10000 AD).
Code: Select all
Planets involved Events
-------------------------------
Venus Jupiter 86
Venus Saturn 55
Mercury Jupiter 43
Mercury Saturn 41
Mercury Venus 40
Venus Uranus 33
Mars Jupiter 25
Mercury Mars 25
Venus Neptune 25
Venus Mars 20
Mercury Neptune 18
Mercury Uranus 14
Mars Uranus 12
Mars Saturn 9
Jupiter Uranus 8
Mars Neptune 7
Jupiter Neptune 7
Jupiter Saturn 3
Saturn Uranus 0
Saturn Neptune 0
Uranus Neptune 0
Art Neuendorffer
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neufer
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by neufer » Mon Mar 19, 2012 12:29 pm
Chris Peterson wrote:
Even better is just to provide a date, May 28, 2013. Which, BTW, will be a very nice conjunction, indeed, with Jupiter and Venus only 1° apart, and only 3° from Mercury. This conjunction will be close to the Sun (as you'd expect, since it involves Mercury), so it will be low on the horizon right after sunset. We can expect some interesting photo opportunities, quite different from those provided by the current conjunction.
Comparable to the Saturn, Mars , and Venus clustering of May 2002:
http://apod.nasa.gov/apod/ap020509.html
However...Venus/Jupiter will be
only half the angular distance from the Sun vis-a-vis 2002's Saturn/Mars
and they will be quite lost in the red sunset
below an even significantly lower 2013 Mercury.
Art Neuendorffer
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Chris Peterson
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by Chris Peterson » Mon Mar 19, 2012 12:36 pm
neufer wrote:However...Venus/Jupiter will be only half the angular distance from the Sun vis-a-vis 2002's Saturn/Mars
and they will be quite lost in the red sunset below an even significantly lower 2013 Mercury.
All three planets will be far enough from the Sun during their 2013 conjunction to be very visible. Certainly, it will be at sunset, but with clear skies, none should be lost in the glow. Venus and Jupiter will have a reasonably long period of visibility; the window to capture or view all three will probably only be a few minutes long, however.
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neufer
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by neufer » Mon Mar 19, 2012 1:55 pm
Chris Peterson wrote:neufer wrote:
However...Venus/Jupiter will be only half the angular distance from the Sun vis-a-vis 2002's Saturn/Mars
and they will be quite lost in the red sunset below an even significantly lower 2013 Mercury.
All three planets will be far enough from the Sun during their 2013 conjunction to be very visible. Certainly, it will be at sunset, but with clear skies, none should be lost in the glow. Venus and Jupiter will have a reasonably long period of visibility; the window to capture or view all three will probably only be a few minutes long, however.
Venus and Jupiter will be only about 15º above the horizon at sunset?
(And Mercury will be the last to set.)
Besides...why is everyone ignoring the morning conjunction of Venus and Jupiter
this September first?
(Venus and Jupiter will be about 30º above the horizon at sunrise then.)
Art Neuendorffer
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Chris Peterson
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by Chris Peterson » Mon Mar 19, 2012 2:18 pm
neufer wrote:Venus and Jupiter will be only about 15º above the horizon at sunset?
(And Mercury will be the last to set.)
Easily enough for an excellent view.
Besides...why is everyone ignoring the morning conjunction of Venus and Jupiter this September first?
(Venus and Jupiter will be about 30º above the horizon at sunrise then.)
I always ignore events in the early morning sky. I consider anything that requires rising before the Sun to be in poor taste.
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neufer
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by neufer » Mon Mar 19, 2012 7:03 pm
Chris Peterson wrote:neufer wrote:
Venus and Jupiter will be only about 15º above the horizon at sunset [in 2013].
(And Mercury will be the last to set.)
Easily enough for an excellent view.
Like this great shot of Mercury about 12º above the horizon at sunset?
The real delight with the recent conjunction (and its corresponding APOD) was in savoring a pseudo Canis Minor like constellation in dark skies that was almost 100 time brighter than Canis Minor. Having these two planets closer together next year is nice but it doesn't begin to make up for not having a pretty dark sky background.
Chris Peterson wrote:neufer wrote:
Besides...why is everyone ignoring the morning conjunction of Venus and Jupiter this September first?
(Venus and Jupiter will be about 30º above the horizon at sunrise then.)
I always ignore events in the early morning sky.
I consider anything that requires rising before the Sun to be in poor taste.
So what's Otto Posterman's excuse
![Question :?:](./images/smilies/icon_question.gif)
Art Neuendorffer
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Sam
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by Sam » Fri Mar 23, 2012 1:05 am
rstevenson wrote:If I said "next Monday" on Monday or any subsequent weekday this week, most everyone around here would know I meant the next Monday that occurs. But if I said it on Saturday I would have to elaborate as to whether I meant in two days time or in nine days time. No one could be sure otherwise. So if today I say "next May" there would be no doubt at all (around here) that I meant May 2012, but the closer it gets to May 2012 the less clear my meaning would become and the greater the requirement for some clarification.
That's "the way people say things" around here.
Even though it didn't make sense to have another Jupiter/Venus conjunction again so soon, I still Googled "Venus-Jupiter conjunction May 2012" vs "Venus-Jupiter conjunction May 2013" just to make sure.
One solution:
oxtweekend.com.
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Sam
"No avian society ever develops space travel because it's impossible to focus on calculus when you could be outside flying." -Randall Munroe
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neufer
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by neufer » Fri Mar 23, 2012 1:27 pm
Sam wrote:
Even though it didn't make sense to have another Jupiter/Venus conjunction again so soon, I still Googled "Venus-Jupiter conjunction May 2012" vs "Venus-Jupiter conjunction May 2013" just to make sure.
There will be 3 separate impressive Jupiter/Venus conjunctions between July 1 and Oct 26, 2015:
http://www.nakedeyeplanets.com/jupiter.htm#conjunctions
Art Neuendorffer