Is Jupiter Brighter When Far from Venus?

[PhanthomJay]

I couldn't help notice how bright Jupiter appeared last night with the crescent moon and Venus by her side. It appeared almost as bright as Venus.

Question: Since Jupiter is on the other side of the sun from Venus right now (right?), shouldn't it be rather dim? I mean it's distance from us must be way farther out than when

 

[davenn]

Question: Since Jupiter is on the other side of the sun from Venus right now (right?), shouldn't it be rather dim? I mean it's distance from us must be way farther out than when

no that's not correct

Jupiter at the moment is at its closest to Earth for some decades, from memory last closest approach was ~ 1963.
Over the last couple of months Jupiter has been great to view through the telescope

The Earth and Jupiter are on the "same side of the sun" not opposite sides

Dave

 

[PhanthomJay]

Oh, no wonder why its so bright! I thought that since we can see Jupiter and Venus at the same time side by side, and that since Venus is closer to the sun than Jupiter, with us in between, that if we see them side by side, Jupiter must be presently on the other side of the sun from Venus, but now I realize I did some bad geometry. Thanks for the response.

 

[SHISHKABOB]

from here: http://www.fourmilab.ch/cgi-bin/Solar/action?sys=-Sf

 

[Chronos]

Three basic factors determine apparent brightness of a planet - its angular diameter, albedo and distance from the sun. Venus has Jupiter beat slightly on both counts. At closest approach Venus has a apparent diameter of about 65" whereas Jupiter has an apparent diameter of about 50". The albedo of Venus is about .66 whereas Jupiter is only around .5. Jupiter is around 7 times more distant than Venus is from the sun, so the sunlight reflected by Jupiter is considerably dimmer than that reflected by Venus.

 

[DaveC426913]

Three basic factors determine apparent brightness of a plane

Four:

Its phase. According to that diagram, Jupiter is a gibbous (or whatever gibbous is called for non-Moon bodies), near full phase.

This affects inner planets much more than outer planets though. We can often see cresent or even new inner planets but we'll never see a crescent outer planet.

 

[Drakkith]

Currently almost 4 months has passed since opposition and Jupiter is now magnitude -2.2, which is about 5 times dimmer than Venus which is magnitude -4.3. Jupiter is almost at its dimmest point.

 

[Chronos]

Jupiter is always 'full moon' as viewed from earth, only bodies nearer than Earth to the sun have phases.

 

[DaveC426913]

Jupiter is always 'full moon' as viewed from earth, only bodies nearer than Earth to the sun have phases.

True, Jupiter cannot be crescent or new, but it can be gibbous.

 

[semiscientist]

Please explain this to me. A planet is not emitting light, right, only defecting it, correct?
Why would a planet like Jupiter reflect so much light as to make it appear as a star?
How come some planets light up completely from the supposed reflection, but other bodies do not? I am no scientist just an inquisitive mind. I do not accept the given explanations. Can someone enlighten me?
Are we being told the truth about stars and planets? Seriously...?
Venus and Jupiter supposedly shine very bright some nights. Why is that, that they appear as stars? How can that be, by plausible explanation?

And, how does anyone know the sun is 93 million miles from earth?
Who measured it? Seriously?

Do people believe this kind of stuff because of some kind of "consensus"?
Was there not a consensus in the 12th century that the Earth was flat?

 

[davenn]

Please explain this to me. A planet is not emitting light, right, only defecting it, correct?

REFLECTING light :) yes

Why would a planet like Jupiter reflect so much light as to make it appear as a star?
How come some planets light up completely from the supposed reflection, but other bodies do not? I am no scientist just an inquisitive mind. I do not accept the given explanations. Can someone enlighten me?

What other bodies ?? name one or two

Are we being told the truth about stars and planets? Seriously...?
Venus and Jupiter supposedly shine very bright some nights. Why is that, that they appear as stars? How can that be, by plausible explanation?
And, how does anyone know the sun is 93 million miles from earth?
Who measured it? Seriously?

All the planets appear as "stars' that is ... pinpoints of light its when you look at the planets with a modest telescope with say an 8" mirror you can discern an actual disk for at least mercury to Uranus. Neptune is a little trickier without a larger scope. I personally haven't viewed Neptune ( not that I recall anyway)

as far as distance to the sun goes...
a quote from the net...
"Another method was explored in 1672 by Cassini and Richer: they measured the parallax (i.e. the variation in angle when seen from different places) under which Mars was seen in Cayenne and Paris, at the moment of opposition. From this, they deduced the distance Earth-Mars. Then, using the Kepler law

a^3 / p^2 = constant
(where a is the distance between the planet and the Sun, and p the sideral time)
they could figure out what was the distance to the Sun."

Do people believe this kind of stuff because of some kind of "consensus"?
Was there not a consensus in the 12th century that the Earth was flat?

OF course we do, we believe it because there's tons of scientifically supporting evidence. There's been telescopes and other instruments pointing into space for at least 2 centuarys

I can't do the maths for you ... its not my forte ... but even long long ago, those much mathematically inclined worked out those things combined with lots of night sky observations

cheers
Dave

 

[Bandersnatch]

Three basic factors determine apparent brightness of a planet - its angular diameter, albedo and distance from the sun.

(emphasis mine)
Isn't that a bit redundant? After all, angular diameter is a function of the distance from the sun(and the actual diameter), so once we've taken the one into account, there's no point in correcting for the other.
It'd make sense to count both, I suppose, had the interplanetary medium been dense enough to disperse appreciable amounts of light on its way toward us, but it's hardly the case.

@Semiscientist: it's the same reason why it's easier to see a white cat in your room shining with the reflected light of a 100W lightbulb than it is to see another 100W lightbulb five blocks away*.
The planets are highly reflective(some of them at least), and close to both the source of light(the Sun) and the observer(us).


*probably not to scale

 

[semiscientist]

okay then, (Bandersnatch), what causes a planet to reflect light?
Seriously, not trying to egg anyone on. I have no scientific background just a curious mind.

AND, this just means the light was strong enough (close enough) to illuminate the cat, but if I were near the cat and the room which was illuminated, I would see a lot more illumination.
But we are talking about darkness, at night.
Why would an object thousands and thousands of miles away, reflect light from a distant star, unless it had some reflective capabilities? and if so...what are they?

 

[semiscientist]

REFLECTING light :) yes
What other bodies ?? name one or two

All the planets appear as "stars' that is ... pinpoints of light its when you look at the planets with a modest telescope with say an 8" mirror you can discern an actual disk for at least mercury to Uranus. Neptune is a little trickier without a larger scope. I personally haven't viewed Neptune ( not that I recall anyway)

as far as distance to the sun goes...
a quote from the net...
"Another method was explored in 1672 by Cassini and Richer: they measured the parallax (i.e. the variation in angle when seen from different places) under which Mars was seen in Cayenne and Paris, at the moment of opposition. From this, they deduced the distance Earth-Mars. Then, using the Kepler law

a^3 / p^2 = constant
(where a is the distance between the planet and the Sun, and p the sideral time)
they could figure out what was the distance to the Sun."

OF course we do, we believe it because there's tons of scientifically supporting evidence. There's been telescopes and other instruments pointing into space for at least 2 centuarys

I can't do the maths for you ... its not my forte ... but even long long ago, those much mathematically inclined worked out those things combined with lots of night sky observations

cheers
Dave

But dozens of scientists will tell you free energy is impossible according to known physics, yet Nikola Tesla proved them all wrong over a 100 years ago, so I do not take scientific method for fact. I prefer an explanation that makes common sense to me.

 

[semiscientist]

Bandersnatch...as you can see, I just joined. I'm no scientist at all. I'm just very curious and wanted to learn. Please understand, and help out, if you will. I don't mean to sound redundant, but I'm scientifically "stupid". I admit.

 

[someGorilla]

what causes a planet to reflect light?

Why would an object thousands and thousands of miles away, reflect light from a distant star, unless it had some reflective capabilities? and if so...what are they?

Maybe you're not aware that nearly EVERYTHING reflects light. Otherwise you couldn't see anything! When you see a person in front of you, what you are actually seeing is the light reflected by her body (or clothes, as the case might be ) towards your eyes. Nothing strange about planets here. That is what "seeing" is!

 

[davenn]

But dozens of scientists will tell you free energy is impossible according to known physics, yet Nikola Tesla proved them all wrong over a 100 years ago, so I do not take scientific method for fact. I prefer an explanation that makes common sense to me.

he didnt prove anything like that ...
Dont get off topic ! that's totally irrelevant and discussions on such are not permitted on the this forum

Answer my question from my previous post please

Dave

 

[semiscientist]

he didnt prove anything like that ... if you think he did
show us all specific links to reviewed papers
Dont get off topic ! that's totally irrelevent

Answer my question from my previous post please

Dave

I'm not trying to argue with anyone, just learn a few things. Sorry.
I cannot understand math equations. I failed algebra 1B.

Also, I was not trying to go off topic, with Tesla, I was just making the statement of why I do not support the scientific model 100%. I believe it to be controlled, at the top. But it's controlled not by what people know and keep them from sharing, but from what they do not yet understand, and that includes many scientists. Tesla lit the world's fair in 1922, i thin kit was, completely free with free energy electricity and built a tower at Wardencliff, CO., to supply the country with free electricity, and he was shut down by JP Morgan,. and if you doubt that, then we'll argue about it somewhere else. Regardless, I still have not understood what would cause a planet thousands of miles away to reflect light from the sun, and for it to be visible to us, here on earth. In my mind, it should be dark out there, where that planet is. If it reflects light, then why does not every object between here and there reflect light similarly?

Seriously and sincerely.

I'm just asking common sense questions. I'm sorry they are not as scientific as some might wish to hear expressed here, but I'm only trying to solve this for myself. I have a hard time believing most of science in relation to the stars because it just does not make sense to me.
You should not need to understand math or science to understand why nature acts the way it does. It should make sense if explained to a rational mind. yes? or No?

 

[semiscientist]

Maybe you're not aware that nearly EVERYTHING reflects light. Otherwise you couldn't see anything! When you see a person in front of you, what you are actually seeing is the light reflected by her body (or clothes, as the case might be ) towards your eyes. Nothing strange about planets here. That is what "seeing" is!

I can relate to this, but not to the concept that light is reflected thousands of miles away for god knows what reason exactly, and yet I cannot see the light between here and there?
That confuses me slightly. Can you help relate it to me, more down to earth, so I can understand? Please? Why is the planet lit up thousands of miles away, yet planet Earth would not be, would it? to a distant civilization? If it's the reflection alone, what causes that?

 

[someGorilla]

I do not support the scientific model 100%. I believe it to be controlled, at the top.

There's no such thing as "the scientific model". And since there's a wild lot of different ideas about the things yet unknown it's difficult to see how it could be "controlled at the top". Of course about the things that are known there is some general consensus, like in every other field of life. Do you think that if you enroll in a university to study physics you will be contacted by some mysterious man threatening your life if you don't follow the directions from "the top"?

Tesla lit the world's fair in 1922, i thin kit was, completely free with free energy electricity and built a tower at Wardencliff, CO., to supply the country with free electricity, and he was shut down by JP Morgan

It would be nice to know WHERE you got that information.

In my mind, it should be dark out there, where that planet is.

"Out there"? It's also dark out here if you want to see it that way. What's the difference between here and Mars? The Earth doesn't emit light. Yet, you can see things. So?

If it reflects light, then why does not every object between here and there reflect light similarly?

You keep repeating that question but you didn't say WHICH objects.

 

[someGorilla]

Why is the planet lit up thousands of miles away, yet planet Earth would not be, would it?

Planet Earth would not be? There's a lot of pictures of Earth taken from space to prove you wrong.

 

[davenn]

.....I'm just asking common sense questions. I'm sorry they are not as scientific as some might wish to hear expressed here, but I'm only trying to solve this for myself. I have a hard time believing most of science in relation to the stars because it just does not make sense to me.
You should not need to understand math or science to understand why nature acts the way it does. It should make sense if explained to a rational mind. yes? or No?

When you get into science, regardless of the field, physics, astronomy, geology <-- my main interest, and others. You very quickly learn that maths is the language of science.

In geophysics I may be studying a particular occurrence in the Earth ... now an astronomer comes along and asks what I am doing ... now if I tried to explain it from a non math non formula point of view, chances are i would just get a blank look from him.
But if I explaind it with physics formula etc, even tho he may know nothing about geophysics, he totally understands what I am talking about because of the commonality of the mathematics

Much of what we know and learn is initially from observation. from there we can use say Newton's Laws or say Faraday's Laws to be able to actually describe the process.

eg. I don't need maths to tell me that if I drop an object ( on earth) its going to fall to the ground. Or if I place a ball on a slope it will roll down that slope.
BUT using the mathematical formula I can describe how that object drops or that ball rolls. I can describe the effects of gravity on those two totally separate experiments

Dave

 

[davenn]

As far as reflectiveness of the different planets goes, it depends on the makeup of the planet Venus, Jupiter, Saturn, Uranus and Neptune all have light gaseous atmospheres
particularly Venus, Jupiter and Saturn. The atmosphere of Uranus is a bule/green colour and this shows up quite well in a telescope. The ability of an object to reflect sunlight is called its albedo ( reflective coefficient) which ranges from 0 for black to 1 for white
Venus, Jupiter and Saturn light atmospheres meant they have a high albedo

Visual Albedos
Venus = 0.75
Jupiter = 0.52
Moon = 0.12

The surface of the moon is quite dark rock hence it doesn't reflect light so well, we only see it so bright because of its relative closeness to us.
Mars, the red planet has an albedo of 0.25, that is it only reflects 25% of the light that falls on it

cheers
Dave

PS you still haven't answered my question

 

[mfb]

And, how does anyone know the sun is 93 million miles from earth?
Who measured it? Seriously?

Thousands of scientists and amateurs. With today's equipment, everybody can confirm it, with a small telescope and a good clock (or a better telescope and without clock).

Why is the planet lit up thousands of miles away, yet planet Earth would not be, would it? to a distant civilization? If it's the reflection alone, what causes that?

If you would stand on mars, Earth would look similar to you like Mars does for us.

Concerning the comparison with stars:
Stars emit light on their own - similar to our sun. But they are so extremely far away that they appear very dim compared to our sun. Planets reflect some sunlight - all planets do that, even earth. And of this reflected light, some fraction hits earth, so we can see other planets.
The cat in a room is a good example, even if the numbers are not similar to planets and stars - you can see the light bulb (the sun) as brightest object. If you do not look directly into it, you can also see the cat (the planet), and you can see the light bulb 200m away (another star).

Modern telescopes can even see some planets orbiting other stars, as those reflect some light from "their" star.

Tesla lit the world's fair in 1922, i thin kit was, completely free with free energy electricity and built a tower at Wardencliff, CO., to supply the country with free electricity

Maybe you mean "free" as in "free beer". But he still needed some generator or other method to generate electricity.

 

[russ_watters]

(emphasis mine)
Isn't that a bit redundant? After all, angular diameter is a function of the distance from the sun(and the actual diameter), so once we've taken the one into account, there's no point in correcting for the other.

No, angular diameter is a function of distance from the earth.

 

[russ_watters]

But dozens of scientists will tell you free energy is impossible according to known physics, yet Nikola Tesla proved them all wrong over a 100 years ago...

No, he didn't.

Consider this: I'm an engineer and I pay an electric bill. If free energy were possible, don't you think I would have already done it to save myself those thousands of dollars a year? [rhetorical: don't answer.]

Was there not a consensus in the 12th century that the Earth was flat?

No, there wasn't. Humans have known Earth was round for thousands of years.

Not sure where you're getting your information about science, but you've come to the right place to get that fixed! However:

I was just making the statement of why I do not support the scientific model 100%. I believe it to be controlled, at the top.

That's not something we can help you with here. Crackpottery and conspiracy theory are strictly forbidden here and since we only discuss the scientific mainstream, it probably won't help you deal with your paranoia that you're being messed with by science -- unless you open your mind and learn for yourself.

 

[russ_watters]

I can relate to this, but not to the concept that light is reflected thousands of miles away for god knows what reason exactly, and yet I cannot see the light between here and there?

You can only see light that hits your eye. Light passing by you is invisible.

Venus and Jupiter supposedly shine very bright some nights. Why is that, that they appear as stars?

Even with a modest pair of binoculars, Venus and Jupiter look nothing like stars. To the naked eye, they are tough to distinguish from stars because their angular diameter is so small you can't see their shape.

 

[Bandersnatch]

No, angular diameter is a function of distance from the earth.

Oh, shoot! Go me and my reading comprehension.
Cheers.