685 replies to this topic

[lanforod]

First thought was it is Comet Ison, but some quick research has NASA stating the comet didn't make it around the sun in one piece and is now dead.

[Mike K.]

Look up at the moon tonight and tell me that it's phase doesn't look odd to you.

Aren't phases of the moon supposed to appear left-to-right and not top-to-bottom? Tonight's moon phase has the top-right side lopped off and it appears at a much less severe angle than it should, no?

Here's a diagram of moon phases to compare with what you can see tonight.

http://visual.merria...phases-moon.jpg

[Holden West]

"Hey man, maybe it's...

 

 

...the dark side of the moon, man!"

[arfenarf]

Maybe this helps:

 

Imagine yourself standing there at midnight, on the dark side of the planet.  The sun is right behind you, blocked by Earth.  In fact, it's kind of under your feet, as the earth's declination at this time of year (the North Pole is leaning away from the sun) means your head is pointing about 60 degrees from "up," relative to the vertical axis of the solar system.  But it is still shining on things not blocked by Earth, which includes that moon, which is sitting beside us right now.  Since we're looking at it kind of sideways, we see the 'left' half of it illuminated by the sun.

 

So as the planet spins you to the East and the moon appears on the horizon, it is being lit from what feels like below you and a little to the left.  Is that what you saw? 

 

I'd upload a picture but I haven't figured that bit out yet.

Edited by arfenarf, 24 December 2013 - 07:44 AM.

[Mike K.]

Last night's moon is pictured below. #2 is what I suppose I expect the moon phase to look like, but granted perhaps the winter solstice creates the phase seen last night.

 

(btw, the line across the moon is an out of focus tree branch that was in the way)

 

Maybe it's the fact that most moon phase diagrams and phases described on calendars depict the moon's changes left-to-right and without any angles. Last night while observing the moon the phase looked far more top-to-bottom than I'm used to seeing and this triggered a re-take in my mind.

 

And I'm not saying the changes happened from one month to the next but the position of the moon relative to the planet changes constantly, and maybe why the phases look so different than they have in the past is due to the fluctuating position of the moon? I dunno, but I find this sort of stuff pretty fascinating

 

PS arfenarf, to upload a photo directly to the forum without having to host it anywhere else, click on the "more reply options" button next to the "post" button below the quick reply form. When you see the full editor you are presented with an option to attach files below the editor. When choosing a file, be sure to click "attach this file" otherwise it will not upload. To position the image where you want within your reply place the cursor where you want the photo to appear and once an image is uploaded you'll see the "Add to post" option. Click that and you're off.

[eseedhouse]

The moon appears from Earth to "wobble" in it's orbit, a phenominon known as "libration".  Before we had lunar orbiters astronomers used this fact to peer further around the "back side" during certain times of year.  Thus they could see a little bit of the "far side" even before the satellites gave us a fuller picture.

 

The main cause is that the Lunar orbit is not a perfect circle, but an ellipse, and it deviates from a perfect circle quite a bit more than the average planetary orbit does.  Also, the moon's axis of rotation is inclined with respect to the earth and this contributes also.

[arfenarf]

PS arfenarf, to upload a photo directly to the forum without having to host it anywhere else, click on the "more reply options" button next to the "post" button below the quick reply form. When you see the full editor you are presented with an option to attach files below the editor. When choosing a file, be sure to click "attach this file" otherwise it will not upload. To position the image where you want within your reply place the cursor where you want the photo to appear and once an image is uploaded you'll see the "Add to post" option. Click that and you're off.

 

Hey, thanks.  

[VicHockeyFan]

The first total lunar eclipse in more than two years will grace the skies Monday, and it's all the more rare because it will be visible above the entire Western Hemisphere.

During the overnight hours of April 14-15, skygazers there will have a front-row seat as the full moon is painted red, creating what many call a "blood moon," as Earth's shadow creeps across the lunar disk.

VIEWING GUIDE:http://news.national...-viewing-guide/

 

[eseedhouse]

During the overnight hours of April 14-15, skygazers there will have a front-row seat as the full moon is painted red, creating what many call a "blood moon," as Earth's shadow creeps across the lunar disk.
 

 

The actual colour is usually more like copper.  No astronomer I know (amateur or pro) has ever called it a "blood moon".  Lunar eclipses are common - I've seen a dozen or so in my 70 year without really trying hard.

 

The color is caused by the fact that earth's atmosphere refacts some of the light that would miss the moon onto the surface, acting rather like a giant lens.  If you ever look at a sunrise or a sunset you see the same phenominon from another angle.

 

Still worth a look, though, but why do the media have to try to make it more important and rare than it actually is?  Oops, silly question...

[VicHockeyFan]

 

The color is caused by the fact that earth's atmosphere refacts some of the light that would miss the moon onto the surface, acting rather like a giant lens.  If you ever look at a sunrise or a sunset you see the same phenominon from another angle.

 

 

 

You would not even think there would be that much light.  If the earth were the size of a basketball (8000mi.), the atmosphere is like the thickness of two sheets of paper (60mi.).

[Bingo]

A 1902 study of  childlore in the United States found that though most young children were unsure of the Moon's composition, that it was made of cheese was the single most common explanation.

 http://en.wikipedia....of_green_cheese

 

So really, a blood moon is just green cheese that has gone bad.   

[eseedhouse]

You would not even think there would be that much light.  If the earth were the size of a basketball (8000mi.), the atmosphere is like the thickness of two sheets of paper (60mi.).

 

Nevertheless it is true.  See here for a good explanation: http://cliffmass.blo...se-weather.html

 

If the Earth had no atmosphere the Moon would disappear entirely because the size of the shadow of the Earth at the distance of the Moon is much larger than the Moon itself. 

 

On very rare occasions when the atmosphere is clouded by dust from large volcanic eruptions the Moon does virtually disappear during eclipses.  I remember this happening at least once during my lifetime, probably around the time of the large eruption of Pinatubo in 1991.

 

As a matter of fact what we call eclipses of the Moon are not technically eclipses of the Moon at all.  They are eclipses of the Sun by the Earth and you can only see that if you are standing on the Lunar surface. 

 

Nevertheless everyone, including astronomers, still call it  an "eclipse of the moon", when it would better be called an "eclipse on the moon".  I don't imagine that will change soon.

Edited by eseedhouse, 14 April 2014 - 12:12 PM.

[VicHockeyFan]

 

If the Earth had no atmosphere the Moon would disappear entirely because the size of the shadow of the Earth at the distance of the Moon is much larger than the Moon itself. 

 

 

 

Not entirely.  It would still get some light from other stars.  Might not be enough to see it with the naked eye from Earth though.

[lanforod]

Maybe its just me, but I can see the dark side of the moon, even when it is just a sliver, crescent, or whatever. Hard to pickup, but it is there, the lighted part helps show where it is though. On 'no' moon nights though, its hard to find it.

 

I've never heard it called an eclipse of the moon. Just a 'lunar eclipse'. Given that a solar eclipse is defined as the moon coming between the earth and the sun and a lunar eclipse is the earth coming between the moon and the sun, there is definitely a disconnect with the terms. The terms were defined as per the point of view of earth.

 

A lunar eclipse should probably be called a Terran eclipse if you're on the moon.

[Holden West]

[VicHockeyFan]

TOTAL Solar Eclipse coming up in 2017, only in the US.    

 

http://www.eclipse20...se2017_main.htm

 

...but this map says we get a 90% version here in Victoria:   http://www.eclipse20...7/zeiler.htm...

 

 

We don't get a full one in Canada until 2024, and it's only Great Lakes and east.

 

http://eclipse.gsfc....hp?Ecl=20240408

[eseedhouse]

Maybe its just me, but I can see the dark side of the moon, even when it is just a sliver, crescent, or whatever.

 

 

This has been observed for thousands of years and the only reason people don't know about it today is, I suppose, because the bright lights of the city make it hard to see.  Out in the darker parts it's plain and obvious, and the ancient phrase "The old moon in the new moon's arms" refers to it.

 

Some people are even amazed when I tell them that the moon is visible in daylight for much of the month.  At the right time of the year, if you look at just the right place, the planet Venus is also visible to the unassisted eye during the daytime.

 

The ingorance of many people about long known astronomical facts is really quite amazing.  Put it down to city lights, I suppose.

 

There have been many reports of UFO's from people who have accidentally stumbled upon Venus shining in the dayligt sky.

[eseedhouse]

A lunar eclipse should probably be called a Terran eclipse if you're on the moon.

No, it would be called an eclipse of the Sun.  And on the moon these are very frequent, indeed exactly as frequent as what we call a "Lunar" eclipse.

 

The Appollo astronauts were the first, and until now the only, people to see an eclipse of the Earth.

 

Technically I suppose we could say that there is an eclipse of the Sun every day.  We call it sunset.  Actually it is caused by the Earth eclipsing the Sun.  It lasts all night!

Edited by eseedhouse, 14 April 2014 - 03:28 PM.

[eseedhouse]

Not entirely.  It would still get some light from other stars.  Might not be enough to see it with the naked eye from Earth though.

 

It would be far to faint for human eyes to see.  The moon would still radiate during such an eclipse, since it is well above absolute zero, and every material object warmer than that radiates electromagnetic waves.  But they are well outside the tiny part of the spectrum our eyes can see.

[eseedhouse]

Another excellent article on Lunar "eclipses" may be found here:

 

http://profmattstras...ight/#more-7582