benos Posted February 11, 2014 Share Posted February 11, 2014 All of the planet's apparent movement across the night sky is due to the rotation of the earth. Although the vast majority of the moon's movement across the night sky is also caused by the rotation of the earth, a small percentage of the moon's movement is due to the rotation of the moon around the earth. I wondered, how much of the moon's movement across one night's sky is caused by the rotation of the moon around the earth. When the moon and a planet happen to be close together, at some time during the night, over a period of two night's observation, we can figure it out. Last night at about 6:30, when I looked at the moon, I could see Jupiter, next to the moon, just a bit to the north. So tonight, when I look at the moon at 6:30, the east-west distance bertween the moon and Jupiter will be the distance the moon moved across the sky, in a 24 hour period, that was due to the rotation of the moon around the earth. Quote Link to comment Share on other sites More sharing options...
Hi-Power Jack Posted February 11, 2014 Share Posted February 11, 2014 How far did it move? Quote Link to comment Share on other sites More sharing options...
Sarge Posted February 12, 2014 Share Posted February 12, 2014 About an inch? Quote Link to comment Share on other sites More sharing options...
AICS308 Posted February 12, 2014 Share Posted February 12, 2014 The movement can also be calculated based on the complete rotation and whether using Sidereal, Synodic, Tropical, Anomalistic, or Draconic orbit values. Quote Link to comment Share on other sites More sharing options...
Biloxi23 Posted February 12, 2014 Share Posted February 12, 2014 Animalistic? Oh sorry, my just repaired cataracts read ANOMOLISTIC wrong. Quote Link to comment Share on other sites More sharing options...
AICS308 Posted February 12, 2014 Share Posted February 12, 2014 Animalistic? Oh sorry, my just repaired cataracts read ANOMOLISTIC wrong. Hey I had just finished cleaning a few guns, the solvent was a little strong. Quote Link to comment Share on other sites More sharing options...
Flatland Shooter Posted February 12, 2014 Share Posted February 12, 2014 Hmm, those Colorado brownies hit the spot. Quote Link to comment Share on other sites More sharing options...
benos Posted February 12, 2014 Author Share Posted February 12, 2014 How far did it move? It looked like approximately 12 "moon widths." Quote Link to comment Share on other sites More sharing options...
Youngeyes Posted February 13, 2014 Share Posted February 13, 2014 All those years of loud gun noises finally takes it's toll. Quote Link to comment Share on other sites More sharing options...
Hi-Power Jack Posted February 13, 2014 Share Posted February 13, 2014 How far did it move? It looked like approximately 12 "moon widths." What does that translate into actual rotation of the Earth? in MOA? or degrees? Wonder if this would correspond to the daily change in the timing of the tides? Quote Link to comment Share on other sites More sharing options...
benos Posted April 8, 2014 Author Share Posted April 8, 2014 Last night at about 10 PM, AZ-time, the moon and Jupiter were next to each other, east / west-wise. So tonight at 10 PM, the moon should appear about 12 - 14 moon-widths, to the east of Jupiter. So the astronomy question of today is: Since the moon rises in the east and sets in thee west, why will the moon be to the east of Jupiter, tonight? Quote Link to comment Share on other sites More sharing options...
meatsauce Posted April 8, 2014 Share Posted April 8, 2014 (edited) I thought the moon rises and sets due east to west only on the equinoxes.? Edited April 8, 2014 by meatsauce Quote Link to comment Share on other sites More sharing options...
meatsauce Posted April 8, 2014 Share Posted April 8, 2014 And I know the sun rises and sets the same time every day, but the moon rises and sets different times every day. Perhaps that has something to do with it? Quote Link to comment Share on other sites More sharing options...
benos Posted April 8, 2014 Author Share Posted April 8, 2014 Keep 'em coming... Quote Link to comment Share on other sites More sharing options...
BritinUSA Posted April 8, 2014 Share Posted April 8, 2014 Lunar Eclipse 14-15 April, red moon rising. Quote Link to comment Share on other sites More sharing options...
StraightUp_OG Posted April 8, 2014 Share Posted April 8, 2014 "Earth swung between the sun and Jupiter on Jan 5th. This was Jupiter’s yearly opposition – when it was opposite the sun – rising in the east as the sun was setting in the west, and setting in the west as the sun was rising in the east. That time has passed, and Jupiter is now visible for less of each night, but it still stays out past midnight throughout April." http://earthsky.org/astronomy-essentials/visible-planets-tonight-mars-jupiter-venus-saturn-mercury Quote Link to comment Share on other sites More sharing options...
benos Posted April 8, 2014 Author Share Posted April 8, 2014 Keep 'em coming... Quote Link to comment Share on other sites More sharing options...
StraightUp_OG Posted April 8, 2014 Share Posted April 8, 2014 (edited) OK I think I get what you are driving at. Parallax Edited April 9, 2014 by StraightUp_OG Quote Link to comment Share on other sites More sharing options...
neckbone Posted April 9, 2014 Share Posted April 9, 2014 Is there beer involved here? Quote Link to comment Share on other sites More sharing options...
benos Posted April 9, 2014 Author Share Posted April 9, 2014 As an example, on one night at 9 PM, the moon and Jupiter were next to each other, east / west-wise. Then on the following night at the same time, the moon is noticeably to the east of Jupiter. There can only be one reason for that. Quote Link to comment Share on other sites More sharing options...
StraightUp_OG Posted April 9, 2014 Share Posted April 9, 2014 Well if it is not speed of the moons orbit around the Earth relative to the conjunction of Jupiter and parallax I give up. Quote Link to comment Share on other sites More sharing options...
benos Posted April 10, 2014 Author Share Posted April 10, 2014 Feels like this one is done... To us, the moon rises in the east and sets in the west. But the moon actually revolves around the earth from west to east, or counter-clockwise (looking down from the north pole). I can't believe it took me till this point in my life to figure that out (from the info in the OP). Quote Link to comment Share on other sites More sharing options...
StraightUp_OG Posted April 10, 2014 Share Posted April 10, 2014 Counter-clockwise orbit of the moon with combined with the axis rotation of the earth = A HA! Never thought about it like that. You know, I learned something today. :-) Quote Link to comment Share on other sites More sharing options...
meatsauce Posted April 13, 2014 Share Posted April 13, 2014 Thanks Brian. I enjoy the questions that make people think or debate. You make a great pedagogue. Quote Link to comment Share on other sites More sharing options...
benos Posted April 14, 2014 Author Share Posted April 14, 2014 In addition to the lunar eclipse tonight / early tomorrow AM, the moon should be fairly close, east/west-wise, to Mars. Quote Link to comment Share on other sites More sharing options...
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