Earth's resonant siblings

[vogon13]

From Introduction to Asteroids, a list of objects in the solar system believed to be in a resonant relationship with earth and the resonances they are closest too:<br /><br />Eros, 4 : 7<br /><br />Alinda, 1 : 4<br /><br />Ganymed, 3 : 13<br /><br />Amor, 3 : 8<br /><br />Icarus, 8 : 9 / 17 : 19<br /><br />Betulia, 4 : 13<br /><br />Geographos, 5 : 7 / 13 : 18<br /><br />Ivar 2 : 5<br /><br />Toro 5 : 8<br /><br /><br />For instance, in the case of Toro, currently, for every 5 times earth goes around the sun, Toro does it 8 times.<br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[silylene old]

Ganymede? If you have a good reference link, I would be interested.<br /><br /><br />Also, to add to your list,<br /><br />Venus 3:2 rotational resonance with Earth <br />and a 8:13 orbital resonance with Earth<br /> <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[vogon13]

1036 Ganymed is an asteroid with a name confusingly similar to a moon of Jupiter.<br /><br />Compare 203 Kallisto and Callisto; and 85 Io and Io.<br /><br /><br />Compare the Venus and Earth one with Toro.<br /><br />It's why Venus and Earth can shuttle Toro back and forth.<br /><br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[Boris_Badenov]

That’s fascinating, do you have a link? <div class="Discussion_UserSignature"> <font color="#993300"><span class="body"><font size="2" color="#3366ff"><div align="center">. </div><div align="center">Never roll in the mud with a pig. You'll both get dirty & the pig likes it.</div></font></span></font> </div>

 

[silylene old]

<font color="yellow">1036 Ganymed is an asteroid with a name confusingly similar to a moon of Jupiter. </font><br /><br />thanks, that cleared it up for me. I was unaware there were the asteroids you mentioned with the nearly the same names as moons. I learn something every day on this forum! <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[vogon13]

Back in the olden days, sonny, we had these things called books.<br /><br />Introduction to Asteroids is a book.<br /><br />It was published in 1988 and is attributed to Clifford Cunningham.<br /><br /><br /><br /><img src="/images/icons/laugh.gif" /> <img src="/images/icons/laugh.gif" /><br /><br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[3488]

Could some of these be lost minor Earth & Venus moons?? <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[vogon13]

I have noted a range of mass ratios for such possible objects. None of the 'siblings' is big enough.<br /><br />Also, the apparent formation mode of earth's moon would have zorched any existing 'moonlets' in the earth's vicinity, and I don't know if that process would have generated durable siblings along with our moon, or whether our moon had subsidiary bodies of its' own.<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[alokmohan]

I am afraid the book is backdated.Since last fifteen years much has been discovered.So you requre to get a current book.Dont feel sorry,things are adding up very rapidly.

 

[dragon04]

I'm trying to read up on and understand this resonance stuff.<br /><br />How can Venus have 2 different resonances with respect to Earth? <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>

 

[superluminal]

That's a very good question indeed.<br />One I have asked before.<br /><br />Why does Venus always present the same face toward Earth when the two are at closest opposition?<br /><br />Why does Venus have the most circular orbit than any other planet in the solar system?<br /><br />Why is the Venusian north pole pointed in the approximate same direction as the Earth's south pole?<br /> <div class="Discussion_UserSignature"> <p><br /><strong><font size="3" color="#3366ff">Columbia and Challenger </font></strong></p><p><strong><font size="3" color="#3366ff">Starships of Heroes</font></strong></p> </div>

 

[dragon04]

<font color="yellow">Why does Venus always present the same face toward Earth when the two are at closest opposition?</font><br /><br />Because the rotational rate of Venus, and the period of close opposition are the same. <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>

 

[vogon13]

A good reference remains a good reference. The book is a very good summation of all observations made up to that time, and provides a good starting point for all the subsequent space craft based findings.<br /><br />List of resonant objects will always be expanding till we start nuking the little guys. Anyone with additions to the list are free to post them. It's how we find things out.<br /><br /><br /><br /><br /><br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[tony873004]

To add to this list:<br />2002 AA29<br />2003 YN107<br />Cruithne<br />85770<br />54509<br />Luna (Earth's Moon) 1:1<br /><br />Not all the objects listed in this thread are truly resonant. Most are only approximate resonances. Any 2 objects will have an approximate resonance. There's an infinite number of integers, so two objects that are almost in a 2:1 resonance might very very well be in a 1000:499 resonance. But it's more meaningful when the numbers are smaller.<br /><br />At any given instance, the resonance between Earth and any object listed in this thread is only approximate. However, over long periods of time, some of them average into exact integer:integer ratios and others do not.<br /><br />The ones that do average exact integer ratios are said to be in mean-motion resonance. Mean means average, so this means that a mean-motion resonance averages to a true integer:integer ratio. For example, Pluto is in a 3:2 mean-motion resonance with Neptune. At any given instance, it might be 3:2.001, which allows Pluto's resonant conjunction to creep closer to Neptune's position. But when it gets too close, Neptune pulls Pluto into a higher, slower orbit and the resonance becomes 3:1.999. This repeats indefinately and averages to exactly 3:2.<br /><br />Other objects that are in approximate 3:2 resonances don't have this reversing mechanism that lock them into mean-motion resonances.<br /><br />Of the objects mentioned in this thread, including the 6 I've added:<br /><br />Approximate:<br /><br />Ganymed<br />Icarus<br />Betulia<br />Geographos (not even that close)<br />Ivar<br />Eros<br />85770 close to 1:1 in a Cruithne-like orbit but not locked<br />Alinda<br />2003 YN107, very similar to 2002 AA29, but doesn't change direction after exiting the quasi-satellite mode like 2002 AA29 does.<br />Venus, both rotational and orbital.<br /><br />-------------------------------------------------------<br /><br />Locked (mean-motion resonance):<br /><br />Amor<br />Toro<br />54509<br />2002 AA29<br></br>

 

[vogon13]

You are welcome to the phrase.<br /><br />BTW, Titan and Iapetus are close to a 5 : 1 resonance, might be handy for Cassini in the extended mission . . . . . <br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[alokmohan]

Are all the moons of Jupiter and saturn resonant?Possibly a general pattern in solar system.

 

[vogon13]

Callisto does not participate in the resonance of Io/Europa/Ganymede.<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[alokmohan]

Any reason?

 

[CalliArcale]

But it may someday. I seem to recall reading that it is gradually approaching a resonance with the other Galilean satellites.<br /><br />It can take time for a resonance to develop. Just as our system is moving towards an Earth-Moon tide-lock, so do other systems evolve over time. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>