Perspective from Neptune

[Kewell]

This is kind of a random question but I was watching a documentary on Neptune. And they say the winds there average around 750mph and up to 1000+mph. I was wondering how do clouds form in that kind of speed? If we could see them from the ground of&nbsp;Neptune would clouds look they are moving extremely fast unlike here on earth where they seem to barely move! Do we know if Neptune has a solid ground or not? <div class="Discussion_UserSignature"> </div>

 

[MeteorWayne]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>This is kind of a random question but I was watching a documentary on Neptune. And they say the winds there average around 750mph and up to 1000+mph. I was wondering how do clouds form in that kind of speed? If we could see them from the ground of&nbsp;Neptune would clouds look they are moving extremely fast unlike here on earth where they seem to barely move! Do we know if Neptune has a solid ground or not? <br />Posted by Kewell</DIV><br /><br />Neptune really doesn't have a solid surface, so you couldn't really stand on anything; you'd be frozen solid anyway! </p><p>Clouds can form in atmosphere's anywhere when there is more of a particular substance than the atmosphere can hold. On earth, that is water vapor, on Mars cater vapor and CO2, on Venus, sulfuric acid, etc. </p><p>On Neptune, it is methane, ammonia, hydrogen sufide, and a few other substances depending on altitude and pressure.</p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[Kewell]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Neptune really doesn't have a solid surface, so you couldn't really stand on anything; you'd be frozen solid anyway! Clouds can form in atmosphere's anywhere when there is more of a particular substance than the atmosphere can hold. On earth, that is water vapor, on Mars cater vapor and CO2, on Venus, sulfuric acid, etc. On Neptune, it is methane, ammonia, hydrogen sufide, and a few other substances depending on altitude and pressure. <br />Posted by MeteorWayne</DIV><br /><br />what are the white bands we see on neptune sometimes then, arent those clouds? <div class="Discussion_UserSignature"> </div>

 

[CalliArcale]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>what are the white bands we see on neptune sometimes then, arent those clouds? <br /> Posted by Kewell</DIV></p><p>Yes, they are clouds, but as MeteorWayne was saying, they are not exactly like Earth clouds, which are made of water vapor.&nbsp; Neptune's clouds are made of chemicals such as methane, ammonia, and hydrogen sulfide. </p> <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>

 

[Carrickagh]

<p><font color="#ff00ff">This is kind of a random question but I was watching a documentary on Neptune. And they say the winds there average around 750mph and up to 1000+mph. I was wondering how do clouds form in that kind of speed?</font> </p><p>It's sort of surprising that Neptune has this weather because it gets only about 1/1000th the energy that Earth receives from the Sun. But Neptune creates more energy than it receives from the Sun. This internal heat source likely fuels some of the "weather" that scientists see. Most of the high speed winds blow in a direction opposite to the planet's rotation. When the cloud bands interact you get the storms, like the original Great Dark Spot. The spot dispappeared, probably due to the amazing weather patterns, however, another later formed in the northern hemisphere.</p><p>The planet is quite cold, and methane will form a vapor at such temperatures. This vapor is what the "clouds" are. The darker, lower, clouds may be made of hydrogen sulfide. Both of these chemicals can exist at the very low temperatures. The wind speed, including potential jet streams, are likely part of the cloud's formation mechanism. </p><p>We haven't had enough time with instruments like Hubble or Keck or Gemini to observe the planet throughout its 40 year long seasons, but I wonder if that would teach us more.</p><p>**</p><p>&nbsp;</p><p>&nbsp;</p> <div class="Discussion_UserSignature"> </div>

 

[centsworth_II]

<p><font color="#333399"><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>...The planet is quite cold, and methane will form a vapor at such temperatures. This vapor is what the "clouds" are....<br /> Posted by Carrickagh</DIV></font></p><p>Just like water clouds on Earth, wouldn't methane clouds either be formed of solid methane particles (frozen methane) or small drops of liquid methane?&nbsp; I would expect methane vapor to be an invisible gas just as water vapor is.&nbsp;</p> <div class="Discussion_UserSignature"> </div>

 

[Carrickagh]

<p>[<font color="#00ff00">QUOTE]Just like water clouds on Earth, wouldn't methane clouds either be formed of solid methane particles (frozen methane) or small drops of liquid methane?</font>&nbsp; <br />Yes, the clouds are likely minuscule drops of liquid/frozen methane. Methane is liquid at around -160C. Neptune's atmosphere is (I believe) below -200C, at least at the cloudtops.</p><p>Neptune also has high, thin cirrus clouds. At least IIRC some were spotted by Voyager2. Like cirrus clouds on Earth these are made up of ice crystals, but in this case the ice would be methane.</p><p><font color="#00ff00">I&nbsp;would expect methane vapor to be an invisible gas just as water vapor is.&nbsp; <br />Posted by centsworth_II[/QUOTE]<br /></font></p><p><font color="#00ff00"><font color="#000000">Yes, you are correct that most vapors would be invisible. As my science teachers would say I should remember correct definiton of terms and not be so casual.<img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-smile.gif" border="0" alt="Smile" title="Smile" /></font></font></p><p>**</p><p>&nbsp;</p> <div class="Discussion_UserSignature"> </div>

 

[3488]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'><font color="#ff0000">Yes, the clouds are likely minuscule drops of liquid/frozen methane. Methane is liquid at around -160C. Neptune's atmosphere is (I believe) below -200C, at least at the cloudtops.Neptune also has high, thin cirrus clouds. At least IIRC some were spotted by Voyager2. Like cirrus clouds on Earth these are made up of ice crystals, but in this case the ice would be methane.**&nbsp; <br /> Posted by Carrickagh</font></DIV></p><p><font size="2"><strong>Hi Carrickhagh,</strong></font></p><p><font size="2"><strong>Yes that's correct. </strong></font></p><p><font size="2"><strong>The Tropopause & lower Stratosphere in Neptune's atmosphere is very cold indeed, approx -230 C. At the 1 Bar Level in the atmosphere, it is around -215 C.&nbsp;</strong></font></p><p><font size="2"><strong>Lower down it gets warmer, as Neptune has a large amount of internal heat, some residual from Neptune's formation (Neptune has approx 17 Earth Masses), some compression & some maybe from contraction.</strong></font></p><p><font size="2"><strong>From Neptune orbit, the Solar Energy is barely 0.7 Watt per Square Metre, as compered to 1,320 Watts per square metre from Earth, so really there is not enough solar energy to power Neptune's storms, some of which rival the power of some of Jupiter's.&nbsp;</strong></font></p><p><font size="2"><strong>Another piece of evidence of the very weak solar intensity out here is Triton, Neptune's big moon. Triton until recently was known to have the lowest average surface temperature of any major body in the solar System, colder even than Pluto.&nbsp; Pluto appears a bit darker so absorbs a little more of the pathetic amount of warmth from the sun out here.</strong></font></p><p><font size="2"><strong>The dwarf planets Eris & Makemake, as well as the giant KBOs 2003 EL61, Sedna, Quaoar, etc are certainly colder also.</strong></font></p><p><font size="2"><strong>Andrew Brown.&nbsp;</strong></font></p> <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>