uranus moons seen overtaking each other for first time

[h2ouniverse]

Hi all,<br /><br />This is the first time in Homo Sapiens history that our species'instruments enable us to observe Uranian moons cross-occultations. Oberon passed in front of the moon Umbriel on 4 May. 321 total occultations and eclipses of the Uranian satellites to come for this Uranian season (Earth in Uranian plane). Some discoveries from ground expected...<br />Without a space mission, that is better than nothing -sigh!-<br />Does anybody know whether valuable science is really expected from these Earth-based observations or is this overhyped?<br /><br />http://space.newscientist.com/article/dn11891-uranus-moons-seen-overtaking-each-other-for-first-time.html<br /><br />regards

 

[h2ouniverse]

See too http://www.apl.ucl.ac.uk/iopw/uworkshop_060905.pdf

 

[Aetius]

Uranus is a wicked cool planet. Look beyond the funny name, and it's an amazing world. <img src="/images/icons/wink.gif" />

 

[h2ouniverse]

I agree.<br />To us, non-Anglo-Saxon people, all puns about exploring Uranus, discovering all hidden faces of Uranus, interest in Uranus, fundamentals of Uranus... are irrelevant and boring. But I am beginning to strongly suspect that this prevents NASA from mounting an expensive in-depth mission to Uranus, that would bring it to wide public exposure. <br />Imagine if what occurred to Galileo probe (falling into a depleted "hole" in Jupiter atmosphere) occurred to a Uranian atmospheric probe. Headline: "Bad luck! While analyzing gas from Uranus NASA has penetrated into the gas hole!" would be a resounding blow with deep implications.<br /><br />A frustration for the rest of the world, with far less-funded space agencies (and anyway lacking the power-generation technology to reach the Outer System) having to wait that NASA dares to cross the line on Uranus.<br /> <br />And yet. Uranus deserves our interest. Uranus is wet (ocean of water in supercritical gas-liquid, high-temperature, high-pressure state). Its round moons present interesting grooves, with potential venting phenomena. <br /><br /><img src="/images/icons/shocked.gif" /> <img src="/images/icons/blush.gif" /> <img src="/images/icons/rolleyes.gif" /> OK I stop the puns. More seriously, given that English language is now lingua franca and cannot be ignored, why not changing its name to the Greek version: Ouranos ? (and pronounce it Oo-rah-nohs).

 

[Aetius]

I liked the name 'Hypercronus', myself. It sounds more 'science-fictiony'. <img src="/images/icons/wink.gif" />

 

[halcyondays]

Whe I was young, I learned to call the planet "Your-AN-us", then it gradually became "Your-AY-nus". In both cases the emphasis was on the middle syllable. I have noticed some people, notably on the sensitive BBC, now say "YOUR-an-us", ie. with the emphasis on the first syllable. Please tell me this is not an issue.

 

[h2ouniverse]

Hard to tell for me, for which English is not a mother language: you are better placed to answer that. Unfortunately, latin-like pronunciation would normally accentuate the penultimate syllab. That would not be enough. The most logical to me would be that this latin name (of greek origin) is pronounced like in latin [Oo-rah-noos], dropping the initial yod that is purely anglo-saxon-added. Even in French that would help by the way (no "your" to kill, but the end of the word is still a pun-generator if last vowel is pronounced like a French "u").

 

[3488]

Hubble takes first image of solar eclipse on Uranus<br />20:41 01 September 2006 <br />NewScientist.com news service <br />Maggie McKee<br /><br />A tiny moon has been caught floating in front of Uranus for the first time, the Hubble Space Telescope reveals. The moon's shadow can also be seen on the planet's cloud tops, creating a solar eclipse on Uranus itself.<br /><br />Hubble imaged the event unexpectedly in July 2006, during a set of observations meant to study the planet's clouds. "When we first got this image back, we looked at it and said, 'What's that bright spot and that dark spot?'" says team member Heidi Hammel of the Space Science Institute in Boulder, Colorado, US. "We thought, it must be a problem with the detector."<br /><br />Then, recognising that it resembled "transit" events seen fairly frequently around other giant planets, such as when Jupiter's moon Io passes in front of that planet's disc, the researchers realised they had seen the first ever transit on Uranus. It featured the 1130 kilometre-wide (700 mile-wide) Ariel, one of the planet's 27 moons.<br /><br />The events are so rare because Uranus, unlike the solar system's other planets, is tilted almost completely on its side, with its rotational axis lying nearly in its orbital plane.<br /><br />Its moons, however, orbit the icy giant above its equator. So when either of Uranus's poles is facing the Sun during the planet's 84-year orbit, the moons do not cross its disc at all as seen from Earth. Instead, they circle it on orbits that resemble the rings around a bull's eye.<br /><br />Rare chance<br />Uranus, its moons and the Sun are only in the right alignment to observe the effect every 42 years. Now, Uranus is approaching such an ideal viewing period – it will reach its equinox, in which the Sun will shine directly over the planet's equator, in 2007. "This is a once-in-a-career event for most of us," Hammel told New Scientist. <br /><br />It is also the first time in the history of astronomy that such o <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>

 

[3488]

Therse Earth based Observations may be of some use.<br /><br />There is a chance that Titania & Oberon may have tenuous atmospheres,<br />owing to their fairly large size & very low surface temperatures of about <br />minus 215 Celsius.<br /><br />Also we have only seen one side of them at decent resolution, by Voyager 2.<br /><br />As the eclipses occur, it may be possible to get veryations in light, as one body passes infront of another.<br /><br />This was done with the Pluto / Charon pair in the 1980s, making the first crude maps <br />of this double KBO.<br /><br />It may be possible to draw crude maps of the unseen hemispheres of the <br />Uranus moons.<br /><br />Other than the above, I do not think we will learn much.<br /><br />I hope the HST will be involved.<br /><br />Andrew Brown. <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>

 

[3488]

New orbital data on two moons of Uranus and two rings suggest the seventh planet may be a more chaotic place than thought.<br /><br />The two new moons, dubbed Cupid and Mab, were discovered in 2003 using the Hubble Space Telescope and archived images from the Voyager 2 spacecraft. Since then, the moons' discoverers, Mark Showalter of the SETI Institute and Jack Lissauer of NASA Ames Research Center, both in California, US, have refined the orbits of the moons and spotted two previously undetected dust rings.<br /><br />“To me, the exciting part of this discovery is the fact that there were these faint outer rings that previously escaped detection,†says Richard French, an astronomer at Wellesley College in Massachusetts, US, who studies the dynamics of planetary rings.<br /><br />The finds bring the number of Uranian moons to 27 and the rings to 12. Cupid orbits a mere 863 kilometres from a larger moon, Belinda, making them the solar system’s closest pair of orbiting satellites that do not share the same orbit. <br /><br />“That really makes Cupid a sitting duck for being the next satellite of Uranus to disappear,†Showalter told New Scientist. Only a tiny change in its orbit is needed for it to collide with Belinda, and that is possible within a million years.<br /><br />Shakespeare and love<br />When Showalter and Lissauer went looking for Cupid in the Voyager 2 pictures, they realised the moon’s orbit had slightly changed in the 20 years between the Hubble and Voyager 2 observations.<br /><br />Based on their brightness, Showalter estimates Mab to be about 24 kilometres across and Cupid to be 18 km in diameter. Though the moons were discovered in 2003, they did not receive their official names until December 2005. Uranian moons are traditionally named after Shakespearean characters. <br /><br />Queen Mab is a fairy that visits people in their dreams, referred to by Mercutio in Romeo and Juliet. The moon Mab is close to the other moons that take their names from fai <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>

 

[h2ouniverse]

Thank you for your clear answer to the initial question. I share your frustration that exploration of this subsystem is not being envisaged short-term.<br /><br />Nota: I feel ashamed. But it's not me who began! <br />As a male homo sapiens below 60 I am afraid I cannot pretend to a "grown-up" mind. Alas, mental age remains low for the male part of the species.<br /><br />More seriously Andrew, I really fear such triviality would stop the media-conscious guys in the agencies.<br />

 

[MeteorWayne]

Andrew, Any idea what the bright area on the 2005 image is? An artifact, or something real? <br /><br />And by the way, I'm glad to say U-rain-us during my lectures.<br />A little humor wakes up the audience, which never hurts <img src="/images/icons/smile.gif" /> <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>

 

[3488]

Hi MeteorWayne.<br /><br />It is real feature, a large short lived storm throwing up a head through the haze.<br /><br />Andrew Brown. <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>