This is an image of the planet Uranus taken by the spacecraft Voyager 2 in 1986. Image: NASA
Auroras (pictured as white spots) flare on Uranus in November 2011.
Image courtesy Laurent Lamy
Posted on 04/13/2012 2:26:59 PM PDT by Red Badger
For the first time, scientists have captured images of auroras above the giant ice planet Uranus, finding further evidence of just how peculiar a world that distant planet is. Detected by means of carefully scheduled observations from the Hubble Space Telescope, the newly witnessed Uranian light show consisted of short-lived, faint, glowing dots – a world of difference from the colorful curtains of light that often ring Earth's poles.
In the new observations, which are the first to glimpse the Uranian aurora with an Earth-based telescope, the researchers detected the luminous spots twice on the dayside of Uranus – the side that's visible from Hubble. Previously, the distant aurora had only been measured using instruments on a passing spacecraft. Unlike auroras on Earth, which can turn the sky greens and purples for hours, the newly detected auroras on Uranus appeared to only last a couple minutes.
In general, auroras are a feature of the magnetosphere, the area surrounding a planet that is controlled by its magnetic field and shaped by the solar wind, a steady flow of charged particles emanating from the sun. Auroras are produced in the atmosphere as charged solar wind particles accelerate in the magnetosphere and are guided by the magnetic field close to the magnetic poles – that's why the Earthly auroras are found around high latitudes.
But contrary to the Earth – or even Jupiter and Saturn – "the magnetosphere of Uranus is very poorly known," said Laurent Lamy, with the Observatoire de Paris in Meudon, France, who led the new research.
The results from his team, which includes researchers from France, the United Kingdom, and the United States, will be published Saturday in Geophysical Research Letters, a journal of the American Geophysical Union.
Auroras on Uranus are fainter than they are on Earth, and the planet is more than 4 billion kilometers (2.5 billion miles) away. Previous Earth-bound attempts to detect the faint auroras were inconclusive. Astronomers got their last good look at Uranian auroras 25 years ago when the Voyager 2 spacecraft whizzed past the planet and recorded spectra from of the radiant display.
"This planet was only investigated in detail once, during the Voyager flyby, dating from 1986. Since then, we've had no opportunities to get new observations of this very unusual magnetosphere," Lamy noted.
Planetary scientists know that Uranus is an oddball among the solar system's planets when it comes to the orientation of its rotation axis. Whereas the other planets resemble spinning tops, circulating around the Sun, Uranus is like a top that was knocked on its side – but still keeps spinning.
The researchers suspect that the unfamiliar appearance of the newly observed auroras is due to Uranus' rotational weirdness and peculiar traits of its magnetic axis. The magnetic axis is both offset from the center of the planet and lists at an angle of 60 degrees from the rotational axis – an extreme tilt compared to the 11 degree difference on Earth. Scientists theorize that Uranus's magnetic field is generated by a salty ocean within the planet, resulting in the off-center magnetic axis.
The 2011 auroras differ not only from Earth's auroras but also from the Uranian ones previously detected by Voyager 2. When that spacecraft made its flyby decades ago, Uranus was near its solstice – its rotational axis was pointed toward the Sun. In that configuration, the magnetic axis stayed at a large angle from the solar wind flow, producing a magnetosphere similar to the Earth's magnetosphere, although more dynamic. Under those 1986 solstice conditions, the auroras lasted longer than the recently witnessed ones and were mainly seen on the nightside of the planet, similar to what's observed on Earth, Lamy said. Hubble can't see the far side of the planet, however, so researchers don't know what types of auroras, if any, were generated there.
The new set of observations, however, is from when the planet was near equinox, when neither end of the Uranian rotational axis aims at the Sun, and the axis aligns almost perpendicular to the solar wind flow. Because the planet's magnetic axis is tilted, the daily rotation of Uranus during the period around the equinox causes each of its magnetic poles to point once a day toward the Sun, likely responsible for a very different type of aurora than the one that was seen at solstice, Lamy explained.
"This configuration is unique in the solar system," added Lamy, who noted that the two transient, illuminated spots observed in 2011 were close to the latitude of Uranus's northern magnetic pole.
Capturing the images of Uranus's auroras resulted from a combination of good luck and careful planning. In 2011, Earth, Jupiter and Uranus were lined up so that the solar wind could flow from the Sun, past Earth and Jupiter, and then toward Uranus. When the Sun produced several large bursts of charged particles in mid-September 2011, the researchers used Earth-orbiting satellites to monitor the solar wind's local arrival two to three days later. Two weeks after that, the solar wind sped past Jupiter at 500 kilometers per second (310 miles per second). Calculating that the charged particles would reach Uranus in mid-November, the team scrambled to scheduled time on the Hubble Space Telescope.
Ever since the Voyager 2 flyby demonstrated that Uranus was a "strange beast," said Fran Bagenal, a planetary scientist with the University of Colorado in Boulder, "we've been really keen to get a better view. This was a very clever way of looking at that."
A better understanding of Uranus' magnetosphere could help scientists test their theories of how Earth's magnetosphere functions, she added. "We have ideas of how things work on Earth and places like Jupiter and Saturn, but I don't believe you really know how things work until you test them on a very different system."
More information: "Earth-based detection of Uranus' aurorae" http://dx.doi.org/ … 2012GL051312
This is an image of the planet Uranus taken by the spacecraft Voyager 2 in 1986. Image: NASA
Auroras (pictured as white spots) flare on Uranus in November 2011.
Image courtesy Laurent Lamy
*popcorn*
The thread is doomed but I’ll BTT it anyway.
The thread title is too dangerouse. It could lead to banning.
Oh man! Gotta lay off the chili. Sorry ‘bout that.
CC
...just here for the off-color jokes. Proceed...
Thanks to scientist, Ben Dover for his discovery.
It does have a certain glow to it.
I’m gonna KIFFR
Rimfire ammo??
I think his sister Eileen Dover helped.
“the magnetosphere of Uranus is very poorly known,”
I tend to agree..
Leave Moochelle alone!
Larry King topic
My college astronomy teacher pronpunced Uranus as (Your uh nuss).
Fry: Did you build the Smelloscope?
Professor Hubert Farnsworth: No, I remembered that I’d built one last year. Go ahead, try it. You’ll find that every heavenly body has its own particular scent. Here, I’ll point it at Jupiter.
Fry: Smells like strawberries.
Professor Hubert Farnsworth: Exactly. And now, Saturn.
Fry: Pine needles. Oh, man, this is great... hey, as long as you don’t make me smell Uranus.
Leela: I don’t get it.
Professor Hubert Farnsworth: I’m sorry, Fry, but astronomers renamed Uranus in 2620 to end that stupid joke once and for all.
Fry: Oh. What’s it called now?
Professor Hubert Farnsworth: Urrectum. Here, let me locate it for you.
Fry: No, no, I, I think I’ll just smell around a bit over here.
and he pronounced it that way too.
LOL, of course this means Bender will soon be here... :)
Uranian spokespersons today reiterated the statement
that, “ Uranian Auroras are for peaceful porposes,
and that any attempts by Earth leaders to portray
them as weapons would be considered threatening
and war like. The Uranian people look forward to
working with the Earthlings into their future
such as if might be.
You mean Urinous?
You mean this isn’t the title for a gay porn movie?
Smells like poo.
I Wanna Kiss Her (We’ll Always Have Uranus)
by Tim Cavanagh
available on: Dr. Demento’s Mementos, Eccentric LP/Picture Disc/CS 8912, 1982 (out-of-print)
Sounds Like Fun, Hits & Giggles Records HG4321, 1996 (see The Demented Address File)
I was ridin’ on a train to Austin, Texas,
When a very lovely lady sat next to me.
When she got up to eat,
She asked if I would hold her seat.
I was more than happy to,
And now there’s more I’d like to do.
I wanna kiss her but, she won’t let me.
I wanna whisper sweet nothin’s in her (r)ear.
I wanna hold her behind...closed doors and more.
I wanna kiss her but, she won’t let me.
When she returned, she said she was an actress.
She showed me an album of pictures of her opening, which she’d been sittin’ on.
She seemed as sweet as she could be,
But I could clearly see
She was the kinda girl who stole men’s hearts,
Then wrecked ‘em.
I wanna kiss her but, she won’t let me.
I wanna whisper sweet nothin’s in her (r)ear.
I wanna hold her behind...closed doors and more.
I wanna kiss her but, she won’t let me.
Well, I’ll never forget that train ride down to Austin.
We shared a seat, and we shared our tales.
But as my heart tries to leave her behind,
Regrets are all I find,
‘Cause I’d hoped I’d get that girl
In the end.
I wanna kiss her but, she won’t let me.
I wanna whisper sweet nothin’s in her (r)ear.
I wanna hold her behind...closed doors and more.
I wanna kiss her but,
I wanna kiss her but,
I wanna kiss her but,
She won’t let me.
The Bell Labs (Lucent) Fruit Loop?
What a God awful logo. The innovation ring they called it. Pffft
Isn’t that where Hillary is from? Uranus?
<
Only during the rainy season.
Isn’t that where Hillary is from? Uranus?
No, that’s Obama.
I thought this was another faggot thread.
When earth’s rotation causes us to face URANUS, I can only hope I’m upwind.
I must say, Uranus is spectacular!
What do the Starship Enterprise and toilet paper have in common?
They both circle Uranus and wipe out Klingons!
News Flash: The massive black hole located dead center of URANUS seems to be pulling the two moons right in.
Very interesting. Thanks for posting.
My hemmoroid is much more prominent than that little pimple, and I don’t need no stinkin Hubble to find it!
(At least that’s what my proctologist says)
And then they spun of a disaster called "avaya".
space-cadets, indeed.
So why would your anus have areolas?
Ur anus? Can you say that on the Internbet?
I hate when Uranus has Klingons.
Lucent Technologies Logo. The had a large operation in my area and were fondly known as the big red a-hole.
When it was first introduced the folks I knew called it the flaming a...hole
You gotta wonder how that ever got approved by the board as the corporate logo.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.