New Red Spot Options

[djellison]

The expectation is that they'll just breeze past. There was an exhibition meeting of the BAA in Cambridge last weekend, and the director of the Jupiter Section showed images that demonstrate that new spot is getting darker and darker red over time, coinciding with it speeding up - and also, the GRS is getting smaller and lighter ( over the past century or so ) suggesting an opposite trend.

Doug

[dilo]

Doug, are you talking about a possible passdown between the two spots? Would be great to see this, even if time scale of the two events (GRS fading and RSJr reddening) seems completely different...

[dilo]

Now almost touching!

Christopher Go comments is:"The GRS and Oval BA are very close now. From the looks of it both storms will just pass by! There is enough clearance between the two storms"

[remcook]

http://www.spaceflightnow.com/news/n0607/21jupiter/

definately not colliding. beautiful gemini image

[Guest_AlexBlackwell_*]

From the latest issue of the journal Earth, Planets and Space:

Oscillating motion of the Jovian Great Red Spot and Numerical Experiments with IG equation
Tadashi Asada and Isao Miyazaki
Earth Planets Space 58, 905-910 (2006)
Abstract

[OWW]

New images from Keck:

http://www.keckobservatory.org/article.php?id=88

[SigurRosFan]

New article:

- Jupiter's Little Red Spot growing stronger (Spaceflight Now)

Red Jr's winds now raging up to approximately 400 miles per hour (wind speed of Great Red Spot).

Why Red Jr's intensity is growing stronger? Change in size or ...

<< According to the team, the increased intensity of the Little Red Spot probably explains why it changed color. >>

[Guest_PhilCo126_*]

So why are the storms red?
Scientists are still puzzled… sulfur, germanium oxide and various carbon compounds have been proposed as an explanation but the coloring agents still remain an enigma…

[ugordan]

I'm curious: is the progenitor to Red Jr. the big, while oval that Cassini saw in 2000?

It certainly looks conspicuous. The funky composite is a MT3/MT2/UV1 as RGB. The oval appears bright in MT3 and very dark in UV so it turns out orange in the composite.

[elakdawalla]

I've been trying to track down the origin of that storm too. Jupiter is hard because no cloud features stay put -- stuff at different latitudes shifts with respect to each other with timescales measured in days, and stuff at different longitudes but the same latitude shifts on slightly longer timescales.

According to some image captions on Photojournal the three white ovals first formed in the 1930s.

Here's the Voyager 1 view, from July 1979. You can see three large white ovals of roughly equal size in the band just south of the Great Red Spot. One is just below the spot, the other two are some distance away.

Here's an early Hubble view from May 1991, with just one of the spots showing up. And here's a very low resolution set from Hubble in July 1994, where you can barely make out the positions of the white spots. They're much closer together than they were in 1979.

Here's a Hubble view from February 1995. Three white ovals are now immediately adjacent. The caption says that the outer two white spots are ones that formed in the 1930s. What's the center one then? This caption also refers to another view from seven months earlier -- I haven't tracked that one down yet. There's a second image on the Hubble site, but there's no caption information saying when it was taken.

Galileo was in position to witness their merger in February 1998 but was of course only able to return tight views. Here are two Galileo views from February 1997 and September 1998. It says that two of the storms were called BC and DE after they formed. What was the third one called? What's the significance of these names? There's a whole bunch more of the February 1997 views here, here, here, here, and here...and 13 more...as well as a blinky movie.

Here's the Cassini view, from October 2000. You see just the one oval, roughly 150 degrees of longitude away from the Great Red Spot. So, yes, ugordan, that's the progenitor to Little Red.

--Emily

[edstrick]

Somebody mis-natigated and a Vogon ship fullof RED NUMBER TWO collided with Jupiter.

[Bjorn Jonsson]

The constantly changing appearance of Jupiter's atmosphere is a fascinating subject. Many of these changes are quite obvious in amateur astronomical telescopes once you are familiar with Jupiter.

The origin of this 'new' red spot can be traced back to 1939 when the three white ovals seen in the Voyager images started forming. They were formed as a result of changes in three separate locations in the South Temperate Zone. Originally they were very long but then steadily contracted, rapidly at first. They were extremely similar to the GRS. These three ovals were known as BC, DE and FA. As previously noted, originally they were very long. At that time they were separated by dark segments known as AB, CD and EF.

In 1998 ovals DE and BC merged into a single oval labeled BE. In March 2000 ovals BE and FA merged into a single white oval (oval BA) visible in the Cassini images. In 2005 this single surviving oval started changing color and in 2006 it had turned red. Interestingly, HST observations revealed that wind speeds in the spot increased after it turned red.

There is a huge amount of information on Jupiter's long term behavior in John Rogers' excellent book The Giant Planet Jupiter (to anyone interested in this subject: If you don't have it, get it!). Patrick Irwin's Giant Planets of Our Solar System discusses this in less detail but from a more technical perspective. There's also some information here and in particular here.

Perhaps even more interestingly, the GRS may disappear in a few decades. It has been steadily contracting and if the same trend continues, by 2040 or so it will be circular. That's believed to be an unstable configuration so something interesting is going to happen - the big question is, exactly what?

Finally I'll end this by venting my frustration: I cannot observe Jupiter until 2010 due to my northerly latitude .

[djellison]

John is the BAA's Jupiter Section director - and I saw a great talk by him a while back where he suggested that the current GRS might not be the one that is supposed to have been visible for so long - but is actually the second GRS since recorded observations of Jupiter begun hundreds of years ago.

Also - the current spot is 'speeding up'. In 1950 it was rotating in around 10 to 12 days. Now it's more like 4 - 6 days - but at the same time it's getting smaller so one can't assume it's getting faster as a result

Observations of Jupiter are one of the great amateur projects still ongoing.

Doug

[nprev]

Fascinating idea that this might not be Galileo's GRS...but if you think about it this makes sense. Jupiter's atmosphere is so dynamic that it's ridiculous to think of the GRS as a permanent feature in terms of geological time.

I recall some simulations a few years ago that indicated that a Spot-like storm almost always arose given a Jovian planet's assumed atmospheric properties, rotation rate, etc. But, it apparently doesn't have to be the same Spot every time. My question is whether two or more of similar magnitudes could be sustained, or does one have to die before another can fully form?

[stevesliva]

I recall some simulations a few years ago that indicated that a Spot-like storm almost always arose given a Jovian planet's assumed atmospheric properties, rotation rate, etc. But, it apparently doesn't have to be the same Spot every time. My question is whether two or more of similar magnitudes could be sustained, or does one have to die before another can fully form?

James Gleick's book Chaos referenced a 1985 paper that showed how a GRS would appear on Jupiter. The photos from the book are amongst these animations. There are some pretty neat videos there.