Comet Elenin

[Nathan]

I just knew Mr Brattle would post on this thread!

[Trudytropics]

Excellent, I have been told not to watch any youtube clips at the moment as for some reason computer crashes everytime I watch a clip. Thats my get out clause

[Dave Brown]

A small (ish) comet discovered late last year was due to breeze past us (in front of our orbit) late October of this year at a distance of some 22,000,000 MILES, many people have attached all sorts of doom and gloom to this visitor and there are copious amounts of such video's on utube.

But NASA maintained that there was no threat at all and people would be able to watch the visitor pass on it's way possibly with the naked eye.

Today things may have changed, the comet appears to be breaking apart, it's estimated nucleus is 6 - 7 miles in diameter ( not verified by nasa ). If this is indeed breaking up then the implications are seriously worrying, debris may change course / slow down, making late October a cometary minefield....

Nasa orbit diagram ( uses Java )
http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=C ... ;cad=0#orb

Astronomer website
http://members.westnet.com.au/mmatti/sc.htm

Now you may think I'm a fruitcake, but I have my reasons for liking a close shave with a commet, but not close enough for a hit obviously.

The global warming theory was put down to rising CO2 levels just didn't stack up as the CO2 increase was tiny compared to the warming. Other research which was poo-poo'd as it couldn't be taxed, was that there was an increase in upper level watervapour, and this co-incided with 'global dimming'. The only thing they couldn't prove was how the water got up there.

Have you noticed how clear the skies have been the last couple of years, and the shadows so stark.... something I have not seen here before.

My theory is that we pick up water vapour from passing commets and this starts off at very high levels gradually making it's way down through the atmosphere. Once out of the atmophere we have brighter hotter continents in summer and brighter colder continents in winter. Every continent has suffered extremes of heat and cold over the last couple of years.

If we pick up a decent amount of water vapour from this comment, perhaps we can return to the more milky skies shading out extreme heat in mid continents in summer, and the extreme cold everywhere in winter.

[Conifers]

Have you noticed how clear the skies have been the last couple of years, and the shadows so stark.... something I have not seen here before.

No!

The skies here haven't changed at all except that light pollution is far worse now than when I was young. Hard to see any other than the very brightest stars at night now, even on a really clear night. That doesn't suggest clear skies!

If we pick up a decent amount of water vapour from this comment,

So it's steam as well as hot air?

[GoggleboxUK]

at Connie.

Dave, there's no way water could pass through our atmosphere in either direction. The space shuttle's exterior records temperatures in excess of 1200c during re-entry,

[flounder]

just looked at your time of posting Dave, liquid lunch?

[Dave Brown]

at Connie.

Dave, there's no way water could pass through our atmosphere in either direction. The space shuttle's exterior records temperatures in excess of 1200c during re-entry,

That is a large fast moving object. Water vapour is not.... and how did all the water get on the planets in the first place. They were formed by attraction of matter. Virtually everything that is here came down from space

[Tom2006]

Water vapour does not exist in space. Water on earth came from hydrogen and oxygen combing to male water and also from asteroids, carrying water, striking the earth. Our atmosphere does not permit water to enter via vapour.

[Dave Brown]

Ok water vapour, as such, does not exist as it is near 0 Kelvin in space, but ice crystals do. Also I was of the understanding that Comets are mostly ice.

I Never believe when it is said "something is not possible" in science. We would never progress if we just accepted the understanding that went before

[Tom2006]

Yes ice came in on asteroids so there is no way a passing comet could increase atmospheric moisture. As for re-writing physics, i like your style Dave.

[Conifers]

Water vapour does exist in space, but only in minute quantities.

The amount the earth would pick up from a comet's tail is too small to have any detectable effect on the upper atmosphere - probably less than 1kg (compared to several tonnes from a shuttle launch). Different matter if the comet nucleus hit, like Comet Shoemaker-Levy which hit Jupiter a few years ago. That would be very spectacular (and highly destructive!), but it isn't going to happen with this comet.

[GoggleboxUK]

at Connie.

Dave, there's no way water could pass through our atmosphere in either direction. The space shuttle's exterior records temperatures in excess of 1200c during re-entry,

That is a large fast moving object. Water vapour is not.... and how did all the water get on the planets in the first place. They were formed by attraction of matter. Virtually everything that is here came down from space

The water got to Earth before the atmosphere existed, most likely by a large ice comet hitting the earth before it has completely cooled to a crust.

The resulting vaporisation of that water would have created the atmosphere over time which, in turn, created an oxygenated environment that retained a certain amount of heat whilst deflecting the harmful excesses of solar radiation thus allowing life to develop.

If a passing comet could add water vapour to our atmosphere we'd all have boiled millions of years ago.

Did you noticing how the shadows became more defined coincide with a new spectacles prescription by any chance Dave? OK, it's not E=mc squared but it's a theory.