New planet

Saruman

Jupiter size planet found.... yes another one.. only this time its orbiting a sun like star in a jupiter like orbit! Increases the chance of earthlike planets out there... when we are able to detect smaller planets (soon i hope) then maybe we can find one nearby!

http://www.nasa.gov/today/index.html#5337

seamus

Wrong forum. Those tricky S's Interesting, but the link for the full story brings up an ftp site which is no use to me. Have they actually *seen* a new planet, or just found more evidence for one existing. Big difference.

Saruman

I got into the full story... its only a text file.. hmm now its asking for a password when i just tried again... must be updating it..
Anyway no they cant SEE the planet... no telescope can see something as dim as a planet outside our own solar system... Hibble cant even see a lot of small planetary bodies in the kuiper belt (out by Pluto). Even Hubble imags of our own planets are not the best!! They are too dim for excellent high exposure images... but stars and nebula are different.. they are very bright and can be picked up by hubble no problem!!

Moriarty

If i remember correct they can defer that there is a planet / planets from the 'wobble' of the star that is induced by a planet sized mass.. eg gravity interacting, so that a planet circling a sun makes the sun 'wobble' slightly because of the planets gravitational pull on it..... or something to that effect

Its 'red shift' they use to measure distance of stars isnt it? the further away the more the light 'shifts' to the red spectrum..?

bonkey

Originally posted by Moriarty
Its 'red shift' they use to measure distance of stars isnt it? the further away the more the light 'shifts' to the red spectrum..?

Yes and no.

The Hubble Constant is a relationship which has been generally observed to hold, which establishes a linear ratio between distance and red-shift.

However, the actual value of the Hubble Constant is almost constantly being revised (although in recent years, the revisions tend to be quite small in scale, where previously they often differed by an order of magnitude). Thus, it is important to note how distance was calculated (red-shift or other methodologies) as all of them are only approximations, and the difference may need to be recalculated when the accuracy of the chosen methodology is revised.

Red-Shift is generally useful for estimating the distance to other galaxies, more than for calculating distance to stars within our own galaxy as the galaxy isnt really expanding - its galaxies which are "receeding" from each other, causing the red-shift.

jc

Scruff

Taken from BBC News\SciTech

Scientists say they are now in a position to try to estimate how many planets may exist in the galaxy and speculate on just how many could be like the Earth. The answer in both cases is billions.

Virtually all the stars out to about 100 light-years distant have been surveyed. Of these 1,000 or so stars, about 10% have been found to possess planetary systems.

So, with about 300 billion stars in our galaxy, there could be about 30 billion planetary systems in the Milky Way alone; and a great many of these systems are very likely to include Earth-like worlds, say researchers.

Current planet detection technology - based on the "wobble" induced in the parent star by the gravitational pull of the orbiting planet - can only detect worlds about the mass of Saturn or larger. Earth-sized worlds are too small to be seen.

But even in this "biased" survey of giants, the smaller worlds predominate - which makes astronomers think that Earth-like worlds do exist. They may even be as common a Jupiter-sized exoplanets.

And if stellar statistics gathered in our local region of space are applied to our galaxy of 300 billion stars, then there may be 30 billion Jupiter-like worlds and perhaps as many Earth-like worlds as well.

an "estimate" of 30 billion.... Don't want to delve into the sci-fi realm but even if a fraction of a percentage of that estimate could support life and another percentage of those intelligent life then statistics alone would make the "We are not alone" camp right! well in the fact that we arent alone anyway...