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NASA Takes Step Forward In Planet Finding
Spy der Mann wrote to mention a piece at Physorg.com about a major breakthrough in planet finding. From the article: "On a crystal clear, star-filled night at Hawaii's Keck Observatory in Mauna Kea, NASA engineers successfully suppressed the blinding light of three stars, including the well-known Vega, by 100 times. This breakthrough will enable scientists to detect the dim dust disks around stars, where planets might be forming. Normally the disks are obscured by the glare of the starlight. Engineers accomplished this challenging feat with the Keck Interferometer, which links the observatory's two 10-meter (33-feet) telescopes. By combining light from the telescopes, the Keck Interferometer has a resolving power equivalent to a football-field sized telescope. The 'technological touchdown' of blocking starlight was achieved by adding an instrument called a 'nuller.' "
I've replicated the same feat at home using a device I call a "lens cap", except I can significantly beat the 100x reduction of star brightness.
I'll entertain all bids on this technology...
Cost? Ability to get large objects into space is about nil right now. And even when it is possible, cost is astronomical (sad pun intended). I believe in the order of $20,000 per pound (156,800 british pounds per stone for those of you on the other side of the pond). Rather expensive.
See my journal for slashdot ID's by year. Mine created in 2005. http://slashdot.org/journal/289875/slashdot-ids-by-year
Actually, yes. It uses the interference patterns between the light received at the two (or more) telescopes to give resolution many times that of the individual instruments. http://en.wikipedia.org/wiki/Interferometry
Be relentless!
It is a good father-son hobby. I built my own 8" newtonian about 27 years ago, dad and I spent a lot of time grinding the mirror, heading down to Meade to buy parts, eyepieces, an equatorial mount, etc. I learned more about my father during that nine month project than I had in my previous sixteen years of existence on this ball of dirt we call the earth.
:-)
We had many years of eyepiece time enjoying and documenting our observations
I still have that telescope, and I think of my recently-departed father whenver I use it.
Oh, yeah, we both learned early on not to drink and grind optics.
-Scott
My other sig is a Glock
There are instruments. From the Great Observatories and the Cosmic Origins projects. The problem though is that it took nearly 25 years for Spitzer to get off the ground and into orbit. The total life time cost is around $1.5 billion. $640-750 million for the satellite and then about roughly the same to run it. It only talks through the DSN which makes things extremly expensive. DI has one of the largetst telescopes that went to 'deep' space and that wan't cheap either. Right now it is on itsway back to earth and a parking orbit. Other than that no science being done. Why? Money. Once again running on the DSN, takes a lot of cash. The former runs at 20MHz and the latter about 115MHz. One uses flash the other didn't 'cause there was no rad-hard flash during design. The tech on the planet is not that same that can be used in space reliably. Forget about all of those assumptions in your calculation you better have the modeling down otherwise you're fscked.
So really the cost is a prohibiting factor as is the technology, not the desire to have telescopes in space.
The question I have to ask is why are we looking for planets?! It's almost as if we've totally leapfrogged the part where we actually find a way to get INTO space and TO planets. It's like we're kids looking through the window of a bar wanting to taste beer. Instead of looking at beer and wondering if it tastes good, we kids should be forging some fake id's and finding out for ourselves.
Finally, since I haven't seen a one sentence synopsis, a nulling interferometer does a careful job making the on-axis starlight received by two telescopes interfere destructively, while off-axis light from circumstellar emission passes through the system. This instrument is designed to study dust emission analogous to the zodiacal light in our own solar system.
Can this be programmed into cheap telescopes for well known light sources?
Is this the answer to light pollution?
I'm guessing that the answer is "no" and "no", respectively, but I'd be interested to find out why not.
Literalism isn't a form of humor, it's you being irritating.
function nuller(object)
set object = null
end function
Really, people. Think before you hit "submit".
You must be new here.
See my journal for slashdot ID's by year. Mine created in 2005. http://slashdot.org/journal/289875/slashdot-ids-by-year
> Can this be programmed into cheap telescopes for well known light sources?
:-(
No. The technology required to combine two light beams in
a coherent way is wa-a-a-y more expensive than a "cheap"
telescope. One must be able to control the length of the
two paths of light to a small fraction of wavelength of
the light. In the case of ordinary visible light, that
means "a small fraction of about 500 nm". That's the
hard part
> Is this the answer to light pollution?
Again, no. If you can perform interferometry, you
can in effect reduce the size of the field of view, if
you wish, and therefore reduce the noise contributed
by background light; but for most purposes, you
still want to see more than just point sources,
which means a reasonable field of view, which
means that there is still plenty of noise from the
background.
Alas.
Michael Richmond "This is the heart that broke my finger."
mwrsps@rit.edu http://stupendous.rit.edu
Except that using the moon blocking the light (as in an eclipse) isn't a good analogy for a nuller. The nulling interferometer doesn't have to put in anything to block the light-- it adjusts the relative phase of light on two different paths so that the on-axis light cancels out, but the off axis light doesn't. There are different instruments that work more like an eclipse, where a stop is used to block the startlight but not the planet light.