If the idea of using people is deemed somehow unfeasible, rabbits or rats or even monkeys could always be used, too.

It is a good idea - someone will do it eventually.  If not NASA or ESA or whoever, then a corporation who wants to see just what their space miners can handle..

We yet do not know what is dark matter. We even not know if it is large objetcs or subatomic particules. Some hints were found recently that there would be numerous MACHOS (massive planet-sized or star-sized objects) so that to explain a fair amount of dark matter. The most common size found was half the mass of the Sun, pointing at (likely) very ancient white dwarves, very weak and thus invisible, but very numerous, maybe the second generation of stars. If this is confirmed, we have an explanation of the dark matter which fits within the known frame of physics, astrophysics and cosmology.

Awesome new views! Very dramatic.
And just  a little too close to the edge for comfort!

http://qt.exploratorium.edu/mars/spirit/na...M9P0625R0M1.JPG

What would be fine is if somebody have the log-log plot, amplitude versus frequency, with expected domain for each gravitationnal wave source, and the expected sensitivity of each instrument.

What I heard (to check) is that the LIGO gravitational wave observatory is curently reaching its full sensitivity, but it still detected nothing (the only thing it could detect, neutron stars spiraling, would happen only once a year in average).

One more question about LISA - unless and until the current LIGO generation of gravity antenna detect ANY gravitational phenomena, should we be vesting in another experiment? IAOTO the waves do exist, but we may be searching with the wrong kind of antenna.

Thanks  James, it was not meant as a criticism, I was just kicking myself. Do you work at U.N.S.W., my son has just started his 1st year Chem/Physics Deg there ?

How could such a probe work?
Basically a test mass, a raw piece of metal, should freely navigate into the solar system, on a trajectory fleeing the sun, while being protected of any spurious accelerations: solar wind, electric/magnetic effecs, outgassing, position control, etc.

To achieve this, it would be completelly enclosed into a metal casing, while having no physical contact/interaction with it. The casing would use thrusters to lock itself on a fixed position relative to the test mass.

So the overall thing navigates as if it was in really complete vacuum, without solar wind, outgassing, etc. and it can provide accurate informations of pure gravitationnal nature, eventually different of the 1/r2 law, or accounting for unknown bodies. The info on the trajectory corrections achieved by the casing would on its side provide very accurate data on solar wind. This makes this probe more interesting and more likely to fly than just a Pioneer anomaly test probe.

The only spurious gravitationnal effect on the test mass would be... the gravitationnal field of the probe itself. Thus the test mass should be placed right at the center of mass of the probe. An error on this would produce a permanent offset that we could not distinguish from true effects. If preleminary calculations show this is a problem, we can use a better overal design: the probe is formed of three parts, linked with cables: at the centre the protective casing, and at the extremities the radio transmitters, thrusters, and any other payload useful for science (and also useful to make this mission more likely). The whole thing rotates on an axis which is perpendicular to the sun direction, right around the test mass.
This design will allow to know preciselly the centre of mass and to adjust it. But above all, any permanent offset will be cancelled, as it will pull at times toward the Sun, at times opposite to the Sun. So we can really maintain the test mass free of spurious gravitationnal effects from the probe itself.

Such a probe would be relatively light wheight, so that it could be launched on an interstellar trajectory directly from the surface of the Earth, without using gravitationnal assistance. So it could bring results after only a few years. Otherwise we can use Jupiter' assistance.
Will this design lead one day to a real experiment?

Once that's done, we're going to do a little shimmy-step to the left and take the same panorama again, to get some "long-baseline stereo" coverage that we'll use to plan upcoming descent into the Inner Basin.

Why didnt someone tell me he was coming to OZ. I could have gone to listen to one of his lectures.

Wasn't entirely sure which of the many great current topics to post this in, but there's a new mission update at http://athena1.cornell.edu/news/mubss/.

Figured this one might become a focal point for discussion a little later today... 

And for those of you who are really into the engineering details: On Sol 581 -- more than nineteen months after we landed -- the solar array output for Spirit was 956 watt-hours. Insane. We have to shut her down every afternoon these days so she won't overheat.

I give up... I googled "vikingmars" and came up with _nada_.  Who is he, and where is his website?

Got my curiosity cooking...

--Bill

One odd series of images-- she seems to have done some back-and-forth-and-over driving across a dune crest, does not seem to be the usual post-drive uplink positioning maneuver:

http://qt.exploratorium.edu/mars/opportuni...WGF0006L0M1.JPG

Here is an animation, with stars aligned.
[attachment=1303:attachment]
It appears to speed up due to an increase in the amount of time between images.

The altenative being rover imortality

Phoenix is likely made of similar stuff.  I guess a lot of it depends on whether or not there are frequent "cleaning events" at that location.