parallax of stars...?

Question

Has anyone suggested measuring parallax of stars from a long distance SPACE probe such as the NEW HORIZON PROBE or THE CASSINI PROBE ?

Answer 1

Nope! not true. Think about how astronomers measure the parallax of stars at present. They take a photograph of a relatively nearby star (one whose distance is been measured) with a very distant objectin the background (such as a quasar) Then they wait 6 months asthe earth will now be at the other side of its orbit thereby using a natural baseline of 2 astronomical units. However it does not have to be the same telescope which takes the second measurement. Similiarly when one measurement is taken from Saturn another can be taken from an earth based telescope (or the Hubble telescope
for that matter) . All that matters is that we have a baseline whi
is considerably larger than 2 astronomical units. In this case we now have a baseline of 30 astronomical units (an increase in accuracy of 15!)


Indeed as soon as a space probe is more than 2 astronomical units away from the Earth we have already a longer baseline than the natural one formed by the Earths orbit around the sun. For a more distant probe such as 'New Horizon'the accuracy will be far better and as the "New Horizon" will not be stopping the farther away it gets the more accurate the Parallax measurements will become.

Answer 2

This has already been done. In fact, most parallax measurements have been done without leaving home--you take a photo of the sky in the summer, then in the winter. This results in a parallax base of 186,000,000 miles (the diameter of the earth's orbit).

In theory, a larger base could be had by using two different long-range probes, or one long-range probe and an earth-based station. In practice, most long-range probes are designed for very specific missions, and astral cartography is usually not one of them.

More importantly, the vast majority of stars are so far away that parallax measurements are impossible, even if we had a telescope on Pluto. Most astral cartography is done by known "yardsticks" such as red giant brightness, or Cepheid stars.

Answer 3

I think there have been plans for specialized orbiting observatories to make those sorts of measurements; I don't know how close to reality any of them are. Theoretically, pictures of star fields from Saturn orbit or other distant location could yield improved parallax measurements, assuming the cameras have enough resolution and sensitivity. The other half of the problem would be someone on Earth to analyze the data.

Answer 4

On the grand scheme of things, how much more parallax can you get from the probes than from earth's orbit? Probably not much, unless the stars are really, really close.

Answer 5

In order to use a probe for that, you would need to add a lot of extra equiptment, and most probes do not have the room for it.

If they were going to do something like that, it would probably be a probe for that purpose only. . .

Answer 6

That would be a great idea! I would like to see stereo 3d pairs of the different constellations. You should be able to actually see the depth, if the parallax is significant.

Check out my website:
http://www/deanrdavis.bigbig.com

I do some 3d photography.

Answer 7

Hi. The best measurements we have so far come from the Hipparcos satellite.