Current state of exoplanet detection...

[robotical]

This is something I've wondered for a while:

Say you were on a planet in Tau Ceti's habitable zone 17 light years away, with current technology and equipment, how much of the solar system could you detect? How long would it likely take you? Assume technology is frozen at current levels and no more equipment will be built or launched.

 

[bushwhacker]

Well besides the star itself. Probably Jupiter and saturn. Possibly the ice giants. as for the rocky planets we dont move sol enough to make a reading .

 

[MeteorWayne]

To be honest, they would likely know nothing about our solar system, if they had been looking as long as we have. They might have some suspicions that Jupiter exists, but confirmation would be a few decades away. As for any other planet, there's no way the data would rise above the noise to a detectable level.If they had been observing for a century, the odds would be better.

 

[thnkrx]

Hmmm....if 'current' were to include the equivilent of COROT (which has been up there a few years now), and *IF* (really big if) our system was 'edge on' from their perspective, then they probably would be in a position, over some decades, to detect all of the gas giants, and *maybe* earth as well (because of earths moon, which might produce a combined image large enough to detect).

Now...if 'current' were to include the equivilent of the newly launched Kepler mission, and we were 'edge on' from their perspective, then in a few decades time they'd likely know about all our planets except maybe Mercury and Pluto.

These are some big 'ifs', though. (we'd also have to hope that our system were on their target list for missions like COROT and Kepler.

 

[MeteorWayne]

And again, my point was, with our current search time, we would have no reliable data about our solar system, which after all is the only one with known life...And it would take decades to even confirm that a planet existed in the habitable zone.

 

[SpaceTas]

The first radial velocity detected planet (51 Peg) was announced in 1995. (Pulsar planets a little earlier) So the search has been on here for 16 years a little over 1 Jupiter orbit. Our measurements have improved but the rule of thumb is you need 2 or 2 orbits to make an announcement. So if the "Tau Ceteans" astronomers had been doing Doppler measurements of Sol the same length of time they would suspect a planet but would not have made an announcement.

Jupiter will not transit Sol as seen from Tau Ceti, because the ecliptic latitude of Tau Ceti is nearly 25 degrees.

 

[robotical]

Thanks to all who replied. I was wondering how just how good we were at detecting planets and wanted to put what we have found into perspective. I figured the best way to do that would be to ask how much we could detect of our own system from another star.

What about Centauri, would our detection improve much?

 

[SpaceTas]

Alpha Centauri system has been looked at closely, with the occasional rumor but no confirmed discovery.

Maybe a earlier post summarizing the detection methods and their current/future abilities would help

Ask the astronomer> methods used to detect exoplanets (on page 3 at moment)