That relatively isnt that far off of an Earth mass planet.Kepler 10-b is an exoplanet is 0.85 Earth masses.2:The TYPICAL maximum range of exoplanet discovery is about 300 light years radius from the sun.There are a few outliers.OGLE-2005-BLG-390Lb is the farthest exoplanet discovered.......
Nope...obsolete idea.
It is without a doubt difficult to discover small mass planets, but we've certainly detected 1.4 Earth mass exoplanets. That relatively isn't that far off of an Earth mass planet.
Kepler 10-b is an exoplanet is 0.85 Earth masses.
2:
The TYPICAL "maximum range" of exoplanet discovery is about 300 light years radius from the sun.
There are a few outliers. OGLE-2005-BLG-390Lb is the farthest exoplanet discovered...about 21000 ly from the sun.
We have the technology to detect Earth-sized planets... with luck. NASA's Kepler mission is basically doing that but it only covers a very teeny tiny portion of the galaxy because it really only points in the same place. At any rate, what it's doing is monitoring all these stars to detect a telltale periodic dimming of the star's light. This would indicate that something is covering part of the star, e.g. a planet. There are fundamental limitation to the technique. The planet has to be on the same plane as our line of sight. If its orbital plane is a few degrees off, it won't come between us and the star, and we won't 'see' it.
For some exoplanets, we can even detect them from smaller telescopes on the ground and figure out the size of the planet. Amateur astronomers can even get in one the fun of observing these (with a strong enough telescope of course).
I don't know what the current maximum detection distance is but so far the most distant exoplanet is 21,500 ± 3,300 light years from us.
Transitting exoplanets are found at the greatest distance, with at least one outside our galaxy. Proper motions studies generally don't work beyond a few hundred lightyears.
