A real breakthrough in parallax measurement and therefore in determining distances of stars in our galaxy, the Milky Way, came with a mission called Hipparchos, after the ancient Greek astronomer that first used the method to estimate the distance of the moon. 

This mission, launched by ESA...

The light is spread over an area four times larger, and it will be only one-fourth as bright as when the projector was half as far away. If you move the projector three times farther away, the light will cover 9 square feet and appear only one-ninth as bright. 

If a star measured in this ma...

Another application of parallax is the reproduction and display of 3D images. The key is to capture 2D images of the subject from two slightly different angles, similar to the way human eyes do, and present them in such a w...

In 2013, ESA launched a telescope called Gaia that charts the positions, parallaxes, and proper motions of more than one billion stars. That number represents only about 1% of the actual number of stars in the galaxy, but that's enough for astronomers to extrapolate the observations to u...

When it comes to measuring distances to other stars, the orbit of Earth around the