A more accurate yardstick for measuring the distance to stars in our galaxy.

Launched by European Space Agency, the GAIA spacecraft used triangulation, like a surveyor's scope, to measure the distance to stars; a technique called "Stellar Parallax." It had a very successful 10 1/2 year run till the fuel for positioning it ran out.

I first learned about Stellar Parallax in freshman astronomy classes.

Stars are so far that distances can't be measured easily. Using the entire earth as a baseline between two telescopes, one can measure out to just a few stars.

Even using the entire earth's orbit, from one side of the sun to the other, will only measures out a bit farther.

Our solar system is orbiting the galaxy, so that creates an even longer baseline.

Gaia operated for slightly over 10 years so our solar system has traveled far as it orbits around the center of our galaxy. That, combined with ever more accurate measuring technology, allows us to measure the distance to many more stars.

This provides better data points for extrapolating the size of things in the universe such as galaxies. It also tells us more about stars, how bright they are and so forth, now that we have more accurate ways of measuring the distance to them.

In the past, most of our distance estimates were extrapolations using other techniques, such as "standard candle brightness," extrapolated from the smaller data set of more accurate parallax measurements.

Ya, I'm probably getting into the weeds now, over people's heads on the technical.

I think I understand it, for the most part, myself. My college astronomy classes continue to come to life as improved technologies enhance the research being done.

Decades ago, I had a fantasy about sending a space probe way out beyond the solar system to create a long baseline back to earth for measuring parallax. Turns out that might not be necessary since our travel, through the galaxy, is creating that baseline, over the years, anyway. No need to send out that spacecraft, Earth, itself, is doing the travelling.

In our orbit around the galaxy, the earth and solar system is traveling at 514,000 miles per hour.

Meanwhile, the Voyager 1 spacecraft, heading out from the solar system, is only traveling at 38,000 miles per hour. Voyager 1 doesn't measure parallax to stars anyway. It does other things.

Our solar system, itself, is traveling so fast around the galaxy that if something on earth was going that fast, it would be going around 142 miles per second, yet it still takes around 230 million years to complete 1 orbit around the galaxy.

Imagine how big the galaxy is.

Voyager 1 travels approximately 10 miles per second. It was launched clear back in 1977 and is just about to reach the "one light day" distance from us.

These calculations, I got from AI and using my hand held calculator.

Now you may have forgotten what I was starting to write about.