Scientists measure the weight of our galaxy using NASA’s Hubble Space Telescope and the European Space Agency’s Gaia satellite.

It seems that the Milky Way weighs in at about 1.5 trillion solar masses, according to the latest measurements. Only a few percent of this is contributed by the approximately 200 billion stars in the Milky Way. Most of the rest of the mass is locked up in dark matter.

Although we cannot see it, dark matter is the dominant form of matter in the universe, and it can be weighed through its influence on visible objects like the globular clusters. “We know from cosmological simulations what the distribution of mass in the galaxies should look like, so we can calculate how accurate this extrapolation is for the Milky Way,” said Laura Watkins of the European Southern Observatory in Garching, Germany, lead author of the combined Hubble and Gaia study. These calculations based on the precise measurements of globular cluster motion from Gaia and Hubble enabled the researchers to pin down the mass of the entire Milky Way. (1)

Measuring something (mass) which we do not know what it is exactly (energy? creation of our observations? strings in multiple dimensions?) or how it is formed (Higgs?) through the use of observations interpreted via assumptions based on simulations based on other assumptions, only in order to discover that most of our galaxy is made up of something which we do not know anything about (dark matter) but which we use in our models that we then use to predict its mass…

Impressive isn’t it?

Building castles of sand on foundations of sand…

At the end we will end of explaining everything.

And a soft wave will hit the shore and will take everything away…

We will cry when this happens.

But our children will laugh…

And they’ll just start playing again!

Don’t be so serious.

Look closely.

And you will see your own small footprints on the beach too…

Can you start laughing?