The whole shebang
Scientists can now weigh the entire galaxy. This is kind of a big deal.
Think about it: How do you estimate the mass of something that large? Our galaxy, the Milky Way, is made up of over 100 billion stars, stretching up to 200,000 light years from edge to edge. Obviously no scale can weigh that.
But a team of scientists thinks it might have a pretty good substitute. By estimating the weight of certain stars in the "streams" of dissolving globular clusters (a fun phrase that indicates a type of star group) encircling the Milky Way, Columbia University's Andreas Küpper and his fellow researchers believe they've got a pretty good model to estimate the galaxy's mass itself.
And — drumroll, please — they estimate that mass to be "210 billion times the mass of the sun with an uncertainty of only 20 percent," as Science Daily reports. Or, as a back of the envelope calculation showed:
I'll let you decide if that's a healthy weight or not.