The findings may help unravel the mysteries behind dark matter, the invisible substance holding galaxies together.
The results also mark the first discovery of dwarf galaxies — small celestial objects that orbit larger galaxies — in a decade.
The objects are a billion times dimmer than the Milky Way, and a million times less massive.
The closest is about 95,000 light years away, while the most distant is more than a million light years away.
“The discovery of so many satellites in such a small area of the sky was completely unexpected,” said Sergey Koposov from the Cambridge University’s Institute of Astronomy and the study’s lead author.
The satellites were found in the southern hemisphere near the Large and Small Magellanic Cloud — the largest and most well-known dwarf galaxies in the Milky Way’s orbit.
Since they contain up to 99 percent dark matter and just one percent observable matter, dwarf galaxies are ideal for testing whether existing dark matter models are correct.
Dark matter — which makes up 25 percent of all matter and energy in our universe — is invisible, and only makes its presence known through its gravitational pull.
The Cambridge findings were released with the results of a separate survey by astronomers with the Dark Energy Survey, headquartered at the US Department of Energy’s Fermi National Accelerator Laboratory.