Gaia satellite data states dwarf galaxies aren't Milky Way's satellites as earlier thought

A new set of data from European ncy's (ESA) Gaia satellite suggested that galaxies nearby Milky Way are newcomers to universe and t satellites as earlier thought. Our galaxy,  Milky Way is surrounded by many dwarf galaxies which orbit it and were thought to be satellite galaxies that accompanied ours for billions of years. In simpler terms, a new study shows that se dwarf galaxies are t as old as scientists thought and have t yet been trapped under  Milky Way's influence. A galaxy is termed dwarf when it comprises stars in numbers between 1,000 to several billion.

Scientists mapped 40 dwarf galaxies around Milky Way

Scientists confirmed aforementioned ory by computing motion of 40 dwarf galaxies that are revolving around Milky Way. According to ESA, astromer François Hammer, and his colleagues from China and parts of Europe calculated movement of galaxies by computing velocities, orbital energy and angular (rotational) momentum of each galaxy. results revealed that each of galaxies was moving too fast as compared to or giant stars and star clusters.

This means that ir speeds are too much to orbit Milky Way yet because ir orbital energy and angular momentum would have been destroyed if that was case. Furr elaborating same, ESA quoted François as saying " Milky Way is a big galaxy, so its tidal force is simply gigantic and it's very easy to destroy a dwarf galaxy after maybe one or two passs". Our galaxy also has a reputation of being a cannibal as it has consumed many dwarf galaxies in its past such as  Gaia-Enceladus, which was destroyed 8-10 billion years ago or  Sagittarius dwarf galaxy 4-5 billion years ago.

Talking about new findings, Timo Prusti, Gaia Project Scientist said as per ESA, "Thanks in large part to Gaia, it is w obvious that history of Milky Way is far more storied than astromers had previously understood. By investigating se tantalising clues, we hope to furr tease out fascinating chapters in our galaxy’s past". Launched in December 2013, ESA's Gaia is a star surveyor which has been assigned a job to create a three-dimensional map of over a thousand million stars throughout our Milky Way galaxy and beyond.

Im: ESA