In 2018, astronomers discovered an unusual galaxy NGC 1052-DF2 in the vicinity of the Milky Way. With similar sizes to our galaxy, it contains 200 times fewer stars. At the same time, there is practically no dark matter in it. Its presence can be determined by the gravitational effect on visible matter.
It is believed that dark matter is a key component necessary for the formation of galaxies. Without it, the primary gas would not have sufficient gravitational attraction to begin to contract and form the first “star islands”. A year later, astronomers discovered another “empty” galaxy NGC 1052-DF4, containing almost no dark matter.
In an attempt to explain the existence of galaxies without dark matter, scientists have conducted a number of studies and concluded that in the event of a galactic collision, it can “fly out” beyond its galaxy and continue moving through space.
The probability of such a scenario confirms that NGC 1052-DF2 and NGC 1052-DF4 are moving away from each other and there are several other dwarf galaxies next to them that can be lined up in a single line. This suggests that they may have the same origin.
