How dark is it in the space and how can new galaxies be seen in the Universe? The scientists decided to give an overall estimate of the number of galaxies using the visibility of the Hubble field, and then multiply it by the total area of the sky. But there are galaxies that are difficult to detect. It has not yet been possible to count them, but space is filled with their faint radiance.
According to the scientists, to measure this glow a special trajectory is required for the movement of astronomical satellites, which must avoid entering the inner part of the solar system and its light pollution based on dust.
The astronomers decided to use New Horizons on the Pluto and the Kuiper Belt for these observations to determine the brightness of the cosmic optical background. As a result, an upper limit was established for the system of faint, barely visible galaxies. There are a total of several hundred billion of them, not two trillion, as previously thought.
The darkness of space is always filled with the faint twinkling of countless stars. Using the technique of new calculations of this background glow, the scientists established that there are fewer invisible galaxies than previously thought.
An astrophysicist Mark Postman of the Space Telescope Science Institute in Baltimore believes that humanity will never know how many galaxies are in the Universe. First, this is due to the fact that many galaxies, and there are trillions of them, do not have a visible glow.
An earlier estimate of the possible number of galaxies was based on observations by the NASA Hubble Space Telescope. Traditional mathematical models were used to calculate the possible number of galactic formations. But the results were such that 90% of the galaxies were beyond the scope of the telescope.
Their glow was very weak and the telescope could not detect them. The new observations made with more modern technology made accurate calculations, ultimately reducing the number of alleged invisible galaxies by their detected faint glow.