How Many Galaxies Are There In The Universe?
How Many Galaxies Are There In The Universe?
Today, we're exploring a single question: How many galaxies exist in the Universe? Galaxies, vast collections of dust, gas, stars, other solar systems, and often black holes, extend beyond our solar system, beyond the Moon, and even beyond the Sun and other planets. The structure of galaxies and the Universe has intrigued astronomers for centuries, and our understanding continues to grow as we discover new galaxies each day.
Because our understanding of the Universe is still evolving, providing a precise count of galaxies remains quite challenging. Nevertheless, scientists have persevered in their efforts, and we now have a reasonable estimate.
How Do Scientists Estimate The Number Of Galaxies In The Universe?
Recent estimates suggest that there could be up to two trillion galaxies in the observable Universe. However, scientists didn't count each one individually. Instead, they examined tiny portions of the Universe, like looking at a pinhead held at arm's length, and counted the galaxies in those sections. This method provided a lower limit estimate of 100-200 billion galaxies in the observable Universe, as there are many galaxies beyond current technological reach. The two trillion estimate comes from converting images from the Hubble Space Telescope into 3D and using new mathematical models. This work suggests that 90% of galaxies in the observable Universe are too faint and distant to be seen with current telescopes. In theory, there could be an infinite number of galaxies, as the Universe itself may be infinite in size.
What Is The Biggest Galaxy In The Universe?
The largest galaxy we know of is probably the ESO 383-76 supergiant elliptical galaxy, which spans about 1,764,000 light-years in diameter. It's situated in the Centaurus Constellation, roughly 654 million light-years from Earth.
However, it's tricky to definitively identify the largest galaxy because our understanding of space is constantly growing, thanks to technologies like the James Webb telescope. Other galaxies have been suggested as the largest, such as IC 1101 and Alcyoneus. The biggest spiral galaxy we've identified is UGC 2885.
When we look at the largest barred spiral galaxy, we find NGC 6872, also known as the Condor Galaxy. It stretches about 522,000 light-years across from one end to the other, which is more than five times the size of our Milky Way. The Condor Galaxy resides in the Pavo Constellation, approximately 212 million light-years away from Earth. Its total diameter, including the "arms," spans about 522,000 light-years, with an isophotal diameter of roughly 717,000 light-years.
