Messier 100 (also known as NGC 4321) is an example of a grand design spiral galaxy located within the southern part of constellation Coma Berenices. It is one of the brightest galaxies in the Virgo cluster, approximately 55 million light-years distant from Earth and has a diameter of 160,000 light years. It was discovered by Pierre Méchain on March 15, 1781 and was subsequently entered in Messier’s catalogue of nebulae and star clusters after Charles Messier made observations of his own on April 13, 1781. The galaxy was one of the first spirals discovered, and was listed as 1 of 14 spiral nebulae by Lord William Parsons of Rosse in 1850. A satellite galaxy named NGC 4323 is present within M100.
Some galaxies near by M100