The Great Wall

Redshift surveys have revealed the largest structures yet observed in the Universe. The prominent concentration of galaxies running diagonally across the northern (that is, upper) portion of the adjacent image has been termed the Great Wall. It appears that

• It covers at least 85 Mpc in declination and 215 Mpc in right ascension. It is likely to be even larger because it is obscured by dust in the plane of our galaxy on one end and hasn't yet been mapped on the other.

• It is less than 7 Mpc thick.

• There is a corresponding structure in the southern sky termed the Southern Wall. Because neither the Northern Wall nor the Southern Wall have been mapped fully, it is even possible that the two join each other in the parts of the sky that have not been examined yet and are part of one much larger structure.