From Space Academy
For many years, scientists have been very much baffled by a weird anomaly far away in space: a mysterious “Cold Spot” about 1.8 billion light-years across. It is cooler than its surroundings by around 0.00015 degrees Celsius (0.00027 degrees Fahrenheit), a fact astronomers discovered by measuring background radiation throughout the universe.
Previously, astronomers believed that this space could be cooler simply because it had less matter in it than most sections of space. They dubbed it a massive supervoid and estimated that it had 10,000 galaxies fewer than other comparable sections of space.