Stock Photo - image of the microwave sky synthesized using data spanning the range of light frequencies detected by Planck. These low frequencies, which cannot be seen with the human eye, cover the range of 30 to 857 gigahertz. The grainy structure of the cosmic microwave background, with its tiny temperature fluctuations reflecting the density variations from which the cosmic web of our universe originated.

Stock Photo: image of the microwave sky synthesized using data spanning the range of light frequencies detected by Planck. These low frequencies.