The European Radio Astronomy Club frequencies, the ionosphere is opaque. Here, two targets are possible: the Sun with its solar flares or Jupiter, which is also a very strong radio source, together with the moon Io, which is a very powerful natural radio wave transmitter. When Jupiter, Io and the Earth are aligned, it is possible to hear this radio source very clearly. The European Radio Astronomy Club The European Radio Astronomy club (ERAC) is Europe's only group coordinating the work of radio astronomers to jointly use radio waves to study the universe at radio wavelengths. It was founded in 1995 by Peter Wright, who
Atmospheric diffraction Earth's surface. This phenomenon is sometimes called the corona effect, not to be confused with the solar corona. On the right is a 1/10-second exposure showing an overexposed full moon. The Moon is seen through thin vaporous clouds, which glow with a bright disk surrounded by an illuminated red ring. A longer exposure would show more faint colors beyond the outside red ring. Another form of atmospheric diffraction or bending of light occurs when light moves through fine layers of particulate dust trapped primarily in the middle layers of the troposphere. This effect differs from water based atmospheric diffraction because