Modern Developments
In more recent years, many projects have attempted to bridge the gap in our knowledge caused by the Zone of Avoidance. The dust and gas in the Milky Way cause extinction at optical wavelengths, and foreground stars can be confused with background galaxies. However, the effect of extinction drops at longer wavelengths, such as the infrared, and the Milky Way is effectively transparent at radio wavelengths. Surveys in the infrared, such as IRAS and 2MASS, have given us a more complete picture of the extragalactic sky. Indeed, two very large nearby galaxies, Maffei 1 and Maffei 2, were discovered in the Zone of Avoidance by Paolo Maffei by their infrared emission in 1968. Even so, approximately 10% of the sky remains difficult to survey as extragalactic objects can be confused with stars in the Milky Way.
Projects to survey the Zone of Avoidance at radio wavelengths, particularly using the 21 cm spin-flip emission line of neutral atomic hydrogen (known in astronomical parlance as HI), have detected many galaxies that could not be detected in the infrared. Examples of galaxies detected from their HI emission include Dwingeloo 1 and Dwingeloo 2, discovered in 1994 and 1996 respectively.
Read more about this topic: Zone Of Avoidance
Famous quotes containing the words modern and/or developments:
“It was announced that the trouble was not “malignant.”... It was a typical triumph of modern science to find the only part of Randolph that was not malignant and remove it.”
—Evelyn Waugh (1903–1966)
“The developments in the North were those loosely embraced in the term modernization and included urbanization, industrialization, and mechanization. While those changes went forward apace, the antebellum South changed comparatively little, clinging to its rural, agricultural, labor-intensive economy and its traditional folk culture.”
—C. Vann Woodward (b. 1908)