Imaginea Astronomica a Zilei

Descopera cosmosul! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

July 6, 1999
See Explanation.  Clicking on the picture will download 
 the highest resolution version available.

A Sun Pillar
Credit: Grant W. Goodge, NOAA Photo Collection, US Dept. of Commerce

Explicatie: (Edit) Have you ever seen a sun pillar? When the air is cold and the Sun is rising or setting, falling ice crystals can reflect sunlight and create an unusual column of light. Ice sometimes forms flat, stop-sign shaped crystals as it falls from high-level clouds. Air resistance causes these crystals to lie nearly flat much of the time as they flutter to the ground. Sunlight reflects off crystals that are properly aligned, creating the sun-pillar effect. In the above picture, the sun-pillar can be traced up to the cloud that is raining the reflecting ice-crystals.

Imaginea de maine: A Dense Ball of Stars


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Autori & editori: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
Reprezentanti tehnici NASA: Jay Norris. Specific rights apply.
Un serviciu al: LHEA at NASA/ GSFC
& Michigan Tech. U.