Imaginea Astronomica a Zilei

Descopera cosmosul! In fiecare zi este prezentata o noua imagine sau fotografie a universului nostru fascinant, insotita de o explicatie scurta din partea unui astronom profesionist.

2002 May 7
See Explanation.  Clicking on the picture will download
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Smog Over New York
Credit: STS-92 Crew, NASA

Explicatie: (Edit) What is not pretty about the above picture? In a word: smog. In 2000 October the orbiting Space Shuttle Discovery photographed upstate New York just at sunset. Visible is golden sunlight reflecting from two of the Great Lakes (Erie and Ontario), and several of the Finger Lakes. Between the clouds at the top and ground at the bottom, however, is a trapped layer of smog. Smog is mostly ozone but may contain small amounts of volatile organic compounds. As opposed to "good smog" in the upper atmosphere, "bad smog" near the ground is created mostly by humans. In the upper atmosphere, ozone reflects back harmful ultraviolet radiation, but when it occurs near the ground, it can be inhaled. Smog continues to be studied with an eye for how it develops and how it affects human health.

Imaginea de maine: On the Sun's Surface

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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.