02 VEEBR. 2005
Avaldamiskuupäev
798
Vaatamised
1824: On 22 February 1824, Pierre Jules-César Janssen was born.
Janssen was a French astronomer who in 1868 devised a method for observing solar prominences without an eclipse.
Janssen observed the total solar eclipse in India. Using a spectroscope, he proved that the solar prominences are gaseous, and identified the chromosphere as a gaseous envelope of the Sun. He noted an unknown yellow spectral line in the Sun in 1868, and told Lockyer (who subsequently recognised it as a new element he named helium, from Greek "helios" for sun).
Janssen was the first to note the granular appearance of the Sun, regularly photographed it, and published a substantial solar atlas with 6000 photographs.
Meedia modaal
20 February
1962: On 20 February 1962, US Marine Colonel John Glenn became the first American to orbit Earth.
18 February
2004: On 18 February 2004, ESA scientists announced they had seen a super-massive black hole ripping apart a star and consuming a portion of it.
Jaga seda lehte
püsige kursis
Telli meie uudiskiri, et saada uusimad uudised, missioonide värskendused ja eksklusiivsed ülevaated otse oma postkasti. Ole esimeste seas, kes saab teada meie tulevastest projektidest ja läbimurretest.