February 17, 2014 - Elegance in Death
Elegance in Death Planetary nebulae represent the final brief stage in the life of a medium-sized star like our Sun. While consuming the last of the fuel in its core, the dying star expels a large portion of its outer envelope. This material then becomes heated by the radiation from the stellar remnant and radiates, producing glowing clouds of gas that can show complex structures, as the ejection of mass from the star is uneven in both time and direction. A spectacular example of this elegant complexity is seen in the bluish lobes of NGC 5189. Most of the nebula is knotty and filamentary in its structure. As a result of the mass-loss process, the planetary nebula has been created with two nested structures, tilted with respect to each other, that expand away from the center in different directions.
Image credit: NASA / ESA / Hubble Heritage Team (STScI / AURA)
Weekly Calendar
February 17-23, 2014
Holidays - Sky Events - Space History
Monday 17
Presidents' Day
1959: Vanguard 2 launched
1965: Ranger 8 launched
1996: NEAR-Shoemaker spacecraft launched
2007: THEMIS spacecraft launched
2009: Dawn spacecraft flies by Mars
Tuesday 18
1930: Pluto discovered by Clyde Tombaugh
1970: HL-10 sets lifting body speed record
1977: First captive flight of space shuttle Enterprise
Wednesday 19
Mars 3° north of Moon
1473: Nicholas Copernicus born
1986: Mir space station launched
Thursday 20
1962: Friendship 7 launched; John Glenn becomes first American to orbit Earth
1965: Ranger 8 impacts the Moon, returns photographs
1994: Clementine enters lunar orbit
Friday 21
Saturn 0.3° north of Moon
1931: Germany's first liquid-fuel rocket launched by VfR flies 10 feet
Saturday 22
Last Qtr Moon 12:15 PM ET
Pallas at opposition
1966: Cosmos 110 launched, sets record for dogs in space (22 days)
1978: First Navstar GPS satellite launched
1996: STS-75 Columbia launched
Sunday 23
Neptune in conjunction with Sun
1987: Supernova 1987a explodes
1990: Pioneer 11 leaves solar system
1997: Flash fire in Mir Kvant module