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April 23, 2018 - GALEX Galaxies Galore

GALEX Galaxies Galore  Fifteen years ago this week, the Galaxy Evolution Explorer (GALEX) ultraviolet space telescope was launched into orbit. For ten years, until it was decommissioned in 2013, GALEX measured the history of star formation in the universe, going back as far as ten billion years. One objective was to observe hundreds of thousands of galaxies and determine how far away each galaxy is from Earth and how fast stars are forming in each galaxy. Seen here is NGC 6744, one of the galaxies most similar to our Milky Way in the local universe. This ultraviolet GALEX view highlights the vast extent of the fluffy spiral arms, and demonstrates that star formation can occur in the outer regions of galaxies. NGC 6744 is in the constellation Pavo and is about 30 million light-years away.

Image credit: NASA/JPL-Caltech

Weekly Calendar

April 23 - 29, 2018

Holidays - Sky Events - Space History

 

Monday 23

1858: Max Planck born
1962: Ranger 4 launched
1963: M2-F1 lifting body first free flight
1996: Priroda module launched to Mir space station

Tuesday 24

Regulus 1.2° south of Moon

1970: China becomes fifth nation to launch its own satellite
1990: STS-31 Discovery launched

Wednesday 25

1962: Second Block I Saturn C-1 (SA-2) launched
1990: Hubble Space Telescope deployed
2003: ISS Expedition Seven crew launched on Soyuz TMA-2

Moon phase Thursday 26

1920: Shapley-Curtis debate on the nature and distance of spiral nebulae
1993: STS-55 Columbia launched

Friday 27

Saturday 28

1900: Jan Oort born
1906: Bart Bok born
1928:
Eugene Shoemaker born
1991:
STS-39 Discovery launched
2001:
Soyuz TM-32 launched; Dennis Tito becomes first space tourist
2003:
GALEX launched
2006:
CloudSat and CALIPSO launched

Sunday 29

Mercury at greatest elongation (27° W)
Full Moon 8:58 PM ET

1985: STS-51B Challenger launched

Suggestions for new history dates or better links? Corrections for errors on this page? Please e-mail me.