May 21, 2018 - Fossil of the Milky Way

Fossil of the Milky Way  Located 19,000 light-years from Earth, Terzan 5 has been classified as a globular cluster since its detection in 1968, but a couple of odd facts set this cluster apart. Astronomers have found evidence that it contains two distinct kinds of stars that differ not only in the elements they contain, but also in how old they are: some of the stars are 4.5 billion years old, while others are 12 billion years old.  In order to have enough material for two such distinct periods of star birth, Terzan 5 must have originally been enormously massive, perhaps 100 million times the mass of the Sun. These characteristics, along with Terzan 5’s location near the central bulge of the Milky Way, lead astronomers to theorize that Terzan 5 may be a living fossil from the formation of our galaxy.

Image credit: NASA, ESA

Weekly Calendar

May 21 - 27, 2018

Holidays - Sky Events - Space History


Monday 21

Victoria Day (Canada)

First Qtr Moon 11:49 PM ET

2010: IKAROS spacecraft launched; first successful solar-sail propulsion

Tuesday 22

1969: Apollo 10 lunar module descends to within 50,000 feet of the lunar surface
2012: Dragon C2+ spacecraft launched, first commercial mission to dock with ISS

Wednesday 23

1984: NASA selects 10th astronaut group

Thursday 24

1962: Aurora 7 launched

Moon phase Friday 25

1961: JFK challenges nation to Moon landing before end of decade
1965: Saturn SA-8 launched
1966: Roll-out of first full-scale Saturn V
1973: Skylab 2 begins 28-day mission
2008: Phoenix lander lands on Mars

Moon phase Saturday 26

1951Sally Ride born

Moon phase Sunday 27

Jupiter 4° south of Moon

2009Soyuz TMA-15 launched carrying ISS Expedition 20/21 crew

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