June 27, 2016 - Ancient Volcanism on Mercury

Evidence of Ancient Volcanism on Mercury  Observations from NASA’s MESSENGER mission revealed variations in Mercury’s surface composition due to volcanism that occurred at different times in its history, as well as a surprising concentration of elements like magnesium and sulfur—much more so than any of the other terrestrial planets. Some of this volcanic activity flooded even older craters with lava, which solidified and left relatively smooth interiors. After more than ten years in space—four of them in orbit around Mercury—the MESSENGER spacecraft’s operational life ended when it impacted the planet’s surface on April 30, 2015. MESSENGER was the first spacecraft to orbit the innermost planet, gathering unprecedented data on the composition, geography, and magnetosphere of Mercury.

Image credit: NASA / JHU APL / CIW

Weekly Calendar

June 27 - July 3, 2016

Holidays - Sky Events - Space History


Moon phase Monday 27

Last Qtr Moon 2:19 PM ET

1982: STS-4 Columbia launched
1995: STS-71 Atlantis launched
1997: NEAR-Shoemaker probe flies by asteroid Mathilde
2013: IRIS spacecraft launched

Moon phase Tuesday 28

Uranus 3° north of Moon

Moon phase Wednesday 29

1868: George Ellery Hale born
1961: Transit 4A launched, first nuclear-powered satellite
1971: Soyuz 11 crew dies during reentry

Moon phase Thursday 30

Mars appears stationary

1908: Tunguska impact levels hundreds of miles of Siberian forest
2001: WMAP spacecraft launched

Moon phase Friday 1

Canada Day (Canada)

Moon at perigee

1917: 100” mirror arrives at Mt. Wilson Observatory
1972: Wernher von Braun retires from NASA
1997: STS-94 Columbia launched

Moon phase Saturday 2

Aldebaran 0.4° south of Moon

1985: European Space Agency launches Giotto probe to study Halley’s Comet

Moon phase Sunday 3

1935: Harrison Schmitt born

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