November 30, 2015 - Around-the-Clock Surveillance

Around-the-Clock Surveillance  The Solar and Heliospheric Observatory (SOHO), launched twenty years ago this week, was the first spacecraft to provide a long-term, uninterrupted view of the Sun. Built for a two-year mission, SOHO’s dozen instruments still study the Sun in a multitude of wavelengths. SOHO moves around the Sun in step with the Earth by slowly orbiting around the First Lagrangian Point, where the combined gravity of the Earth and Sun keep SOHO in an orbit locked to the Earth-Sun line. This 2002 SOHO image shows a widely spreading coronal mass ejection as it blasts more than a billion tons of matter out into space at millions of kilometers per hour. The image is rotated so the blast seems to be pointing down. An image of the Sun from a different day was superimposed on the corona.

Image credit: Courtesy of SOHO / LASCO / EIT consortium. SOHO is a project of international cooperation between ESA and NASA.

Weekly Calendar

November 30 - December 6, 2015

Holidays - Sky Events - Space History


Moon phase Monday 30

1954: Elizabeth Hodges bruised by a ten-pound meteorite in Alabama
2000: STS-97 Endeavour launched

Moon phase Tuesday 1

1957: Ballistic shape of Mercury spacecraft proposed by Max Faget
2013: Chang'e-3 spacecraft launched to Moon

Moon phase Wednesday 2

1974: Pioneer 11 closest approach to Jupiter during flyby
1988: STS-27 Atlantis launched
1990: STS-35 Columbia launched
1992: STS-53 Discovery launched
1993: STS-61 Endeavour launched
1995: SOHO launched

Moon phase Thursday 3

Last Qtr Moon 2:40 AM ET

1973: Pioneer 10 closest approach to Jupiter during flyby
2014: Hayabusa 2 launched on asteroid sample return mission

Moon phase Friday 4

Jupiter 1.8° north of Moon

1965: Gemini VII launched
1978: Pioneer-Venus 1 orbiter arrives in orbit around Venus
1996: Mars Pathfinder launched
1998: STS-88 Endeavour launched

Moon phase Saturday 5

Moon at apogee
Mars 0.1° north of Moon

2001: STS-108 Endeavour launched
2014: Orion spacecraft launched on first uncrewed test flight

Moon phase Sunday 6

Hanukkah begins at sunset

1998: Unity and Zarya modules are connected to form International Space Station core

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