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April 1, 2013 - Magnetic Personality

Magnetic Personality Like a lightbulb that heats the air around it but remains cool to the touch, the Sun’s “surface” (actually a turbulent mass of moving plasma known as the photosphere) is cooler than either its interior or its atmosphere (the corona). Fifteen years ago this week, NASA’s Transition Region And Coronal Explorer began a mission to study this transition region for clues about how this could be. TRACE’s mission, which ended in 2010, did not solve the mystery, but it seems that the Sun’s powerful magnetic field, which undergoes a regular eleven-year cycle of activity, plays an important role in this counter-intuitive phenomenon. In this TRACE image from 2001, a “solar maximum” year, a dramatic display of coronal loops arc high above two regions of active magnetic storms on the Sun’s surface.

Image credit: TRACE / NASA / Stanford-Lockheed Martin Institute for Space Research

Weekly Calendar

April 1-7, 2013

Holidays - Sky Events - Space History

Moon phase Monday 1

Easter Monday (Canada)

1960: TIROS 1 launched
1997: Comet Hale-Bopp’s closest approach to Sun
1998: TRACE launched

Moon phase Tuesday 2

1845: First photograph of Sun taken
2010: Soyuz TMA-18 launched carrying ISS Expedition 23 crew

Moon phase Wednesday 3

Last Quarter Moon 12:37 AM ET

1966: Luna 10 becomes first spacecraft to orbit the Moon
1973: Salyut 2 space station launched

Moon phase Thursday 4

1930: American Rocket Society founded
1968: Apollo 6 launched
1983: STS-6 Challenger launched
1997: STS-83 Columbia launched
2000: First commercial mission to Mir
2011: Soyuz TMA-21 launched carrying ISS Expedition 27/28 crew

Moon phase Friday 5

1973: Pioneer 11 launched
1975: Soyuz 18-1, first in-flight abort
1990: Pegsat launched
1991: STS-37 Atlantis launched
2010: STS-131 Discovery launched

Saturday 6

Neptune 6° south of Moon

1965: Early Bird (Intelsat 1) launched
1984: STS-41C Challenger launched

Sunday 7

1991: Compton Gamma Ray Observatory deployed
2001: Mars Odyssey Orbiter launched
2007: ISS Expedition 15 crew launched

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