All Sky Steve
Explanation:
Familiar
green and red tinted auroral emission floods the sky
along the northern (top) horizon in this
fish-eye panorama projection from September 27.
On the mild, clear evening the Milky Way tracks through the zenith of
a southern Alberta sky and ends where the six-day-old Moon sets
in the southwest.
The odd, isolated, pink and whitish arc across the south
has come to be known as Steve.
The name was given to the phenomenon by the
Alberta
Aurora Chasers Facebook group who had recorded
appearances of the aurora-like feature.
Sometimes mistakenly
identified as a proton aurora or proton arc,
the mysterious Steve arcs seem associated with aurorae but
appear closer to the equator than the auroral curtains.
Widely documented by
citizen scientists
and recently directly explored by a
Swarm mission satellite,
Steve arcs have been measured as
thermal emission from flowing gas rather than
emission excited by energetic electrons.
Even though a reverse-engineered acronym that fits the
originally
friendly name is Sudden Thermal Emission from Velocity Enhancement,
his origin is still mysterious.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.
