~1~15~11~ Space Weather Update~ Active Sunspots Incoming~ [1]

PHOBOS-GRUNT RE-ENTRY TODAY: Russia's malfunctioning Mars probe, Phobos-Grunt, will re-enter the atmosphere today, creating a brilliant fireball over a still-unknown part of Earth. Best estimates [2] of the re-entry time range from 1700 UT to 2200 UT on Jan. 15th. The Aerospace Corporation has published some possible ground tracks [3].

 

ACTIVE SUNSPOTS: Crackling with C-class solar flares, a pair of active sunspots is emerging over the sun's northeastern limb. NASA's Solar Dynamics Observatory photographed the pair during the early hours of Jan. 15th:

 

[4]

 

These sunspots have the potential for strong eruptions. Sunspot 1401 produced an M1-flare on Jan. 14th. Two days earlier, while it was still on the farside of the sun, sunspot 1402 produced a partially-eclipsed flare of uncertain magnitude that created waves of ionization in the atmosphere over Europe.

 

NOAA forecasters estimate a 30% chance of more M-flares during the next 24 hours. Solar flare alerts: text [5], voice [6].

 

POLAR STRATOSPHERIC CLOUDS: An apparition of polar stratospheric clouds [7] is underway around the Arctic Circle. "It is almost as good as the aurora borealis," says Göran Strand, who took this picture last night from Östersund, Sweden:

 

[8]

 

Eric Schandall of Oslo, Norway, adds this report: "We have seen them for three evenings over Oslo, with the ones on Jan. 13th being the most dramatic and beautiful [9] so far."

 

Also known as "nacreous [10]" or "mother of pearl" clouds, these icy clouds form in the lower stratosphere when temperatures drop to around minus 85ºC. Sunlight shining through tiny ice particles ~10µm across produce the characteristic bright iridescent colors by diffraction and interference.

 

"Nacreous clouds far outshine and have much more vivid colours than ordinary iridescent clouds [11], which are very much poor relations and seen frequently all over the world," writes atmospheric optics expert Les Cowley. "Once seen they are never forgotten."

 

Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/POES

Planetary K-index
Now: Kp= 0 quiet
24-hr max: Kp= 1 quiet
explanation [21] | more data [22]

Interplanetary Mag. Field
B_total: 4.0 nT
B_z: 1.5 nT north
explanation [23] | more data [24]
Updated: Today at 1317 UT

Coronal Holes: 14 Jan 12

[25]

A solar wind stream flowing from the indicated coronal hole should reach Earth on Jan. 16-17. Credit: SDO/AIA.