Active sunspot 1401 erupted yesterday, 19th January around 16:30 UTC, producing an M3-class solar flare and a full-halo coronal mass ejection (CME). The Solar and Heliospheric Observatory recorded the cloud expanding almost directly toward Earth
Analysts at the Goddard Space Weather Lab say strong geomagnetic storms are possible when the cloud arrives this weekend. Their animated forecast track predicts an impact on 21st Jan. at 22:30 UT (+/- 7 hrs).
The cloud is also heading for Mars, due to hit the Red Planet on Jan. 24th. NASA's Curiosity rover, en route to Mars now, is equipped to study solar storms and might be able to detect a change in the energetic particle environment when the CME passes by.