Colossal 'Martian sunspot' is so big it was seen from Mars. Now it's facing Earth.

The gargantuan sunspot group AR3576 from end to end stretches for more than 124,274 miles ( 200,000 kilometers ) It contains at least four dark cores each larger than Earth .

The magnetically complex sunspot is already crackling with solar flares.

Forecasts predict this sunspot could pose a threat for X-class solar flares — the most powerful type of solar flare.

Strong solar flares can also be accompanied by CMEs.