Auroras in the northern United States didn't happen after all

One of the biggest draws for skywatchers in the northern part of the world are the brightly colored auroras in the sky at night. The northern lights can only be seen from very northern latitudes typically. Earlier this week, predictions were that people down into the northern United States might be able to see the auroras in the sky.

Forecasters had predicted that auroras might be visible in the night sky in the northern United States on Thursday night after the sun launched a plume of charged particles towards the Earth this week. However, the northern lights never materialized for viewers in the United States. The National Weather Services Space Weather Prediction Center downgraded the expected strength of the geomagnetic storm from strong to minor.

On Monday of this week, the sun produced a coronal mass ejection, which is a cloud of plasma. After the ejection happened on Monday, the shock was pushed ahead and interacted with Earth's geomagnetic field Wednesday night. Sadly, the interaction with the geomagnetic field of our planet was not to the degree predicted.

Skywatchers had a bit of hope as there was a small chance that the solar wind coming behind the shock might cause stronger geomagnetic storms. As for why the prediction was so off, forecasting space weather is challenging. The sun is very far from Earth at 93 million miles. To put it in perspective, forecasters say that if the sun were a basketball, the Earth would be about the size of the BB, and the Earth and sun would sit on opposite ends of an NBA basketball court.

Other reasons predicting space weather is so difficult has to do with the ballistics of the ejection and if the plasma cloud directly hits the atmosphere or glances off it. The most challenging thing to contend with for a coronal mass ejection is the embedded magnetic field. The magnetic field is invisible and is a significant factor in the strength and whether auroras are created on Earth.