But in an extreme solar event, he said, the dose could become 5,000 times larger.

There are two important solar events in addition to the equinoxes.

Some of the petroglyphs are aligned with certain annual solar events.

He looked for landscape features that could have marked lunar and solar events.

At the midpoints between these four solar events, cross-quarter days are celebrated.

They involve issues like the tiny number of people who will be able to see the solar and lunar events when they occur.

But that wasn't really a significant solar event, just a momentary aberration.

It would've taken a significant solar event to trigger the recent quakes.

For many centuries, up to 1925, astronomers counted the hours and days from noon, because it was the easiest solar event to measure accurately.

She was particularly interested in transient solar events and solar cycle variations.