名古屋太郎/wikimedia, CC BY-SA
If you you’ve never seen a solar eclipse before, you should make an effort to witness the breathtaking event on August 21. While only people in the US will be able to see the total eclipse – in which the moon completely blocks the light from the sun – those living in parts of South America, Africa and Europe should be able to see at least a partial solar eclipse.
Solar eclipses occur when the moon passes between the Earth and the sun so that it blocks part or all of the sunlight as viewed from a particular location on our planet. Earth is the only planet in the solar system where this can happen in this way. This is because of the moon’s size and its relative distance from the sun – when viewed from the Earth, it can identically cover the bright solar disc to reveal the tenuous, wispy outer atmosphere of the star (called the solar corona).
An eclipse does not happen every time the moon travels around the Earth. This is because its orbit has a slight inclination (about five degrees) relative to our planet’s journey around the sun. However when aligned correctly, the result is an awesome, emotional experience. Once the eclipse has begun, the moon continues to eat its way across the blazing sun before darkness falls, the temperature drops and the sky is dominated by a radiant crown around the moon. It happens approximately every 18 months.
During an eclipse the sun’s corona becomes visible to observers on Earth. NASA
On August 21, the moon’s shadow will travel west to east, touching land at Lincoln Beach, Oregon at 09:05 Pacific Daylight Time before speeding across North America at up to 1km per second and finally exiting close to Charleston, South Carolina, at 16:09 Eastern Daylight Time. The longest total eclipse will occur close to the town of Carbondale, Illinois – lasting about two minutes and 40 seconds.