Earth’s final total solar eclipse will happen in less than a billion years (Synopsis) [Starts With A Bang]

“We live in a moment of history where change is so speeded up that we begin to see the present only when it is already disappearing.” -R. D. Laing

This coming Monday, tens of millions of people will gather to watch the total solar eclipse that will go coast-to-coast across the continental United States. Total solar eclipses like this happen, on average, about once every 18 months, due to the frequency of alignment as well as the Moon’s apparent angular size. At present, about 40% of all solar eclipses are total eclipses, with annular eclipses making up 50% and hybrid eclipses the other 10%.

The Moon and Sun each take up approximately half a degree on the sky as viewed from Earth. When the Moon is slightly larger in angular size than the Sun is and all three bodies perfectly align, a total solar eclipse is the result. Image credit: Romeo Durscher / NASA / Goddard Space Flight Center.

However, this ratio has changed with time, and will continue to change. The Moon is migrating farther away from Earth, and annular eclipses are becoming more common, while total eclipses are becoming more rare. Although the migration rate is small — mere centimeters per year — that adds up over millions of years. At some point in the future, the Moon’s shadow will be completely unable to fall on Earth’s surface any longer.

While approximately half of all eclipses today are annular in nature, the increasing Earth-Moon distance means that in approximately 600-700 million years, all solar eclipses will be annular in nature. Image credit: Wikimedia Commons user Kevin Baird.

How does it all work, and how long will it take? Find out, and learn when the final total solar eclipse Earth will ever experience will be!

from ScienceBlogs http://ift.tt/2wXjPNZ

“We live in a moment of history where change is so speeded up that we begin to see the present only when it is already disappearing.” -R. D. Laing

This coming Monday, tens of millions of people will gather to watch the total solar eclipse that will go coast-to-coast across the continental United States. Total solar eclipses like this happen, on average, about once every 18 months, due to the frequency of alignment as well as the Moon’s apparent angular size. At present, about 40% of all solar eclipses are total eclipses, with annular eclipses making up 50% and hybrid eclipses the other 10%.

The Moon and Sun each take up approximately half a degree on the sky as viewed from Earth. When the Moon is slightly larger in angular size than the Sun is and all three bodies perfectly align, a total solar eclipse is the result. Image credit: Romeo Durscher / NASA / Goddard Space Flight Center.

However, this ratio has changed with time, and will continue to change. The Moon is migrating farther away from Earth, and annular eclipses are becoming more common, while total eclipses are becoming more rare. Although the migration rate is small — mere centimeters per year — that adds up over millions of years. At some point in the future, the Moon’s shadow will be completely unable to fall on Earth’s surface any longer.

While approximately half of all eclipses today are annular in nature, the increasing Earth-Moon distance means that in approximately 600-700 million years, all solar eclipses will be annular in nature. Image credit: Wikimedia Commons user Kevin Baird.

How does it all work, and how long will it take? Find out, and learn when the final total solar eclipse Earth will ever experience will be!

from ScienceBlogs http://ift.tt/2wXjPNZ