This article originally appeared on Conversation. The publication posted the article on Space.com. Expert Voices: Commentary and Insights…
Samantha Rolf, Lecturer in Astrobiology and Chief Technical Officer, Bayfordbury Observatory, University of Hertfordshire
The solar eclipses that are usually portrayed in films are total solar eclipses – a fairly rare event. This is probably what you think of when you hear the word “eclipse.”
A total eclipse is when the moon and sun line up in the sky in such a way that the moon covers the entire surface of the sun – this is called totality. Somewhere on Earth, they happen about every 18 months.
Connected: The 2021 Ring of Fire eclipse: when, where and how to see the annular solar eclipse on June 10
But we cannot experience totality every time, because the shadow of the moon travels along a narrow path along the surface of the earth. Anywhere on Earth, this can happen about once every 375 years.
The ability to see a total solar eclipse is highly dependent on your location and the presence of a cloudless sky (or at least patchy clouds). While totality is not very common, you are likely to have many partial solar eclipses from your location over the years. If you are fortunate enough to find yourself on the path of a total or partial eclipse, be prepared and know what to expect.
In the UK we will see a partial eclipse on June 10, 2021. Here are some tips for what to do during an eclipse.
1. Please note that the moon blocks sunlight and heat.
During any eclipse, blocking out sunlight and heat means it will get darker and cooler. How dark and how cool depends on how much sun is covered. With partial eclipses greater than 50%, enough light can be blocked to create the impression of dusk.
This can confuse local wildlife. You may notice that the birds become silent and the bats may start to come out to feed, even if it may be the middle of the day.
Read more: Lunar and solar eclipses make animals do strange things
Depending on the season, you can bring a sweater or coat with you. The local temperature may drop by several degrees. In 2001, Zambia experienced a drop of 5 degrees Celsius (9 degrees Fahrenheit), and in 1834 a difference of 15 degrees Celsius (27 degrees Fahrenheit) was recorded.
2. Check Einstein’s theory of relativity.
Newton thought gravity was a force between two objects, but Einstein’s 1915 general theory of relativity was based on the idea that gravity causes spacetime to bend. This means that massive objects such as stars cause the light path to bend as it passes by.
The sun is a massive object that, according to Einstein’s theory, bends the light of distant stars as it passes in front of them. Usually the sun is too bright to notice this light. But in a few dark minutes of total eclipse, you can see stars near the Sun.
Just over 100 years ago, a man named Arthur Eddington organized an expedition to two locations. One team traveled to Principe Island in West Africa and the other to Sobral, Brazil. Photographing the eclipse from two locations allowed comparative measurements of the positions of the stars to confirm the correctness of Einstein’s theory.
3. Think about our ancestors.
Even if you didn’t know it was happening beforehand, you are not worried about a total solar eclipse. With our current scientific understanding of the orbits of objects in our solar system, we would understand why this is happening. We can (and often do) allow many eclipses, especially partial ones, to pass us by unnoticed.
Ancient scientists conducted experiments the size of the Earth, Sun and Moon about 2,000 years ago, experiments that you can try for yourself today. Our ancestors did not have our modern understanding.
Thus, cultures from all over the world have come up with stories to explain what is happening. Historical solar eclipses led to a truce between warring nations, scared the king to death, and was generally considered an omen.
4. See how it goes – it’s safe
We live on this planet at a time when the distance to the Moon’s orbit means that the apparent sizes of the Sun and the Moon in the sky are about the same. The moon is very slowly moving away from the Earth, so our descendants will not always enjoy total solar eclipses.
On the days leading up to the event, check the weather and note the start time, maximum point, and end of the eclipse.
You can safely observe a partial or total solar eclipse with objects from around the house – you can use homemade pinhole cameras or even a kitchen colander. Never look directly into the sun without special equipment, as this can cause permanent eye damage.
One weird thing that we don’t understand during a total eclipse is the shadow streaks – lines of light and darkness that appear on the earth just before the eclipse. If you are on the path to totality, you can try to write down any of their testimonies.
By taking just a few minutes to notice and enjoy these astronomical events, you can feel more connected to the environment and your place on planet Earth.
This article is reprinted from The Conversation under a Creative Commons license. Read the original article.
Follow all Expert Voices issues and discussions – and participate in discussions – on Facebook and Twitter. The views expressed are those of the author and do not necessarily reflect the views of the publisher.