As the countdown begins to the longest total lunar eclipse of the 21st century, the common question being asked is what exactly is going to happen:
• For a start, the total lunar eclipse, in combination with mars opposition and conjunction, will mean that on July 27 (Friday) Blood Moon and total lunar eclipse will outshine every other eclipse to take place between the years 2001 and 2100.
• In other words, the moon will enter the shadow of the earth for about four hours, and the event will be seen clearly across at least three continents.
• As a result, the Moon will slowly turn from its familiar pearly white color to a reddish color then back to its original color all over a period of around five hours.
Deep red to orange
• During the eclipse, when the moon passes through the shadow cast by Earth, the moon will take on a deep red to orange color rather than completely disappear from sight.
• Scientists say the Moon appears to be reddish because of Rayleigh scattering (the same effect that causes sunsets to appear reddish) and the refraction of that light by Earth’s atmosphere into its umbra.
• According to the Dubai Astronomy Group, the eclipse will last one hour and 43 minutes – nearly 40 minutes longer than the January 31 Super Blue Blood Moon combo.
• During this period, many more stars can be seen than what could usually be seen during the full Moon.
• It will be a good opportunity to capture rare wide field shot of the eclipsed Moon complimented by a background of stars.
• Lunar eclipses are visible from anywhere on Earth where it is nighttime. However, the duration of the eclipse will depend on how close to moonrise or moonset the eclipse starts in your location.
• From some places, the entire eclipse will be visible, while in other areas the Moon will rise or set during the eclipse.
• However, for the observation of Mars, masses will be able to monitor Mars through good quality telescopes and see some features of the surface of Mars, which is an unusual chance.
• Earth takes a year to orbit the sun once while Mars takes about two years to orbit once.
• The year 2018 is very special for Mars as it will appear brighter in our sky this year than it has since 2003.
• Conjunction of the moon with Mars will also visible during the event of lunar eclipse.
What NASA says
According to NASA, the total eclipse will last 1 hour, 42 minutes and 57 seconds, though a partial eclipse precedes and follows, meaning the moon will spend a total of 3 hours and 54 minutes in the Earth’s umbral shadow.
The eclipse will be visible from Europe, Africa and the Middle East between sunset and midnight on July 27 and then between midnight and sunrise on July 28 in much of Asia and Australia.
“It’s called a blood moon because the light from the sun goes through the earth's atmosphere on its way to the moon and the Earth’s atmosphere turns it red in the same way that when the sun goes down it goes red,” Andrew Fabian, professor of astronomy at the University of Cambridge.
When the moon moves into the conical shaped shadow of the earth, it goes from being illuminated by the sun to being dark. Some light, though, will still reach the moon because it is bent by the earth’s atmosphere.
Blot out the sun
“If you were standing on the moon in this eclipse, you would see the sun and then the earth would come in the way and blot out the sun,” said Fabian. “The rim of the earth would be glowing because light is being scattered by the Earth’s atmosphere.”
The same day, Mars will be at its brightest as it travels close to earth, so observers may be able to see what looks like an orange-red star which is in fact the so called red planet.
When asked if the eclipse might be an omen of some sort, Fabian, who said he will try to observe the eclipse, laughed: “Absolutely not. Astrology is not something we follow.”
The eclipse of the moon will not be visible from North America or most of the Pacific. The next lunar eclipse of such a length is due in 2123.
(With Reuters inputs)