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Top 11 Rarest Astronomical Events In Your Life. Photo KnowInsiders
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For thousands of years, humans have discovered and witnessed countless amazing astronomical phenomena occurring on this Earth. In particular, there are extremely rare phenomena that people can encounter only once their life.

Read on this list and see what astrological events you have been lucky to witness.

Top 11 Rarest Astronomical Events In Your Life

1. Halley’s Comet

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Photo Pinterest
First Noticed: 240 BC

Who Discovered It: Astronomer Edmund Halley (officially in 1531)

Last Occurrence:1986

Considered the most common comet known in the Solar System, Halley's comet is named after astronomer Edmond Halley, who calculated that the star would pass by Earth every 75-76 years.

The last appearance of Halley's comet was in 1986, and the next is predicted to be in 2061. According to Space, "when Halley sweeps across the Earth in 2061, the comet will be on the same side of the Earth and will have much brighter colors than in 1986".

2. Comet Hale-Bopp

Comet Hale-Bopp was an unusually bright comet that flew by Earth, reaching its closest approach to the planet in 1997. It was most spectacular in the Northern Hemisphere and visible to the naked eye for about 18 months.

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Photo oxygen

Hale-Bopp was probably one of the most viewed comets in history. With an absolute magnitude of -1, the comet was one of the brightest comets to reach the inner solar system in recorded history, NASA said(opens in new tab). Hale-Bopp appeared 1,000 times brighter (opens in new tab)than Halley's Comet did at the same distance. Its twin blue-and-white tails were clearly visible even from light-polluted areas such as Chicago.

Sadly, there was a tragic footnote to the appearance of Hale-Bopp, 39 people who were part of the "Heaven's Gate" cult in San Diego committed mass suicide as the comet came close to Earth.

One of the most-viewed comets ever

There are over 5,000 images of this comet available via a webpage maintained by NASA’s Jet Propulsion Laboratory.

It attracted so many people not only because of its rarity and beauty, but also because it enabled people to jump – in their minds – back in time. Some 4,200 years ago, when Hale-Bopp last passed the Earth and sun, the Egyptian pyramids were newly being polished by sand, and the Epic of Gilgamesh, considered the first great work of Western literature, was not yet written.

Where is the comet now?

Comet Hale-Bopp is in the constellation Octans with an estimated magnitude of +25.6. The comet is over 4,266,045,046 miles (6,865,534,000 kilometers) distant from the sun. This is roughly the same distance from the sun as Pluto.

3. Blue Moon

Photo time and date
Photo time and date

What is a blue moon?

Cultures around the world, including the Native Americans, have given names to each of the full Moons, with each typically happening in its own month.

For example the 'wolf moon' is usually the full Moon occurring within January. With the cycle of the phases of the Moon lasting approximately one month, and there being 12 months in a year, we typically have 12 full moons each year.

However, the phases of the Moon actually take 29.5 days to complete, meaning 354 days total for 12 full cycles. This falls some way short of the 365/366 days in a calendar year: therefore, roughly every two and a half years a 13th full moon is seen. This additional full moon does not fit with the normal naming scheme and so is instead referred to as a ‘blue moon’.

How often does a blue moon happen?

Normally blue moons come only about every two or three years. In 2018 unusually, we had two blue moons in one year and only two months apart – and one was a lunar eclipse! The next time we will get two blue moons in a year will be 2037.

When is the next blue moon?

The next blue moon takes place on 22 August 2021. This is because it will be the third of four full Moons in an astronomical season (in this instance, the period between the Summer Solstice and the Autumn Equinox).

Future Blue moon dates

2023 31 August

2026 31 May

2028 31 December

What colour is a blue moon?

Blue moons aren’t blue! Blue moons remain the same colour as any other full moon except in two rare cases. During a lunar eclipse, the Moon can turn blood red, lit only by the light that is bent around the Earth by its atmosphere onto the face of the Moon. As lunar eclipses occur only during full moons, and blue moons are one type of full moon, very rarely a blue moon will be red! In very rare circumstances, the Moon can appear blue, but in this case it is a colour added to the

Moon by viewing it through a haze of dust particles in our atmosphere, perhaps from a recent volcanic eruption. In this case, from space, the Moon will look just as grey as it always has!

4. Total solar eclipse

Photo instaforex
Photo instaforex

The concept of "total eclipse" is probably not too strange to us. This is not a rare phenomenon at the global level, but the phenomenon that occurs every 18 months is only happening in a specific location. It takes centuries for this phenomenon to return to one location.

Belgian meteorologist and astrologer Cassini calculated that a total solar eclipse, at any given time on Earth, could only happen again once every 375 years.

Interesting facts

-Each year there are between 2 and 5 solar eclipses.

-The total solar eclipse, when the Moon completely obscures the Sun and leaves only the faint solar corona, is known as a Totality.

-Total solar eclipses are rare, happening only once every 18 months.

-There is another type of solar eclipse, known as a hybrid eclipse, which shifts between a total and annular eclipse depending on where you view it from on Earth. These are comparatively rare.

-The speed of the Moon as it moves across the Sun is approximately 2,250 km (1,398 miles) per hour.

-From either the North or South Pole, only a partial solar eclipse is able to be viewed.

-A total solar eclipse can last a maximum of 7 minutes and 30 seconds.

-269 km is the maximum width of the path of totality.

5. The Great White Thunder Storm

Photo NASA
Photo NASA

Also called Great White Spots, these storms occur every 20 – 30 years on the northern hemisphere of Saturn, when it’s most tilted toward the Sun. The massive storm formation is filled with clouds that are rich in ammonia, complete with violent thunder and lightning. The storm measures half the diameter of Earth, with approximately 10 string lightning bolts happening every second, with lengths of 10,000 miles, vaporizing water content in Saturn’s atmosphere.

The intensity of the thunder and lightning grows as the water condenses, creating storms that are said to be 10,000 times stronger than the ones we have on Earth. The weight of the water in the atmosphere causes the storms, resulting in the cooling of the upper atmosphere which gets so cold that it takes 20 – 30 years to trigger the next storm. The next one should occur around 2030 to 2040, so let’s hope we’re around to see it live.

6. The Transit of Venus

Photo instaforex
Photo instaforex

In astronomy, a 'transit' occurs when a smaller body passes in front of a larger one. A 'Transit of Venus' happens when Venus is seen in silhouette against the bright face of the Sun.

Although Venus, the Earth and the Sun roughly line up every 584 days, the alignment is not usually precise. Venus' orbital motion usually takes it 'above' or 'below' the Sun as seen from Earth (for the same reason, the Moon does not block out sunlight – causing a solar eclipse – every month). On some rare occasions, the alignment is close enough that Venus blocks out some of the light from the Sun, causing a Transit of Venus. There have only been seven transits of Venus since the telescope was invented in 1610.

On average, Transits of Venus happens every 80 years or so. However, this average figure is very misleading, because transits occur in a 'pair of pairs' pattern that repeats every 243 years. First, two transits take place in December (around Dec 8th), 8 years apart. There follows a wait of 121 years 6 months, after which two June transits occur (around June 7th), again 8 years apart. After 105 years 6 months, the pattern repeats.

Previous transits of Venus

The transit of Venus observed in 1874 by Jules Janssen (click to enlarge). The grid pattern was used to measure precise positions in the image. Credit: RAS Archives

The first person to predict a transit of Venus was Johannes Kepler, who calculated that one would take place on 6 December 1631. Kepler died in 1630, and there is no record of anyone seeing the 1631 event.

Jeremiah Horrocks (sometimes spelled 'Horrox'), a young English astronomer, studied Kepler's planetary tables and discovered that a Transit of Venus should occur on 1639 November 24, just a month after he made the calculation. Horrocks observed part of the transit from his home at Much Hoole, near Preston, Lancashire. His friend William Crabtree also saw it from Manchester, having been alerted by Horrocks. As far as is known, they were the only people to witness the transit. Tragically, Horrocks's promising scientific career was cut short when he died in 1641, aged about 22.

The English astronomer Edmund Halley later realised that observations of Transits of Venus could be used to determine the distance between the Earth and the Sun. The method involves observing and timing a transit from widely spaced latitudes, which show small differences in Venus's track across the Sun (resulting from parallax). Halley died in 1742, but the transits of 1761 and 1769 were observed from many places around the world. James Cook's expedition to Tahiti in 1769 is one of the most famous, and it went on to become a world voyage of discovery. However, results on the Sun–Earth distance were disappointingly inaccurate, as the observations were plagued by many technical difficulties.

Nevertheless, optimistic astronomers tried again with the 1874 transit a century later; some of their efforts are illustrated in the RAS Archives. Unfortunately, as far as determining the value of the AU was concerned, the results were again disappointing. Astronomers began to realise that the practical problems with Halley's simple idea were just too great to overcome. Even so, there was enormous public interest in the 1882 transit, and it was mentioned on the front pages of most newspapers. Thousands of ordinary people saw it, and Professor Sir Robert Stawell Ball described his own feelings on watching the transit in his 1885 book, The Story of Astronomy.

7. Planetary Alignment of The Moon, Mars, Mercury, Venus, Jupiter and Saturn

This rare alignment includes the five planets easily spotted with the naked eye: Mercury, Venus, Mars, Jupiter, and Saturn. Each is bright enough to be seen even in light-polluted city skies, with brilliant Venus being the brightest and Mercury the faintest. Our closest planets will appear to be arranged across the sky in the same order as their distance from the sun.

Photo space
Photo space

This planetary alignment can be glimpsed by the vast majority of the world’s population, but some will be better positioned than others. For those in the northern latitudes, above cities like New York and London, the planet closest to the sun, Mercury, will be near the horizon and may be washed out by the glare of dawn. In these regions, the other planets will also hug the eastern horizon, making it a bit of a challenge to easily see all the planets.

The best views will be centered around the tropics and in the Southern Hemisphere, where the planets will rise higher in the predawn sky. But no matter where you are, the best recommendation is to seek out an unobstructed view of the eastern horizon about one hour to 30 minutes before local sunrise.

When will be the next?

The panorama will be particularly impressive because the planets will appear huddled close together. And if you miss this spectacle, you’ll have to wait until 2040 to get another chance.

8. Comet ISON

ISON is a comet orbiting very close to the Sun discovered by two Russian astronomers - Vitali Nevski and Artyom Novichonok on September 21, 2012. However, on November 28, 2013, it was completely disbanded.

According to astronomers, when exposed to the Sun at a distance of more than a million kilometers, the material contained on this comet begins to heat up, evaporate, and then break down into small pieces and release dust in streaks in space.

9. Leonid Meteor Storms

Photo royal museum greenwich
Photo royal museum greenwich

An abundant meteor shower brought about by the comet Tempel-Tuttle is named Leonid, due to the location of their radiant in the Leo constellation. These meteors seem to radiate from that position in the sky and they occur every year around November 17. This annual Leonid shower can deposit around 12 – 13 tons of particles across the face of the Earth. Sometimes accompanied by storms, they were first documented in 902 A.D.

Previously thought to be an atmospheric phenomenon, the study of the Leonid shower has helped the scientific community with further insights into the study of meteors. The event in 1833 was particularly spectacular, as it is estimated that over 100,000 meteors occurred per hour and after the storm dissipated, it was believed that over 240,000 meteors occurred during the nine hours of the storm, which happened over the east of North America.

10. A Huge Star Nursery

Photo space
Photo space

There are at least 150 regions in the Milky Way that contain globular clusters with approximately one million stars, which are ancient and keeping secrets about their formation. In 2006 a pre-natal cluster was discovered that was full of gas but contained virtually no stars. This rare celestial object exists deep inside the Antennae galaxies that are 50 million light-years away from Earth, where scientists hope that many new stars will be birthed.

These scientists state that such regions stay star-free for about 1 million years, and the reason why this rare astronomical event is exciting is because it affords us the opportunity to learn about the Universe’s mysterious ways. It’s believed that these regions are responsible for the birthing of most of these stunning globular clusters captured by the Hubble Space Telescope, along with the colliding galaxies that are said to produce them.

11. The Triple Jovian Eclipse on Jupiter

Photo NASA, ESA, and E. Karkoschka
Photo NASA, ESA, and E. Karkoschka

What is called a Triple Jovian Eclipse occurs on Jupiter, created by a lineup of three Galilean moons: Europa, Callista and Io. While we marvel at lunar and solar eclipses, this triple eclipse across the face of the gas giant would be awesome, if it were possible to view it from the perspective looking out from the surface of Jupiter. According to experts, we won’t get to see it again until 2032.

Jupiter has a whopping 16 moons, but the rare alignment of the 3 biggest moons, showing the shadows on Jupiter’s surface from our perspective, holds great wonder for space enthusiasts. This event has been captured before, by NASA’s Hubble Space Telescope, however it’s difficult to obtain images of the entire occurrence, since Jupiter moves quickly across the telescope’s view. Hopefully, we’ll have a better chance of seeing it in all its glory next time, if technology allows it.

Astronomical events you shouldn’t miss in 2023

January 30 - Mercury at Greatest Western Elongation. The planet Mercury reaches greatest western elongation of 25 degrees from the Sun. This is the best time to view Mercury since it will be at its highest point above the horizon in the morning sky. Look for the planet low in the eastern sky just before sunrise.

March 20 - March Equinox. The March equinox occurs at 21:17 UTC. The Sun will shine directly on the equator and there will be nearly equal amounts of day and night throughout the world. This is also the first day of spring (vernal equinox) in the Northern Hemisphere and the first day of fall (autumnal equinox) in the Southern Hemisphere.

April 22, 23 - Lyrids Meteor Shower. The Lyrids is an average shower, usually producing about 20 meteors per hour at its peak. It is produced by dust particles left behind by comet C/1861 G1 Thatcher, which was discovered in 1861. The shower runs annually from April 16-25. It peaks this year on the night of the night of the 22nd and morning of the 23rd. These meteors can sometimes produce bright dust trails that last for several seconds. The thin crescent moon will set early in the evening leaving dark skies for what should be an excellent show. Best viewing will be from a dark location after midnight. Meteors will radiate from the constellation Lyra, but can appear anywhere in the sky.

May 5 - Penumbral Lunar Eclipse. A penumbral lunar eclipse occurs when the Moon passes through the Earth's partial shadow, or penumbra. During this type of eclipse the Moon will darken slightly but not completely. The eclipse will be visible throughout all of Asia and Australia and parts of eastern Europe and eastern Africa.

July 28, 29 - Delta Aquarids Meteor Shower. The Delta Aquarids is an average shower that can produce up to 20 meteors per hour at its peak. It is produced by debris left behind by comets Marsden and Kracht. The shower runs annually from July 12 to August 23. It peaks this year on the night of July 28 and morning of July 29. The nearly full moon will block most of the fainter meteors this year. But if you are patient, you may still be able to catch a few good ones. Best viewing will be from a dark location after midnight. Meteors will radiate from the constellation Aquarius, but can appear anywhere in the sky.

August 31 - Full Moon, Supermoon, Blue Moon. The Moon will be located on the opposite side of the Earth as the Sun and its face will be will be fully illuminated. This phase occurs at 01:37 UTC. This is also the third of four supermoons for 2023. The Moon will be near its closest approach to the Earth and may look slightly larger and brighter than usual. Since this is the second full moon in the same month, it is sometimes referred to as a blue moon.

October 14 - Annular Solar Eclipse. An annular solar eclipse occurs when the Moon is too far away from the Earth to completely cover the Sun. This results in a ring of light around the darkened Moon. The Sun's corona is not visible during an annular eclipse. The eclipse path will begin in the Pacific Ocean off the coast of southern Canada and move across the southwestern United States and Central America, Columbia, and Brazil. A partial eclipse will be visible throughout much of North and South America.

December 13, 14 - Geminids Meteor Shower. The Geminids is the king of the meteor showers. It is considered by many to be the best shower in the heavens, producing up to 120 multicolored meteors per hour at its peak. It is produced by debris left behind by an asteroid known as 3200 Phaethon, which was discovered in 1982. The shower runs annually from December 7-17. It peaks this year on the night of the 13th and morning of the 14th. This should be an great year for the Geminids. The nearly new moon means dark skies for what should be an excellent show. Best viewing will be from a dark location after midnight. Meteors will radiate from the constellation Gemini, but can appear anywhere in the sky.

December 21, 22 - Ursids Meteor Shower. The Ursids is a minor meteor shower producing about 5-10 meteors per hour. It is produced by dust grains left behind by comet Tuttle, which was first discovered in 1790. The shower runs annually from December 17-25. It peaks this year on the the night of the 21st and morning of the 22nd. The waxing gibbous moon will block out most of the faintest meteors this year. But if you are patient, you should still be able to catch a few good ones. Best viewing will be just after midnight from a dark location far away from city lights. Meteors will radiate from the constellation Ursa Minor, but can appear anywhere in the sky.


Astronomers believe that the number of rare and unique events in the world is going to increase. So if you are not lucky to witness the rarest ones above, you will have plenty of chances to experience. Follow astrological events’ schedule and prepare the best devices and location to observe!

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