Number 10 Halley's Comet

Halley's comet was named after astronomer Edmond Halley, who calculated its period of

orbit, it is the only known short-period comet that is regularly visible to the naked eye

from Earth.

It is seen from Earth every 75-76 years and so, technically, some lucky humans will get

to see it twice in their lifetime.

The first Halley's Comet witnessed in the space age – in 1986 – saw several spacecraft

approach its vicinity to establish its composition. High-powered telescopes also observed the

comet as it swung by Earth.

This fly-by provided the first observational data on the structure of a comet's nucleus,

the mechanism of comets, and tail formation.

But for those of you who missed it in 1986, don't worry because it'll next appear

in 2061.

In the meantime you can see its remnants every year. The Orionid meteor shower, which is

spawned by Halley's fragments, occurs annually in October.

Number 9 Near Earth Asteroid Flyby

On April 13th, 2029, an asteroid called 99942 Apophis will pass between the Moon and Earth.

Following its discovery in 2004, Apophis - which is the size of three-and-a-half football fields

- gathered the immediate attention of scientists and the media.

Initial calculations of its orbit by astronomers indicated a 2.7 percent possibility of an

Earth impact during the close flyby, so naturally humanity feared for the end of the world.

Fortunately though, further analysis by NASA showed that Apophis will miss Earth by 31,300

kilometers. That's actually closer than some geostationary satellites, which orbit the

Earth at a range of 36,000 km, but still far enough away that we don't need to fear for

our lives.

The flyby will be one for the record books, as it will be the closest flyby of an asteroid

of its size in recorded history - and it could be the last chance astronomers have to get

an up close look at Apophis for a very, very, long time.

Number 8 Solar Eclipse

Okay, so we are slightly cheating with this one, as solar eclipses can usually be seen

somewhere on Earth each year, but 2027 has something special in store.

Solar eclipses occur when the Moon passes between the Sun and the Earth, and it fully

or partially blocks the Sun. In a total eclipse, the disc of the Sun is fully obscured by the

Moon, whereas in partial and annular eclipses only part of the Sun is obscured.

Typically, the duration of a total eclipse is in the range of 2-6 minutes. But the longest

solar eclipse to date lasted for 7 minutes, 28 seconds. It happened around 743 BC and

would have been visible across Southern Africa.

The next time a solar eclipse will have a duration of this length will be on 16th July

2186, but most of us won't be around to see that.

So instead set yourself a reminder for Monday 2nd August 2027, when the second longest solar

eclipse of the century will occur. It will have a maximum duration of 6 minutes and 23

seconds.

It will pass through the Straits of Gibraltar then across the North African coast, before

dipping down to Yemen and Somalia.

Number 7 Supernova

On average, a supernova goes off twice a century in a galaxy the size of the Milky Way, so

scientists believe the magnificent astronomical event is imminent.

Supernovae are explosions that occur at the end of life for stars more massive than our

Sun. The massive star explodes when it has used up all its hydrogen fuel and its core

collapses just before it explodes, ejecting most of its mass into space.

They are triggered in two ways: either by the sudden re-ignition of nuclear fusion in

a compact star, or by the collapse of the core of a massive star.

The last one was spotted three decades ago, on February 23rd, 1987. Nicknamed 'Supernova

1987A', it blazed with the power of 100 million suns for several months following

its discovery and was one of the brightest exploding stars in more than 400 years.

But when will the next supernova occur? Well, in 2013 astronomers from Ohio State University

calculated that a supernova occurring within our galaxy will be visible from Earth sometime

in the next 50 years.

It would be visible to telescopes but there's also a 20% chance that the supernova would

be visible to the naked eye in the night sky.

Number 6 Venus Occults Jupiter

The last time Venus and Jupiter passed in front of - or occulted - one another was nearly

200 hundred years ago, in January 1818.

At this time in history, the Battle of Koregaon between the British East India Company and

the Peshwa faction of the Maratha Confederacy was in full swing.

Those mid-battle were probably not focusing on the night sky, and even if they were, only

observers in a remote island of Japan were likely to see the occultation if they made

a very special effort to look for it in the bright morning twilight.

Skip ahead to the 21st Century and for the first time since 1818, on 22nd November 2065,

Venus will pass directly before Jupiter and form into a single, bright star, low down

in the dawn skyline.

Get your telescope ready for the event, because it will be almost impossible to view with

the naked eye, as it will be occurring during the daytime and in close proximity to the

sun.

Number 5 Leonid Meteor Shower

First noticed in 1833, this rare astronomical phenomenon occurs when Earth passes through

the orbit of periodic comet Tempel-Tuttle.

Leonid meteors are caused by tiny meteoroids that burn up in our planet's atmosphere as

Earth passes close to the dust-strewn orbit of Tempel-Tuttle.

Skywatchers have observed major Leonid meteor showers every 33 years or so from 1833, when

the meteor shower was said to have produced a whopping 100,000 meteors an hour.

Most years, Leonid storms are a minor event, boasting no more than 10 to 15 shooting stars

per hour. But on very rare occasions when this dense filament of dust plows directly

into our planet, meteor rates can soar to 100,000 per hour or more.

If you want to catch this spectacular sight, Tempel-Tuttle will next cause a major Leonid

meteor shower in 2031.

Number 4 Planetary Alignment

The possibility of an alignment between all of the planets in the solar system is very

rare. The closest that the eight planets will come to being aligned will occur on May 6th,

2492.

But unless we figure out how to bring cryogenically frozen corpses back to life, none of us will

be alive to witness that astronomical event.

On the bright side, space scientists estimate that there will be a rare planetary alignment

of Mars, Mercury, Venus, Jupiter, Saturn and the crescent Moon on September 8th, 2040.

That's just 23 years away, and is much more doable.

Clustered well to the east of the Sun, the planets will stage a breathtaking show at

7:30 pm, so mark your calendars now!

Number 3 Supermoon

In November 2016, stargazers worldwide enjoyed a rare event, a Supermoon that was 14% bigger

than its normal size. This was the closest the moon had been to earth since January 26th,

1948.

If you missed out on catching a glimpse of the 2016 supermoon, there's an even better

astronomical event on the horizon. The closest supermoon of the century will occur on December

6th, 2052, and it will be a once in a lifetime experience.

The term “supermoon” is typically defined as a full moon that coincides with the lunar

orb's closest approach to Earth.

In 2052 our celestial neighbor will be just around 140,000 kilometers away. But what possible

impact could it have on us?

Well, many studies over the years have been aimed at finding out any statistical connection

between the moon - particularly the full moon - and human biology or behavior.

Reliable studies comparing the lunar phases to births, heart attacks, deaths, suicides,

psychiatric hospital admissions and epileptic seizures among other things, have time and

time again found little or no connection.

Number 2 Transit Of Earth From Mars

As of 2017, humans are not currently on any other planets - well, as far as we know - so

if a transit of Earth were about to occur anywhere soon, we could not see it. The one

noteworthy future exception, though, is Mars.

For those of you unsure what we mean by 'transit of Earth from Mars', it essentially means

when the Earth passes directly between the Sun and Mars, obscuring a small part of the

Sun's disc for an observer on the Red Planet.

No one has ever seen a transit of Earth from Mars, but if NASA's plan to get humans living

on Mars by the 2030s goes ahead, this could be possible for the next such transit, which

will take place on November 10th, 2084.

This transit will be the first and only time that this phenomenon will occur in the 21st

century, with the next one predicted for 2394. And by then, we should definitely have colonized

the planet.

Number 1 The Birth Of A Star

Look up to the stars in 2022, because one of the night sky's most visible constellations,

Cygnus, will be getting a new addition, and everyone on Earth will be able to see it.

Located about 1,800 light-years away, the star system KIC 9832227 in Cygnus has long

been a focus of study.

For years, the pair of glittery specks in this system have been circling around each

other, moving closer and closer, and now astronomers believe they will soon merge in an explosive

event known as a nova.

It'll be a momentous occasion for scientists as it's the first time they have ever been

able to predict the birth of a new star and this will allow them to observe the process

as it unfolds.

For us average folks, it's going to be pretty damn extraordinary too, being able to witness

a once in a lifetime astronomical event without the use of a telescope.

Thanks for watching today's video, we hope you enjoyed it! And if space is what you're

into why not check out 10 Unknown Signals From Outer Space and we'll see you next

time!