Humanity has long looked up into the night sky and wondered what all those twinkling
lights above us really were.
With the discovery of the telescope we began to identify these far-off lights as other
suns, and soon mankind began to imagine what worlds may lie in the vast void of space.
Could there possibly be worlds with life just like ours, or perhaps life that we might not
even recognize- where there even planets around these far-off stars in the first place?
It wasn't until 1988 that humanity discovered its first exoplanet, and with the launch of
the Kepler space telescope not only have we confirmed the existence of exoplanets, but
have discovered thousands of them, and some of them are truly like nothing anyone ever
imagined!
Hello and welcome to another episode of The Infographics Show- today we're taking a look
at the most extreme planets discovered so far in our galaxy!
Planets are small- really small in comparison to stars- and even our most powerful telescopes
aren't good enough to visually identify them, so how do scientists discover exoplanets they
can't physically see in the first place?
Well one technique is called the radial velocity method, where a star is carefully observed
over long periods of time to detect tiny variations in the speed at which the star moves towards
or away from Earth.
Because all stars are in orbit around the Milky Way core and at various speeds, other
stars are constantly moving either towards or away from us, and unless that star has
a planet it should always be moving at a steady pace.
Yet due to gravity a large enough planet can actually 'tug' against its sun just enough
to make it wobble a tiny percentage of a fraction.
Through careful observation, scientists can actually measure this wobble and by calculating
the star's mass, figure out how big the culprit planet actually is.
Another technique to discover exoplanets is called the Transit method, where a star is
once again carefully monitored for a long period of time and its average brightness
is calculated.
When a planet in orbit around that star moves between us and it, it causes the brightness
of its star to dim by a tiny, tiny, tiny little fraction- but that's enough for our super-sensitive
telescopes to detect!
Just how tiny of a fraction of a percentage point of light does a planet block?
Imagine standing a mile away from a lighthouse as a moth flies across the giant spotlight
at the top of the tower- your eyes will never detect the minute dimming the tiny insect
causes, but NASA's super-sensitive computers definitely can.
This technique has been used by NASA's planet-hunting Kepler space telescope with great success,
discovering over 3,000 planets to date!
So, once NASA knows that a planet is there it can tune its most powerful telescopes onto
the host star and use something called spectroscopy to analyze the incoming light waves.
Spectroscopy analyzes incoming light- or more accurately electromagnetic radiation- and
splits it up into its various wavelengths, just like a prism splits light into a rainbow
of colors.
Because of the varying energy levels of electrons in atoms and molecules, each element in the
periodic table absorbs and emits only certain wavelengths of EM radiation.
As the light from a star shines down on a planet, some of that light pushes through
the atmosphere and heads our way- by seeing what wavelengths of EM radiation we receive
from a star we can thus discover what a transiting planet's atmosphere is made up of.
So what kind of planets has NASA discovered so far?
Well, everything from living hells to some real headscratchers...
12.
Hottest Planet Ever
Mercury is the hottest planet in the solar system- at a distance of 36,000,000 miles
(57,910,000 km) from the sun, temperatures on the day side reach a scorching 806 degrees
Fahrenheit (430 C).
This makes Mercury a real hot house, but doesn't even come close to comparing with KELT-9B,
a planet discovered in orbit around a star 2.5 times more massive than our sun.
While scientists cannot yet measure the distance from the planet to its star, they do know
that the surface temperature of KELT-9B is an incredible 7,772 degrees Fahrenheit (4300
C)!
That's hotter than most stars with a lower mass than our sun!
While a rocky planet like Mercury would be a permanently molten ball of lava, KELT-9B
is a Jupiter-type gas giant who's atmosphere is being burned off by its parent star.
11.
Coldest Planet
With the axing of Pluto as a planetary body, Neptune is officially the coldest planet in
our solar system, with frigid temperatures of -360 degrees Fahrenheit (-218 C), where
its so cold that methane condenses into rain.
However, orbiting a tiny, cool star known as a red dwarf, planet OGLE-2005-BLG-390Lb,
or 'Hoth' as it is affectionately known in reference to the Star Wars films, is a complete
ice cube at -369 degrees Fahrenheit (-223 C).
At such icy cold temperatures, just 50 degrees above absolute zero, the planet doesn't have
much of an atmosphere, with most gases frozen solid and lying as snow on the ground of this
rocky, earth-sized planet.
10.
Largest Planet
Stars are heavenly bodies that reach such massive size that gravity in their core ignites
nuclear fusion, however some stars- known as brown dwarfs- are big enough to start nuclear
fusion but not large enough to sustain the process.
Planet DENIS-P J082303.1-491201b has a whopping 28.5 times the mass of Jupiter, or 9063 times
the mass of Earth!
Planet Denis is so massive that scientists are debating whether it's still a planet at
all, or if it should be relabeled a brown dwarf, while the planet itself ironically
orbits a confirmed brown dwarf.
9.
The Smallest
Smaller than Mercury but slightly larger than our moon, Kepler-37b is the smallest planet
ever discovered.
A confirmed rocky world, it orbits its parent star closer than Mercury does around our sun,
making it far too hot for liquid water or any hope of life on its surface.
Kepler 115.03 could be smaller, but little is known about it so far.
8.
The Oldest
Our universe is 13.8 billion years old,and planet PSR B1620-26b is only 1.1 billion years
younger than that.
This old timer is a gas giant that's 2.5 times the mass of Jupiter and is 12.7 billion years
old and orbits two host stars that rotate around each other in a binary system formation.
This old man of our universe is in fact so old that it has outlived both of its stars,
a neutron star and a white dwarf, and if that wasn't enough it's even survived one of its
stars exploding into a supernova!
Because it is one of the first planets ever formed, this methuselah world likely doesn’t
have many of the heavy elements such as carbon and oxygen needed to create life, which was
formed later in the universe's evolution via exploding stars.
Planets today really do have it easy, back in PSR B1620's days a planet had to walk uphill
both ways in the snow and survive exploding supernovas just to evolve life!
7.
The Youngest
At only 2 million years old, the planetary system V830 Tauri is the youngest in our galaxy
so far discovered.
An astronomical toddler, the host star has the same mass as our sun but twice the radius,
meaning it hasn't contracted fully into its final shape yet.
A gas giant with three quarters the mass of Jupiter orbits this infant star and it too
is likely still evolving, acquiring more mass by colliding with other planetary bodies like
asteroids and even gobbling up smaller, newborn planets in its path.
This evolving system has also likely not yet seen the development of all of its final planets,
and over the next few million years remnant gas and dust orbiting the star will either
pull together by gravity to form other planets, or be swallowed up by Tauri's Jupiter-like
gas giant.
6.
Planet Being Eaten Alive
Orbiting far too close to its parent star for its own good, planet WASP-12b is a carbon-rich
gas giant.
Spotted by the Hubble telescope being distorted into an egg shape by the gravity of its sun,
its atmosphere is being sucked into its hungry parent star.
The host star is eating WASP-12b's atmosphere at a rate of about 189 quadrillion tons per
year, with scientists estimating that the planet has only 10 million years of life left.
5.
Death by X-rays
When a star between 10 and 29 times the size of our sun collapses, its core can become
a neutron star- one of the densest objects in the universe.
Neutron stars are so dense in fact that a matchbox-sized lump of material would weigh
a staggering 3 billion tons!
Their magnetic fields are also between 100 million to 1 quadrillion times as strong as
the earth's, and they can spin as fast as several hundred times per second.
Neutron stars emit beams of electromagnetic radiation as they spin, bathing any planets
caught in the path with extreme levels of radiation.
Planets PSR B1257+12A, B, and C, all orbit a neutron star that emits deadly blasts of
radiation several hundred times per second as it spins, scouring the surface of these
planets with radiation so extreme it would immediately destroy DNA.
If you were standing on the surface of one of these worlds and somehow shielded from
instant-death, you would see the star in the sky above you like a disco ball spinning out
of control, strobing the sky several hundred times per second!
4.
Glass Rains
Hot Jupiters are planets about the size of Jupiter that orbit really close to their sun,
making them...
well... hot.
Planet HD 189733 B is a hot Jupiter with a gorgeous blue atmosphere laden with silicate
particles that orbits its star in a whopping 2 days- imagine celebrating a birthday almost
four times a week!
While the atmosphere may look inviting and similar to Earth's, the winds actually whip
around the planet at 4,350 mph (7,000 kph) and cause rainstorms of molten glass that
blow sideways!
3.
Darkest Planet
A true incognito world, Jupiter sized planet TrES-2b has an atmosphere made up of light-absorbing
chemicals like vaporized sodium, potassium, and gaseous titanium oxide, making the planet
reflect less than 1% of light.
This makes it the darkest planet ever discovered, and despite analyzing its atmosphere scientists
still aren't completely sure why TrES-2b is so dark.
The only light the planet emits is a very faint red glow as a result of its proximity
to its sun, making TrES-2b the stealthiest planet ever discovered and darker than coal.
2.
Should've Put A Ring On It (Or A Few Million)
Saturn is the most iconic planet in our solar system, ringed by an absolutely beautiful
system of rings made up of pulverized debris and dust.
Commonly referred to as the 'Queen of the Solar System' due to its elegance, Saturn
is sadly completely trumped by planet Super Saturn J1407b, a planet 20 times more massive
than Saturn with a ring system that's more than 200 times as large!
The ring system stretches 180 million kilometers end to end, which is more than the distance
between the Earth and the sun.
No doubt beautiful, but perhaps Super Saturn J1407b is making up for something...
1.
Fastest
If you thought celebrating your birthday once every 2 days might have made you feel old
before, imagine how old you would feel if instead you celebrated it once every 10 hours!
Due to the force of gravity, the closer a planet is to its star, the faster it moves,
and no planet moves faster than SWEEPS-10, which orbits its star at a distance of only
745,000 miles (1.2 million km) and makes a complete orbit once every 10 hours!
Due to its extreme proximity, this hot Jupiter needs all of its 1.6 times the mass of our
own Jupiter to resist being torn to shreds by its parent star, though like many others
it too will one day be obliterated as its atmosphere is destroyed by its sun.
Another speedy exoplanet is PSR J1719-1438b, which has an orbit time of 2.177 hours.
Despite only hunting for exoplanets for 25 years, our galaxy is already yielding some
incredible and fascinating worlds, begging the question of just what else is out there?
As our technology and techniques continue to improve, we're bound to discover even stranger,
colder, and hotter worlds, and if we're lucky, maybe one day we might get to visit.
Which world on our list would you like to visit one day?
Which of these planets is the most extreme?
Let us know in the comments.
Also, be sure to check out our other video Is NASA Hiding A Planet (Planet X / Nibiru)?
Thanks for watching, and as always, please don’t forget to like, share and subscribe.