About 420 light years away lies a very young planet around a very young sun-like star, with Saturn like rings around it. What is not like Saturn is the truly colossal size of the rings. Transit observations revealed that this gas giant planet has rings 200 times larger than the rings of Saturn. And so the title of the Lord of the Rings goes to J1407b — a Super Saturn at least 20 times more massive than Saturn itself.

Here is how the planet’s ring system size compares to its sun:

The large ring system was discovered due to it deeply eclipsing the planet’s sun for weeks. The rings have a lot of material in it (containing the mass of an entire Earth), which block the light of the planet’s sun. Here is a video showing the drop in the star’s brightness during the ring-eclipse:

Extending ~180 million km in length, the size of the rings beat the Earth-Sun distance. The question is how do such large rings even exist when they should be torn apart by the gravity of the planet’s sun.

An interesting way this was solved was proposing that the rings were spinning in the opposite direction to that of its planet around its sun. This means that the particles that make up the ring system are never too close to the sun for too long, and thus can stay together in a ring formation in the face of the star’s intense gravitational pull. Here’s an animation:

The rings stay intact when spinning counter-clockwise as opposed to clockwise spinning with respect to the planet’s spin, hence solving the mystery. Now the question is how do you get rings spinning in the opposite direction in the first place? Well, more answers to find out for Science.

There is another interesting thing about these rings. Did you notice the ring gap in the above video at 0:09?

Since the gap is quite substantial and the planetary system quite young, it is thought that the gap in the rings is cause by a newly formed moon up to 80% the mass of Earth. What we are seeing here is a Jupiter/Saturn like vast moon system being formed. Only larger.

After the 13 years of Stunning Saturn Science that NASA’s Cassini spacecraft has given us, one can only imagine the beautiful imagery and intricate data that will be revealed when (and if) we send a spacecraft to this Lord of the Rings. Meanwhile here’s a simulated version:

Dreamy. Just to think that there are such extreme worlds out there in the Universe waiting to be discovered, simply boggles my mind.

#1: A planet being eaten by its star — Wasp-12b

Imagine a planet ~2 times the size of Jupiter. Now imagine it being pulled by the extreme gravitational force of its sun making the planet egg-shaped.

In a mere 10 million years of cosmic time, the planet Wasp-12b will be completely destroyed by its sun, becoming a part of it.

#2: Planets bathed with excessive radiation — Pulsar Planets

Among the very first exoplanets to be discovered, the 3 planets PSR B1257+12 A, B and C (discovered in the 1990s) are the last places you want to look for Life. The Neutron star they orbit spins around itself faster than you can blink your eye. It emits excessive radiation pulses from both its poles in the process.

Such intense bathing of radiation from its parent star while extremely hostile to Life, creates dazzling auroras on the planets. Makes you wonder how safe the planet from Interstellar would be, bombarded by the excessive radiation from around the Black Hole.

#3: Rains of molten glass — HD 189733 b

Look at this beautiful deep blue planet:

Very Earth-like? Not quite. This Hot Jupiter planet has winds that blow at more than 7000 km/h and is likely to have rains of molten glass, blowing sideways! In fact, the deep blue color observed is because of scattering of blue light (Rayleigh scattering) by the silicate particles in its atmosphere.

#4: A planet darker than coal — TrES-2b

The large Jupiter-sized planet TrES-2b has an atmosphere that absorbs pretty much all of the light of its sun. Reflecting less than 1% of sunlight makes it the darkest known planet around any star, darken than coal even.

This amazing discovery was made using NASA’s Kepler telescope. The planet’s exotic atmosphere have been found to contain light-absorbing chemicals like vaporized sodium & potassium and gaseous titanium oxide, yet none of these chemicals fully explain the extreme blackness of TrES-2b. The only faint light that the planet emits is due to it being very hot, a faint red glow the result of its proximity to its sun.

#5: A planet hotter than most stars — KELT-9b

At more than 4800 degrees Celsius, KELT-9b is hotter than the surface of most stars in the Universe. The planet is even more unusual in that it orbits perpendicular to the spin axis of its star (i.e pole to pole) and nobody knows why. Imagine a planet ~3x the mass of Jupiter and bring it very close to the Sun, tilt its orbit 90 degrees and let it feel the heat:

A polar opposite (pun intended) of this planet would be the planet named Hoth after the Star Wars ice planet. Hoth (in real life) is the coldest planet ever known at -220 degrees Celsius worth of coldness on its surface.

#6: Super Saturn J1407b— The largest ring system ever found

Saturn’s rings are among the most beautiful sights in the Solar System. Now imagine a planet that is at least 20 times more massive than Saturn with a ring system that is more than 200 times as large. That’s Super Saturn J1407b for you.

In the image above, the rings of J1407b are shown eclipsing the young sun-like star J1407, as they would have appeared in early 2007 when the discovery was made. The rings of this planet are so huge that they stretch 180 million km end to end, larger than the distance between the Earth and the Sun.

There is also expected to be a large moon of the planet which is almost the same mass as the Earth (Original Paper). The planet itself is so big its possible that its a Brown Dwarf star instead.

The Galaxy is full of extreme worlds that are born to break the rules, rules that we thought were there. But the more Science we did, we found time and again that Nature finds its ways in curious ways.

So which one is your favorite? :)

Through the lens of a Physicist, here is what I think… in the form of a poem!

Space is vast, near-infinite and empty,
But only so much of it we can see..

Stuck in a direction of time are we,
And yet we claim how we came to be..

Welcome to Space-time’s infinite array,
Where everything lies farther and farther away..

Magnificent Galaxies may be big and bright,
But their separation speaks stronger than their light..

Even the Stars are not as close as they seem,
Mere little dots that come and go as they dim..

Yet, even those tiny dots can be the most violent of all,
Massive Supernovae and Gamma ray bursts leading their fall..

This is a Universe where the stars are born to die,
Some form black holes, to space-time they can lie..

Even the smaller stars are hostile in time,
So are the planets that are considered benign..

Space is cold & time unforgiving,
Space is harsh & with time, it defies living..

Just what is then the purpose of life?
Or are we just a roll of dice?

Life is purposeless and meaningless,
Every sentient species alone in the vast space-time emptiness..

The last bit about the lack of time for two species to communicate is pulled from the Drake equation, which gives an estimate of the number of Intelligent civilizations with whom communication is possible:

A part of the argument in the Fermi Paradox suggests that the amount of time for which an Intelligent species exists to communicate its existence is quite small and space is quite big.

Is the Fermi Paradox really a paradox?

#1: White Dwarf stars are the size of the Earth, but have the mass of a Sun

One of the first White Dwarfs to be found, Sirius B is merely the size of the Earth, making it quite small for a star.

And yet it manages to cram about the same mass as our Sun, making it much denser. Sirius B’s powerful gravitational field is 350 000 times greater than Earth’s, meaning that a 68 kg person would weigh 25 million kg on its surface!

Such high density was thought to be impossible by the scientific community a century ago, paraphrased nicely by Arthur Eddington, after the discovery of such a White Dwarf:

We learn about the stars by receiving and interpreting the messages which their light brings to us. The message of the Companion of Sirius when it was decoded ran: “I am composed of material 3,000 times denser than anything you have ever come across; a ton of my material would be a little nugget that you could put in a matchbox.” What reply can one make to such a message? The reply which most of us made in 1914 was — “Shut up. Don’t talk nonsense.”

#2: More massive a White Dwarf, the less its size!

Past the Red Giant stage and shedding of all the outer layers of gas, the leftover core of Sun-like stars is not capable of fusing matter to release light and energy. Gravity thus takes over and crams the electrons in such stars to give the high density that they are known for. More the gravity due to higher mass, more the crushing.

For gravity to compress a White Dwarf even further, it must force all the electrons to occupy all available spaces (energy state). Beyond that, Quantum Mechanics won’t allow gravity to compress the star any more: Pauli’s Exclusion Principle says that no 2 electrons can occupy the same energy state. This maximum limit for gravity being able to crush a White Dwarf gives the maximum mass it can have, known as the Chandrasekhar limit. The most massive White Dwarf star is thus the smallest one around.

#3: White Dwarfs can actually go Supernova!

White Dwarf stars are sometimes found in close binary systems where the other star is less massive than our Sun is. Due to the proximity of these stars and the high gravitational pull of the White Dwarf, it pulls in matter from the companion!

The matter forms an accretion disk around the White Dwarf (due to conservation of angular momentum) before falling on it with tremendous amounts of energy. The in-falling matter increases the density of the White Dwarf. If the density crosses the maximum limit for the stability of a White Dwarf (as discussed above), it results in a runaway Carbon fusion detonation that causes the entire star to go Supernova and destroys the entire star in a matter of seconds.

#4: White Dwarfs can be Pulsars too!

The White Dwarf star AR Sco has an electromagnetic field 100 million times more powerful than Earth and rotates around itself in a mere 2 minutes. Such a powerful magnetic field produces intense lighthouse-like beams of radiation and particles, which shoot its companion Red Dwarf star to generate an enormous electric current in it.

Such highly polarized radiation emission controlled by the star’s magnetic field was only ever seen before in Neutron Stars. Such stars are called Pulsars and now White Dwarfs have the claim to that fame too.

#5: White Dwarfs as a bright source of gravitational waves

1600 Light-years away, 2 dense White Dwarfs are locked in a spiral dance around each other, every orbit a mere 5 minutes. They will eventually collapse together to form an even denser Neutron Star, as the orbit decays continually thanks to laws of General Relativity. This releases gravitational waves as visualized here:

It is expected that this system is one of the brightest sources of gravitational waves known to humans and will be a prime target for the upcoming gravitational wave space observatory LISA.

#6: White Dwarfs can be used to determine the age of the Universe

Even though White Dwarfs no longer fuse matter to generate heat and light, their small surface area implies they cool very slowly, remaining hot for a long time. The cooler a White Dwarf star gets, the more time it takes to cool further, like a cup of coffee. Since the Universe is still quite young, all known White Dwarfs are still quite hot and shine white. It will take billions of years for a White Dwarf to go dim red.

As the cooling takes place slower and slower with time, for a White Dwarf to form a dead Black Dwarf, it will take trillions of years. By looking at the stage of cooling of the oldest White Dwarfs there are, the Hubble Space Telescope was used to determine the age of the Universe, in agreement with other estimates of 13–14 billions years.

Oh, and seismological observations of a White Dwarf suggest that their cores are crystallized like diamonds.

Rogue planets are planets without stars and thus orbit the galaxy directly. This makes them incredibly difficult to find because they don’t reflect any starlight or are undetectable by common exoplanet detection methods. Yet Science paved the way to find just one such planet lurking in the dark about 80 light years away. The faint red glow of the rogue planet PSO J318.5–22 was directly imaged by the Pan-STARRS PS1 telescope. Seeing that such rogue planets are hard to find, it makes sense that one is 6 times more massive than Jupiter, making it relatively easy to spot.

Rogue planets are everywhere

Gravitational microlensing observations of 50 million stars in the Milky Way found 10 Jupiter-sized rogue planets. This helped scientists estimate that there are at least 2 rogue planets for every star in the Galaxy (Paper). This means that there are potentially billions of rogue planets out there, lurking silently in the dark. Many of them are likely Earth-sized too.

A dead and desolate planet with no heat and light from a Sun seems like the last place to look for Life. However, there are ways rogue planets can retain heat and have suitable conditions for Life:

#1: Rogue planets with Hydrogen dominated atmosphere can retain heat

Not having a Sun has its advantages too, one being that exposure of the planet’s atmosphere to Ultra-Violet (UV) light is minimal. This helps even an Earth-sized rogue planet retain a Hydrogen dominated atmosphere. The paper Life-sustaining planets in interstellar space? suggests that such an atmosphere can trap the planet’s heat through pressure induced far-infrared radiation. Under the right conditions (like a fully convective atmosphere), liquid water oceans are also possible.

#2: Rogue planets can be geologically active

A large natural satellite like our Moon generates tidal forces on Earth that cause significant heating due to friction. This heating increases geological activity of the planet.

Early on after planetary formation, terrestrial planets with a large satellite (like the Earth-Moon system) can interact with Jupiter-sized bodies and get kicked out of the star system. Simulations of the same suggest that about 5% of such terrestrial planets retain their satellite even after being pushed out of the system. The tidal heating caused by such a moon provides a longer span for geological activity for such rogue planets, giving a chance for Life to arise.

#3: Moon of rogue planets can potentially harbour Life

Free floating planetary-mass objects can eventually form a mini planetary system around them, much like the Jupiter mini-system. The sub-brown dwarf OTS-44 is known to be surrounded by a disk of at least 10 Earth masses. OTS-44 can thus have a set of moons going around it in the future.

Just like how the tidal forces of Jupiter are responsible for its moon Europa’s subsurface ocean, moons around such rogue planets can have subsurface liquid water oceans too by the very same mechanism.

Coupled this with possible sea floor volcanism and hydrothermal vents (that are considered to have been the birthplace of Life on Earth), such exomoons of these rogue exoplanets stand a chance at producing Life, even if bacterial.

In 2013, a possible discovery of an exomoon around a rogue planet was announced in this paper.

The Future

The possibilities of Life existing on rogue planets is thus not as tiny as we think at first go. Our current capabilities of finding rogue planets is not so good but NASA’s upcoming Wide Field InfraRed Survey Telescope (WFIRST) is expected to expand our search significantly. Only then with significantly more data, can we even begin to contemplate the real possibilities of Life on such dark worlds.

If we find any form of Life (however primeval) on dark and desolate exoplanets that have no Sun of their own, it would be clear that Nature still has a gazillion mysteries of its inner workings hidden from us, waiting to be understood.