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The Horrors of Exoplanets

Exoplanets are mysterious, bizarre, but ultimately exciting.

After all, with the help of the Kepler space telescope and advanced exoplanet-hunting techniques, for the first time we’re directly observing a veritable menagerie of alien worlds. Through exoplanetary studies, we’re beginning to even understand our place in the Universe.

Despite all this fascination however, many of these alien worlds seem downright scary.

Phantom worlds are on the prowl; ghosts dance in exoplanets’ atmospheres; entire worlds are even getting ripped apart!

Here’s a look at the top 10 of the scariest alien worlds likely to frighten even Captain Jean-Luc Picard back into his shuttlecraft.

Read more

(via scientificthought)

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10 Things You Didn’t Know About Black Holes
Stars whose size is 10 or 15 times as massive as the Sun, generally have a fate of becoming black holes. Small stars, however, die as white dwarfs or neutron stars. So how do large stars become black holes? As stars begin to grow old, they gradually expand and they slowly run out of their supply of hydrogen and then helium. This causes contraction of their cores and expansion of the outer layers. The stars start becoming cooler and less bright and they come to a stage which is known as the red giant phase. Now, for a star which is even 3 times or more the mass of the Sun, undergoes detonation (a violent release of energy caused by a chemical or nuclear reaction) in cataclysms known as supernovae. Such kind of explosion results in scattering of most of a star into the space. However, it also leaves behind a cold remnant of the star, which is no longer able to execute any nuclear fusion reaction. As there is no fusion in the dead remnants of a massive supernova star, there is no creation of any energy which can oppose the inward pull of gravity caused by the star’s own mass. Thus, the star enters a phase where it begins to collapse in upon itself. This is the formation of the black hole, wherein, it starts shrinking to zero volume. So, with volume being zero, density becomes infinite, so much that even light becomes unable to escape its massively strong gravitational pull. As a result of this, even the light of the dead remnants of the star gets trapped in its orbit and this dark star evolves to become what is known as a black hole.
It has been estimated that there might be black holes of enormous size, which may be existing at the center of our galaxy, ‘The Milky Way’. These holes are assumed to be having the mass of 10 - 100 billion suns. Now, that is something which is ‘HUGE’, in block letters!
Cygnus X-1 is the black hole that is located about 8000 light years away from our planet Earth. This is the closest black hole to Earth, known to man.
Although, black holes are associated with the reputation of having the strongest suction force, they do not bear the capability to absorb the whole universe. Anything such as planets, light and other matter, can be pulled into the grasp of black holes, only if they happen to cross what is known as the event horizon. The radius of this event horizon is known as the Schwarzschild radius and at this radius, the escape velocity equals the speed of the light. So, once an object has passed through it, it must travel faster than light in order to escape it. That is the reason why, even light cannot escape the event horizon of a black hole.
As mentioned earlier, in this part of black holes in space, only the largest of stars are capable to end up as black holes. Only these stars are massive enough to get compressed to the Schwarzschild radius. While, smaller stars end up as white dwarfs or neutron stars.
There are several black holes which exist in binary star systems. Stars which are neighboring such holes, will keep on shrinking as their mass will continually be pulled by these holes. Gradually, the black holes will go on increasing, until the other stars have vanished.
As light cannot escape from a black hole, it cannot be directly observed. However, scientists use the presence of matters which swirl around the hole. Such matters are usually gas and dust and they heat up and emit radiation which can be detected.
Talking about our Sun becoming a black hole, the phenomenon won’t occur. This is because the sun is not massive enough to shrink into a black hole. However, it will end up to become a white dwarf, after several billion years.
The center of a black hole is void of time and space.
A giant elliptical galaxy in the constellation Virgo, is assumed to home the largest known black hole. This hole is about 3 billion times the mass of the Sun.
Larger black holes are known to suck up other smaller ones which are close to their vicinity.
No matter, how many facts people come up with, black holes represent an endless journey in the vast darkness of the space. The concept which lay hidden in the lap of black holes, perhaps, is the most appropriate analogy to the saying ‘sky is the limit!’
In the image: Simulation of gas cloud approaching the black hole at the center of the Milky Way

expose-the-light:

10 Things You Didn’t Know About Black Holes

Stars whose size is 10 or 15 times as massive as the Sun, generally have a fate of becoming black holes. Small stars, however, die as white dwarfs or neutron stars. So how do large stars become black holes? As stars begin to grow old, they gradually expand and they slowly run out of their supply of hydrogen and then helium. This causes contraction of their cores and expansion of the outer layers. The stars start becoming cooler and less bright and they come to a stage which is known as the red giant phase. Now, for a star which is even 3 times or more the mass of the Sun, undergoes detonation (a violent release of energy caused by a chemical or nuclear reaction) in cataclysms known as supernovae. Such kind of explosion results in scattering of most of a star into the space. However, it also leaves behind a cold remnant of the star, which is no longer able to execute any nuclear fusion reaction.

As there is no fusion in the dead remnants of a massive supernova star, there is no creation of any energy which can oppose the inward pull of gravity caused by the star’s own mass. Thus, the star enters a phase where it begins to collapse in upon itself. This is the formation of the black hole, wherein, it starts shrinking to zero volume. So, with volume being zero, density becomes infinite, so much that even light becomes unable to escape its massively strong gravitational pull. As a result of this, even the light of the dead remnants of the star gets trapped in its orbit and this dark star evolves to become what is known as a black hole.

  • It has been estimated that there might be black holes of enormous size, which may be existing at the center of our galaxy, ‘The Milky Way’. These holes are assumed to be having the mass of 10 - 100 billion suns. Now, that is something which is ‘HUGE’, in block letters!
  • Cygnus X-1 is the black hole that is located about 8000 light years away from our planet Earth. This is the closest black hole to Earth, known to man.
  • Although, black holes are associated with the reputation of having the strongest suction force, they do not bear the capability to absorb the whole universe. Anything such as planets, light and other matter, can be pulled into the grasp of black holes, only if they happen to cross what is known as the event horizon. The radius of this event horizon is known as the Schwarzschild radius and at this radius, the escape velocity equals the speed of the light. So, once an object has passed through it, it must travel faster than light in order to escape it. That is the reason why, even light cannot escape the event horizon of a black hole.
  • As mentioned earlier, in this part of black holes in space, only the largest of stars are capable to end up as black holes. Only these stars are massive enough to get compressed to the Schwarzschild radius. While, smaller stars end up as white dwarfs or neutron stars.
  • There are several black holes which exist in binary star systems. Stars which are neighboring such holes, will keep on shrinking as their mass will continually be pulled by these holes. Gradually, the black holes will go on increasing, until the other stars have vanished.
  • As light cannot escape from a black hole, it cannot be directly observed. However, scientists use the presence of matters which swirl around the hole. Such matters are usually gas and dust and they heat up and emit radiation which can be detected.
  • Talking about our Sun becoming a black hole, the phenomenon won’t occur. This is because the sun is not massive enough to shrink into a black hole. However, it will end up to become a white dwarf, after several billion years.
  • The center of a black hole is void of time and space.
  • A giant elliptical galaxy in the constellation Virgo, is assumed to home the largest known black hole. This hole is about 3 billion times the mass of the Sun.
  • Larger black holes are known to suck up other smaller ones which are close to their vicinity.

No matter, how many facts people come up with, black holes represent an endless journey in the vast darkness of the space. The concept which lay hidden in the lap of black holes, perhaps, is the most appropriate analogy to the saying ‘sky is the limit!’

In the image: Simulation of gas cloud approaching the black hole at the center of the Milky Way

White Holes

A white hole, in general relativity, is a hypothetical region of spacetime which cannot be entered from the outside, but from which matter and light may escape. In this sense it is the reverse of a black hole, which can be entered from the outside, but from which nothing, including light, may escape. (However, it is theoretically possible for a traveler to enter a rotating black hole, avoid the singularity, and travel into a rotating white hole which allows the traveler to escape into another universe.)

Like black holes, white holes have properties like mass, charge, and angular momentum. They attract matter like any other mass, but objects falling towards a white hole would never actually reach the white hole’s event horizon.

See also; Event Horizons

(Source: kenobi-wan-obi, via scientificthought)

"O Night, diapered with fires innumerable! hast thou not written in flaming letters on these Constellations the syllables of the great enigma of Eternity? The contemplation of thee is a wonder and a charm. How rapidly canst thou efface the regrets we suffered on the departure of our beloved Sun! What wealth, what beauty hast thou not reserved for our enraptured souls! Where is the man that can remain blind to such a pageant and deaf to its language!"

Camille Flammerion

Astronomy for Amateurs

Translated by Frances A. Welby

Venus towards the top right and solar flares to the bottom. 

Venus towards the top right and solar flares to the bottom.