Comet ISON
js
Nearby dust clouds in the Milky Way
Credit: NASA, ESA, and The Hubble Heritage Team (STScI/AURA)
IC 5148 is a beautiful planetary nebula located some 3000 light-years away in the constellation of Grus (The Crane). The nebula has a diameter of a couple of light-years, and it is still growing at over 50 kilometres per second — one of the fastest expanding planetary nebulae known. The term “planetary nebula” arose in the 19th century, when the first observations of such objects — through the small telescopes available at the time — looked somewhat like giant planets. Although the name stuck, it represents the expanding shell of gas ejected from old red giant stars late in their lives.
And now this one resembles a lovely blossom with layered petals.
Credit: European Southern Observatory
lesbians in space
To celebrate 26 years in space, Hubble has captured this magnificent view of NGC 7635, better known as the Bubble Nebula. The “bubble” is created by the stellar wind from a hot, young central star that is 10-20 times the mass of our Sun.
This is magical. whitevinyldesign.com/solarbeat
via wired
Because every planet has its own orbital period, “it ends up generating this unending, interesting pattern,” Twyman says. For example, Mercury, which has an orbit of 88 Earth days, is the backbeat to the sound, while Pluto, which takes approximately 248 years to orbit the sun, rarely makes an appearance in the music. “It really lends itself to generating ambient music,” he says. You can tweak the speed of orbit, slowing it down to make a soothing tinkle of a child’s mobile or speeding it up to orchestrate a chaotic planetary choir. New features allow you to add sound effects like echo, flutter and bass, and you can choose from eight different chords to personalize the sound. READ MORE
Perseus Black hole
Black holes are objects that have collapsed under their own weight to a point, creating an object that is very small but enormously dense. It is a region of space that has a gravitational pull so strong that no imminent particle or electromagnetic radiation can escape from it. This astonishing concept of black hole was first given by John Michell in 1783.He proposed that if you take the sun and compress it to a very small volume it would have a gravitational pull so strong that you have to travel at speeds greater than the speed of light to escape it.At first black holes are thought to be theoretical concepts which do not exist. But later they turned out to be very real. So how do these giant suckers form?
In order to understand the formation of a black hole we need to understand the formation and the life cycle of stars. A star is formed when large amounts of dust and gases, mainly hydrogen gas condense and collapse under its own gravitational force. As the gas collapses, the atoms of the gas collide with each other at higher and higher speeds resulting in the heating of the gas. Ultimately the gas becomes so hot that when the hydrogen atoms collide they don’t bounce off, but fuse together to form helium atoms, same as in the hydrogen bomb. As a result a large amount of heat is released which is the reason why stars shine. This heat increases the pressure of the gas until it balances out the gravitational pull and the gas stops contracting. Hence a star is formed.
The stars are usually stable as long as they have hydrogen in them. As the hydrogen runs out, the fusion reaction stops. To keep the fusion reaction going the star turns to its helium reserve. After it runs out of helium, it switches to carbon, and then oxygen. Stars with the mass of our Sun stop at this point as they don’t have enough energy to continue the fusion process and become white dwarfs. But stars with about 5 times the mass of our sun continue further to produce silicon, aluminum, potassium so on up to iron. No further energy can be produced by fusing iron atoms so the star starts to cool down. Once the external force of radiation stops acting the gravitational pull takes over and the star begins to contract. The entire mass of the star collapses into smaller and smaller volume of space. Eventually when the star has contracted to a certain critical radius, the gravitational field at the surface becomes so strong that even light cannot escape it. And this is how a black hole is formed.
Another way of formation of black hole is when two neutron stars collide with each other. When they collide their combined mass results in a very high gravitational force that leads to a collapse and a black hole is formed.
In this image, information from the Chandra X-ray Observatory is combined with images from the Hubble Space Telescope. NASA believes these two black holes are spiraling toward each other and have been doing so for 30 years.