Galaxies are the building blocks of the Universe. Each of them comprises some hundred billion radiant stars, such as our sun, which extend across about 50,000 light years. Every galaxy is embedded in a spherical halo made of dark matter that cannot be seen but is detected through its massive gravitational attraction. The exact nature of this matter is still unknown.
In 1960, Dr. Frank Drake developed an equation that predicts the number of intelligent civilizations in our galaxy. It's a simple equation -- the number of intelligent civilizations in our galaxy is equal to the product of all the following numbers:
- The total number of stars in the galaxy
- The fraction of stars that have planets orbiting them
- The number of planets orbiting each star that are capable of supporting life
- The fraction of planets capable of supporting life that actually do support life
- The fraction of planets supporting life that support intelligent life
NGC 253 is one of the brightest and dustiest spiral galaxies in the sky but we are always learning new things about it. Astronomers using the Very Large Telescope's (VLT) near-infrared eye called NACO, an adaptive optics instrument, are now saying that the center of NGC 253 hosts a scaled-up version of Sagittarius A*, the bright radio source that lies at the core of the Milky Way, and which we know harbors a massive black hole.
"We have thus discovered what could be a twin of our Galaxy's Centre," says co-author Almudena Prieto, part of the group of astronomers from the Instituto de Astrofísica de Canarias (Spain) and lead author of a new paper on the topic, which also disclosed a group of new young, massive and dusty stellar nurseries there.
Transiting exoplanets are routinely detected when they pass in front of their parent star as viewed from the Earth, which only happens by chance. The transit event causes a small drop in the observed starlight, which can then be detected.
In an article in the International Journal of Astrobiology
, P. McCafferty discusses the possibility of a red, blood-like life form living inside meteors.
This conclusion raises the possibility that, in space, there are objects that contain red, blood-like cells. In other words, comets possibly harbour life. Such an image of a comet, containing a liquid interior teeming with red cells, is difficult to imagine and even harder to accept.
At 1014 gauss, atoms are compressed into tiny needles whose widths are only 1% of their lengths. X-ray photons readily undergo an exotic process where they change into matter and anti-matter particles briefly, before rejoining and turning back into light. Even at a distance of 1000 km, the slight polarization of water molecules would tear apart any Earth organism. So where do you find magnetic fields of such awe-inspiring strength? Attached to exotic objects in deep space, of course.
The unique planetary nebula NGC 2818 is nested inside the open star cluster NGC 2818A. Both the cluster and the nebula reside 10,400 light-years (3.2 kiloparsecs) away, in the southern constellation Pyxis, also called the Compass.
NGC 2818 is one of very few planetary nebulae in our galaxy located within an open cluster. Open clusters, in general, are loosely bound and they disperse over hundreds of millions of years. Stars that form planetary nebulae typically live for billions of years. Hence, it is rare that an open cluster survives long enough for one of its members to form a planetary nebula. This open cluster is particularly ancient, estimated to be nearly one billion years old.
What is life is a valid question to some because they would simply like to make some. Yet others, although they don't know what it is, search for life in other planets like Mars. How do you find life if you don't know what it is?
Researchers have discovered that the mysterious overweight stars known as blue stragglers are the result of 'stellar cannibalism', where plasma is gradually pulled from one star to another to form a massive, unusually hot star that appears younger than it is. The process takes place in binary stars star systems consisting of two stars orbiting around their common centre of mass. This helps to resolve a long standing mystery in stellar evolution.
XMM-Newton has caught the fading glow of a tiny celestial object, revealing its rotation rate for the first time. The new information confirms this particular object as one of an extremely rare class of stellar zombie – each one the dead heart of a star that refuses to die.