Nasa finds water on the moon

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This is Nasas's picture of the day and an official report that they found water on the moon: Water Detected at High Latitudes on the Moon

NASA's Moon Mineralogy Mapper, an instrument on the Indian Space Research Organization's Chandrayaan-1 mission, took this image of Earth's moon. It is a three-color composite of reflected near-infrared radiation from the sun, and illustrates the extent to which different materials are mapped across the side of the moon that faces Earth. Small amounts of water were detected on the surface of the moon at various locations. This image illustrates their distribution at high latitudes toward the poles. Blue shows the signature of water, green shows the brightness of the surface as measured by reflected infrared radiation from the sun and red shows an iron-bearing mineral called pyroxene.

Image Credit: ISRO/NASA/JPL-Caltech/Brown Univ./USGS

Einstein - black holes and gravitional lens

The theory of general relativity has important astrophysical applications. Notably, it predicts the existence of black holes—regions of space in which space and time are distorted in such a way that nothing, not even light, can escape—as an end-state for massive stars. There is evidence that, indeed, such black holes as well as more massive varieties are responsible for the intense radiation emitted by certain types of astronomical objects (such as active galactic nuclei or microquasars). The bending of light by gravity can lead to the curious phenomenon of multiple images of the same astronomical object being visible in the sky, an effect called gravitational lensing which has spawned an active new branch of astronomy. General relativity also predicts the existence of gravitational waves, which have been measured indirectly; a direct measurement is the aim of projects such as LIGO. In addition, it is the basis of current cosmological models of an expanding universe. Photo: Extragalactic astronomy: gravitational lensing. This Hubble Space Telescope image shows several blue, loop-shaped objects that actually are multiple images of the same galaxy. They have been duplicated by the gravitational lens effect of the cluster of yellow, elliptical and spiral galaxies near the photograph's center. The gravitational lens is produced by the cluster's tremendous gravitational field that bends light to magnify, brighten and distort the image of a more distant object. Text Source: Nationmaster; Knowledgehush.

Einstein our next door neighbor

It's amazing how little of his theory is known by many of us and how much we like him. Einstein has lived in poverty and was not bright as a student. His clothes are normal, no suits, nothing that implies he is a superior person. He could be our next door neighbor. He spent most of his time at home studying his theories and trying to proof them to their colleagues. In order to proof the theory of relativity to skeptical physicist he decided to use this postulate: if relativity was true, then rays of starlight that passed near the Sun would be bent compared to the same rays when the Sun was elsewhere in the sky. In each case, the relativistic effects are caused by gravity from the Sun's huge mass. It only requires photos of solar eclipses to measure shifts in star positions and there was some of them so that the astrophysics could use. When they did examine previous photographs of solar eclipses, they found that the pictures were unsuited to proving or disproving Einstein's claim: the telescopes had been set to track the Sun's motion across the sky, not the stellar motions, and the slight differences between these perspectives obscured the small, predicted shifts in star positions. However, as time went by and other experiments gave equivocal results, the solar-eclipse experiment represented the best chance to test the truth of relativity. It was his British friend Sir Arthur Eddington, an renowned astrophysicist who believed in Einstein, that constructed a telescope with few resources and did try twice to photograph solar eclipse. The second time was in the spring of 1919 that Sir Eddington went on an expedition to Australia to take photographs of a solar eclipse that it was possible to confirm the correctness of general relativity theory. It change it all we are using his theory on daily basis without even knowing that without this theory many things would be different.

Photography: one of the many photos Sir Eddington took from Australian solar eclipse in 1919

Galileo drawings of the moon - 1653

Galileo's Sidereus Nuncius, this edition from 1653. Galileo first described crater and mountains. Needless to remember that he was almost burned because of his ideas. He did many drawings of the moon and they are amazing.

55 Cancri - Our solar system cousin?

2009 is the year dedicated to astronomy. Five planets were already found in 55 Cancri the system that looks like our solar system. According to Nasa: "This artist's concept illustrates two planetary systems - 55 Cancri and our own. Blue lines show the orbits of planets, including the dwarf planet Pluto in our solar system. The 55 Cancri system is currently the closest known analogue to our solar system, yet there are some fundamental differences." "The similarities begin with the stars themselves, which are about the same mass and age. Both stars also host big families of planets. Our solar system has eight planets, while 55 Cancri has five, making it the record-holder for having the most known exoplanets. In fact, 55 Cancri could have additional planets, possibly even rocky ones that are too small to be seen with current technologies. All of the planets in the two systems have nearly circular orbits. In addition, both planetary systems have giant planets in their outer regions. The giant located far away from 55 Cancri is four times the mass of our Jupiter, and completes one orbit every 14 years at a distance of five times that between Earth and the sun." (emphasis mine)