Astrophysicist Dr. Neil DeGrasse Tyson was asked by a reader of TIME magazine, "What is the most astounding fact you can share with us about the Universe?" This is his answer:
Tag Archives | Universe
Leonid Ksanfomaliti, an astronomer based at the Space Research Institute of Russia’s Academy of Sciences, analyzed photographs taken by a Russian landing probe during a 1982 during a mission to explore the heavily acid-clouded planet.
Venus is roughly the same size as Earth, but it has a thick atmosphere dominated by carbon dioxide. With an atmospheric pressure 92 times Earth’s, a waterless and volcano-riddled surface and a surface temperature of 894 degrees, the planet has never been considered a serious target of research into the possibility of extraterrestrial life.
But in his article, published in the magazine Solar System Research, Ksanfomaliti says the Russian photographs depict objects resembling a “disk,” a “black flap” and a “scorpion.”
“What if we forget about the current theories about the non-existence of life on Venus?” he wrote. “Let’s boldly suggest that the objects’ morphological features would allow us to say that they are living.”
Read More: Yahoo News
The asteroid, estimated to be about 11 m (36 ft) in diameter, was first detected on Wednesday. At its closest, the space rock — named 2012 BX34 — passed within about 60,000 km of Earth — less than a fifth of the distance to the Moon. Astronomers stressed that there had been no cause for concern. "It's one of the closest approaches recorded," said Gareth Williams, associate director of the US-based Minor Planet Center. "It makes it in to the top 20 closest approaches, but it's sufficiently far away ..." he told the BBC. The asteroid's path made it the closest space-rock to pass by the Earth since object 2011 MD in June 2011.Here's more from Space.com:
VY Canis Majoris is a red hypergiant star located in the constellation Canis Major. At between 1800 and 2100 solar radii (8.4–9.8 astronomical units, 3.063 billion km or 1.7 billion miles in diameter), it is currently the largest known star and also one of the most luminous known ...
There’s always something, says a Swedish study. Phenomenica reports:
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Scientists claim to have produced particles of light out of vacuum, proving that space is not empty.
An international team says that its ingenious experiment in which tiny parcels of light, or photons, are produced out of empty space has confirmed that a vacuum contains quantum fluctuations of energy, the ‘Nature’ journal reported.
In fact, the scientists have demonstrated for the first time a strange phenomenon known as the dynamical Casimir effect, or DCE for short.
The DCE involves stimulating the vacuum to shed some of the myriad “virtual” particles that fleet in and out of existence, making them real and detectable. Moreover, the real photons produced by the DCE in their experiment collectively retain a peculiar quantum signature that ordinary light lacks.
The research, led by Chris Wilson of Chalmers University of Technology in Sweden, shows that a related dynamic effect can occur when such a mirror moves very fast through the vacuum.
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A team of astronomers led by Sergey Koposov and Vasily Belokurov of Cambridge University recently discovered two streams of stars in the Southern Galactic hemisphere [of the Milky Way] that were torn off the Sagittarius dwarf galaxy. This discovery came from analysing data from the latest Sloan Digital Sky Survey (SDSS-III) and was announced in a paper released that connects these new streams with two previously known streams in the Northern Galactic hemisphere.
“We have long known that when small dwarf galaxies fall into bigger galaxies, elongated streams, or tails, of stars are pulled out of the dwarf by the enormous tidal field,” said Sergey Koposov.
The Sagittarius dwarf galaxy used to be one of the brightest of the Milky Way satellites. Its disrupted remnant now lies on the other side of the Galaxy, breaking up as it is crushed and stretched by huge tidal forces. It is so small that it has lost half of its stars and all its gas over the last billion years.
Edward Lovett and Ned Potter Report on ABC News:
We have a visitor — a large asteroid called 2005 YU55 that is expected to come within approximately 201,700 miles of Earth on Tuesday, according to NASA. That’s slightly less than the distance from Earth to the moon.
Asteroids often pass this close, but most are tiny. Countless thousands of pieces come plunging into the atmosphere, but they burn up without doing any harm. If they’re as large as grains of sand, we may, if we’re lucky, see them in the night sky as shooting stars.
But 2005 YU55 is at least 1,300 feet wide — larger than an aircraft carrier, according to radar measurements. The last time an asteroid this big passed by was in 1976, and the next one scientists know of won’t be until 2028, NASA says. (There have been some rude surprises in between, but not involving anything remotely as large.)
Don Yeomans, manager of NASA’s Near-Earth Object Program Office at Jet Propulsion Laboratory, in Pasadena, Calif., said this fly-by is an opportunity to learn more about c-type — that is, carbon-based — asteroids, to find “clues as to what it was like when our solar system was forming.”
More: ABC News
Via the Daily Galaxy:
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The large-scale structure of the Universe appears to be dominated by vast “hyperclusters” of galaxies, according to the new the Sloan Digital Sky Survey, compiled with a telescope at Apache Point, New Mexico. The survey plots the 2D positions of galaxies across a quarter of the sky. The science team has concluded that it could mean that gravity or dark energy — or something completely unknown — is behaving very strangely.
We know that the universe was smooth just after its birth. Measurements of the cosmic microwave background radiation (CMB), the light emitted 370,000 light years after the big bang, reveal only very slight variations in density from place to place. Gravity then took hold and amplified these variations into today’s galaxies and galaxy clusters, which in turn are arranged into big strings and knots called superclusters, with relatively empty voids in between.
On even larger scales, though, cosmological models say that the expansion of the universe should trump the clumping effect of gravity.
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Microbes born on Earth are already pre-adapted for journeying through space, living in space, and not just surviving but flourishing in radioactive environments where they are continually exposed to radiation by ions similar to what might be encountered in a nebular cloud.
In 1958, physicists discovered clouds of bacteria, ranging from two million bacteria per cm3 and over 1 billion per quart, thriving in pools of radioactive waste directly exposed to ionizing radiation and radiation levels millions of times greater than could have ever before been experienced on this plane.
The world’s first artificial nuclear reactor was not even built until 1942. Prior to the 1945, poisonous pools of radioactive waste did not even exist on Earth. And yet, over a dozen different species of microbe have inherited the genes which enable them to survive conditions which for the previous 4.5 billion years could have only been experienced in space.