Experts Question Claim Tunguska Meteorite May Have Come from Mars.

In 1908 a blazing white line cut across the sky before exploding a few miles above the ground with a force one thousand times stronger than the nuclear blast that leveled Hiroshima, Japan.
The resulting shock wave felled trees across more than 800 square miles in the remote forests of Tunguska, Siberia.
For over 100 years, the exact origins of the Tunguska event have remained a mystery. Without any fragments or impact craters to study, astronomers have been left in the dark. That’s not to say that all kinds of extraordinary causes haven’t been invoked to explain the event. Various people have thought of everything from Earth colliding with a small black hole to the crash of a UFO.
Russian researchers claim they may finally have evidence that will dislodge all conspiracy theories, but that “may” is huge. A team of four believes they have recovered fragments of the object — the so-called Tunguska meteorite — and even think they are Martian in origin. The research, however, is being called into question.
In a detective-like manner, the team surveyed 100 years’ worth of research. The researchers read eyewitness reports and analyzed aerial photos of the location. They performed a systematic survey of the central region in the felled forest and analyzed exotic rocks and penetration funnels.

Previously, numerous expeditions failed to recover any fragments that could be attributed conclusively to the long-sought Tunguska meteorite. But then Andrei Zlobin, of the Russian Academy of Sciences’ Vernadsky State Geological Museum, discovered three stones with possible traces of melting. He published the results in April 2013.
Zlobin’s discovery paper was received with skepticism and Universe Today covered the news immediately. A curious question arose quickly: why did it take so long for Zlobin to analyze his samples? The expedition took place in 1988, but it took 20 years before the three Tunguska candidates were nominated and another five years before Zlobin finished the paper.
By Zlobin’s admission, his discovery paper was only a preliminary study. He claimed he didn’t carry out a detailed chemical analysis of the rocks, which is necessary in order to reveal their true nature. Most field experts quickly dismissed the paper, feeling there was more work to be done before Zlobin could truly know if these rocks were fragments from the Tunguska meteor.
Today, new research is moving forward with an analysis of the rocks originally discovered by Zlobin. But an interesting new addition to the collection is a rock called “John’s Stone” — a large boulder discovered in July, 1972. While it’s mostly a dark gray now it was much lighter at the time of its discovery. “John’s Stone has an almond-like shape with one broken side,” lead author Dr. Yana Anfinogenov told Universe Today.
Now the skeptical reader might be asking the same question as before: why is there such a large time-lapse between the discovery of John’s Stone and the analysis presented here? (It’s interesting to note that while this elusive rock has been reviewed in the literature for over 40 years, this is the first time it has appeared in an English paper). Anfinogenov claimed that new data (especially concerning Martian geology) allowed for a much better analysis today than it did in recent years.

“The ground near John’s Stone presents undeniable impact signs suggesting that the boulder hit the ground with a catastrophic speed,” Anfinogenov told Universe Today. It left a deep trace in the permafrost which allowed researchers to note its trajectory and landing velocity coincides with that of the incoming Tunguska meteorite.
John’s Stone also contains shear-fractured splinter fragments with glossy coatings, indicating the strong effect of heat generated when it entered our atmosphere. The research team attempted to reproduce those glossy coatings found on the splinters by heating another fragment of John’s Stone to 500 degrees Celsius. The experiment was not successful as the fragment disintegrated in high heat.
“The authors do not present a strong case that the boulder known as John’s Stone was involved in the Tunguska event, or that it originated from Mars,” said Dr. Phil Bland, a meteorite expert at Curtin University in Perth, Australia.
They claim the mineral structure and chemical composition of the rocks — a quartz-sandstone with grain sizes of 0.5 to 1.5 cm and rich in silica — match rocks found on Mars. But their paper lacks any microanalysis of the samples, or isotopic study.
While there is a strong case that an impact on Mars could easily eject rock fragments that would then hit the Earth, something doesn’t match up. “The physics of ejecting material from Mars into interplanetary space argues for fragments with diameters of one to two meters, not the 20 to 30 meter range that would be required for Tunguska,” Bland told Universe Today.
It seems as though planetary geologists will require a much stronger case than this to be truly convinced John’s Stone is the Tunguska meteorite, let alone from Mars.
The paper is currently under peer-review but is available for download here.

Source: UT

Dyson Spheres: How Advanced Alien Civilizations Would Conquer the Galaxy (Infographic)

 Ancient extraterrestrial civilizations, millions of years older than humanity, would need enormous amounts of energy. By creating a swarm of satellites in a spherical shell, they could harness much of the power of their star.
Science fiction author Olaf Stapledon described spherical, energy-trapping alien structures in his 1937 novel "Star Maker": 
"Not only was every solar system now surrounded by a gauze of light traps, which focused the escaping solar energy for intelligent use, so that the whole galaxy was dimmed, but many stars that were not suited to be suns were disintegrated, and rifled of their prodigious stores of sub-atomic energy."

Incredible Technology: How to Search for Advanced Alien Civilizations

Recalling Stapledon's description, physicist Freeman Dyson proposed similar structures in a scientific paper in 1960. Dyson realized that alien civilizations could be recognized by their waste heat, which would be detectable as infrared radiation. Dyson proposed that really advanced civilizations would re-engineer their solar systems, perhaps dismantling planets to form a shell of satellites around their star to capture its energy. 

Astrophysicist Nikolai Kardashev proposed in 1962 that very old and advanced civilizations would be of three types:
A Type I civilization harnesses all the resources of a planet. Carl Sagan estimated that Earth rates about 0.7 on the scale.
A Type II civilization harnesses all the radiation of a star. Humans might reach Type II in a few thousand years.
A Type III civilization harnesses all the resources of a galaxy. Humans might reach Type III in a few hundred thousand to a million years.
A solid shell around a star would be gravitationally unstable, and would probably require more material than all of the planets of a solar system could provide. Instead, practical Dyson spheres would be made from millions of individual solar-collecting satellites.
Solar sails could remain in place by balancing against the pressure of light from the sun. The satellite would not be in orbit, it would actually hover in space. Such a satellite is called a "statite." Rings of statites would form a cloud around the star, collecting its energy and beaming it back to the home planet.

Dyson spheres and other mega-structures appear frequently in science fiction. In his 1970 novel "Ringworld," Larry Niven features a ring-shaped artificial structure girdling an alien star. In the 1992 “Star Trek: The Next Generation” episode "Relics," the starship Enterprise encounters a Dyson sphere in the form of a rigid shell surrounding a star.

Source: LS

A History of Curious Artifacts Sent Into Space.

Since the dawn of the Space Age in 1957, thousands of artifacts and memorabilia have been flown into space. Some have been hoisted on brief suborbital flights, while others have been flung out of the solar system, never to return. And of course, it’s become a fashionable — and highly commercialized — trend as of late to briefly loft products, stuffed animals, etc via balloon towards the tenuous boundary of space. Fly a souvenir or artifact into orbit, and it goes from mundane to priceless. But a few may also serve as a final testament to the our ephemeral existence as a species long after our passing.
Here’s a look at some of the most memorable objects sent into space:

The Florida State Quarter dispatched with New Horizons. Image Credit: NASA/Bill Rodgers, JHU/APL.

New Horizons Memorabilia
Launched on January 19th, 2006, New Horizons is headed towards a historic encounter with Pluto and its moons next year. From there, New Horizons will survey any Kuiper Belt objects of opportunity along its path and then head out of the solar system, becoming the fifth spacecraft to do so. In addition to a suite of scientific instruments, New Horizons also carries the ashes of Pluto discoverer Clyde Tombaugh, a Florida & Maryland state quarter, a piece of Scaled Composites SpaceShipOne, and an American flag. These will doubtless confuse any extraterrestrial salvagers!

The Humanoids Where Here: the plaque affixed the the Pioneer 10 & 11 spacecraft. Credit: NASA/JPL.

The Pioneer Plaques
The first spacecraft sent on escape trajectories out of our solar system, the Pioneer 10 and 11 spacecraft each carry a plaque which serves as a sort of postcard “greeting” to any future interceptors. The plaque depicts a diagram of the solar system, a map of our location in the galaxy using the positions of known pulsars, and a nude man & woman, which actually generated lots of controversy.  Scientist James Van Allen tells of deliberately placing a fingerprint on the Pioneer 10 plaque in his biography The First Eight Billion Miles.

Earth’s Greatest Hits: the Golden Record attached to the Voyager 1 and 2 spacecraft. Credit: NASA/JPL.

The Voyager 1 and 2 Golden Records
Conceived and designed in part by Carl Sagan, these records contain images and sounds of the Earth that’ll most likely outlive humanity. The records carry greetings in 55 languages, music ranging from Mozart to Chuck Berry, 116 images and more, along with instructions and a stylus for playback.  The record is also enclosed in an aluminum cover electroplated with Uranium-238, which an alien civilization could use to date its manufacture via half-life decay.

A closeup of the “Mars Penny.” Credit: NASA/JPL-Caltech.

The Mars Curiosity Penny
Strange but true: The Mars rover Curiosity carries a 1909 U.S. Penny for a backup camera calibration target.  The penny itself is embedded just below the primary color calibration targets used by Curiosity’s MArs Hand Lens Imager (MAHLI). Rare enough on Earth, the 1909 Lincoln “Mars penny” will be priceless to future collectors!

Jupiter-bound figurines from left: Jupiter, Juno, & Galileo. Credit: NASA.

Juno’s LEGO Figurines
Mini-figurines of Galileo and the Roman deities Jupiter and Juno were launched in 2011 aboard NASA’s Juno spacecraft en route to Jupiter . LEGO has flown products aboard the U.S. Space Shuttles and to the International Space Station previously, but Juno’s cargo represents the “most distant LEGO launch” ever. The figurines will burn up in Jupiter’s atmosphere along with the spacecraft at the end of the mission in October 2017.

An Apollo 15 postal cover flown to the Moon. Credit: NASA.

Apollo 15 Postal Covers Fiasco
Apollo 15 astronauts got in some hot water over a publicity scheme. The idea that stamp collector and dealer Hermann Sieger approached the astronauts with was simple: 400 commemorative postage stamp covers would be postmarked at point of departure from the Kennedy Space Center and again at the return point of arrival aboard the USS Okinawa after their circuitous journey via the Moon. NASA was less than happy with the whole affair, and Command Module Pilot Al Worden recounts the aftermath in his book, Falling to Earth.

A Marsbound DVD… Courtesy of Lockheed Martin/LSP.

Last year’s MAVEN mission to Mars also carried haiku submitted by space fans.  Over 12,530 valid entries were submitted and over 1,100 haiku received the necessary minimum of two votes to be included on a DVD disk affixed to the spacecraft. MAVEN reaches orbit around Mars in October 2014.

The copy of the Soviet pennant aboard Luna 2 on display at the Kansas Cosmoshpere. Credit: Patrick Pelletier under a Wikimedia Creative Commons Attribution-Share Alike 3.0 Unported license.

Luna 2: A Russian Pennant on Moon
On September 12^th, 1959, the Soviet Union’s Luna 2 spacecraft became the first man-made object to impact the Moon. Luna 2 carried two spherical “pennants” composed of pentagon-shaped elements engraved with the USSR Coat of Arms and Cyrillic letters translating into “CCCP/USSR September 1959.” An identical pennant is now on display in the Kansas Cosmosphere.

EchoStar XVI in its clean room. Credit: Space Systems Loral.

A GeoSat Time Capsule Aboard EchoStar XVI
A disk entitled Last Pictures similar to the Voyager records was placed on a satellite headed to geosynchronous orbit in 2012. Launched aboard EchoStar XVI, Last Pictures is an ultra-archival disk containing 100 snapshots of modern life along with interviews with several 21^st century artists and scientists.  Geosynchronous satellites aren’t subject to atmospheric drag,  and may be the last testament to the existence of humanity on Earth millions of years hence.

An artist’s conception of NASA’s Lunar Prospector mission leaving Earth orbit. Credit: NASA.

Lunar Prospector Carries An Astro-Geologist’s Ashes to the Moon
Though he never made the selection to become an astronaut, scientist Eugene Shoemaker did make a posthumous trip to the Moon.  The Lunar Prospector spacecraft departed Earth with Shoemaker’s ashes on January 7th, 1998 in a capsule wrapped in brass foil. Lunar Prospector impacted the south pole of the Moon on July 31^st, 1999.

The SpaceX Dragon capsule on approach to the ISS during the COTS 2 mission. Credit: NASA.

SpaceX Takes Star Trek Actor to Space
The ashes actor James Doohan (AKA Scotty) were launched aboard a 2012 SpaceX flight to the International Space Station. The COTS Demo Flight, or COTS 2, was the first commercial spacecraft to berth at the ISS. SpaceX had flown a small amount of Doohan’s ashes on the 2008 unsuccessful test launch of the Falcon 1 rocket.

The “Top Secret Payload” of the Dragon capsule revealed. Credit: Chris Thompson/SpaceX.

Cheese Wheel Makes a Suborbital Journey
All eyes were also on SpaceX during their December 8^th 2010 maiden flight of the Dragon space capsule. And the hinted mystery cargo? None other than a wheel of cheese, a nod by SpaceX CEO Elon Musk to a classic Monty Python sketch.
The Apollo 12 “Moon Museum”
Did it really go into space? One of the legends surrounding the Apollo program is the existence of what’s been dubbed the “Moon Museum.”  This was a postage stamp-sized “gallery” of art which included a sketch by Andy Warhol and other 1960s artists that was supposedly attached to descent stage of Apollo 12 and left on the Moon.  It will be up to future lunar visitors to confirm or deny its existence!
…And lastly, I give you the “Space Hubcap”
Was the first man-made object propelled into space actually a 1 ton armor plate? On August 27^th, 1957 — just two months prior to Sputnik 1 — the Pascal-B underground nuclear test was conducted in southern Nevada.  During the explosion, a steel plate cap was blasted off of a test shaft. The plate could be seen in the initial high-speed video frames, and it was estimated to have reached a speed six times the sufficient escape velocity to depart Earth. To this day, no one knows if this strange artifact of early Space Age folklore still roams the void of space, or simply vaporized due to atmospheric compression at “launch”.

Read more: http://www.universetoday.com/109026/a-history-of-curious-artifacts-sent-into-space/#ixzz2t2erE83T