There may be a volcanic vent on the central peak of Tycho crater, according to an Indian research team. (Image: NASA Goddard/Arizona State University)
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A team of researchers at India’s Physical Research Laboratory (PRL) claims it has found evidence of relatively recent volcanic activity on the Moon, using data from NASA’s Lunar Reconnaissance Orbiter and the Chadrayaan-1 spacecraft. According to the findings the central peak of Tycho crater contains features that are volcanic in origin, indicating that the Moon was geologically active during the crater’s formation 110 million years ago.
In an article by the Deccan Herald, a Bangalore-based publication, the PRL researchers claim that vents, lava channels and solidified flows of inner crustal material found within Tycho were made as recently as 100 million years ago — after the creation of the crater.
This could indicate that there was pre-existing volcanic activity within the Moon at the site of the Tycho impact, lending credence to the idea that the Moon was recently geologically active.
In addition, large boulders ranging in size from 33 meters to hundreds of yards across have been spotted on Tycho’s central peaks by LRO, including one 400-foot (120-meter) -wide specimen nestled atop the highest summit. How did such large boulders get there and what are they made of?
A 400-foot-wide boulder within the central peak of Tycho. (NASA/GSFC/LROC)
The researchers hint that they may also be volcanic in origin.
“A surprise findings revealed the presence of large boulders–about 100 meter in size –on top of the peak. Nobody knew how did they reach the top,” said Prakash Chauhan, a PRL scientist.
Without further studies it’s difficult to determine the exact origin and ages of these lunar formations. The team awaits future research by Chandrayaan-II, which will examine the Moon from orbit as well as land a rover onto the lunar surface. Chandrayaan-II is expected to launch in early 2014.
The PRL team’s findings were published in the April 10 issue of Current Science.
Saturn on April 3, 2012 with the moons Dione (Top-Left) and Tethys (Bot.-Right) as the ringed planet approaches opposition.Credit: Efrain Morales.
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Now is the time to take a look at the planet Saturn, as the ringed planet will be at opposition this weekend, making its closest approach to Earth on April 15, 2012. Its face will be fully illuminated by the Sun, so get out those telescopes, binoculars and your imaging equipment! We want to see your photos! Efrain Morales from the Jaicoa Observatory took this image of Saturn and some of its moons on April 3.
The giant planet’s rings are now optimally angled at over 13 degrees, revealing them better than they have appeared in the past five years. To see the rings of Saturn during opposition, in the northern hemisphere point your telescopes east to southeast at nightfall and south around midnight. For reference, Saturn will be near the bright star Spica, in the constellation Virgo. In the southern hemisphere, Saturn will be above the eastern horizon at 10pm local time, still near Spica.
If the skies aren’t clear in your area, the Slooh Space Observatory will broadcast a free, real-time feed of Saturn at opposition. Their coverage will begin on Sunday, April 15th, starting at 6:30 p.m. PDT/9:30 p.m. EDT/01:30 UTC (April 16th). Slooh will provide two distinct observatory feeds — one from a remote location in South Africa and the second from their world-class observatory site in Canary Islands off the coast of Africa. The broadcast can be accessed at Slooh’s homepage or by visiting Slooh’s Google+ page, where you will be able to see a panel of experts interact live via G+ Hangouts On Air.
The experts include Duncan Copp, producer of many astronomical documentaries, including “In the Shadow of the Moon”; Amanda Hendrix, Cassini’s deputy project scientist from NASA’s Jet Propulsion Laboratory; and Bob Berman, author of numerous astronomy books and contributing editor and monthly columnist for Astronomy Magazine.
“In 40 years of observing the heavens and watching people’s reactions to celestial glories, I’ve found that no object elicits more amazement and sheer wonder than Saturn. I am thrilled to be part of Slooh’s live close-up visit to that magnificent planet,” said Bob Berman.
Send us your images of Saturn by joining our Flickr group, or send us your images by email (this means you’re giving us permission to post them). Please explain when and where you took it, the equipment you used, etc.
I for one welcome our alien dinosaur overlords…maybe.
Dinosaurs once roamed and ruled the Earth. Is it possible that similar humongous creatures may have evolved on another planet – a world that DIDN’T get smacked by an asteroid – and later they developed to have human-like, intelligent brains? A recent paper discussing why the biochemical signature of life on Earth is so consistent in orientation somehow segued into the possibility that advanced versions of T. Rex and other dinosaurs may be the life forms that live on other worlds. The conclusion? “We would be better off not meeting them,” said scientist Ronald Breslow, author of the paper.
The building blocks of terrestrial amino acids, sugars, and the genetic materials DNA and RNA have two possible orientations, left or right, which mirror each other in what is called chirality. On Earth, with the exception of a few bacteria, amino acids have the left-handed orientation. Most sugars have a right-handed orientation. How did that homochirality happen?
If meteorites carried specific types of amino acids to Earth about 4 billion years, that could have set the pattern the left-handed chirality in terrestial proteins.
“Of course,” Breslow said in a press release, “showing that it could have happened this way is not the same as showing that it did. An implication from this work is that elsewhere in the universe there could be life forms based on D-amino acids and L-sugars. Such life forms could well be advanced versions of dinosaurs, if mammals did not have the good fortune to have the dinosaurs wiped out by an asteroidal collision, as on Earth.”
But not everyone was impressed with the notion of dinosaurs from space. “None of this has anything to do with dinosaurs,” wrote science author Brian Switek in the Smithsonian blog Dinosaur Tracking. “As much as I’m charmed by the idea of alien dinosaurs, Breslow’s conjecture makes my brain ache. Our planet’s fossil record has intricately detailed the fact that evolution is not a linear march of progress from one predestined waypoint to another. Dinosaurs were never destined to be. The history of life on earth has been greatly influenced by chance and contingency, and dinosaurs are a perfect example of this fact.”
Until relatively recently, Mercury was one of the most poorly understood planets in the inner solar system. The MESSENGER mission to Mercury, is changing all of the that. New results from the Mercury Laser Altimeter (MLA) and gravity measurements are showing us that the planet closest to our sun is thin skinned and wrinkled, which is very different from what we originally thought.
The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft was launched back in 2004. It took a long time getting to its destination, completing 3 flybys of Mercury before finally entering orbit a little over a year ago. Currently, the spacecraft is in a highly eccentric polar orbit, approaching the planet much closer in the north than in the south. This allows the northern hemisphere to be probed and imaged at enviably high resolutions, but leaves the southern hemisphere poorly understood.
Even so, the data returned from MESSENGER is showing us some quite unanticipated findings. Two papers from the MESSENGER team, published in today’s issue of Science, are showing some surprising results from the laser altimeter and gravity experiments.
Using NASA’s Deep Space Network, Earth-based radio tracking of MESSENGER has allowed minute changes in the spacecraft’s orbit to be monitored and recorded. From this, Dr. Maria Zuber of MIT and her team calculated a model of Mercury’s gravity. Meanwhile, the on-board laser altimeter has provided invaluable topographic information. Combined together, these data have allowed the MESSENGER team to glean a great deal of information about the planet’s interior workings.
One of the most striking findings is that the iron-rich core of Mercury is very large. A combination of measurements and models suggest that the core has both a solid interior portion and a liquid outer portion. And while it is not certain how much of the core is solid and how much is liquid, it is clear that the total core has a radius of about 2030 km. This is a huge core, representing 83% of Mercury’s 2440 km radius!
The internal structure of Mercury is very different from that of the Earth. The core is a much larger part of the whole planet in Mercury and it also has a solid iron-sulfur cover. As a result, the mantle and crust on Mercury are much thinner than on the Earth. Credit: Case Western Reserve University
Furthermore, these calculations suggest that the layer above the core is much denser than previously expected. Results from MESSENGER’s X-Ray spectrometer indicate that the crust, and by extension the mantle, are too low in iron to explain this high density. Dr. Zuber’s team think that the only way to explain this discrepancy is by the presence of a solid iron-sulfur layer just above the core. Such a layer could be anywhere from 20 to 200 km thick, leaving only a very thin crust and mantle at the top. This kind of interior structure is completely different from what was originally suggested for Mercury, and it is nothing like what we have seen in the other planets!
This striking fact may help explain some unexpected altimeter results, which show that Mercury’s topography has less variation than other planets. The total difference between the highest and lowest elevations on Mercury is only 9.85 km. Meanwhile, the Moon has a total difference of 19.9 km between its highest and lowest points, and on Mars this difference is 30 km. Dr. Zuber and her team speculate that the presence of the core so close to the surface could keep the mantle hot, allowing topographic features to relax. In such a scenario, the lithosphere under tall impact-formed mountains would sink down into a mushy mantle that cannot support their weight. Conversely, the thin lithosphere under impact basins would rebound upwards, taking part of the mobile mantle with it.
In fact, the gravity data shows evidence of exactly this kind of process, in the form of “mascons”. These mass concentrations form when large imacts make the local crust very thin, allowing denser mantle material to rise closer to the surface as the lithosphere rebounds from the impact event. Mascons are well known from studies on the Moon and Mars, and now MESSENGER’s gravity data has revealed three such mascons on Mercury, located in the Caloris, Sobkou, and Budh basins.
The elliptical polar orbit of the MESSENGER spacecraft means that measurements at the North Pole of Mercury are much better than those at the South Pole, or even at the equator. This is evident in the better spatial resolution that can be seen at the high latitudes in this elevation map of the northern hemisphere. Major impact structures are identified by black circles. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Interestingly enough, the mascons in Sobkou and Budh basins are not immediately obvious. They only show up when the effects of a regional topographic high are adjusted for. This topographic feature is a large quasi-linear rise that extends over half the circumference of Mercury in the mid-latitudes. The rise even passes through the northern part Caloris basin (which is large enough that its mascon is not overwhelmed by the rise). Studies of this rise by the MESSENGER team suggest that it is relatively young, having formed well after the formation of the basins, after the volcanic flooding of their interiors and exteriors, and even after some of the later impact craters that cover the flooded surfaces.
Dr. Zuber and her team also identified another young topographically elevated region, the Northern Rise, located in the lowlands surrounding the North Pole. They speculate that these young rises represent a buckling of the lithosphere, which happened when the planet’s interior cooled and contracted. This interpretation is supported by the presence of lobate scarps and ridges that can be seen around the planet, and which represent faulting of the crust when it was compressed.
So, it seems that Mercury is unlike the other planets of the Solar System. It appears to have a disproportionately large core that is covered by a thin skin of mantle and lithosphere. Furthermore, this skin seems to have wrinkled like a raisin’s when the huge core of the planet shrunk as it cooled.
Sources
Gravity Field and Internal Structure of Mercury from MESSENGER, Smith et al., Science V336 (6078), 214-217, April 13 2012, DOI:10.1126/science.1218809
Topography of the Northern Hemisphere of Mercury from MESSENGER Laser Altimetry, Zuber et al., Science V336 (6078), 217-220, April 13 2012, DOI:10.1126/science.1218805
Bright spots of Uranus' short-lived auroras have been imaged with the Hubble Space Telescope.
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Astronomers have finally succeeded in capturing the first Earth-based images of the curious and fleeting auroras of Uranus using the Hubble Space Telescope, careful planning… and no small amount of luck.
Unlike Earthly auroras, whose long-lived curtains of glowing green, red and purple have been the subject of countless stunning photos over the past months, Uranus’ auroras are relatively dim and short-lived, lasting only several minutes at most. They were first witnessed on Uranus by Voyager 2 in 1986, but never by any Earth-based telescopes until November of 2011. Using Hubble, an international team of astronomers led by Laurent Lamy from the Observatoire de Paris in Meudon, France spotted two instances of auroras on the distant planet… once on November 16 and again on the 29th.
Two instances of Uranian aurora imaged in Nov. 2011. (L. Lamy)
Auroras are known to be created by a planet’s magnetosphere, which on Earth is aligned closely with the rotational axis — which is why auroras are seen nearest the polar latitudes. But Uranus’ magnetic field is quite offset from its rotational axis, which in turn is tipped nearly 98 degrees relative to its orbital path. In other words, Uranus travels around the Sun rolling on its side! And with a 60-degree difference between its magnetic and rotational axis, nothing on Uranus seems to point quite where it should. This — along with its 2.5-billion-mile (4 billion km) distance — makes for a “very poorly known” magnetic field.
“This planet was only investigated in detail once, during the Voyager flyby, dating from 1986. Since then, we’ve had no opportunities to get new observations of this very unusual magnetosphere,” said Laurent Lamy, lead author of the team’s paper Earth-based detection of Uranus’ aurorae.
Rather than rings of bright emissions, as witnessed on Earth as well as Saturn and Jupiter, the Uranian auroras appeared as bright spots of activity on the planet’s daytime side — most likely a result of Uranus’ peculiar orientation, as well as its seasonal alignment.
It’s not yet known what may be happening on Uranus’ night side, which is out of view of Hubble.
When Voyager 2 passed by Uranus in 1986 the planet was tipped such that its rotational axis was aimed toward the Sun. This meant that its magnetic axis — offset by 60 degrees — was angled enough to encounter the solar wind in much the same way that Earth’s does. This created nightside auroras similar to Earth’s that Voyager saw.
By 2011, however, Uranus — which has an 84-year-long orbit — was near equinox and as a result its magnetic axis was nearly perpendicular with its orbital plane, aiming each end directly into the solar wind once a day. This makes for very different kinds of auroras than what was seen by Voyager; in fact, there’s really nothing else like it that astronomers know of.
“This configuration is unique in the solar system,” said Lamy.
Further investigations of Uranus’ auroras and magnetic field can offer insight into the dynamics of Earth’s own magnetosphere and how it interacts with the solar wind, which in turn affects our increasingly technological society.
The team’s paper will be published Saturday in Geophysical Research Letters, a journal of the American Geophysical Union.
Astronaut Don Pettit is not only a scientist and on-orbit fix-it guy extraordinaire, but he is also a poet. Who knew? Since April is National Poetry Month, Pettit has written a couple of poems while on his tour of duty on the International Space Station. “By venturing into unknown territory, discoveries will be made that tickle our imagination and enrich our minds,” he says. “On the frontier, you can once again see the world through the eyes of a child.”
Read two of his recent poems, below:
I Wonder Why
I wonder why the sky is up, and why the stars abound?
And why the Sun comes up each morn, and why the Earth goes ’round?
I wonder what the Sun on Mars, would bring at dusk and dawn?
I wonder what two moons would say, from Earth lit sky when Sun is gone
I wonder if Mars mountain crags would be a sight to hold?
I wonder if I’d dare to climb, how could I be so bold!
I wonder when Man’s mind will grow, and cease to be so small
I wonder when we’ll venture forth, I hope before we fall
I wonder if we’ll never dare, to reach up through the sky
Forever doomed to live on Earth, and this, I wonder why?
Space is My Mistress
Space is my Mistress,
and she beckons my return.
Since our departure I think of you
and yearn to fly across the heavens arm in arm.
I marvel at your figure,
defined by the edges of continents.
You gaze at me with turquoise eyes,
perhaps mistaken for ocean atolls.
You tease me to fall into your bosom,
sculptured by tectonic rifts,
only to move away as if playing some tantalizing game.
Time and time we turn together,
through day, and night, and day,
repeating encounters every 90 minutes with a freshness,
as if we have never seen our faces before.
We stroll outside together,
enveloped by naked cosmos,
filled with desire to be one.
So close,
you sense my every breath,
which masks your stare through visor haze.
We dance on the swirls of cloud tops,
while skirting the islands of blue.
You know my heart beats fast for you.
Oh, Space is my mistress,
and when our orbits coincide,
we will once again make streaks of aurora across the sky.
North Korean Unha-3 three stage rocket erected at seaside launch pad days ago. Roxket was launched on April 12 and failed shortly after liftoff
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North Korea has just gone ahead with their announced intentions to defy international warnings and launched the highly controversial Unha-3 long range missile a short while ago at 7:39 AM local time on Friday the 13th (2239 GMT, 6:39 PM EDT Thursday), as reported by CNN, NBC, Fox and other news media on live TV broadcasts at 7 PM EDT, Thursday evening. [Story Updated]
The 3 stage rocket apparently failed in flight quickly and broke apart within the first 90 seconds to 2 minutes and never reached orbit, according to US, Japanese and South Korean officials who have been closely monitoring the developing situation the past few weeks.
Missile tests by North Korea are banned by UN Security Council resolutions.
The White House is expected to issue a statement shortly. Read the official NORAD statement below.
North Korean had invited news media from around the world to view the rocket up close at the launch pad a few days ago, an unprecedented action of openness. But the actual launch and exact timing was not announced ahead of time.
The international reporters who had gathered for the event were caught off guard, in the North Korean capital of Pyongyang, many hundreds of miles distant from the launch site.
The failure is a huge embarrassment to the prestige of the North Korea’s new leader, 28 year old Kim Jong Un, who was promoted to the leadership upon the recent death of his father Kim Jong Il.
Japanese Defense Ministry officials are quoted by NBC and CNN as saying the rocket fell into the ocean after flying about 75 miles. The cause of the rocket failure is not known at this time.
Animation of the planned Unha-3 rocket launch. Credit: Analytical Graphics, Inc. (AGI)
North Korea’s neighbors and the West had strongly condemned North Korean’s launch plans saying this launch was really a disguised test of a military ballistic missile that could be easily converted for military purposes and strike as far as the US West Coast with a nuclear warhead.
North Korean said they were merely launching a small and peaceful experimental weather satellite which they displayed to the media days ago. The timing coincides with the anniversary of the 100th birthday of Kim Il Sung, deceased founding father and former leader of North Korea
The Unha-3 rocket blasted off from the Tongchang-ri, rocket base on North Korea’s west coast near the Chinese border on a southerly course. The trajectory was aimed to skirt along the coasts of South Korea and Japan, causing those countries great concern if the rocket were to develop problems in flight and veer off course and crash on land, potentially causing damage or loss of life in a worst case scenario.
The 90 ton Unha-3 rocket is about 100 feet (30 m) tall.
The UN Security council has scheduled an emergency meeting on Friday in New York to deal with the situation.
There has been no official announcement from the North Korean Government as of this writing.
Further details will be added here as this breaking news story unfolds
—–
NORAD released the following statement this evening April 12, 2012
“North American Aerospace Defense Command (NORAD) and U.S. Northern Command officials acknowledged today that U.S. systems detected and tracked a launch of the North Korean Taepo Dong-2 missile at 6:39 p.m. EDT. The missile was tracked on a southerly launch over the Yellow Sea.”
“Initial indications are that the first stage of the missile fell into the sea 165 km west of Seoul, South Korea. The remaining stages were assessed to have failed and no debris fell on land. At no time were the missile or the resultant debris a threat.”
Although somewhat blobby and deformed, this is in fact a spiral galaxy, located in the southern constellation Hydra. Imaged by Hubble as part of a survey of galactic bulges, NGC 4980 exhibits what’s called a “pseudobulge” — an inline central concentration of stars whose similar spiral motion extends right down into its core.
As opposed to classical bulges, in which stars orbit their galaxy’s core in all directions, pseudobulges are made up of stars that continue along the spiral motion of the galactic arms all the way into the center. Pseudobulges are typically seen to contain stars that are the same age as most of the others in the galaxy.
In contrast, classical bulges usually contain stars older than those found in the disk, leading astrophysicists to believe that galaxies with classical bulges had undergone one or more collisions with other galaxies during their evolution.
Our own Milky Way is thought to have a pseudobulge, while some spiral galaxies have no discernible bulge at all.
This image is composed of exposures taken in visible and infrared light by Hubble’s Advanced Camera for Surveys. The image is approximately 3.3 by 1.5 arcminutes in size. NGC 4980 is located about 80 million light-years from Earth.
All asteroids and comets visited by spacecraft as of November 2010 Credits: Montage by Emily Lakdawalla. Ida, Dactyl, Braille, Annefrank, Gaspra, Borrelly: NASA / JPL / Ted Stryk. Steins: ESA / OSIRIS team. Eros: NASA / JHUAPL. Itokawa: ISAS / JAXA / Emily Lakdawalla. Mathilde: NASA / JHUAPL / Ted Stryk. Lutetia: ESA / OSIRIS team / Emily Lakdawalla. Halley: Russian Academy of Sciences / Ted Stryk. Tempel 1, Hartley 2: NASA / JPL / UMD. Wild 2: NASA / JPL.
In today’s Weekly Space Hangout, Emily Lakdawalla from the Planetary Society mentioned an animation of recently released images from the Rosetta mission’s flyby of asteroid Lutetia. It was put together and processed by Ian Regan, and Emily suggested you play this on a hand-held device (like a smart phone) in a dark room and move it around like you yourself are maneuvering the flyby! Try it — it is a very cool effect!
And while you’re at it, you also need to check out Emily’s montage poster of asteroids and comets, below:
his image taken by NASA's Wide-field Infrared Survey Explorer (WISE) shows a blazar -- a voracious supermassive black hole inside a galaxy with a jet that happens to be pointed right toward Earth. These objects are rare and hard to find, but astronomers have discovered that they can use the WISE all-sky infrared images to uncover new ones. Image credit: NASA/JPL-Caltech/Kavli
Astronomers are actively hunting a class of supermassive black holes throughout the universe called blazars thanks to data collected by NASA’s Wide-field Infrared Survey Explorer (WISE). The mission has revealed more than 200 blazars and has the potential to find thousands more.
Blazars are among the most energetic objects in the universe. They consist of supermassive black holes actively “feeding,” or pulling matter onto them, at the cores of giant galaxies. As the matter is dragged toward the supermassive hole, some of the energy is released in the form of jets traveling at nearly the speed of light. Blazars are unique because their jets are pointed directly at us.
“Blazars are extremely rare because it’s not too often that a supermassive black hole’s jet happens to point towards Earth,” said Francesco Massaro of the Kavli Institute for Particle Astrophysics and Cosmology near Palo Alto, Calif., and principal investigator of the research, published in a series of papers in the Astrophysical Journal. “We came up with a crazy idea to use WISE’s infrared observations, which are typically associated with lower-energy phenomena, to spot high-energy blazars, and it worked better than we hoped.”
The findings ultimately will help researchers understand the extreme physics behind super-fast jets and the evolution of supermassive black holes in the early universe.
WISE surveyed the entire celestial sky in infrared light in 2010, creating a catalog of hundreds of millions of objects of all types. Its first batch of data was released to the larger astronomy community in April 2011 and the full-sky data were released last month.
This artist's concept shows a "feeding," or active, supermassive black hole with a jet streaming outward at nearly the speed of light. Such active black holes are often found at the hearts of elliptical galaxies. Not all black holes have jets, but when they do, the jets can be pointed in any direction. If a jet happens to shine at Earth, the object is called a blazar. Image credit: NASA/JPL-Caltech
Massaro and his team used the first batch of data, covering more than one-half the sky, to test their idea that WISE could identify blazars. Astronomers often use infrared data to look for the weak heat signatures of cooler objects. Blazars are not cool; they are scorching hot and glow with the highest-energy type of light, called gamma rays. However, they also give off a specific infrared signature when particles in their jets are accelerated to almost the speed of light.
One of the reasons the team wants to find new blazars is to help identify mysterious spots in the sky sizzling with high-energy gamma rays, many of which are suspected to be blazars. NASA’s Fermi mission has identified hundreds of these spots, but other telescopes are needed to narrow in on the source of the gamma rays.
Sifting through the early WISE catalog, the astronomers looked for the infrared signatures of blazars at the locations of more than 300 gamma-ray sources that remain mysterious. The researchers were able to show that a little more than half of the sources are most likely blazars.
“This is a significant step toward unveiling the mystery of the many bright gamma-ray sources that are still of unknown origin,” said Raffaele D’Abrusco, a co-author of the papers from Harvard Smithsonian Center for Astrophysics in Cambridge, Mass. “WISE’s infrared vision is actually helping us understand what’s happening in the gamma-ray sky.”
The team also used WISE images to identify more than 50 additional blazar candidates and observed more than 1,000 previously discovered blazars. According to Massaro, the new technique, when applied directly to WISE’s full-sky catalog, has the potential to uncover thousands more.
“We had no idea when we were building WISE that it would turn out to yield a blazar gold mine,” said Peter Eisenhardt, WISE project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., who is not associated with the new studies. “That’s the beauty of an all-sky survey. You can explore the nature of just about any phenomenon in the universe.”
