SpaceJibe

August 27, 2014

Photos from the first spacecraft to rendezvous with a comet

Filed under: Asteroids, Comets — bferrari @ 4:04 pm

On Wednesday, for the first time ever, a human spacecraft made a controlled rendezvous with acomet. This is what it saw as it approached:

For generations of people raised on sci-fi movies, the video might not look like a huge deal. But it’s pretty amazing to realize that this choppy little clip is an actual image of a real comet — the most detailed look we’ve ever had.

The spacecraft is the European Space Agency’s Rosetta probe, and the comet is 67P/Churyumov–Gerasimenko, a roughly 2.5 mile-wide chunk of rock, dust, and ice that’s currently 250 million miles away from Earth, about halfway between the orbits of Mars and Jupiter.

A close up, taken on August 6th. (ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)

A close up, taken on August 6th. (ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)

The probe was launched in 2004 specifically to study this comet, and is now within about 62 miles of it. Rosetta traveled nearly 4 billion miles to get there, looping around Earth and Mars several times in order to use their gravity to add momentum to its flight path. 

Two previous probes have briefly flown by comets, but neither came nearly as close as Rosetta. Additionally, in 2005, NASA’s Deep Impact Probe was intentionally crashed into a comet to analyze its interior.

Rosetta, though, will be the first mission to study a comet close-up for an extended period of time. The plan is for the probe to begin orbiting the comet within the next six weeks and accompany it for about a year, deploying a small landing craft in mid-November to analyze soil and rock samples.

A detail of the comet's surface, taken on August 6th. (ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)

A detail of the comet’s surface, taken on August 6th. (ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)

Scientists hope that measurements collected by Rosetta will help us learn more about the composition of comets in general. This sort of information could be quite relevant to understanding the formation of all planets, and even the development of life on Earth: comets formed during the earliest stages of the solar system, and some scientists believe that the water on Earth was originally delivered by comets and asteroids.

For an idea of how big this comet is, we bring you a nice image from the European Space Agency comparing it to some well-known buildings and mountains:

 (European Space Agency)

(European Space Agency)

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June 30, 2014

Ancient asteroid destroyer finally found, and it’s a new kind of meteorite

Filed under: Asteroids, Comets, Earth, Inner Solar System, Kuiper Belt, Oort Cloud — bferrari @ 8:56 am

Illustration of a meteor shower.argus/Shutterstock.com

For 50 years, scientists have wondered what annihilated the ancestor of L-chondrites, the roof-smashing, head-bonking meteorites that frequently pummel Earth.

Now, a new kind of meteorite discovered in a southern Sweden limestone quarry may finally solve the mystery, scientists report. The strange new rock may be the missing “other half” from one of the biggest interstellar collisions in a billion years.

“Something we didn’t really know about before was flying around and crashed into the L-chondrites,” said study co-author Gary Huss of the University of Hawaii at Manoa.

The space rock is a 470-million-year-old fossil meteorite first spotted three years ago by workers at Sweden’s Thorsberg quarry, where stonecutters have an expert eye for extraterrestrial objects. Quarriers have plucked 101 fossil meteorites from the pit’s ancient pink limestone in the last two decades. [Photos: New Kind of Meteorite Found in Sweden]

Researchers have nicknamed the new meteorite the “mysterious object” until its formal name is approved, said lead study author Birger Schmitz, of Lund University in Sweden and Chicago’s Field Museum. It will likely be named for a nearby church, the sterplana, he said.

Mysterious find

Geochemically, the meteorite falls into a class called the primitive achondrites, and most resembles a rare group of achondrites called the winonaites. But small differences in certain elements in its chromite grains set the mysterious object apart from the winonaites, and its texture and exposure age distinguish the new meteorite from the other 49,000 or so meteorites found so far on Earth.

“It’s a very, very strange and unusual find,” Schmitz told Live Science’s Our Amazing Planet.

The new meteorite was recently reported online in the journal Earth and Planetary Science Letters, and the study will appear in the journal’s Aug. 15 print edition.

Until now, all of the quarry’s fossil meteorites were L-chondrites. Schmitz, who has led the chondrite cataloging, admitted the rock hunt had become “quite boring.”

But the rare find has not only revitalized interest in the quarry, it has also brought together the world’s top meteorite experts for a global hunt through geologic time. Thanks to Schmitz’s careful detective work on meteorites, scientists now know that each kind of meteorite leaves behind a unique calling card: tough minerals called spinels. Even if meteorites weather away, their spinels linger for hundreds of million of years in Earth rocks. Schmitz and his cohorts think they can pin down how many meteorites rained down on Earth in the past 2.5 billion years, as well as what kind fell, by extracting extraterrestrial spinels from sedimentary rocks. Their work may confirm suspicions that recent meteorite falls represent a mere fraction of the rocks drifting in space.

“I think our new finding adds to the understanding that the meteorites that come down on Earth today may not be entirely representative of what is out there,” Schmitz said. “One thing our study shows is that we maybe don’t know as much as we think we know about the solar system.”

Ancient wreckage

The limestone quarry preserves the remnants of a cosmic cataclysm that took place 470 million years ago, during the Ordovician Period. Scientists think there was an enormous crash between two large bodies out in the asteroid belt. The crash blew apart two asteroids, or an asteroid and comet, slinging dust and debris toward Earth. One of the impactors was the source of all L-chondrite meteorites. But no one has ever found a piece of the rock that hit the L-chondrite parent, until now.

The Swedish meteorite’s exposure age the length of time it sailed through space is the key to placing the fossil space rock at the scene of the crash. The meteorite zipped from the asteroid belt to Earth in just 1 million years. That’s the same remarkably young exposure age as the L-chondrites recovered from the Thorsberg quarry, suggesting the rocks sprayed Earth in the same wave of space debris. [Infographic: Asteroid Belt Explained]

Meteorite expert Tim Swindle, who was not involved in the study, praised the team’s careful analysis and said it was unlikely that any other meteorite but an Ordovician fragment would have such a short exposure age. “Very, very few modern meteorites have exposure ages that low,” said Swindle, a professor at the University of Arizona in Tucson. “Typically, it takes things longer to get here from the asteroid belt,” he said. “It’s a telling argument.”

But because so little is left of the original meteorite almost all its minerals have been altered to clay Swindle thinks there’s wiggle room for linking it to known classes of meteorite, instead of calling it a new find.

“I think it’s entirely plausible [that it’s a new kind of meteorite], and it’s a great study, but that’s not a guarantee they’ve got it right,” Swindle said. “But if they didn’t, it’s because of new things we’ll find out in future work, not because of their analysis.”

The geochemical tests were performed on sand-sized chromite spinels, which confirmed the rock’s extraterrestrial origin. The altered clay is also about 100,000 times richer in iridium than terrestrial rocks. Iridium is the element that marks the meteorite impact horizon when the dinosaurs went extinct.

Hunt for space history

Schmitz now plans to search for these strange achondrite spinels in the quarry sediments, as well as in other rocks of the same age around the world. Ordovician meteorite spinels from L-chondrites have been found in China, Russia and Sweden, and small micrometeorites have been discovered in Scotland and South America. Researchers think about 100 times as many meteorites fell on Earth during the Ordovician compared with today, but only about a dozen impact craters of the proper age have been identified. [Crash! 10 Biggest Impact Craters on Earth]

A bigger quest is also in the works. Schmitz and his colleagues plan to dissolve tons of rock in acid in a global search for meteoritic spinel grains. This detective work will help researchers pin down the history of the asteroid belt and solar system. Spinels can provide an estimate of how many meteorites fell in the past, and what kind hit Earth. These tiny pieces of vanished meteorites may fill in missing history, because meteorite impact craters often vanish due to geologic forces.

“This can give you a ground truth for models for how the solar system may have evolved over time,” said Gary Huss, a co-author on the Swedish meteorite study who will collaborate on the spinel search. “I think a lot of people have worried for some time that we don’t really know what’s going on in the asteroid belt.”

Source

June 23, 2014

NASA moving ahead with asteroid-capture plan, wants to grab one in 2019

Filed under: Asteroids, Cool, Gadgets, Inner Solar System, Moons, Space Ships, Wierd — bferrari @ 1:50 pm
This undated handout two-picture combo of artist conceptions provided by NASA/JPL Caltech shows what NASA says are good candidates for a mission to capture an asteroid, haul it to the moon for astronauts to visit.(AP Photo/NASA/JPL Caltech)

This undated handout two-picture combo of artist conceptions provided by NASA/JPL Caltech shows what NASA says are good candidates for a mission to capture an asteroid, haul it to the moon for astronauts to visit.(AP Photo/NASA/JPL Caltech)

When NASA said last year it was planning to capture an asteroid, park it close to the moon and later send astronauts to explore it, many people had to check the calendar to confirm the space agency wasn’t simply demonstrating it had a sense of humor.

Well, make no mistake, NASA’s Asteroid Redirect Mission (ARM) is certainly real, and the agency recently offered a progress report on its ambitious plan, which essentially involves grabbing a space rock using a robotic spacecraft before putting it in a stable orbit around the moon.

The process of getting hold of the asteroid has been likened to popping it into a bag with a drawstring

“You bag it,” NASA’s Donald Yeomans said. “You attach the solar propulsion module to de-spin it and bring it back to where you want it.”

The space agency is currently in the middle of deciding which of two missions to go with – the first idea is to “fully capture” a small asteroid in open space, while the second is to collect a “boulder-sized sample” from a much bigger asteroid.

2019

The mission, whichever it decides to go for, is on schedule to take place just five years from now, in 2019, with NASA planning to make its final decision on which asteroid to capture a year earlier.

In the meantime, concept studies are set to take place over a six-month period, beginning this July, in which the agency will work on refining key concepts and technologies for its grand mission.

“With these system concept studies, we are taking the next steps to develop capabilities needed to send humans deeper into space than ever before, and ultimately to Mars, while testing new techniques to protect Earth from asteroids,” William Gerstenmaier, associate administrator for NASA’s Human Exploration and Operations Mission Directorate, said in a release.

2011 MD

So far, nine asteroids have been selected as candidates for ARM, with each ticking the boxes for orbit type and size. The sun-orbiting Spitzer space telescope has identified one asteroid in particular – 2011 MD – as having the ideal characteristics for the full-capture mission. Spitzer’s data shows 2011 MD to be about 20 feet in size, fitting nicely within NASA’s desire for a rock no larger than 32 feet. Once secured in a stable orbit, the agency plans to send astronauts to explore the asteroid some time in the 2020s.

“Observing these elusive remnants that may date from the formation of our solar system as they come close to Earth is expanding our understanding of our world and the space it resides in,” said John Grunsfeld, associate administrator for NASA’s Science Mission Directorate. “Closer study of these objects challenge our capabilities for future exploration and will help us test ways to protect our planet from impact.”

NASA has said it thinks there are some 4,700 potentially hazardous asteroids (PHAs) flying around ‘near’ Earth, with each one big enough to ruin our day should it score a direct hit. PHAs are defined by NASA as any space rock currently within five million miles of Earth with a diameter greater than 330 feet.

Source

October 9, 2013

Meet the asteroid that might hit Earth in 2880

Radar image of 1950 DA acquired by the Arecibo Observatory on March 4, 2001. (NASA/JPL/S. OSTRO)

Radar image of 1950 DA acquired by the Arecibo Observatory on March 4, 2001. (NASA/JPL/S. OSTRO)

There are over 10,000 near-Earth objects (NEOs) that have been identified so far — asteroids and comets of varying sizes that approach the Earth’s orbital distance to within about 28 million miles. Of the 10,000 discoveries, roughly 10 percent are larger than six-tenths of a mile in size — large enough to have disastrous global consequences should one impact the Earth.

This is one of them.

First discovered in February 1950, 1950 DA is a 1.1-kilometer-wide asteroid that was observed for 17 days and then disappeared from view. Then it was spotted again on Dec. 31, 2000 — literally on the eve of the 21st century. Coupled with radar observations made a few weeks later in March 2001 it was found that, along with a rather high rotation rate (2.1 hours), asteroid 1950 DA has a trajectory that will bring it very close to Earth on March 16, 2880. How close? Close enough that, within a specific 20-minute window, a collision can not be entirely ruled out.

Top 10 Ways to Stop an Asteroid

The image above was made from radar observations by the Arecibo Observatory in Puerto Rico in March 2001, when 1950 DA passed within 4.8 million miles of Earth. Is this the mug shot of a future continent-killer?

Radar analysis and research of 1950 DA performed by NASA’s Jet Propulsion Laboratory scientists J.D. Giorgini, S. J. Ostro, Don Yeomans and several others from JPL and other institutions revealed that the impact probability from 1950 DA in March 2880 is, at most, 1 in 300 based on what is known about the asteroid so far.

1 in 300 may sound like a slim chance, but actually this represents a risk 50% greater than that of the average hazard due to all other asteroids from now to then.

However, that’s a maximum value. The study also noted the collision probability for 1950 DA as being in the range from 0 to 0.33%. That upper limit could increase or decrease as more is learned about the asteroid. (The next opportunity for studying 1950 DA via radar is in 2032.)

There are many factors that influence the path of an asteroid through space. Its spin rate, reflectivity (albedo), composition, mass, terrain variations… gravitational interactions with other bodies, some of which may not even have been discovered yet… all of these can affect the movement of an asteroid and, more specifically, its exact position at a future point in time. While many of these things still aren’t precisely known for 1950 DA, one in particular could end up being the saving grace for our descendants: the Yarkovsky effect.

PHOTOS: Russian Meteor Strike Aftermath

A small but important force acting upon asteroids, the Yarkovsky effect is a “nudge” created by thermal emission. As an asteroid gathers heat energy from the sun, it releases some of that energy back into space. Thanks to Newtonian mechanics the sheer act of doing so creates a physical push back on the asteroid itself, altering its course ever so slightly. Over a long span of time, this slight alteration could result in the relocation of 1950 DA away from the spot in space where Earth will be on March 16, 2880… at least enough so that a miss is certain.

In fact, recent research by JPL scientists D. Farnocchia and S.R. Chesley have taken into consideration the Yarkovsky effect on 1950 DA based on known values from previous observations, as well as new research suggesting that the asteroid has a retrograde rotation. While their latest assessment does put the risk of an impact in 2880 within the lower end of the probability spectrum (4×10^-4, or -0.58 on the Palermo Scale) it is still far from zero, and in fact remains higher than any other known potential impacts.

PHOTOS: NASA’s Asteroid Capture Mission

So what would happen if the half-mile-wide 1950 DA were to hit Earth? While that depends on a lot of things, such as its composition, speed, angle of impact, where it impacts, etc., needless to say it would cause a lot of damage across a large area. I’m talking an energy release upwards of half a million megatons, which, were it to strike say, New York City, everything within at least a 100-mile radius would be flattened by the force of the impact alone — that’s halfway to Boston and Washington, DC. And that’s not even taking into consideration the air blast, atmospheric dust cloud, secondary impacts from debris, or damage from any resulting tsunami (if the impact were in the ocean)… the destruction would easily extend out many more hundreds of miles, and the repercussions — physical, financial, economic, and emotional — would extend around the globe.

But again, precisely where 1950 DA will be in another 866 1/2 years (and whether or not it will occupy the same point in space as our planet) relies on many factors that aren’t well known — even though its orbit is pretty well understood. More in-depth observations will need to be made, and that is why asteroids like this must be carefully — and continually — watched.

Luckily, 35 generations offers plenty of time to improve our knowledge. According to JPL’s Near-Earth Object program, “If it is eventually decided 1950 DA needs to be diverted, the hundreds of years of warning could allow a method as simple as dusting the surface of the asteroid with chalk or charcoal, or perhaps white glass beads, or sending a solar sail spacecraft that ends by collapsing its reflective sail around the asteroid. These things would change the asteroids reflectivity and allow sunlight to do the work of pushing the asteroid out of the way.”

ANALYSIS: Meet Asteroid 2013 MZ5, 10,000th Near-Earth Object

Still, whether because of ongoing research, faith in future generations of scientists, or just sheer probability, JPL remains confident that 1950 DA should cause little concern. “The most likely result will be that St. Patrick’s Day parades in 2880 will be a little more festive than usual as 1950 DA recedes into the distance, having passed Earth by.”

Let’s just hope the luck of the Irish is with our planet big time that year…

Source

February 15, 2013

Hundreds injured by blasts as meteor falls in Russia

Filed under: Asteroids, Cool, Cosmology, Inner Solar System, Near Earth Objects (NEOs), Wierd — bferrari @ 9:53 am

Fire in the sky: 500 injured as meteor falls in Russia A 10-ton meteor streaked at supersonic speed over Russia’s Ural Mountains on Friday, setting off blasts that injured some 500 people and frightened countless more.

A meteor streaked through the sky and exploded Friday over Russia’s Ural Mountains with the power of an atomic bomb, its sonic blasts shattering countless windows and injuring more than 750 people. The spectacle deeply frightened thousands, with some elderly women declaring the world was coming to an end.

The meteor — estimated to be about 10 tons — entered the Earth’s atmosphere at a hypersonic speed of at least 33,000 mph and shattered about 18-32 miles above the ground, the Russian Academy of Sciences said in a statement.

It released the energy of several kilotons above the Chelyabinsk region, the academy said.

Amateur video broadcast on Russian television showed an object speeding across the sky about 9:20 a.m. local time, just after sunrise, leaving a thick white contrail and an intense flash.

 

‘We saw a big burst of light then went outside to see what it was and we heard a really loud thundering sound.’

– Eyewitness Sergey Hametov, a resident of Chelyabinsk, the biggest city in the affected region

 

“There was panic. People had no idea what was happening. Everyone was going around to people’s houses to check if they were OK,” said Sergey Hametov, a resident of Chelyabinsk, a city of 1 million about 930 miles east of Moscow.

“We saw a big burst of light, then went outside to see what it was and we heard a really loud thundering sound,” he told The Associated Press by telephone.

The explosions broke more than 1 million square feet of glass, city officials said.

The city administration said 758 people sought medical care after the explosions and most were injured by shards of glass. Athletes at a city sports arena were among those cut up by the flying glass.

 

It was not immediately clear if any people were struck by space fragments.

Another Chelyabinsk resident, Valya Kazakov, said some elderly women in his neighborhood started crying out that the world was ending.

City officials said 3,000 buildings in the city were damaged by the shock wave, including a zinc factory where part of the roof collapsed.

Small pieces of space debris — usually parts of comets or asteroids — that are on a collision course with the Earth are called meteoroids. They become meteors when they enter the Earth’s atmosphere. Most meteors burn up in the atmosphere, but if they survive the frictional heating and strike the surface of the Earth they are called meteorites.

Meteors typically cause sizeable sonic booms when they enter the atmosphere because they are traveling much faster than the speed of sound. Injuries on the scale reported Friday, however, are extraordinarily rare.

Sky fall: When do meteorites strike?

A meteor exploded in the sky above Russia on Friday, causing a shockwave that blew out windows and injured hundreds.

Meteor vs. meteorite: What’s the difference?
Meteors are pieces of space rock, usually from larger comets or asteroids, which enter the Earth’s atmosphere. Many burn up by the heat of the atmosphere; those that strike are called meteorites.

How fast do meteorites go?
They often hit the ground at tremendous speed — up to 18,642 mph. That releases a huge amount of force.

How common are they?
Smaller strikes happen five to 10 times a year. Large impacts are rarer but still occur about every five years. Most of these strikes happen in uninhabited areas where they don’t cause injuries to humans.

Source: AP

 

The meteor hit less than a day before the asteroid 2012 DA14 is to make the closest recorded pass of an asteroid to the Earth — about 17,150 miles. But the European Space Agency in a tweet said its experts had determined there was no connection.

Some fragments fell in a reservoir outside the town of Cherbakul, the regional governor’s office said, according to the ITAR-Tass.

A 20-foot-wide crater was found in the same area, which could come from space fragments striking the ground, the news agency cited military spokesman Yaroslavl Roshchupkin as saying.

Reports conflicted on what exactly happened in the clear skies. A spokeswoman for the Emergency Ministry, Irina Rossius, told the AP there was a meteor shower, but another ministry spokeswoman, Elena Smirnikh, was quoted by the Interfax news agency as saying it was a single meteor.

 

 

Donald Yeomans, manager of the U.S. Near Earth Object Program in California, said he thought it was probably “an exploding fireball event.”

“If the reports of ground damage can be verified, it might suggest an object whose original size was several meters in extent before entering the atmosphere, fragmenting and exploding due to the unequal pressure on the leading side vs. the trailing side (it pancaked and exploded),” Yeoman said in an email.

“It is far too early to provide estimates of the energy released or provide a reliable estimate of the original size,” Yeomans added.

The site of Friday’s spectacular show is about 3,000 miles west of Tunguska, which 1908 was the site of the largest recorded explosion of a space object plunging to Earth. That blast, attributed to a comet or asteroid fragment, is generally estimated to have been about 10 megatons; it leveled some 80 million trees.

The dramatic events prompted an array of reactions from prominent Russians.

Prime Minister Dmitry Medvedev, speaking at an economic forum in the Siberian city of Krasnoyarsk, said the meteor could be a symbol for the forum, showing that “not only the economy is vulnerable, but the whole planet.”

Vladimir Zhirinovsky, a nationalist leader noted for vehement statements, said “It’s not meteors falling. It’s the test of a new weapon by the Americans,” the RIA Novosti news agency reported.

Deputy Prime Minister Dmitry Rogozin said the incident showed the need for leading world powers to develop a system to intercept objects falling from space.

“At the moment, neither we nor the Americans have such technologies” to shoot down meteors or asteroids, he said, according to the Interfax news agency.
Source

January 9, 2013

Asteroid Apophis to whiz past Earth tonight — and return for more in 2036

An artist's rendering of the asteroid Apophis. (European Space Agency)

An artist’s rendering of the asteroid Apophis. (European Space Agency)

A European space telescope has captured new images of the huge asteroid Apophis, revealing that the potentially hazardous object is actually bigger than previously thought — and you have a chance to see the space rock yourself in two free webcasts tonight.

Asteroid Apophis has long been billed as a “doomsday asteroid” because of a 2004 study that predicted a 2.7 percent chance of the space rock hitting Earth when it passes within 22,364 miles of the planet in April 2029, European Space Agency officials said. Later studies proved, however, that the asteroid poses no threat to Earth during that flyby, but astronomers continue to track the object since it will make another pass near Earth in 2036.

 

Today, ESA officials announced that its infrared Herschel Space Observatory has discovered that Apophis is about 1,066 feet wide, nearly 20 percent larger than a previous estimate of 885 feet.

“The 20 percent increase in diameter … translates into a 75 percent increase in our estimates of the asteroid’s volume or mass,” study leader Thomas Müller of the Max Planck Institute for Extraterrestrial Physics in Garching, Germany, said in a statement. [Photos of Near-Earth Asteroid Apophis]

‘Alone among all these near-Earth asteroids that have passed our way in recent years, Apophis has generated the most concern worldwide.’

– Slooh president Patrick Paolucci

Tonight’s two free webcasts will stream live views of Apophis from telescopes in Italy and the Canary Islands tonight (Jan. 10). The webcasts, offered by the stargazing websites Slooh Space Telescope and Virtual Telescope Project, will show Apophis as a bright light moving across the night sky. The asteroid is too small to be seen through small backyard telescopes.

The Slooh Space Camera webcast will begin at 7 p.m. EST (0000 Jan. 10 GMT). The Virtual Telescope webcast will begin an hour later at 8 p.m. EST (0100 GMT). You can watch both live webcasts of asteroid Apophis here on SPACE.com tonight.

Apophis will be just under 9.3 million miles from Earth at the time of tonight’s webcasts, amateur astronomer Gianluca Masi of the Virtual Telescope Project told SPACE.com.

“Alone among all these near-Earth asteroids that have passed our way in recent years, Apophis has generated the most concern worldwide because of its extremely close approach in 2029 and [chances of a] potential impact, albeit small, in 2036,” Slooh president Patrick Paolucci said in a statement.

In addition to asteroid Apophis, astronomers regularly scan the night sky for asteroids  that may pose a potential impact threat to Earth. NASA’s Near-Earth Object Office and Asteroid Watch program is based at the agency’s Jet Propulsion Laboratory in Pasadena, Calif.

You can track Apophis directly via the Virtual Telescope Project here: http://www.virtualtelescope.eu/webtv/

The webcast from the Slooh Space Camera can also be seen here: http://events.slooh.com/
Source

June 28, 2012

1969 Fireball meteorite reveals new ancient mineral

Filed under: Asteroids, Big Bang, Cool, Cosmology, Exoplanets, Inner Solar System — bferrari @ 8:18 am
The new mineral, panguite, occurring with the scadium-rich silicate called davisite was found embedded in a piece of the Allende meteorite. (Caltech / Chi Ma)

The new mineral, panguite, occurring with the scadium-rich silicate called davisite was found embedded in a piece of the Allende meteorite. (Caltech / Chi Ma)

A fireball that tears across the sky is not just a one-time skywatching event — it can reap scientific dividends long afterward. In fact, one that lit up Mexico’s skies in 1969 scattered thousands of meteorite bits across the northern Mexico state of Chihuahua. And now, decades later, that meteorite, named Allende, has divulged a new mineral called panguite.

Panguite is believed to be among the oldest minerals in the solar system, which is about 4.5 billion years old. Panguite belongs to a class of refractory minerals that could have formed only under the extreme temperatures and conditions present in the infant solar system.

The name of the titanium dioxide mineral, which has been approved by the International Mineralogical Association, honors Pan Gu, said in Chinese mythology to be the first living being who created the world by separating yin from yang (forming the earth and sky).

“Panguite is an especially exciting discovery since it is not only a new mineral, but also a material previously unknown to science,” study researcher Chi Ma, a senior scientist at Caltech, said in a statement.

Until now, panguite had neither been seen in nature nor created in a lab. “It’s brand-new to science,” Ma told LiveScience in an interview.

The scientists used a scanning-electron microscope to view the panguite within a so-called ultra-refractory inclusion embedded within the meteorite. Inclusions are the minerals that get trapped inside meteorites as they are forming. The ultra-refractory type includes minerals that can resist high temperatures and other conditions in extreme environments, such as those thought to exist as our solar system was forming.

High-tech lab analyses revealed panguite’s chemical composition and crystal structure, which Ma said is new, and as such, could be explored for novel engineering materials.

The Allende meteorite, where the mineral was hidden, is the largest of a class of carbonaceous chondrites found on Earth. Chondrites are primitive meteorites that scientists think were remnants shed from the original building blocks of planets. Most meteorites found on Earth fit into this group. (When meteors hit the ground they are called meteorites.)

Before they reach terra firma, most meteorites are fragments of asteroids (space rocks that travel through the solar system), while others are mere cosmic dust shed by comets. Rare meteorites are impact debris from the surfaces of the moon and Mars. The Allende meteorite likely came from the asteroid belt between Mars and Jupiter, scientists say.

Studying panguite and other components of the Allende meteorite are essential for understanding the origins of the solar system, Ma said. In fact, Ma’s team has discovered nine new minerals, including panguite, in the Allende space rock.

The new mineral is detailed in the July issue of the journal American Mineralogist.

Source

August 3, 2011

Dawn eyes Vesta’s Full Charm

Filed under: Asteroids, Cool, Inner Solar System, Space Ships — bferrari @ 8:40 am

NASA has released the first “full-frame” image of asteroid Vesta, an impressive view of the Clanger homeworld captured by the Dawn spacecraft on 24 July at a distance of roughly 3,200 miles (5,200 kilometres).

Vesta

Vesta

Marc Rayman, Dawn‘s chief engineer, enthused: “Now that we are in orbit around one of the last unexplored worlds in the inner solar system, we can see that it’s a unique and fascinating place.”

Jim Green, planetary division director at NASA HQ, agreed. He said: “The new observations of Vesta are an inspirational reminder of the wonders unveiled through ongoing exploration of our solar system.”

Dawn is now poised to carry out four “intensive science orbits” of the asteroid belt giant, kicking off on 11 August at an altitude of 1,700 miles (2,700 kilometres) above Vesta’s 330 mile (530 kilometre) diameter bulk.

NASA explains that as well as cameras, the spacecraft is packing instruments including “the gamma ray and neutron detector and the visible and infrared mapping spectrometer”.

The agency elaborates: “The gamma ray and neutron detector uses 21 sensors with a very wide field of view to measure the energy of subatomic particles emitted by the elements in the upper yard (meter) of the asteroid’s surface.

“The visible and infrared mapping spectrometer will measure the surface mineralogy of both Vesta and Dawn’s next target, the dwarf planet Ceres.”

Dawn is due to depart Vesta after a year, heading off to a 2015 rendezvous with Ceres – the largest asteroid belt object, measuring an imposing 606 by 565 miles (975 by 909 kilometres).

Source

June 15, 2010

Japanese Asteroid Probe Makes Historic Return to Earth

Filed under: Asteroids, Cool, Gadgets, Inner Solar System, Space Ships — bferrari @ 6:13 am
An artist's illustration of the sample return capsule from Japan's Hayabusa asteroid probe returning to Earth on June 13, 2010 to end its 7-year mission.

An artist's illustration of the sample return capsule from Japan's Hayabusa asteroid probe returning to Earth on June 13, 2010 to end its 7-year mission.

A Japanese space capsule returned to Earth and plunged through the atmosphere over the Australian outback Sunday, capping a seven-year space journey that took it to a nearby asteroid in a historic attempt to collect pieces of a billion-year-old space rock.

The capsule, released by Japan’s Hayabusa asteroid probe, returned around 10 a.m. EDT (1400 GMT) in the Woomera Prohibited Area of South Australia.

The re-entry capsule, which may contain a precious space rock sample, separated from the rest of the spacecraft about three hours before it plummeted down to Earth.

The small 16-inch wide canister planned to land with the help of a parachute and a heat shield to protect it from the fiery temperatures of reentry. The rest of the Hayabusa spacecraft was expected to burn up in Earth’s atmosphere. [Graphic: How Japan’s Hayabusa Asteroid Mission Worked]

The probe will be recovered and transported back to Japan, where scientists will open it and find out whether it succeeded in returning a piece of the asteroid.

The return was monitored by an envoy from NASA, which sent scientists to observe the probe’s re-entry through Earth’s atmosphere to study how its heat shield performed.

“The capsule comes in with the speed of a natural meteor – an asteroid if you like,” said Peter Jenniskens of the SETI Institute in Mountain View, Calif., principal investigator of the NASA observation project. “The velocity is incredible.”

A precious sample

Hayabusa, a mission of the Japanese Aerospace Exploration Agency (JAXA), had a long and tumultuous voyage of roughly 1.25 billion miles (2 billion kilometers). In 2005, the probe landed on the asteroid 25143 Itokawa and attempted to dig up a sample to return to Earth.

Glitches during this process prevented the sample collection from going as planned, but scientists are still hopeful that the probe was able to pick up some asteroid dust or pebbles to bring back with it.

“We won’t know for a long time because the capsule will be recovered, hopefully, and then brought to Japan and opened there,” Jenniskens told SPACE.com.

Even of “only a couple of particles much smaller than a grain of sand” were collected, they would be extremely useful for scientific research, since they would be the first pieces of a space rock ever returned by a robotic mission, said NASA’s Don Yeomans, the U.S. project scientist for the Hayabusa mission.

Long journey

Over the years Hayabusa has run into a number of snags that forced an extra three years to be added on to its mission. A fuel leak, communications loss and ion engine problems were just a few that threatened to kill the asteroid probe before it could ever return home.

“They’ve had so many challenges they’ve overcome,” Yeomans said. “They lost their batteries, they lost their attitude control system, they lost two of the three reaction wheels.”

“They’ve had to start using duct tape and bailing wire and chewing gun to correct for these things,” he joked.

That’s why it’s so gratifying to many of the researchers who’ve worked on the project that the spacecraft is finally home safe.

“It’s very exciting,” Jenniskens said. “It’s an incredible achievement by JAXA to actually go and visit an asteroid, land on it, try to collect materials and bring it back to Earth. The fact that they’ve been able to bring it back to Earth is incredible.”

Source

October 7, 2009

Phew! NASA Downgrades Asteroid-Strike Threat

Filed under: Asteroids, Inner Solar System, Near Earth Objects (NEOs) — bferrari @ 2:35 pm

LOS ANGELES — NASA says the chances of an 885-foot (270-meter) asteroid striking Earth in 2036 have been downgraded.

Scientists initially believed there was a 1-in-45,000 chance that Apophis could hit the planet on April 13, 2036. But NASA said Wednesday the threat has been dropped to 1-in-250,000 after it recalculated the asteriod’s path.

Earth got a scare in 2004, when initial readings suggested the newly discovered Apophis seemed to have a chance of hitting in 2029. Further observations ruled out any possibility of an impact.

Apophis is scheduled to make a close but harmless approach in 2029.

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