quarta-feira, 30 de janeiro de 2008

O antecessor soviético da Spaceship Two!

ss2blog-CEncontrei recentemente, algures na blogosfera, estas fotos de um modelo de uma nave espacial soviética, se não me engano de finais da década de 70. Ainda não tinha sido criado o Buran, o vaivém espacial soviético, conhecido por ser tão incrivelmente parecido com o Space Shuttle, mas com a vantagem de poder ser operado sem tripulação, voando de forma completamente automática - algo que os americanos ainda hoje não conseguem.

Esta seria, portanto, uma tentativa de fazer frente ao avanço dos americanos em termos de naves reutilizáveis.

Para os que leram o artigo que recentemente publiquei neste blog sobre a Spaceship Two, de Burt Rutan, as semelhanças serão imediatamente claras!

Bons designs costumam ser imitados. Espero que a Spaceship Two tenha melhor futuro do que este projecto, que nunca saíu desta fase de modelo.

ss2blog-B ss2blog-D

Sonda New Horizons tira a primeira foto de Plutão

Clique para aumentar.
É apenas um pequeno ponto, o que faz desta foto uma mera curiosidade - a primeira foto de Plutão tirada pela New Horizons, que ainda levará cerca de 7 anos até lá chegar! Mas será uma viagem fantástica, que nos dará as primeiras imagens da superfície do último dos 'planetas'. Entre aspas, porque Plutão foi, depois do lançamento da New Horizons, 'despromovido' a 'planeta-anão'. Curiosamente foram também descobertos outros 'planetas-anões', para além da órbita de Plutão. Especialistas nesta área da astronomia afirmam que nos próximos anos poderão ser descobertos bastantes mais, o que decerto será extremamente interessante. Como seria também extremamente interessante, um dia, conhecermo-los a todos! Mas provavelmente já não estarei vivo nesse dia...

Fonte: New Horizons

Pluto in Hi-Def
Release Date:
Jan 24, 2008

This image demonstrates the first detection of Pluto using the high-resolution mode on the New Horizons Long-Range Reconnaissance Imager (LORRI). The mode provides a clear separation between Pluto and numerous nearby background stars. When the image was taken on October 6, 2007, Pluto was located in the constellation Serpens, in a region of the sky dense with background stars.

Typically, LORRI’s exposure time in hi-res mode is limited to approximately 0.1 seconds, but by using a special pointing mode that allowed an increase in the exposure time to 0.967 seconds, scientists were able to spot Pluto, which is approximately 15,000 times fainter than human eyes can detect.

New Horizons was still too far from Pluto (3.6 billion kilometers, or 2.2 billion miles) for LORRI to resolve any details on Pluto’s surface – that won’t happen until summer 2014, approximately one year before closest approach. For now the entire Pluto system remains a bright dot to the spacecraft’s telescopic camera, though LORRI is expected to start resolving Charon from Pluto – seeing them as separate objects – in summer 2010.

terça-feira, 29 de janeiro de 2008

Próximo eclipse total da Lua será em 21 de Fevereiro

Aqui ficam os diagramas do eclipse, que deverá começar por volta da 1 hora da manhã, hora de Lisboa. Clique nas imagens para aumentar. Infelizmente começa muito tarde, e é no meio da semana, pelo que será difícil a quem trabalha assistir a este espetáculo. Já no Brasil as horas serão mais simpáticas. O eclipse total é relativamente breve, cerca de 25 minutos. Todas as fotos e vídeos serão benvindos!


domingo, 27 de janeiro de 2008

Satélite de espionagem poderá caír nos próximos dias

Segundo as informações disponíveis, este satélite está fora de controlo, e poderá caír em qualquer lugar da Terra. Previsões mais exactas, neste tipo de ocorrências, só são possíveis nas últimas órbitas, por isso o pré-aviso é sempre curto.

Fonte: LA Times


U.S. warns satellite will fall to Earth soon
Officials monitoring the spy apparatus say it is losing orbit. Exactly when and where it will crash isn't yet known.

By Richard A. Serrano, Los Angeles Times Staff Writer

January 27, 2008

WASHINGTON -- Senior government officials said Saturday that they were closely watching a failing U.S. spy satellite that had begun the process of "de-orbiting" and cautioned that the large device was no longer controllable and could hit the Earth as early as late February.

"Appropriate government agencies are monitoring the situation," said Gordon Johndroe, a spokesman for the National Security Council. "Numerous satellites over the years have come out of orbit and fallen harmlessly. We are looking at potential options to mitigate any possible damage this satellite may cause."

U.S. officials are unable to maneuver the satellite, and Johndroe declined to say whether it would be possible to shoot down the spy apparatus before it plummets to Earth. He would not divulge further specifics.

At the Pentagon, Air Force Lt. Col. Karen Finn confirmed that Defense officials thought the satellite could hit the Earth soon but that more analysis would be needed to better determine when, where and in what condition the satellite might crash.

"We are monitoring it," she said. "The NSC has been talking to us about this, and they confirm it is a de-orbiting satellite."

White House officials had little more to say about the situation beyond what the Pentagon and the National Security Council disclosed.

The Associated Press, citing unnamed sources, hinted that the satellite could contain hazardous materials, but the sources were not certain.

Nevertheless, administration officials took the precaution of notifying U.S. lawmakers and other nations, and pledged to keep them aware of the situation as the satellite's failure nears.

Many commercial satellites contain small rockets that ground controllers use to adjust their orbits, and solar panels and rechargeable batteries for power.

Batteries in solar power systems usually are considered hazardous for disposal purposes.

Satellites launched toward planets farther from the sun more often rely on nuclear power.

Some early U.S. and Russian satellites orbiting Earth also used nuclear power, and several accidents over the years resulted in releases of radioactive material.

The contents and operation of U.S. military and spy satellites are classified.

The most significant uncontrolled re-entry by a U.S. craft was Skylab in 1979. Debris from the 78-ton abandoned space station fell into the Indian Ocean and over remote areas of Australia.

In 2000, NASA engineers used rockets aboard the 17-ton Compton Gamma Ray Observatory to bring the satellite down in the Pacific Ocean. And in 2002, officials think debris from a 7,000-pound science satellite fell into the Persian Gulf.


quinta-feira, 24 de janeiro de 2008

A Spaceship 2, de Burt Rutan

Foi finalmente apresentada a sucessora da Spaceship One, de Burt Rutan, que foi a primeira nave privada a ultrapassar a barreira dos 100 Kms de altitude, em 2004, vencendo o X-Prize. Esta nova versão será capaz de transportar mais passageiros.

Juntamente com a Spaceship Two, será também construído um novo avião de lançamento, o White Knight 2, que terá a particularidade de ter dois cockpits - clique nas imagens abaixo para aumentar.

Fonte: MSNBC



The new designs for Virgin Galactic's SpaceShipTwo rocket plane and WhiteKnightTwo mothership were unveiled in New York today, and they include some unexpected twists. In fact, you could be excused if you think you're seeing double, or even triple.

Today's event was the most detailed look yet at the craft that will carry on the legacy of SpaceShipOne, the first commercially developed spaceship and winner of the $10 million Ansari X Prize in 2004.

The biggest twist is that the WhiteKnightTwo plane has spread out and sprouted another passenger cabin on its 140-foot-long wing. The two cabins and four Pratt & Whitney jet engines straddle a central mount for the rocket plane, which will be carried to an altitude of 50,000 feet and dropped. Then SpaceShipTwo will light up its hybrid rocket engine for the final push to the edge of outer space, reaching an altitude of at least 68 miles (110 kilometers).

The twin cabins are basically carbon copies of the SpaceShipTwo cabin, so riding on WhiteKnightTwo will give passengers a taste of what the big blast to space will be like. While commercial astronauts are taking their trip to see the curving earth below the black sky of space, the passengers on WhiteKnightTwo will experience a lower-altitude version of the experience - including a bit of zero-G.

Burt Rutan, the craft's designer and head of California-based Scaled Composites, imagined a scenario in which a husband riding in the mothership watches his wife take off in the spaceship, sitting only 25 feet away.

"You'll say, 'Honey, have a nice flight,'" Rutan told scores of journalists and dignitaries at the American Museum of Natural History. "While she is enjoying black sky and weightlessness, you, in the launch airplane, will be doing parabolas and floating about the cabin."

Stan Honda / AFP - Getty Images
Richard Branson, the billionaire founder of the Virgin Group, and Scaled
Composites aerospace designer Burt Rutan unveil scale models of the
WhiteKnightTwo carrier aircraft, at left, and the SpaceShipTwo rocket plane amid hoopla at the American Museum of Natural History.

SpaceShipTwo is designed to carry six passengers and two pilots into space, with enough headroom to allow for free floating. It's about twice as large as SpaceShipOne, with 18-inch-wide windows and reclining seats for fare-paying fliers.

More than 100 people are already in line for spaceflights, at a cost of $200,000 per person, and Rutan expects there to be thousands more: He said the innovations incorporated into SpaceShipTwo will make human spaceflight "at least as safe as the airliners of the late '20s."

One of the reporters was surprised at that: Shouldn't spaceflight ideally be as safe as commercial aviation is today?

"Don't believe anyone who tells you that the entry level of new spaceships will be as safe as the modern airliner," Rutan responded. He noted that the fatality rate for orbital spaceflight has been 4 percent, and that he was aiming for the suborbital SpaceShipTwo to be "hundreds of times safer."

When will it fly?
Virgin Galactic said work on SpaceShipTwo was nearly 60 percent complete, and WhiteKnightTwo was more than 80 percent complete.

In the past, Virgin Galactic has said passenger flights could start in the 2009-2010 time frame - but that was before last July's fatal accident at Scaled Composites' Mojave testing ground. The development of SpaceShipTwo's rocket engine has been held up because of the accident investigation, and today Virgin Galactic is saying only that WhiteKnightTwo will go into flight tests later this year. Gliding drop tests of the SpaceShipTwo craft, sans engine, could begin this year as well, said Stephen Attenborough, Virgin Galactic's commercial director.

"This is very unlikely to be a program that will be delivered on a straight line," Attenborough told me.

Several would-be passengers attended today's event, and were easily recognizable because of their black Virgin-branded flight suits. Perveen Crawford, Virgin Galactic's first paid-up customer from Hong Kong, told me that she was ready to go anytime.

"It doesn't matter how it looks, just take me up there," she said.

Virgin Galactic's founder, British billionaire Richard Branson, has said he'll give his 89-year-old father, Edward, a ride on SpaceShipTwo as a sign of his confidence in its safety. "They'll have to do it fairly quickly, or I won't be around," Edward Branson told me jokingly after the news conference.

Edward Branson hasn't yet gone through astronaut training, but 80 other fliers-to-be have taken practice sessions at the NASTAR Center in Pennsylvania. Passengers are expected to endure accelerations of up to 3.5 times Earth's gravity, or 3.5 G's, on the way up - and up to 6 G's coming down. NASTAR's centrifuge duplicates that flight profile for training purposes.

Stan Honda / AFP - Getty Images
British billionaire Richard Branson and aerospace designer Burt Rutan
hold up a scale model of the SpaceShipTwo rocket plane hitched
aboard its WhiteKnightTwo carrier aircraft after today's news briefing.

In the wake of the centrifuge sessions, Attenborough said two fliers have withdrawn from the flight program because of health concerns, and three have delayed their training - which translates into a higher-than-expected 93 percent success rate.

People wouldn't necessarily be the only payload: Virgin Galactic President Will Whitehorn said the WhiteKnightTwo air-launch system could also be adapted for putting satellites into orbit. Even on the passenger flights, scientific experiments could ride along just as they do on government-supported spaceflights, "helping to answer key questions about climate and the mysteries of the universe," Richard Branson said.

Making their mark
Compared with the pointy-nosed look of SpaceShipOne, the cabin designs for SpaceShipTwo and WhiteKnightTwo look a bit more rounded, more like a business jet than a Looney Tunes rocketship. The white-and-red colors of the first commercial spaceship were replaced on the scale models shown today with a white, blue and black motif.

The twin tails and the belly of the SpaceShipTwo craft were emblazoned with a design based on the iris of Richard Branson's eye.

Branson had history on his mind as he addressed today's audience.

"2008 really will be the year of the spaceship," he said. Later on, Branson was asked whether he hoped he'd go down in history for backing the first commercial spaceline. Branson quickly gave the credit to Rutan, but then noted that everyone would like to leave their mark on earth.

"I suppose we'd all like to make our mark when we're out of Earth, too," Branson said.

You can get your own look at the new design concepts at Virgin Galactic. And stay tuned for further updates later today, here on the Log.

Update for 5 p.m. ET: Some of the folks posting comments have noted that Branson has positioned himself as a champion of climate consciousness as well as commercial spaceflight. During comments at this morning's news conference as well as at an afternoon session, Branson tried to address that pairing.

He noted that environmentalist James Lovelock was among the first to sign up for a seat on SpaceShipTwo. "He's told me that he thinks this project is one of the most important industrial projects of the 21st century," Branson said.

Branson also downplayed aviation's contribution to greenhouse-gas production. He argued that "seemingly benign" factors such as information technology were actually bigger contributors to the carbon dioxide problem - and that space technologies could make a big contribution to analyzing and even solving environmental ills.

This afternoon's audience was aimed primarily at space boosters rather than journalists, and there was somewhat more whooping and hollering as Branson and Rutan gave their spiel. That brought a smile to Rutan's lips.

"This is a better crowd ... I've always said that my best talks are when there's absolutely no press at all," Rutan joked.

terça-feira, 22 de janeiro de 2008

Foto espetacular - a Terra, de noite

Nesta imagem vemos um crescente, na parte inferior da foto, onde a Terra ainda é iluminada pelo Sol, e onde se podem ver detalhes da superfície. Não podem ser vistas as luzes das cidades porque são demasiado fracas em relação ao brilho deste crescente.

Clique para aumentar.

segunda-feira, 21 de janeiro de 2008

A NASA arrisca-se a estar a criar o maior vibrador do Mundo!

Surgem os primeiros problemas com o foguetão Ares I, que deverá ser o foguetão que substituirá o Space Shuttle como meio de lançamento para naves tripuladas dos Estados Unidos. Estes problemas prendem-se com vibrações perigosas de toda a estrutura, que serão agora estudadas pela NASA durante os próximos anos. Creio ser um problema grave e de difícil solução, uma vez que nunca foram usados foguetões de combustível sólido para lançar astronautas no espaço. É uma área onde não há experiência, e assim o potencial de risco e de ocorrência de desastres é maior, contrariando o objectivo da NASA de criar um meio de lançamento mais seguro do que o Space Shuttle.

NASA Moon Rocket May Shake Too Much

The Associated Press
Saturday, January 19, 2008; 1:25 AM

WASHINGTON -- NASA is wrestling with a potentially dangerous problem in a spacecraft, this time in a moon rocket that hasn't even been built yet.

Engineers are concerned that the new rocket meant to replace the space shuttle and send astronauts on their way to the moon could shake violently during the first few minutes of flight, possibly destroying the entire vehicle.

"They know it's a real problem," said Carnegie Mellon University engineering professor Paul Fischbeck, who has consulted on risk issues with NASA in the past. "This thing is going to shake apart the whole structure, and they've got to solve it."

If not corrected, the shaking would arise from the powerful first stage of the Ares I rocket, which will lift the Orion crew capsule into orbit.

NASA officials hope to have a plan for fixing the design as early as March, and they do not expect it to delay the goal of returning astronauts to the moon by 2020.

"I hope no one was so ill-informed as to believe that we would be able to develop a system to replace the shuttle without facing any challenges in doing so," NASA administrator Michael Griffin said in a statement to The Associated Press. "NASA has an excellent track record of resolving technical challenges. We're confident we'll solve this one as well."

Professor Jorge Arenas of the Institute of Acoustics in Valdivia, Chile, acknowledged that the problem was serious but said: "NASA has developed one of the safest and risk-controlled space programs in engineering history."

The space agency has been working on a plan to return to the moon, at a cost of more than $100 billion, since 2005. It involves two different rockets: Ares I, which would carry the astronauts into space, and an unmanned heavy-lift cargo ship, Ares V.

The concern isn't the shaking on the first stage, but how it affects everything that sits on top: the Orion crew capsule, instrument unit, and a booster.

That first stage is composed of five segments derived from the solid rocket boosters that NASA uses to launch the shuttle and would be built by ATK Launch Systems of Brigham City, Utah.

The shaking problem, which is common to solid rocket boosters, involves pulses of added acceleration caused by gas vortices in the rocket similar to the wake that develops behind a fast-moving boat, said Arenas, who has researched vibration and space-launch issues.

Those vortices happen to match the natural vibrating frequencies of the motor's combustion chamber, and the combination causes the shaking.

Senior managers were told of the findings last fall, but NASA did not talk about them publicly until the AP filed a Freedom of Information Act request earlier this month and the watchdog Web site Nasawatch.com submitted detailed engineering-oriented questions.

The response to those questions, given to both Nasawatch and AP, were shared with outside experts, who judged it a serious problem.

NASA engineers characterized the shaking as being in what the agency considers the "red zone" of risk, ranking a five on a 1-to-5 scale of severity.

"It's highly likely to happen and if it does, it's a disaster," said Fischbeck, an expert in engineering risks.

The first launch of astronauts aboard Ares I and Orion is set for March 2015.

Do site NASAWatch

NASA's Exploration Systems Mission Directorate Responds to Ares 1 and Orion Questions

Keith Cowing
Thursday, January 17, 2008

Editor's note: Earlier this month I submitted a series of questions to NASA's Exploration Systems Mission Directorate (ESMD) regarding the Ares 1 and Orion projects. The following was provided to me by ESMD PAO today:
Questions from Keith Cowing, NASA Watch

Q: Do launch vibroacoustics, oscillations, etc. generated by the current Ares I design exceed acceptable baselined limits for the Orion spacecraft? Do these oscillations exceed limits and/or pose a risk to the crew inside the Orion spacecraft? If so, to what extent to they exceed acceptable limits?

Q: Using a standard NASA 5x5 risk management matrix, what is the current risk rating of Ares I vibroacoustics and oscillations issue by the Constellation and Ares programs?

Q: Have any presentations given by ATK, NASA or other contractor personnel in November or December 2007 - or at any other time - characterized the risk (using a standard NASA 5x5 risk management matrix) to Ares I first stage development as being 4x5 due to incomplete requirements and/or insufficient performance from the DAC-1 Ares I Design?

Q: Are studies underway at NASA to reduce the weight of Orion and associated hardware so as to allow additional weight to be added to the Ares I to alleviate oscillation issues and/or conform to lower performance (payload capacity) by the Ares I?

Q: Is NASA looking at stiffening the Ares I structure so as to pass vibrations on to the Ares I upperstage and payloads i.e. Orion? If so what loads will be transferred to upper stages and/or payloads (Orion)?

Q: Is NASA looking to use a dampening system to handle these vibroacoustic or oscillation loads? If so, what is the weight of such this system? How much would the weight of such a system affect Ares I payload capacity? What would be the added cost of such a dampening system?

Q: Is a tiger team or working group working to report back to Ares and/ or Constellation program managers on these Ares I vibration and oscillation issues? Is this tiger team due to report its findings in March 2008? If not March 2008, when are these results due to be reported and to whom will these results be reported?

Q: Is any portion of the current tiger team's deliberations or proposed solutions considered to be restricted information due to ITAR concerns?

Q: Was NASA Administrator Griffin made aware of these Ares I vibration issues in 2007? If so, when was he made aware of these issues? Who told him about these issues? What specifically was Griffin told about these issues? What was Griffin's response to these issues?

Q: Is NASA currently working on any plans for alternate ways to launch the Orion spacecraft? Do these alternate approaches involve the use of EELVs? Do they involve other commercially available launch vehicles? Do they involve use of shuttle-derived launch systems? Do they involve the use of any launch vehicle design or concept with the working name of "Jupiter" or "Direct"?

Q: If Administrator Griffin was ware of these design issues in 2007 did he inform Congress of these issues? If so, when? Has information on these design issues been presented to members of Congress or to Congressional staff by anyone at NASA?

Q: Has any information on these Ares I design issues been presented to the Government Accountability Office? If so, when?

NASA's Exploration Systems Mission Directorate responds:

Thrust oscillation, also called resonant burning, is a phenomenon characterized by increased acceleration pulses that may be felt during the latter stages of first-stage powered flight. Depending on the amplitude of these pulses, the impact on the vehicle structure and astronauts may be significant.

Thrust oscillation is a characteristic of all solid rocket motors including the first stage of the Ares I launch vehicle. Vortices, created inside the solid rocket motor by the burning propellant or other flow disturbances, can coincide, or tune, with the acoustic modes of the motor combustion chamber, generating longitudinal forces. These longitudinal forces may increase the loads experienced by the Ares I during flight, and may exceed allowable loads on various portions of the vehicle and allowable forces on the astronaut crew.

During any new development program, program risks must be identified and resolved prior to hardware development. Thrust oscillation is such a risk. It is being reviewed, and a mitigation plan is being developed. NASA is committed to resolve this issue prior to the Ares I Project's preliminary design review, currently scheduled for late 2008.

By March 2008, the space agency anticipates having:

* Characterized the potential impact of thrust oscillation (sensitivities to the crew and vehicle components)
* Assessed design feasibilities
* Formulated a plan to manage sensitive design parameters (tests, trade studies and analyses required)

NASA has given careful consideration to many different launch concepts (shuttle-derived, evolved expendable launch vehicle, etc.) over several years. This activity culminated with release of the Exploration Systems Architecture Study in 2005. Since then, the baseline architecture has been improved to decrease life cycle costs significantly.

NASA's analysis backs up the fact that the Ares family enables the safest, least expensive launch architecture to meet requirements for missions to the International Space Station, the moon and Mars. NASA is not contemplating alternatives to the current approach.

NASA is studying the phenomenon of resonant burning of the Ares I first stage in order to improve prediction of the phenomenon and its associated impacts. Thrust oscillation forces may be reduced by vehicle structures, as is the case with the space shuttle and Titan IV.

NASA is working to understand how thrust oscillation may impact the entire stack - Ares first stage, upper stage, and Orion crew vehicle -- and to determine how to minimize the impact. NASA is assessing all vehicle system impacts and defining potential solutions. This includes reviewing thrust oscillation impacts on the Orion, upper stage, J-2X engine, reaction control system, first stage, and avionics. Such a thorough approach -- working with all systems to identify all scenarios and their corresponding sensitivities -- is crucial for successful mitigation.

The Constellation Program has brought in experts from NASA and industry to review these issues and lessons already learned from similar induced responses - namely, affects on launch vehicle hardware and allowable amplitudes of thrust oscillation. The Orion and Ares teams are holding detailed discussions and developing a plan to fully characterize Ares I thrust oscillation, assess any design changes that may be proposed, and manage sensitive design parameters with additional tests, trade studies and analyses.

An integrated thrust oscillation focus team is reviewing the various components of the Ares I and Orion integrated vehicle and the potential impacts of thrust oscillation on the motor, loads and controls, first stage, upper stage, and Orion.

All "at risk" items are being defined (including structural, performance, and human risk items), and a resolution matrix is being established. The goal is to have risks defined and quantified and a mitigation path determined by March 2008.

After the Ares I system design review in late October 2007, thrust oscillation was identified as a risk by the Ares Project and assigned a risk of four-by-five (out of five-by-five) on the NASA risk matrix. NASA uses the risk matrix as a way to track the probability that a risk may manifest itself and the overall impact if the risk does manifest itself. Risks are scored from 1 (low) to 5 (high) for both probability and overall impact.

The thrust oscillation risk is not directly associated with launch vehicle performance or first-stage development. The thrust oscillation risk is associated with the integrated stack, meaning the assembled Ares I first stage, upper stage and Orion crew vehicle. Ares I performance is tracked on a monthly basis, and Ares I consistently has met its performance requirements with margin.

The administrator makes it a practice to be fully informed on all matters concerning shuttle operations and Ares and Orion development. Details on the thrust oscillation issue were communicated to senior agency management first in October 2007 at the Exploration Systems Mission Directorate quarterly program review and again in mid-November 2007 at the Constellation integrated stack status meeting, which the NASA administrator attended.

At the November meeting, the Ares I thrust oscillation issue was addressed as a very small portion of a much broader briefing to the NASA administrator. Steve Cook, manager of the Ares Projects Office at NASA's Marshall Space Flight Center, led the discussion. In response, the administrator stated that he understood the challenge and that he was aware that a team had been working on the issue since early November.

Because it is early in the process, NASA is still working to characterize the potential impact, assess design feasibilities and formulate a plan to address the technical analysis on the thrust oscillation issue. Therefore, NASA has not held a formal briefing for congressional staff or Government Accountability Office staff but has been open about this issue since first learning about it.

Thrust oscillation is a new engineering challenge to the developers of Ares - but a challenge very similar to many NASA encountered during the Apollo Program and development of the space shuttle. Every time NASA faces an engineering challenge - and it faces many - agency engineers examine all the options for addressing the issue. NASA has an excellent track record of resolving technical challenges. NASA is confident it will solve this one as well.

quinta-feira, 17 de janeiro de 2008

Novas imagens de alta resolução da superfície de Mercúrio

À medida que vão sendo processadas as imagens da primeira aproximação da MESSENGER a Mercúrio, vão sendo divulgadas novas imagens de alta definição da superfície. São de esperar mais imagens nos próximos dias.

Clique nas imagens para aumentar.


As MESSENGER approached Mercury on January 14, 2008, the spacecraft’s Narrow-Angle Camera on the Mercury Dual Imaging System (MDIS) instrument captured this view of the planet’s rugged, cratered landscape illuminated obliquely by the Sun. The large, shadow-filled, double ringed crater to the upper right was glimpsed by Mariner 10 more than three decades ago and named Vivaldi, after the Italian composer. Its outer ring has a diameter of about 200 kilometers (about 125 miles). MESSENGER’s modern camera has revealed detail that was not well seen by Mariner 10, including the broad ancient depression overlapped by the lower-left part of the Vivaldi crater. The MESSENGER science team is in the process of evaluating later images snapped from even closer range showing features on the side of Mercury never seen by Mariner 10. It is already clear that MESSENGER’s superior camera will tell us much that could not be resolved even on the side of Mercury viewed by Mariner’s vidicon camera in the mid-1970s.

This MESSENGER image was taken from a distance of about18,000 kilometers (11,000 miles), about 56 minutes before the spacecraft's closest encounter with Mercury. It shows a region roughly 500 kilometers (300 miles) across, and craters as small as 1 kilometer (0.6 mile) can be seen in this image.

Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Just 21 minutes after MESSENGER’s closest approach to Mercury, the Narrow Angle Camera (NAC) took this picture showing a variety of intriguing surface features, including craters as small as about 300 meters (about 300 yards) across. This is one of a set of 68 NAC images showing landscapes near Mercury’s equator on the side of the planet never before imaged by spacecraft. From such highly detailed close-ups, planetary geologists can study the processes that have shaped Mercury’s surface over the past 4 billion years. One of the highest and longest scarps (cliffs) yet seen on Mercury curves from the top center down across the right side of this image. (The Sun is shining low from the left, so the scarp casts a wide shadow.) Great forces in Mercury’s crust have thrust the terrain occupying the left two-thirds of the picture up and over the terrain to the right. An impact crater has subsequently destroyed a small part of the scarp near the top of the image.

This image was taken from a distance of only 5,800 kilometers (3,600 miles) from surface of the planet and shows a region about 170 kilometers (about 100 miles) across.

Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

During its flyby of Mercury, the MESSENGER spacecraft acquired high-resolution images of the planet's surface. This image, taken by the Narrow Angle Camera (NAC) on the Mercury Dual Imaging System (MDIS), was obtained on January 14, 2008, about 37 minutes after MESSENGER's closest approach to the planet. The image reveals the surface of Mercury at a resolution of about 360 meters/pixel (about 1180 feet/pixel), and the width of the image is about 370 kilometers (about 230 miles). This image is the 98th in a set of 99 images that were taken in a pattern of 9 rows and 11 columns to enable the creation of a large, high-resolution mosaic of the northeast quarter of the region not seen by Mariner 10. During the encounter with Mercury, the MDIS instrument acquired image sets for seven large mosaics with the NAC.

This image shows a previously unseen crater with distinctive bright rays of ejected material extending radially outward from the crater's center. A chain of craters nearby is also visible. Studying impact craters provides insight into the history and composition of Mercury as well as dynamical processes that occurred throughout our Solar System. The MESSENGER Science Team has begun analyzing these high-resolution images to unravel these fundamental questions.

Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

quarta-feira, 16 de janeiro de 2008

A imagem do dia!

Acabei de descobrir isto num site de t-shirts. Lembrei-me daquelas pessoas que diziam que acharam obsceno o espetáculo dos astronautas a colocarem a bandeira americana na Lua... Bom, o facto é que quem lá foi... foram eles :)

MESSENGER mostra pela primeira vez a face desconhecida de Mercúrio

Clique para aumentar.
Quando a sonda Mariner 10 passou por Mercúrio, em 1974 e 1975, fotografou sempre a mesma metade do planeta. Agora, 33 anos depois a MESSENGER fotografou cerca de metade da face de Mercúrio que não foi observada então.

A MESSENGER ainda passará duas vezes por Mercúrio, antes de finalmente entrar em órbita do planeta, em Março de 2011.


MESSENGER’s First Look at Mercury’s Previously Unseen Side

When Mariner 10 flew past Mercury three times in 1974 and 1975, the same hemisphere was in sunlight during each encounter. As a consequence, Mariner 10 was able to image less than half the planet. Planetary scientists have wondered for more than 30 years about what spacecraft images might reveal about the hemisphere of Mercury that Mariner 10 never viewed.

On January 14, 2008, the MESSENGER spacecraft observed about half of the hemisphere missed by Mariner 10. This image was snapped by the Wide Angle Camera, part of the Mercury Dual Imaging System (MDIS) instrument, about 80 minutes after MESSENGER's closest approach to Mercury (2:04 pm EST), when the spacecraft was at a distance of about 27,000 kilometers (about 17,000 miles). The image shows features as small as 10 kilometers (6 miles) in size. This image was taken through a filter sensitive to light near the red end of the visible spectrum (750 nm), one of a sequence of images taken through each of MDIS’s 11 filters.

Like the previously mapped portion of Mercury, this hemisphere appears heavily cratered. It also reveals some unique and distinctive features. On the upper right is the giant Caloris basin, including its western portions never before seen by spacecraft. Formed by the impact of a large asteroid or comet, Caloris is one of the largest, and perhaps one of the youngest, basins in the Solar System. The new image shows the complete basin interior and reveals that it is brighter than the surrounding regions and may therefore have a different composition. Darker smooth plains completely surround Caloris, and many unusual dark-rimmed craters are observed inside the basin. Several other multi-ringed basins are seen in this image for the first time. Prominent fault scarps (large ridges) lace the newly viewed region.

Other images obtained during the flyby will reveal surface features in color and in much more detail. Collectively, these images and measurements made by other MESSENGER instruments will soon provide a detailed global view of the surface of Mercury, yielding key information for understanding the formation and geologic history of the innermost planet.

segunda-feira, 14 de janeiro de 2008

MESSENGER fará a maior aproximação a Mercúrio dentro de poucas horas

Clique para aumentar.
Durante esta aproximação serão tiradas cerca de 1200 fotografias. Na foto acima já são visíveis crateras, e serão de esperar detalhes muito melhores nas próximas horas.


Today, January 14, 2008, at 19:04:39 UTC (2:04:39 pm EST), MESSENGER will experience its closest approach to Mercury, passing just 200 kilometers (124 miles) above the planet's surface. As the MESSENGER spacecraft continues to speed toward Mercury, the Narrow Angle Camera, part of the Mercury Dual Imaging System (MDIS) instrument, acquired this crescent view of Mercury. The image was taken on January 13, 2008, when the spacecraft was at a distance of about 760,000 kilometers (470,000 miles) from Mercury. Mercury is about 4880 kilometers (about 3030 miles) in diameter, and the smallest feature visible in this image is about 20 kilometers (12 miles) across.

During the historic flyby encounter today, extensive scientific data will be gathered. The MDIS instrument will acquire over 1200 images of Mercury, including images of portions of the surface never before viewed by a spacecraft. The MDIS instrument is just one member of a whole suite of instruments that will be used to study Mercury during the flyby. The Mercury Atmospheric and Surface Composition Spectrometer (MASCS) will observe Mercury's surface as well as its tenuous atmosphere. The MESSENGER Magnetometer (MAG) will accurately measure Mercury's magnetic field, and the Energetic Particle and Plasma Spectrometer (EPPS) will characterize Mercury's space environment and interactions with the solar wind. The Mercury Laser Altimeter (MLA) will sense surface topography along a narrow profile. The Gamma-Ray and Neutron Spectrometer (GRNS) and X-Ray Spectrometer (XRS) will make the first measurements of Mercury’s surface elemental composition.

MESSENGER will begin to transmit the new data to Earth once all of the scientific measurements are completed, about 22 hours after the spacecraft's closest approach to Mercury. These flyby data will shed light on fundamental scientific questions related to the formation and evolution of the planet Mercury. As scientists analyze the data, the MESSENGER spacecraft will continue on its planned journey, which includes two more encounters of Mercury in October 2008 and September 2009, before entering an orbit around Mercury in March 2011.

Image acquired on January 13, 2008, 06:34 UTC.

sexta-feira, 11 de janeiro de 2008

O Telescópio Espacial Hubble ficará 90 vezes mais potente!

Após a futura missão de reparação do Hubble, nos próximos meses, calcula-se que a capacidade do Hubble se torne 90 vezes maior do que aquela que tem tido até à avaria da ACS - Advanced Camera for Surveys.

Adicionalmente, a ACS também irá ser reparada, embora esta operação seja extremamente delicada, e nunca tentada no espaço, pelo que as possibilidades de sucesso são impossíveis de calcular neste momento.

A ACS é a 'camera principal' do Hubble, que obteve as imagens espetaculares que todos nós estamos habituados a ver nos meios de comunicação social.

Resta-nos esperar que o intenso treino a que os astronautas da missão de serviço estão a ser sujeitos seja suficiente para levar a bom porto tão importante missão.

Fonte: New Scientist Space

Upgraded Hubble telescope to be 90 times as powerful

  • 17:58 08 January 2008
  • NewScientist.com news service
  • David Shiga, Austin
Space shuttle astronauts will attempt an unprecedented in-orbit repair of key Hubble Space Telescope (HST) instruments during the servicing mission scheduled for August 2008. The repairs, along with the addition of two new instruments, will make Hubble 90 times as powerful as it was after its flawed optics were corrected in 1993.

In October 2006, NASA announced plans to carry out a fourth and final servicing mission for Hubble, in which it would install two new scientific instruments and replace the observatory's batteries and gyroscopes. But previously the agency has not said whether it would attempt a difficult repair of two key instruments that have broken down in recent years.

The Advanced Camera for Surveys (ACS), which died in January 2007, was Hubble's highest resolution camera and its most-used instrument. And the Space Telescope Imaging Spectrograph (STIS), which failed in 2004, measured light spectra in the ultraviolet, allowing it to gauge the distance and composition of distant galaxies.

Now, the space agency says it will try something never attempted in the three previous Hubble servicing missions – a finicky electronics repair job in space, where astronauts have the challenge of doing everything while wearing bulky spacesuit gloves.

Without the repair mission, Hubble would likely die by 2011, when its last functioning gyroscope is expected to fail. But with new gyroscopes and batteries installed on the upcoming servicing mission, HST should last at least until 2013, and possibly into the 2020s.

Early galaxies

Two powerful new instruments will be installed on the mission. The Wide Field Camera 3 (WFC3) will allow Hubble to see fainter and more distant galaxies than anything it has seen before, shedding light on the early universe.

This could allow Hubble to see galaxies so far away that we see them as they were just 400 million years after the big bang, says Sandra Faber of the University of California in Santa Cruz, US, a member of the panel that recommended that NASA carry out the final servicing mission.

To date, the most distant galaxies seen by Hubble appear to be from about 800 million years after the big bang, which occurred 13.7 billion years ago. "The universe evolves extremely rapidly at these early times, so a [time] difference like this makes a huge difference in the structure and size of galaxies [that exist in those eras]," Faber said at a press conference on Tuesday at a meeting of the American Astronomical Society in Austin, Texas, US.

Another new instrument, the Cosmic Origins Spectrograph (COS), can obtain ultraviolet light spectra of very faint, distant objects such as quasars – huge black holes that are glowing as they gobble up surrounding gas. COS can measure much fainter objects than STIS, although STIS can get more detailed spectra of the objects it can see.

'90 Hubbles'

With its new instruments, Hubble will be 90 times as powerful as it was supposed to be when first launched – it will be like having 90 of the original Hubble Space Telescopes, astronomers say. The improvement comes from a combination of increased sensitivity and wider fields of view, allowing Hubble to see 900 galaxies where its original instruments would have revealed only 10. HST will be about 60% more powerful than it was right after the third servicing mission, before ACS and STIS failed.

The most challenging part of the mission will be to repair ACS and STIS. "We're going to do something that has never been done in space," said John Grunsfeld, NASA's lead spacewalking astronaut for the servicing mission.

Both repairs involve astronauts unfastening dozens of tiny screws to replace some circuit boards on each of the instruments – all while wearing bulky spacesuit gloves. Such a feat has never been attempted before in space.

The astronauts will also have to cut through metal layers to reach the circuit boards, creating sharp edges that could be hazardous to spacesuits. In the case of ACS, Grunsfeld may not even be able to see the screws he is working with because of the way the instrument is angled inside HST.

Risky business

Grunsfeld has been practicing this tricky manoeuvre in a "neutral buoyancy laboratory" – a water tank designed to simulate the weightlessness of orbit. "Amazingly ... training in a neutral buoyancy lab in the spacesuit, I've been able to do this," he said.

He added that he is willing to put his life on the line for the risky mission. "I still believe that Hubble science and the Hubble programme is still something worth risking my life [for], and I know I have six other crew members who believe that as well," he said.

NASA science chief Alan Stern said although the mission is still scheduled for August 2008, it could slip because of the launch delays the space shuttle has been experiencing in its missions to assemble the International Space Station. "Our watchword in all of this is safety," he said, adding that if the servicing mission needed to wait until October or even later to make sure the shuttle is safe, then NASA would wait.

During the mission, new insulation blankets will be wrapped around Hubble to make up for cracks in existing insulation and a fine guidance sensor will be added to help HST point itself precisely. Astronauts will also install a "soft capture mechanism" to allow a future robotic mission to grab onto Hubble at the end of its lifetime so that it can safely re-enter the atmosphere and crash into the ocean.

Sonda MESSENGER a dias de encontro histórico com Mercúrio!

Imagem de Mercúrio obtida ontem, 10 de Janeiro de 2008.
Serão de esperar imagens bastante mais detalhadas nos próximos dias.
Clique para aumentar.

A MESSENGER é uma sonda que deverá entrar em órbita do planeta Mercúrio em 2011. Para tal terá de efectuar uma série de manobras, entre as quais várias passagens pelo planeta. A primeira será na segunda-feira, por volta das 18:00. Poderá obter mais detalhes no site oficial da missão MESSENGER. Será a primeira vez, desde há 3 anos, que uma sonda passará por Mercúrio!

Fonte: MSNBC

Mercury probe closes in for historic flyby
Messenger to map previously uncharted regions of closest-in planet
By Tariq Malik
updated 6:54 p.m. ET Jan. 10, 2008

A NASA spacecraft has a date with Mercury next week for a flyby that will return the first detailed views of the small planet in more than 30 years.

The Messenger probe will skim just 124 miles (200 kilometers) above Mercury's uncharted hemisphere during its closest pass at 2:04 p.m. ET Monday, marking the first of three flybys to bleed off speed and enter orbit around the planet.

"Our spacecraft is lined up and ready to go," Marilyn Lindstrom, NASA's Messenger program scientist, said during a Thursday briefing, adding that the probe has already returned its first images of its target. "Mercury, here comes Messenger."

Launched in August 2004, Messenger — short for the bulky moniker MErcury Surface, Space ENvironment, GEochemistry and Ranging — is the first spacecraft to visit Mercury since NASA's Mariner 10 probe swung past the planet three times between 1974 and 1975. But unlike its predecessor, Messenger will rendezvous with Mercury four times, making three flybys before ultimately entering orbit in 2011 for a one-year science campaign.

The $446 million mission is aimed at probing the secrets of Mercury, ranging from its wispy thin atmosphere to an unusually dense interior. The mission will also generate the first maps of the 55 percent of the planet's rocky surface that Mariner 10 missed during its three planetary passes.

"More than half the planet's never been seen before," said Messenger principal investigator Sean Solomon, of the Carnegie Institution of Washington. "That will change on Monday."

Messenger's Mercury flyby actually begins in earnest around midday Sunday, when the probe will turn itself away from Earth to bring its science instruments to bear on its planetary target. The spacecraft will snap more than 1,200 photographs of Mercury during its first rendezvous while a protective sunshade keeps its cameras and other instruments at room temperature. The sun-facing side of the shade may reach temperatures of around 600 degrees Fahrenheit (315 degrees Celsius), researchers said.

For 14 minutes, the probe's power-generating solar panels will be in Mercury's shadow, forcing the spacecraft to briefly rely solely on its batteries, said Eric Finnegan, Messenger systems engineer. The probe will use the gravitational pull of Mercury to slow its speed by about 5,000 miles per hour (8,046 kilometers per hour) during the flyby, he added.

Messenger is expected to re-establish contact with Earth about midday on Tuesday, 22 hours after the closest Mercury approach, and then beam back images to its eager science team. The probe has already flown past Earth once and Venus twice as it spiraled down the solar system on the 4.9 billion-mile (7.9 billion-kilometer) trek to Mercury.

"Now, we're just a few days away from our first glimpse of Mercury in 33 years," said Solomon. "It is an understatement to say that the science team is extremely excited."

quarta-feira, 9 de janeiro de 2008

Telescópio espacial Hubble poderá ficar em óbita mais uma década!

A missão de 'reparação' do HST deverá ocorrer durante este ano, e aparentemente já inclui a reparação da Advanced Camera for Surveys, a camera que obtém as imagens espetaculares que estamos habituados a ver.

Fonte: MSNBC

Space telescope could stay up for a decade
Plan would keep Hubble working through 2013, with disposal around 2020
By Jeanna Bryner
updated 12:38 p.m. ET Jan. 8, 2008

AUSTIN, Texas - The orbiting space telescope that just won't quit collecting gobs of celestial data well beyond its expected twilight is set for a major tune-up and upgrade, NASA scientists said Tuesday at a meeting of the American Astronomical Society.

This servicing mission will be the Hubble Space Telescope's fifth and last.

The latest word is that the space shuttle Atlantis could lift off in August with a crew of seven astronauts and a cargo of equipment, tools and new instruments for Hubble. But that launch date could change. "That's dependent upon the shuttle flights between now and the servicing mission," said Alan Stern, associate administrator for NASA's Science Mission Directorate in Washington. He added that safety always comes first.

Orbiting at about 350 miles (563 kilometers) above Earth, Hubble is above the atmosphere and doesn't have to contend with shifting pockets of air that distort images made by ground-based telescopes. This atmospheric distortion is the reason stars appear to twinkle.

Hubble's clear view has meant, for one, that over its 16-plus years in orbit, the telescope has sent back a spectacular photo album of sci-fi-like jets from black holes, galaxies in all stages of evolution and snapshots of planets in our own solar system.

"Hubble is, without exaggeration, a national treasure," Stern said, "and all of NASA is looking forward to seeing it receive this tune-up and upgrade."

The public's love for Hubble, along with political pressure, has played a role in NASA's decision to service the observatory, a mission deemed risky compared to other shuttle ventures.

Hubble hugger
During the 11-day Hubble service mission, which will include five spacewalks, shuttle astronauts will install two new science instruments plus a set of gyroscopes to help stabilize the telescope, as well as batteries and thermal blankets to keep the observatory operating until at least 2013.

Astronauts will also install a soft capture mechanism that will allow a future unmanned spacecraft to dock with Hubble in about 2020 and deorbit it for a controlled plunge and disposal in the ocean.

Leading the spacewalks will be self-labeled "Hubble Hugger," astronaut John Grunsfeld, who had told Space.com last year he wanted to be on the mission.

"As both an astronaut and an astronomer, the opportunity to go back to Hubble is more than a dream come true," said Grunsfeld. "When we left Hubble in 2002, I was convinced it would be the last time I would see my friend Hubble Telescope," said Grunsfeld, wearing a NASA flight suit and space gloves.

However, he noted, "this mission promises to be quite challenging."

For instance, astronauts will attempt the first-ever on-orbit repair of two existing instruments, the Space Telescope Imaging Spectrograph, or STIS, and the Advanced Camera for Surveys, which failed a year ago this month.

Installed on Hubble in February 1997, the STIS separates incoming light into its constituent colors, giving astronomers a chemical map of distant objects. Since its deployment, STIS has been critical in the confirmation of black holes at the centers of galaxies, made the first discovery of an atmosphere around an exoplanet and helped confirm the age of the universe.

Better science
Two additions to Hubble's science cargo will include the Wide Field Camera 3, a panchromatic camera that is expected to provide sharp images over a wide range of colors; and the Cosmic Origins Spectrograph.

The Cosmic Origins Spectrograph will probe the large-scale structure of the universe, the so-called cosmic web, in which strands of galaxies transect seemingly empty space like a gargantuan 3-D spider web. The universe's invisible "glue," called dark matter and thought to make up about 85 percent of all matter in the universe, gives the web its structure, astronomers say.

Astronomers infer the existence of the cosmic web just as a child might know a Christmas tree exists by looking at the colorful lights that outline its branches. Instead of little bulbs, the stars and galaxies trace out the cosmic web.

In the end, scientists expect to breathe new and improved life into Hubble.

"Our goal for this mission is to leave Hubble at the apex of its scientific capabilities," said David Leckrone, Hubble senior project scientist at NASA's Goddard Space Flight Center in Maryland. The addition of new instruments along with repairs of others should give astronomers a full "toolbox" for resolving many cosmic conundrums, Leckrone said.

Asteroide poderá colidir com Marte

Durante o último mês têm vindo a ser refinados os cálculos da probabilidade de um asteróide colidir com o planeta Marte. Embora esta probabilidade ainda seja baixa, já é razoavelmente alta para que se estejam a planear observações da cratera que irá deixar, e que poderá trazer novos dados sobre a estrutura do planeta. Com as várias sondas que actualmente orbitam o planeta, e os dois rovers na superfície, a quantidade e qualidade dos dados que poderão ser obtidos é incrível.

Fonte: MSNBC

Actualização a 11 de Janeiro: ontem foram recalculadas as probabilidades de impacto para 0,01%, ou seja, é altamente improvável que o asteróide caia em Marte. Pelo menos agora. Link.

Asteroid’s Martian impact: What might happen
Collision could prove to be a valuable boon for planetary science
By Leonard David and Tariq Malik
updated 6:57 p.m. ET Jan. 3, 2008

The possibility of an asteroid walloping the planet Mars this month is whetting the appetites of Earth-bound scientists, even as they further refine the space rock's trajectory.

The space rock in question — Asteroid 2007 WD5 — is similar in size to the object that carved Meteor Crater into northern Arizona some 50,000 years ago and is approaching Mars at about 30,000 miles per hour (48,280 kph).

Whether the asteroid will actually hit Mars or not is still uncertain.

Such an impact, researchers said, could prove to be a valuable boon for planetary science since NASA's Mars Reconnaissance Orbiter (MRO) and a flotilla of other spacecraft are already in position to follow up any impact from orbit.

"An impact that we could witness/follow-up with MRO would be truly spectacular, and could tell us much about the hidden subsurface that could help direct a search for life or life-related molecules," said John Rummel, NASA's senior scientist for astrobiology at the agency's Washington, D.C., headquarters.

Observations of the asteroid between Dec. 29 and Jan. 2 allowed astronomers to slightly lower the space rock's odds of striking Mars to about 3.6 percent (down from 3.9), giving the object a 1 in 28 chance of hitting the planet, according to a Tuesday report from NASA's Near Earth-Object program office at the Jet Propulsion Laboratory in Pasadena, Calif.

More observations may further reduce the asteroid's impact chances to nil, NEO officials said. The space rock's refined course stems from observations by astronomers at New Mexico Tech's Magdalena Ridge Observatory.

But if WD5 does smack into Mars, some astronomers have a fair idea of what havoc it may spawn. The likely strike zone would be near the equator, but to the north of the current position of NASA's Opportunity rover at Victoria Crater, NASA officials have said.

Mark Boslough, a collision dynamics expert at New Mexico's Sandia National Laboratory, said the atmosphere at Mars' surface is similar to that of Earth at an altitude of 12 miles (20 km). Some space rocks that target Earth explode under the pressure created as they stream into our atmosphere. But they tend not to explode until much below the 12-mile mark.

"So this won't be an airburst," Boslough said. "It will either hit the ground intact and make a single crater, or break up and generate a cluster of craters."

The collision, were it to occur, could also create a visible dust plume as ejecta is lofted high into the Martian atmosphere, he said.

The resulting crater could reach more than a half-mile (0.8-km) in diameter, or about the size of the Opportunity rover's Victoria home, NASA added.

Boslough's break-up scenario is reminiscent of Comet P/Shoemaker-Levy 9, which broke into more than 20 fragments as it neared Jupiter in 1994, then repeatedly pummeled the gas giant over the course of six days. The resulting impact scars were visible to telescopes on Earth, in orbit and NASA's Galileo probe, which was en route to Jupiter at the time of the collision.

Like Galileo at Jupiter, NASA's MRO probe and its High-Resolution Imaging Experiment (HiRISE) camera would be in prime position for a martian collision. With its ability to resolve objects three feet (one meter) across, HiRISE has been billed as the most powerful camera ever sent to study Mars.

"If the asteroid hits Mars, we'll get a great look at the crater within a few days of impact," said HiRISE principal investigator Alfred McEwen of the University of Arizona's Lunar and Planetary Laboratory in Tucson.

Actualização em 23 de Janeiro de 2008: As probabilidades deste asteroide caír em Marte foram reduzidas por cálculos posteriores, mas ainda são superiores a 0.

E uma animação do possível impacto, como poderia ser visto em Marte:

Os tamanhos dos planetas e das estrelas