Uma Homenagem à Phoenix Mars Lander

01010100 01110010 01101001 01110101 01101101 01110000 01101000 <3

Depois de uma missão de enorme sucesso, a Phoenix Mars Lander deixou recentemente de emitir sinais para a Terra, tal como era previsto, com o início do Inverno Marciano. Como o Sol já não incide sobre os painéis solares da Phoenix, esta foi perdendo potência até que se tornou impossível continuar a operar. Há uma esperança, muito ténue, de que volte a funcionar no fim do Inverno Marciano. Mas isto não está previsto, deveremos considerar esta missão terminada, e de enorme sucesso! Parabéns à NASA e ao Jet Propulsion Laboratory (JPL)!

Fonte: Wired

Mars Phoenix Lander Runs Out of Juice
By Alexis Madrigal Email
November 10, 2008

The phenomenally popular Mars Phoenix Lander mission has officially come to an end.

Originally slated for a mere 90 days near the Martian north pole, clever NASA power engineers kept the Lander doing science for nearly two months beyond that goal. But now mission officials are certain: The lander has run out of power for its internal heater and is presumed to be frozen on the arctic plain.

"At this time, we're pretty convinced that the vehicle is no longer available for us to use," said Barry Goldstein, Phoenix project manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "We're ceasing operations and declaring an end to mission operations at this point."

As late as last week, the team was still trying to eke a few more experiments out of the robotic lander, even as the declining amount of solar energy in the pole area made their task more difficult.

The mission's legacy, however, will not be defined by its longevity so much as by its problem-light successes and legions of fans. Driven by a clever social media strategy that built a huge Twitter following, the NASA mission struck a chord with space lovers, who watched with rapt attention as the lander made a picture-perfect landing and proceeded to become the first human spacecraft to "taste" Martian water.

"If we're successful, this mission will be remembered for being the first to do direct analysis of ice or water on the surface of Mars," predicted NASA's Mike Gross, who engineered the mission's scientific instrumentation, back in May.

Indeed, Phoenix primary investigator, Peter Smith, led off his eulogy for the Lander noting that his team discovered ice, before recounting the mission's success measuring Martian weather and finding perchlorate, a known energy source for some microbes on Earth.

"It's been a great mission, a highlight of my life," Smith said.

It will take months to analyze the 25,000 photographs and the data from the dozens of experiments that the Lander conducted over the last several months, but the mission is already seen as a major success for relatively cheap robotic missions. At $480 million, the Phoenix lander cost about as much as a single Shuttle mission.

In fact, the mission's biggest failure — not finding evidence of life — doesn't have much to do with the execution of the mission so much as the Red Planet itself.

"We've seen nutrients and energy sources," Smith said. "That leads to the question: Is this a habitable zone?"

But, just like the mission, Smith left the ultimate question of extraterrestrial life unanswered, saying just that his team needed time to go back to their labs and examine the data from the mission in greater detail.

@MarsPhoenix, the lively voice of the lander, sent her last message six minutes ago.

"01010100 01110010 01101001 01110101 01101101 01110000 01101000 <3,">

That's binary for "Triumph," and the herald of a new digital-savvy era for the National Aeronautics and Space Administration.

Descoberta em Marte está a ser mantida em segredo

Ainda não se sabe o que é que a sonda Phoenix descobriu em Marte que seja tão importante que a NASA tenha decidido informar o Presidente Bush - mantendo a informação em segredo para o resto do Mundo. Mas em breve, talvez em meados do mês de Agosto, iremos saber.

Fonte: Universe Today


The White House is Briefed: Phoenix About to Announce "Potential For Life" on Mars
Written by Ian O'Neill

It would appear that the US President has been briefed by Phoenix scientists about the discovery of something more "provocative" than the discovery of water existing on the Martian surface. This news comes just as the Thermal and Evolved Gas Analyzer (TEGA) confirmed experimental evidence for the existence of water in the Mars regolith on Thursday. Whilst NASA scientists are not claiming that life once existed on the Red Planet's surface, new data appears to indicate the "potential for life" more conclusively than the TEGA water results. Apparently these new results are being kept under wraps until further, more detailed analysis can be carried out, but we are assured that this announcement will be huge…

So why is there all this secrecy? According to scientists in communication with Aviation Week & Space Technology, the next big discovery will need to be mulled over for a while before it is announced to the world. In fact, the Jet Propulsion Laboratory science team for the MECA wet-chemistry instrument that made these undisclosed findings were kept out of the July 31st news conference (confirming water) so additional analysis could be carried out, avoiding any questions that may have revealed their preliminary results. They have also made the decision to discuss the results with the Bush Administration's Presidential Science Advisor's office before a press conference between mid-August and early September.

Although good news, Thursday's announcement of the discovery of water on Mars comes as no surprise to mission scientists and some are amused by the media's reaction to the TEGA results. "They have discovered water on Mars for the third or fourth time," one senior Mars scientist joked. These new MECA results are, according to the Phoenix team, a little more complex than the water "discovery." Scientists are keen to point out however, that this secretive news will in no way indicate the existence of life (past or present) on Mars; Phoenix simply is not equipped make this discovery. What it can do is test the Mars soil for compounds suitable to support life. The MECA instrument does have microscopes capable of resolving bacterial-scale life forms however, but this is not the focus of the forthcoming announcement, sources say.

This new MECA discovery, combined with TEGA data will probably expose something more compelling, completing another piece of the puzzle in the search for the correct conditions for life as we know it to survive on Mars. Critical to this search is to understand how the recently confirmed water and Mars regolith behave together under the Phoenix lander in the cold Martian arctic.

The MECA instrument had already made the landmark discovery that Mars "soil" was much like the soil more familiar on Earth. This finding prompted scientists to indicate that the minerals and pH levels in the regolith could support some terrestrial plants, indicating this would be useful for future Mars settlers.

What with the discovery of water, and the discovery that Mars soil is very much like the stuff we find on Earth, it is hard to guess as to what the MECA's second soil test has discovered. What ever it is, it sounds pretty significant, especially as NASA and the University of Arizona are taking extraordinary steps to avoid any more details being leaked to the outside world. I just hope were not getting excited over something benign…

Já viram se isto tivesse acontecido durante a aterragem da Phoenix?

Sonda Phoenix fotografada da órbita de Marte

Mais um trabalho da câmera HiRISE, do Mars Reconnaissance Orbiter, que mostra em grande detalhe o local de aterragem da Phoenix em Marte. Clique nas imagens para aumentar.

A fotografia da Década!

Clique para aumentar.

Esta foto, absolutamente única no seu género, mostra a sonda Phoenix (o pequeno ponto branco em baixo) a descer para Marte, ainda suspensa pelo seu pára-quedas (o ponto branco maior, em cima)! Foi tirada de órbita (!!) pela câmera HiRISE da sonda Mars Reconnaissance Orbiter. É a primeira vez na História que é fotografada uma sonda a descer para Marte - ou para qualquer outro planeta, incluindo a Terra!

Fonte: Site Oficial da Phoenix


Camera On Mars Orbiter Snaps Phoenix During Landing

May 26, 2008 -- A telescopic camera in orbit around Mars caught a view of NASA's Phoenix Mars Lander suspended from its parachute during the lander's successful arrival at Mars Sunday evening, May 25.

The image from the High Resolution Imaging Science Experiment (HiRISE) on NASA's Mars Reconnaissance Orbiter marks the first time ever one spacecraft has photographed another one in the act of landing on Mars.

Meanwhile, scientists pored over initial images from Phoenix, the first ever taken from the surface of Mars' polar regions. Phoenix returned information that it was in good health after its first night on Mars, and the Phoenix team sent the spacecraft its to-do list for the day.

"We can see cracks in the troughs that make us think the ice is still modifying the surface," said Phoenix Principal Investigator Peter Smith of the University of Arizona, Tucson. "We see fresh cracks. Cracks can't be old. They would fill in."

Camera pointing for the image from HiRISE used navigational information about Phoenix updated on landing day. The camera team and Phoenix team would not know until the image was sent to Earth whether it had actually caught Phoenix.

"We saw a few other bright spots in the image first, but when we saw the parachute and the lander with the cords connecting them, there was no question," said HiRISE Principal Investigator Alfred McEwen, also of the University of Arizona.

"I'm floored. I'm absolutely floored," said Phoenix Project Manager Barry Goldstein of NASA's Jet Propulsion Laboratory, Pasadena, Calif. A team analyzing what can be learned from the Phoenix descent through the Martian atmosphere will use the image to reconstruct events.

HiRISE usually points downward. For this image, the pointing was at 62 degrees, nearly two-thirds of the way from straight down to horizontal. To tilt the camera, the whole orbiter must tilt. Mars Reconnaissance Orbiter was already pointed toward the expected descent path of Phoenix to record radio transmissions from Phoenix.

McEwen said, "We've never taken an image at such an oblique angle before."

Monday's tasks for Phoenix include checkouts of some instruments and systems, plus additional imaging of the lander's surroundings.

Inevitável! Marcianos manifestam-se contra a invasão americana de Marte!

Os 7 minutos de terror da Phoenix

Vídeo que descreve os 7 minutos da fase 'EDL' - Entry, Descent, Landing - da Phoenix.

Mais imagens de Marte

A superfície da zona ártica de Marte, mostrando vários 'polígonos',
possivelmente criados por camadas de gelo subterrâneo. Clique para aumentar.

Um dos polígonos referidos. Clique para aumentar.

As primeiras imagens da Phoenix a partir de Marte

Estas são algumas das primeiras imagens enviadas para a Terra pela Phoenix a partir da superfície de Marte. Chegaram ontem por volta das 2:30 da madrugada (acordei com os aplausos na NASA TV!). Mostram os painéis solares abertos, um dos pés da sonda, e o horizonte de Marte. A Phoenix aterrou numa planície muito plana, com poucos rochedos. A superfície apresenta falhas em forma de polígono, possivelmente formadas pela presença de gelo subterrâneo.

A descida da Phoenix

Vídeo da cobertura da descida da Phoenix até Marte, pela NASA TV. O vídeo começa quando a Phoenix já estava a entrar na atmosfera de Marte. A tensão era óbvia, a 'irmã' desta sonda despenhou-se no Pólo Sul de Marte em 1999, mas desta vez toda a gente estava sorridente. Pessoalmente pensei que estavam todos a deitar foguetes antes da festa, mas felizmente era só a confiança de quem fez um bom trabalho.

A narrativa de quem lia a telemetria é dramática, e simplesmente inesquecível. Um dia histórico.

Um dia Histórico - a Phoenix aterra com sucesso em Marte!

Pela primeira vez em 32 anos, desde as sondas Viking - era eu um miúdo de 10 anos - a NASA fez aterrar em Marte uma sonda sem o auxílio de airbags - o que permitiu um controlo de aterragem muito mais preciso, mas também muito mais arriscado.

Os últimos segundos foram fantásticos, com a telemetria da Phoenix a ser lida em tempo real, com a indicação da abertura do pára-quedas, separação do pára-quedas, ligação dos foguetes, e indicações da altitude, até à confirmação da aterragem.

A aterragem foi tão perfeita que a sonda está com apenas 0,25º de inclinação em relação à horizontal!

O próximo ponto crítico será a abertura dos painéis solares, sem a qual a missão não poderá progredir a 100%.

Dentro de cerca de uma hora e meia chegarão as primeiras imagens do Pólo Norte de Marte. Não sei se estarei acordado nessa altura, mas amanhã estarão aqui as imagens!

Já bebi um Porto em homenagem à Phoenix! Parabéns NASA, parabéns JPL!

Aterragem da Phoenix em Marte dentro de poucas horas

A transmissão em directo pela NASA TV começa hoje pelas 11 horas da noite, hora de Lisboa. A aterragem deverá ser por volta da meia-noite e 53 minutos. As primeiras imagens poderão surgir por volta das 3 da madrugada. Vamos manter os dedos cruzados e esperar que tudo corra bem. Se tal acontecer, será a primeira vez em 32 anos que a NASA consegue aterrar uma sonda em Marte só com controlo por foguetes e sem o auxílio de airbags!

Fonte: NASA

Nota - a todos os tempos abaixo deverá somar 8 horas, já que são a hora oficial da costa oeste.

NOTE: The times below for the Phoenix spacecraft events on May 25 are for a nominal scenario. Remaining navigational adjustments before May 25 could shift the times by up to about half a minute. In addition, the times for some events relative to others could vary by several seconds due to variations in the Martian atmosphere and other factors. For some events, a "give or take" range of times is given, covering 99 percent of possible scenarios from the atmospheric entry time. For events at Mars, times are listed in "Earth-receive time" (ERT) rather than "spacecraft event time" (SCET). This means the listed time incorporates the interval necessary for radio signals traveling at the speed of light to reach Earth from Mars. On landing day, May 25, the two planets are 275 million kilometers apart (171 million miles), which means it takes the signal 15 minutes and 20 seconds to reach Earth. For some spacecraft events, engineers will not receive immediate radio confirmation.

-- Trajectory correction maneuver opportunity (TCM6X), 8:46 a.m.
-- News briefing, noon
-- Begin non-commentary live television feed from JPL control room, 3 p.m.
-- Begin commentated live television feed from JPL control room, 3:30 p.m.
-- Propulsion system pressurization, 4:16 p.m.
-- Begin "bent-pipe" relay relay (continuous transmission of Phoenix data as it is received) through NASA's Mars Odyssey spacecraft to Goldstone, Calif., Deep Space Network station, 4:38 p.m.
-- Green Bank, W. Va., radio telescope listening for direct UHF from Phoenix, 4:38 p.m.
-- Cruise stage separates, 4:39 p.m.
-- Spacecraft turns to attitude for atmospheric entry, 4:40 p.m.
-- Spacecraft enters atmosphere, 4:46:33 p.m.
-- Likely blackout period as hot plasma surrounds spacecraft, 4:47 through 4:49 p.m.
-- Parachute deploys, 4:50:15 p.m., plus or minus about 13 seconds.
-- Heat shield jettisoned, 4:50:30 p.m., plus or minus about 13 seconds.
-- Legs deploy, 4:50:40 p.m., plus or minus about 13 seconds. -
- Radar activated, 4:51:30 p.m.
-- Lander separates from backshell, 4:53:09 p.m., plus or minus about 46 seconds.
-- Transmission gap during switch to helix antenna 4:53:08 to 4:53:14 p.m.
-- Descent thrusters throttle up, 4:53:12 p.m.
-- Constant-velocity phase starts, 4:53:34 p.m., plus or minus about 46 seconds.
-- Touchdown, 4:53:52 p.m., plus or minus about 46 seconds.
-- Lander radio off 4:54:52 p.m., plus or minus about 46 seconds.
-- Begin opening solar arrays (during radio silence) 5:13 p.m.
-- Begin NASA's Mars Reconnaissance Orbiter playback of Phoenix transmissions recorded during entry, descent and landing, 5:28 p.m. However, data for analysis will not be ready until several hours later.
-- Begin Europe's Mars Express spacecraft playback of Phoenix transmissions recorded during entry, descent and landing, 5:30 p.m. However, data for analysis will not be ready until several hours later.
-- Post-landing poll of subsystem teams about spacecraft status, 5:30 p.m.
-- Mars Odyssey "bent-pipe" relay of transmission from Phoenix, with engineering data and possibly including first images, 6:43 to 7:02 p.m. Data could take up to about 30 additional minutes in pipeline before being accessible. If all goes well, live television feed from control room may show first images as they are received. The first images to be taken after landing will be of solar arrays, to check deployment status.
-- News briefing, 9 p.m.


Fonte: New Scientist Space


Peanuts and Rolling Stones on hand for Mars landing

* 00:34 25 May 2008
* NewScientist.com news service
* Ivan Semeniuk, Pasadena

Bring on the peanuts; it's time to land on Mars.

One day before the Phoenix spacecraft arrives at the Red Planet, good luck charms and helpful aphorisms are on full display as engineers and scientists associated with the project deal with the stress of their mission's most critical hours.

Project manager Barry Goldstein has already ordered the peanuts that will be available tomorrow in the mission support area where his Entry, Descent and Landing team will track Phoenix's fiery plunge through the Martian atmosphere.

The peanuts are a Jet Propulsion Lab tradition, but unlike at the last Mars landing, these peanuts will still be in their shells. "I think we need to go through the process" of opening up the peanuts to calm edgy nerves, he told New Scientist.

In addition to the peanuts, lucky blueberries will also make an appearance - a nod to the Opportunity rover, which found iron-rich spherules, nicknamed blueberries, soon after it became the last spacecraft to successfully touch down on Mars.

If it lands successfully, Phoenix will dig into the soil near the northern polar cap to study ice thought to lie just below the surface. This should reveal whether Mars has maintained periodic habitability up to the present day, which would be possible if the planet periodically changes its tilt as a result of gravitational tugs by Jupiter. Such wobbles would cause the northern permafrost to melt and moisten the soil every so often.

At a press briefing today, principal investigator Peter Smith of the University of Arizona in Tucson, US, quoted poet Ralph Waldo Emerson while summing up the scientific rationale for the mission, which could be the first to touch water on Mars: "Go where there is no path; leave a trail for others to follow."

On a somewhat less poetic, but eminently more pragmatic note, Douglas McCuistion, NASA's Mars programme director, invoked a line famously sung by Mick Jagger: "You can't always get what you want, but if you try sometime you get what you need."
Course correction

Certainly, regardless of the returns that scientists want to see coming back from Phoenix in the coming weeks, the spacecraft needs to land intact or the $420 million mission will effectively be a write-off. "We bet the whole farm on landing safely," says Smith.

Later today, Goldstein and his team will decide if a course correction is needed to nudge the lander's trajectory towards a destination that is roughly 10 kilometres or so eastward of its latest projected landing site. The correction would require the spacecraft to turn itself sideways and then fire its hydrazine propellant for six seconds before resuming to its Mars-facing orientation.

According to mission manager Joe Guinn, the manoeuvre would only be executed if Phoenix appears to be drifting away from a region of the Martian northern plains that has the most desirable landing profile.

The desirable region falls in a topographic "green zone" - so-called because of its colour code in Mars Reconnaissance Orbiter (MRO) images. The green zone is defined as having no more than three large boulders (1.5 metres across) per hectare.
Dust storm

In addition to the surface terrain, Phoenix's landing could also be affected by atmospheric conditions. MRO images reveal that a minor dust storm swept across the landing site earlier today, but the disturbance is expected to dissipate well before the probe's touchdown at 1653 PDT on Sunday (0053 GMT on Monday).

While Phoenix can accommodate a high-speed entry through a dusty atmosphere, a large amount of dust over the landing site would mean a reduction in the power available to spacecraft on the surface once its solar panels are deployed.

Goldstein said that a data set with updated information on atmospheric conditions can be sent to the spacecraft up to 3 hours before the landing. Such information will be crucial for determining when key events of the landing sequence take place, including deployment of the parachute that will slow the spacecraft to a point where its pulsing thrusters can take over for a soft landing.

Tudo a postos para a aterragem da Phoenix em Marte

Será no Domingo, dia 25 de Maio.

Vamos manter os dedos cruzados. O predecessor da Phoenix, o Mars Polar Lander, despenhou-se perto do Pólo Sul de Marte em 1998. Não é garantido que esta nova sonda vá aterrar com sucesso.

Link: Site Oficial da Missão Phoenix

Fotografada avalanche em Marte!

Talvez a foto mais incrível da história da exploração do Espaço!

Clique para aumentar.

A Mars Reconnaissance Orbiter estava a passar precisamente por cima desta zona, próxima do Pólo Norte marciano, quando se deu uma avalanche! A camera de altíssima resolução HiRISE tirou a primeira foto de uma avalanche noutro planeta, e mostra mais uma vez que Marte é um planeta muito mais dinâmico do que pensávamos até há alguns anos atrás!

Fontes:

• MSNBC
• HiRISE

NASA captures dynamic Martian avalanche

First-ever photo shows tan clouds billowing away from foot of a ravine

Space.com

updated 3:50 p.m. ET March 3, 2008

A NASA spacecraft has taken the first-ever image of an avalanche in action near Mars' north pole.

The High Resolution Imaging Experiment on NASA's Mars Reconnaissance Orbiter took the photograph Feb. 19. The image, released today, shows tan clouds billowing away from the foot of a towering slope, where ice and dust have just cascaded down.

The camera was tracking seasonal changes on Mars when it inadvertently caught the avalanche on film.

HiRISE mission scientist Ingrid Daubar Spitale of the University of Arizona was the first person to notice the avalanche when sifting through images.

"It really surprised me," she said. "It's great to see something so dynamic on Mars. A lot of what we see there hasn't changed for millions of years."

The full image reveals features as small as a desk in a strip of terrain 3.7 miles (6 kilometers) wide and more than 10 times that long, at 84 degrees north latitude. Reddish layers known to be rich in water ice make up the face of a steep slope more than 2,300 feet (700 meters) tall, running the length of the image.

Mars' north pole is covered by a cap of ice, and it even snows there.

The scientists suspect that more ice than dust probably makes up the material that fell from the upper portion of the scarp.

"If blocks of ice broke loose and fell, we expect the water in them will be changing from solid to gas," said Patrick Russell of the University of Berne, Switzerland, a HiRISE team collaborator. "We'll be watching to see if blocks and other debris shrink in size. What we learn could give us a better understanding of one part of the water cycle on Mars."

What set off the landslide and whether such events are common on Mars is something else the team will be looking at.

"We don't know what set off these landslides," Russell said. "We plan to take more images of the site through the changing Martian seasons to see if this kind of avalanche happens all year or is restricted to early spring."

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

Space.com

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:

Imagem detalhada de um dos 'buracos' em Marte

Clique para aumentar.

Já falei destes buracos aqui e aqui. Esta nova imagem é muito mais detalhada e mostra bastantes detalhes no interior do 'buraco'.

Parece tratar-se de uma entrada para uma gruta, do lado direito, mas pode ser apenas um efeito da sombra.

Como este 'buraco' está localizado num lado de um vulcão, é possível que tenha sido criado quando um túnel de magma abateu.

Fonte: Bad Astronomy (ver nº 9)

NASA apresenta planos para missão tripulada a Marte

Quem segue estas questões da exploração do espaço sabe que planos nunca faltam, por isso estes planos poderão parecer apenas isso - apenas planos. Têm de significativo, no entanto, virem da própria NASA, o que lhes poderá conferir alguma credibilidade. No entanto ainda fazem referência a tecnologias muito futuristas e não testadas, como a propulsão nuclear.

Note-se também o prazo alargadíssimo de uma possível missão a Marte - 2031, ou seja, a 24 anos de distância. Muitos de nós não veremos homens a caminhar em Marte, mesmo que a NASA, por uma vez na sua existência, pudesse cumprir os prazos definidos nos seus planos.

Mas vale a pena a leitura da apresentação oficial.

Fonte: Flight Global


NASA manned Mars mission details emerge
Rob Coppinger

A 400,000kg (880,000lb) Marship would be assembled in orbit using the Ares V cargo launch vehicle for a 900-day mission to the red planet, according to details that have emerged about NASA's new Constellation programme's manned Mars mission.

The spacecraft would take a "minimal crew" to Mars in six to seven months, with the crew spending up to 550 days on the surface, according to the programme's design reference architecture 5.0, currently in development.

Each of the three to four Ares V rockets used to launch the Marship elements into low Earth orbit would need a 125,000kg payload capacity and use a 10m (32.7ft) fairing.

Crews would be sent every 26 months, will need up to 50,000kg of cargo, use an aerodynamic and powered descent method and the 40min communications delay between Earth and Mars would require autonomy or at least asynchronous operation with mission control.

Notionally launched in February 2031, the first crew's flight would be preceded by the cargo lander and surface habitat being sent in December 2028 and January 2029, respectively using two Ares V launches.

The lander will arrive around October 2029 and the habitat November the same year. Nuclear power is the preferred surface energy source. The crew will arrive in August 2031.

A second mission's habitat and lander will be launched by two Ares Vs in late 2030/early 2031 to reach Mars at the same time as the first crew. In the first quarter of 2033, the second mission's crew will leave Earth to arrive at Mars by December, while the first crew leaves Mars in January 2033 after a 17-month stay, to reach Earth by September.

The details were included in a presentation at "Enabling Exploration: The Lunar Outpost and Beyond", the October meeting of NASA's Lunar exploration analysis group.

It also states, "Conjunction class missions (long-stay) [have] fast inter-planetary transits. Successive missions provide functional overlap of mission assets," referring to the presence of a following mission's habitat and cargo lander being on Mars when its preceding mission's crew are there already.

Novas imagens dos 'buracos' em Marte mostram paredes

Os buracos descobertos há algum tempo na superfície de Marte (de que falei aqui) estão a ser de novo fotografados, pela camera HiRISE, do Mars Reconnaissance Orbiter. Uma dessas fotos revela uma parede, o que parece negar que o buraco seja uma entrada para uma enorme gruta subterrânea, sendo apenas... um buraco.

No entanto, em minha opinião, e se clicarem na imagem à direita, nada está ainda provado, na realidade não se sabe o que há do lado esquerdo da imagem.

Continuarei a seguir este 'mistério'.

Fonte: New Scientist

Strange Martian feature not a 'bottomless' cave after all

20:49 30 August 2007
NewScientist.com news service
David Shiga

An extremely dark feature on Mars is probably just a pit – not the entrance to a deep cavern that future astronauts could call home, a new image reveals.

The 150- by 157-metre feature was first noticed in an image taken by NASA's Mars Reconnaissance Orbiter on 5 May 2007 using a camera called the High Resolution Imaging Science Experiment (HiRISE).

Viewed from directly overhead, the dark spot showed no evidence of walls or a floor, leading some HiRISE scientists to suspect it was the opening to a cavern (scroll down for image).

That would have been exciting, since caves might be good places to search for life, as they offer protection from intense ultraviolet radiation from the Sun. Caves could also provide shelter for any future human visitors to Mars.

The new image, however, suggests the feature is just a vertical shaft cutting into the surface. Taken on 8 August from a different angle, the image reveals a wall on the feature's eastern side.

Bouncing robots

It is not clear how deep the pit is, because its floor has still not been seen. But the HiRISE team says it must be at least 78 metres deep.

Similar "pit craters" form on the flanks of volcanoes in Hawaii when lava deep underground drains away, causing the overlying rock to collapse downward, forming a well.

Although this particular feature did not turn out to be a cave entrance, Mars may have caves in the form of intact "lava tubes" – long tube-shaped cavities sometimes left behind when underground lava drains away. Some collapsed lava tubes are known on Mars and intact ones may well be present too.

Scientists have designed small bouncing robots that could one day investigate Martian caves.

Futuro dos rovers Spirit e Opportunity em grave risco devido à tempestade global em Marte

A tempestade global de areia em Marte (de que já aqui falei) continua a piorar, e a NASA está a ponderar a possibilidade agora bem real de vir a perder um ou ambos os rovers Spirit e Opportunity.

Esta imagem compara a distribuição do pó na atmosfera de Marte
antes da tempestade (22 de Junho) e agora, durante a tempestade.

Os rovers tinham previstas missões que não iam além dos 90 dias. No entanto já estão a funcionar em Marte há mais de 3 anos! Mas o fim pode estar próximo, já que estes robots dependem da luz solar para carregar as suas baterias, e também para os manter quentes - muitos dos circuitos electrónicos dos rovers não podem ser expostos a temperaturas excessivamente baixas.

Esta tempestade é tão intensa que apenas chega à superfície 1% da radiação solar!

Esta sequência de imagens foi captada a partir do rover Opportunity, entre
14 de Junho e 19 de Julho de 2007. Os números no topo representam a
opacidade da atmosfera.

Links:

• Space.com 1, 2
• NASA Jet Propulsion Laboratory - filme em Quicktime (26Mb), legendado em inglês
  

Mars rovers struggle to weather dust storm
3:05 PM, 7/22/07,

NASA's twin Mars rovers are struggling to weather widespread dust storms that have reduced solar power generation to critically low levels. If conditions worsen, one or both robots could succumb to frigid temperatures and "bite the dust" after three-and-a-half years of unprecedented exploration.

"The team is concerned. We all have very strong bond with these two rovers," said John Callas, rover project manager at the Jet Propulsion Laboratory in Pasadena, Calif. "We think of them as our children and we're worried for them right now because they're in this dangerous environmental condition on Mars.

"We're trying to help them as much as we can, but there's only so much we can do from the ground," he said by telephone Friday. "Ultimately it comes down to that. But these things are such intrepid, feisty vehicles. So the mood is 'guarded optimism.' We're watching the weather every day."

The dust storms flared up over the past month just as engineers were preparing to order Opportunity into Victoria Crater to study exposed bedrock that might hold valuable clues about the role of water on the red planet in the distant past.

Instead, the rover remains parked outside the crater, its electronic systems shut own to conserve power under a deeply overcast sky. Half a world away, the Spirit rover was in much the same state, although slightly more power positive than Opportunity.

"The figure of merit on the weather that we track is atmospheric opacity," Callas said. "The higher that number is (known by the Greek letter tau), the more sunlight is lost. Our last estimates of tau for Opportunity was around 5, which means that less than 1 percent of the direct sunlight is getting through the atmosphere. That means that basically the solar array energy is coming from the diffuse sunlight. So it's like a very overcast day and all you have is diffuse light.

"The tau for Spirit is right now at about 4, so it's not as high but it's still exceedingly high. And these numbers are higher than any numbers ever measured by Viking. The highest number Viking measured was about 4. Mariner 9, when it arrived at (Mars) the entire planet was covered with a massive global dust storm that obscured the surface. This is not quite at that scale, but this is probably the worst we've seen in, I don't know, over a decade, I guess."

Spirit and Opportunity landed on opposite sides of Mars three weeks apart in January 2004. They were designed to operate for at least 90 days and while hopes were high they would survive the harsh martian environment beyond their design life, no one expected them to last as long as they have. As of last week, Opportunity had logged some 1,240 days on Mars and the rovers are considered among the most successful interplanetary missions ever launched.

At present, the ongoing martian dust storm is best described as "hemispheric." It doesn't shroud the entire planet but Spirit and Opportunity, on opposite sides of Mars, are both affected.

"A possible outcome of this storm is that one or both rovers could be damaged permanently or even disabled," NASA said in a statement Friday. "Engineers will assess the capability of each rover after the storm clears."

The forecast, Callas said, is "not good. More of the same."

"And it's been variable. We've been spoofed a couple of times where the tau would spike up and then it would turn around and drop down a little bit and we'd think oh, well the worst is past. And then it would just turn around again and spike back up to a new record."

Conditions are slightly worse over Opportunity. Solar panel output stood at around 720 watt hours of electricity before the dust storm began. Seven hundred watt hours is enough electricity to power a 100-watt bulb for seven hours.

When the solar panel output dropped below 400 watt hours a day, Opportunity was parked and its science observations terminated. On July 17, power output dropped to 148 watt hours and one day later, to 128 watt hours, barely enough for the heaters needed to keep the electronics warm enough to prevent problems.

"What we've had to do is pretty much take everything out of the sequence the rover normally does," Callas said. "So it just wakes up and goes back to sleep after being up for a short amount of time. We do have communications sessions, but right now we're sprinkling them about every three days."

Flight controllers sent commands to Opportunity Friday but did not plan to check in again until Monday.

Callas said the electronics in each rover is mounted inside an insulated box and that is thermostatically protected. The avionics system is designed to operate at temperatures as low as minus 40 degrees Fahrenheit and to survive, powered down, at temperatures as low as minus 67 degrees. Below that, the rover would be at risk of failures from cracked wires or damage to other components.

So far, ground temperatures near Opportunity are running at around minus 26 degrees. And even if one or both orbiters ultimately had to be powered down and temperatures dropped below allowable limits, "it would not be certain death," Callas said. "There's some expectation that if we got outside of our operating regimes that the hardware would hang together."

When the sky eventually clears, "the rover would power back up, it would wake up on its own and it would boot up and it would start phoning home."

Callas said as long as the rovers remain power positive - generating more electricity than they consume - "we could ride this out forever."

"But if it gets just a little bit worse, then that could tip us over the edge and then we'd start running negative," he said. "What you do is, you're taking more energy out of the batteries each day than you're putting back in."

Eventually, the batteries would be drained and no power would be available for the heaters. Engineers are hopeful it won't come to that.

Foi há 10 anos - a Mars Pathfinder aterrou em Marte

4 de Julho de 1997


A Pathfinder foi a primeira aterragem com sucesso em Marte, a seguir às missões Viking, de 1976, e era composta por duas secções - uma 'estação-base' e um pequeno rover, o Sojourner.

O site da missão foi, na altura, bombardeado com centenas de milhares de visitas por dia. Eu, como tantos outros, ligava-me ao site logo de manhãzinha, do emprego, para ver as últimas fotos de Marte.

A base da 'Mars Pathfinder', fotografada pelo pequeno rover Sojourner.

O pequeno rover Sojourner.

Assim, além de testar as tecnologias que mais tarde seriam aplicadas nos rovers Spirit e Opportunity (ainda a operar em Marte), a Mars Pathfinder também mostrou, nos anos iniciais da Internet e da World Wide Web, ser possível ter um grande êxito com um site sobre investigação científica, e abriu assim o caminho à variedade de sites sobre estes temas que conhecemos hoje. E na altura não havia banda-larga! Era tudo modems a 28kbps, ou menos!

Os 'Twin Peaks', em cima à direita.

Ficaram famosas, na altura, as panorâmicas do local da aterragem, com o destaque para duas pequenas elevações, que foram baptizadas 'Twin Peaks', em homenagem a uma série de TV muito em voga na altura.

A Pathfinder operou com sucesso durante 90 dias (era previsto funcionar 30), findos os quais deixou de transmitir para a Terra.

No fim da missão tinham sido enviadas para Terra 16.000 imagens da 'base', e 550 imagens do rover!

Pensa-se, através de fotos de muito alta resolução tiradas da órbita de Marte, que o rover Sojourner ainda tenha funcionado por mais uns dias após a Pathfinder parar de transmitir para a Terra,

Talvez um dia se venha a saber o que realmente se passou com o pequeno robot! Talvez o local seja designado como Histórico, e protegido para as gerações vindouras. Assim espero, e orgulho-me de ter sido um dos que, à distância, exploraram Marte, quase em directo, pela primeira vez na História da Humanidade.

Links:

• Site Oficial da missão Mars Pathfinder
• Unmanned Spaceflight
• Planetary Society