Posted on by Fraser Cain

Audio: Get Ready for Deep Impact

Deep Impact’s impactor module on a collision course with Comet Tempel 1. Image credit: NASA/JPL. Click to enlarge.
Listen to the interview: Get Ready for Deep Impact (6.1 MB)

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Fraser: Can you give me a preview for what we’re going to be seeing on July 4th?

Dr. Lucy McFadden: I wish I knew exactly what was going to happen on July 4th, but this is an experiment. I can tell you what we think we might see, but chances are it may be significantly different.

So, we have a spacecraft on its way to Comet Tempel 1, which is a short-period comet that orbits – comes into the inner solar system – about once every 5.5 years. It is about the size of Washington DC. It can be fit into the area of Washington DC, but it’s a little bit elongated. It’s about 14 km by 4 km by 4 km, and as our spacecraft is heading toward it, we have planned to actually separate the spacecraft into two parts. Let me set the stage here, this comet is in orbit around the Sun. It’s coming to its closest point of the Sun, called its perihelion, and thus be moving at its fastest speed through the solar system in early July. Our spacecraft is also in orbit around the Sun, and it’s heading to intercept the orbit of the comet. 24 hours before we plan to impact this comet, we’re going to separate the two spacecraft, the impactor and the flyby. The impactor will continue on its collision course to the comet, and the flyby – or mother ship – will slow down a little bit and change its direction ever so slightly so that it will be able to watch as the impactor hits the comet. When it hits the comet, when we have this cosmic collision in space, what’s going to happen is the energy of the impact is going to propagate into the comet itself, in the form of a shock wave. This shock wave will plough into the comet; how deep, we don’t know. But at some point, the force of the material in the comet itself will push back on the advancing energy shock wave and push material out of the comet. We will have formed a crater with ejected material coming out of the hole that we created.

Now, you may ask, why are we doing this? We’re doing this to take a look – to take advantage of the opportunity of this comet being so close to us – to take a look at the inside of the comet; to see what the inside is made of, and see what structure is there.

To elaborate more, I think I need to give you some perspective on what comets are, and what they are in the solar system. I like to say they’re the oldest and coldest part of the solar system. They formed at the edges of the solar system, hundreds of thousands of times the distance that the Earth is from the Sun. So, everything where comets formed is cold. They also formed 4.5 billion years ago, when the solar system was forming. They have never been incorporated into a planet. So they’re both old and cold as well. We’re taking advantage of the comets coming closer to the Earth to use it as a laboratory and as a probe to distant edges of the solar system in both space and time.

Fraser: Now, Deep Impact only launched a couple of months ago, so did we get really lucky with Tempel 1 being at the wrong place at the right time?

Dr. McFadden: Yeah, well, from my perspective it was at the right place at the right time.

Fraser: I was more looking from the perspective of the comet.

Dr. McFadden: Let me say two things here. First of all, the comet isn’t going to be harmed. Let’s get some perspective here in terms of the mass of the spacecraft versus the mass of the comet. Or the energy of the spacecraft versus the energy of the comet in motion. It’s equivalent to a gnat, or a small mosquito being run into by a 767 aircraft. So, we’re not going to hit the comet. But, needless to say, I’ll let you take the perspective of the comet if you want. But yes, it was in the right place, or the wrong place, at this time. NASA said, when it issued its announcement of opportunity for space exploration missions, they said that this announcement covers money available within a certain time frame, and the time frame was between 2000 and 2006. And so, we went looking for comets that were available during the time NASA would give us money, and then when we found Comet Tempel 1 close to perihelion, when it’s moving fastest, that also pleased us because the faster the comet’s moving, the more energy involved in the transfer to create the crater. So, it’s good from that point of view. And then there’s a third, but secondary reason why Comet Tempel 1 is good; it’s not as active as some comets might be. There’s not as much dust and jet activity associated with Comet Tempel 1, which might be confusing or make it hard for us to actually observe the formation of the crater when we hit it. So, Comet Tempel 1 fits.

Fraser: How are we going to be observing it from here on Earth and from space?

Dr. McFadden: We have the spacecraft observing it from space – our Deep Impact spacecraft. We have the Rosetta spacecraft, which is heading to another comet, will also observe it from space. We have NASA’s three Great Observatories: Chandra, Hubble and Spitzer will be observing it. Three different wavelengths; Chandra’s an X-ray telescope, and Hubble’s an optical and near-infrared imaging telescope. We’ll be observing some spectroscopy with Hubble too. And then Spitzer’s an infrared telescope. So, we’ll be using those. As well as all the major observatories around the world will be observing the comet, before, during and after impact. So we’re having a worldwide observing campaign.

Fraser: And how will the pictures from Deep Impact compare to the pictures we saw from Stardust?

Dr. McFadden: It’s interesting, I’m using the images from Stardust to practice interpreting the images we get from Deep Impact. We will get a closer look at Comet Tempel 1 than the Stardust spacecraft did; we will be flying closer – we’ll be flying 500 km from Comet Tempel 1, whereas the Stardust spacecraft was 1,100 or 1,300 km distant.

Fraser: I remember that Stardust got hit quite a bit by debris, how will Deep Impact do if it’s going to be closer to the comet?

Dr. McFadden: You have to remember that the main objective of Stardust was to collect dust, so, they wanted to get hit. So they flew into the region with the largest dust density. What we do when we fly through that same region is we turn the spacecraft away into shield mode to protect the telescope during the time when we should be getting the greatest number of hits from dust and debris. And we actually fly at an angle. Most of the debris exists in the plane of the orbit, in the direction of its motion, and so the spacecraft will fly past it at an angle; so there’ll be a short, 20 minute period when we will not be observing to protect the cameras.

Fraser: Once Deep Impact completes its flyby, will you have any additional scientific targets you’d like to be able to use the spacecraft for, once it gets out of visual range of Tempel 1?

Dr. McFadden: There are currently no specific plans for observing in a follow-on mission; that has to be approved by NASA. We have done some research and know that there are another comet or two that we could observe, but we haven’t gotten approval for that yet.

Fraser: So, in your wildest dreams, what will turn up on July 4th?

Dr. McFadden: Well, my wildest dream is that the impactor will go into the comet and come out the other side, but that’s not very likely.

Fraser: Okay then, maybe a less wild dream.

Dr. McFadden: Okay, less wild, in order of probability is that the comet will have the consistency of a brick, for example, and the impactor will hit it and not do much damage to the surface, or not really create much of an impact because the comet is the consistency of a brick. But that’s not very likely either. On the other extreme, what if the comet is like Corn Flakes? If it’s like Corn Flakes, we should get a spectacular display of ejecta. We call it an ejecta curtain during the formation of the crater, and I’m hoping that that’s what we’ll see, because that would be very dramatic. And hopefully we could watch as we’re taking fast pictures with very short exposures repeatedly. We’ll be clicking as we go by. If we have a big ejecta curtain, we should be able to see the ejecta form, or traveling along in space, and that will allow us to determine the most information about the internal structure of the comet itself. So that’s what I’m hoping will happen.

Posted on by Fraser Cain

Planetary Systems Can Form in Hellish Surroundings

Artist interpretation of protoplanetary systems forming inside a nebula. Image credit: CfA. Click to enlarge.
Meeting this week in Cambridge, Mass., astronomers using the Submillimeter Array (SMA) on Mauna Kea, Hawaii, confirmed, for the first time, that many of the objects termed “proplyds” found in the Orion Nebula do have sufficient material to form new planetary systems like our own.

“The SMA is the only telescope that can measure the dust within the Orion proplyds, and thereby assess their true potential for forming planets. This is critical in our understanding of how solar systems form in hostile regions of space,” said Jonathan Williams of the University of Hawaii Institute for Astronomy, lead author on a paper submitted to The Astrophysical Journal.

Surviving in the chaotic regions within the Orion Nebula where stellar winds can reach a staggering two million miles per hour and temperatures exceed a searing 18,000 degrees Fahrenheit, the question remained – would enough material endure to form a new solar system or would it be eroded away into space like wind and sand eroding away desert cliffs? It now appears that these protoplanetary disks are quite tenacious, bringing new grounds for optimism in the search for planetary systems.

Imaged by the Hubble Space Telescope back in the early 1990s as misshapen silhouettes against the nebular background, the most spectacular proplyds appear bright. Their surrounding ionized cocoons glow due to their close proximity to a nearby hot star formation called the Trapezium. The Trapezium is a star cluster consisting of more than 1,000 young, hot stars that are only 1 million years old. They condensed out of the original cold, dark cloud of gas that now glows from their ionizing light. They are crowded into a space about 4 light-years in diameter, the same as the distance between the Sun and Proxima Centauri, the next closest star in space.

Blasted by the solar winds of the Trapezium, the proplyds are the next generation of smaller stars to arise in Orion, this time with visible discs that may be forming planets. It has remained unclear, however, whether they contained enough material to form stable planetary systems. Using the SMA, astronomers now have been able to probe deep inside these disks to measure their mass and to unravel the formation process presented by these potential infant solar systems.

“While the Hubble pictures were spectacular, they revealed only disk-like shapes that did not tell us the amount of material present,” said David Wilner, of the Harvard-Smithsonian Center for Astrophysics (CfA). Since some of the discs appear to be comparable in size and mass to our own solar system, this strengthens the connection between the Orion proplyds and our origins.

Since most Sun-like stars in the Galaxy eventually form in environments like the Orion Nebula, the SMA results suggest that the formation of solar systems like our own is common and a continuing event in the Galaxy.

“The same cycle of birth, life and death we experience here on Earth is repeated in the stars overhead. Now, the SMA provides us with a front-row seat in unraveling the wonder of these cosmic events,” reflected Wilner.

Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center for Astrophysics (CfA) is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe.

Original Source: CfA News Release

Posted on by Fraser Cain

Podcast: Get Ready for Deep Impact

July 4th is Independence Day In the United States, and Americans typically enjoy their holiday with a few fireworks. But up in space, 133 million kilometres away, there’s going to be an even more spectacular show… Deep Impact. On July 4th, a washing machine-sized spacecraft is going to smash into Comet Tempel 1, carve out a crater, and eject tonnes of ice and rock into space. The flyby spacecraft will watch the collision from a safe distance, and send us the most spectacular pictures ever taken of a comet – and its fresh bruise. Dr. Lucy McFadden is on the science team for Deep Impact, and speaks to me from the University of Maryland.
Continue reading “Podcast: Get Ready for Deep Impact”

Posted on by Fraser Cain

Large Rocky Planet Discovered

Artist illustration of the rocky planet around the M dwarf Gliese 876. Image credit: NSF. Click to enlarge.
Taking a major step forward in the search for Earth-like planets beyond our own solar system, a team of astronomers has announced the discovery of the smallest extrasolar planet yet detected. About seven-and-a-half times as massive as Earth, with about twice the radius, it may be the first rocky planet ever found orbiting a normal star not much different from our Sun.

All of the nearly 150 other extrasolar planets discovered to date around normal stars have been larger than Uranus, an ice-giant about 15 times the mass of the Earth.

“We keep pushing the limits of what we can detect, and we’re getting closer and closer to finding Earths,” said team member Steven Vogt, a professor of astronomy and astrophysics at the University of California, Santa Cruz.

?Today’s results are an important step toward answering one of the most profound questions that mankind can ask: Are we alone in the universe?? said Michael Turner, head of the Mathematical and Physical Sciences Directorate at the National Science Foundation, which provided partial funding for the research.

The newly-discovered ?super-Earth? orbits the star Gliese 876, located just 15 light years away in the direction of the constellation Aquarius. This star also possesses two larger, Jupiter-size planets. The new planet whips around the star in a mere two days, and is so close to the star’s surface that its temperature probably tops 400 to 750 degrees Fahrenheit (200 to 400 degrees Celsius)?oven-like temperatures far too hot for life as we know it.

Nevertheless, the ability to detect the tiny wobble that the planet induces in the star gives astronomers confidence that they will be able to detect even smaller rocky planets in orbits more hospitable to life.

“This is the smallest extrasolar planet yet detected and the first of a new class of rocky terrestrial planets,” said team member Paul Butler of the Carnegie Institution of Washington. “It’s like Earth’s bigger cousin.”

The team measures a minimum mass for the planet of 5.9 Earth masses, orbiting Gliese 876 with a period of 1.94 days at a distance of 0.021 astronomical units (AU), or 2 million miles.

Though the team has no direct proof that the planet is rocky, its low mass precludes it from retaining gas like Jupiter. Three other purported rocky planets have been reported, but they orbit a pulsar, the flashing corpse of an exploded star.

“This planet answers an ancient question,” said team leader Geoffrey Marcy, professor of astronomy at the University of California, Berkeley. “Over 2,000 years ago, the Greek philosophers Aristotle and Epicurus argued about whether there were other Earth-like planets. Now, for the first time, we have evidence for a rocky planet around a normal star.”

Marcy, Butler, theoretical astronomer Jack Lissauer of NASA/Ames Research Center, and post-doctoral researcher Eugenio J. Rivera of the University of California Observatories/Lick Observatory at UC Santa Cruz presented their findings today (Monday, June 13) during a press conference at NSF in Arlington, Va.

Their research, conducted at the Keck Observatory in Hawaii, was supported by NSF, the National Aeronautics and Space Administration, the University of California and the Carnegie Institution of Washington.

A paper detailing the results has been submitted to The Astrophysical Journal. Coauthors on the paper are Steven Vogt and Gregory Laughlin of the Lick Observatory at the University of California, Santa Cruz; Debra Fischer of San Francisco State University; and Timothy M. Brown of NSF?s National Center for Atmospheric Research in Boulder, Colorado.

Gliese 876 (or GJ 876) is a small, red star known as an M dwarf ? the most common type of star in the galaxy. It is located in the Aquarius constellation, and, at about one-third the mass of the sun, is the smallest star around which planets have been discovered. Butler and Marcy detected the first planet there in 1998; it proved to be a gas giant about twice the mass of Jupiter. Then, in 2001, they reported a second planet, another gas giant about half the mass of Jupiter. The two are in resonant orbits, the outer planet taking 60 days to orbit the star, twice the period of the inner giant planet.

Lissauer and Rivera have been analyzing Keck data on the Gliese 876 system in order to model the unusual motions of the two known planets, and three years ago got an inkling that there might be a smaller, third planet orbiting the star. In fact, if they hadn’t taken account of the resonant interaction between the two known planets, they never would have seen the third planet.

“We had a model for the two planets interacting with one another, but when we looked at the difference between the two-planet model and the actual data, we found a signature that could be interpreted as a third planet,” Lissauer said.

A three-planet model consistently gave a better fit to the data, added Rivera. “But because the signal from this third planet was not very strong, we were very cautious about announcing a new planet until we had more data,” he said.

Recent improvements to the Keck Telescope’s high-resolution spectrometer (HIRES) provided crucial new data. Vogt, who designed and built HIRES, worked with the technical staff in the UC Observatories/Lick Observatory Laboratories at UC Santa Cruz to upgrade the spectrometer’s CCD (charge coupled device) detectors last August.

“It is the higher precision data from the upgraded HIRES that gives us confidence in this result,” Butler said.

The team now has convincing data for the planet orbiting very close to the star, at a distance of about 10 stellar radii. That’s less than one-tenth the size of Mercury’s orbit in our solar system.

“In a two-day orbit , it’s about 200 degrees Celsius too hot for liquid water,” Butler said. “That tends to lead us to the conclusion that the most probable composition of this thing is like the inner planets of this solar system ? a nickel-iron rock, a rocky planet, a terrestrial planet.”

“The planet’s mass could easily hold onto an atmosphere,” noted Laughlin, an assistant professor of astronomy at UC Santa Cruz. “It would still be considered a rocky planet, probably with an iron core and a silicon mantle. It could even have a dense steamy water layer. I think what we are seeing here is something that’s intermediate between a true terrestrial planet like the Earth and a hot version of the ice giants Uranus and Neptune.”

Combined with improved computer software, the new CCD (charge coupled device) detectors designed by this team for Keck’s HIRES spectrometer can now measure the Doppler velocity of a star to within one meter per second ? human walking speed ? instead of the previous precision of three meters per second. This improved sensitivity will allow the planet-hunting team to detect the gravitational effect of an Earth-like planet within the habitable zone of M dwarf stars like Gliese 876.

“We are pushing a whole new regime at Keck to achieve one meter per second precision, triple our old precision, that should also allow us to see Earth-mass planets around sun-like stars within the next few years,” Butler said.

“Our UC Santa Cruz and Lick Observatory team has done an enormous amount of optical and technical and detector work to make the Keck telescope a rocky planet hunter, the best one in the world,” Marcy added.

Lissauer also is excited by another feat reported in the paper submitted to the journal. For the first time, he, Rivera and Laughlin have determined the line-of-sight inclination of the orbit of the stellar system solely from the observed Doppler wobble of the star. Using dynamical models of how the two Jupiter-size planets interact, they were able to calculate the masses of the two giant planets from the observed shapes and precession rates of their oval orbits. Precession is the slow turning of the long axis of a planet’s elliptical orbit.

They showed that the orbital plane is tilted 40 degrees to our line of sight. This allowed the team to estimate the most likely mass of the third planet as seven and a half Earth masses.

“There’s more dynamical modeling involved in this study than any previous study, much more,” Lissauer said.

The team plans to continue to observe the star Gliese 876, but is eager to find other terrestrial planets among the 150 or more M dwarf planets they observe regularly with Keck.

“So far we find almost no Jupiter-mass planets among the M dwarf stars we’ve been observing, which suggests that, instead, there is going to be a large population of smaller mass planets,” Butler noted.

Original Source: Carnegie Institute News Release

Posted on by Fraser Cain

What’s Up This Week – June 13 – June 19, 2005

Comet Tempel 1. Deep Impact Gallery. Click to enlarge.
Monday, June 13 – Today in 1983, Pioneer 10 made space history as it became the first manmade object to leave our solar system.

Have you been watching your equinox marker? Today marks an important date for the Sun’s journey across the sky. In ancient times, and even in our modern ones, sundials are used to measure time. The position of the Sun today will allow a well placed sundial will match a standard clock. Although a sundial is fairly accurate, we apply a correction known as the Equation of Time and only four times a year does it reach zero.

Comet 9/P Tempel 1 is sailing through Virgo and is now nearing magnitude 9 – putting it within reach of most telescopes. If you haven’t found the object of Deep Impact yet, you’ll be happy to know that Heaven’s Above is now offering highly accurate locator charts. In a smaller scope, it is dim, small, and has a slight concentration toward the core. For the very large scope, note the intense stellar nucleus and wide fan of the tail. I have been observing this comet now for weeks and it looks very much like the picture in a big scope. Now, go… Find it!

Tuesday, June 14 – For those located near 40 degrees north, today will be the earliest sunrise of the year. Tonight the Moon reaches first quarter and this would be a wonderful opportunity to look for the “Alpine Valley” in the lunar northern hemisphere. Valles Alpes will appear as a long, dark scar running through the foothills west of crater Aristotle.

If you would like more of a challenge, then know that Pluto is now at opposition and viewable in Serpens Caudia west of Xi Serpentis. At close to magnitude 14, the tiny planet will require at least a moderate-sized telescope to view, and a very accurate locator chart. In order to distinguish Pluto from background stars, I suggest sketching the field and observing over a number of nights to see which “star” moves.

Wednesday, June 15 – For most observers, Jupiter and the Moon will have wonderfully close encounter as they follow each other across the sky. Tonight on the lunar surface, look just south of central for the descending three rings of Ptolmaeus, Alphonsus and Arzachel. To the west of Arzachel near the terminator, you will see the smooth floor of Mare Nubium. Look for a very curious feature called the “Straight Wall”. It will appear like a very thin, black line that extends from crater Thebit.

While out, take the time to check out Alpha Herculis -Ras Algethi. You will find it not only to be an interesting variable, but a colorful double as well. The primary star is one of the largest known red giants and at about 430 light years away, it is also one of the coolest. Its 5.4 magnitude greenish companion star is easily separated in even small scopes – but even it is a binary! This entire star system is enclosed in an expanding gaseous shell that originates from the evolving red giant. Enjoy it tonight.

Thursday, June 16 – North Australia and New Zealand are featured on this universal date as the Moon occults Jupiter. Be sure to check out this IOTA webpage for precise times in your area. You won’t want to miss it…

The June Lyrids meteor shower will also peak in the early morning hours and will be best after the the Moon has set. With the radiant near bright Vega. you may see up to 15 faint blue meteors per hour from this branch of the May Lyrid meteor stream.

Valentina Tereshkova became the first woman in space, 32 years ago today. She flew aboard the Russian spacecraft, Vostok 6, and her solo flight is still unique.

Although the Moon will fade the view, telescope users might be able to just make out Comet 2004 Q2 Machholz as it passes about a degree east of Alpha Canum. Although we have explored Cor Caroli before, take the time again to check out the soft orange and lavender colors of this splendid double star.

Friday, June 17 – Ah, to waltz around the “Bay of Rainbows” with you! Tonight the lunar surface will offer the telescopic opportunity to view one of perhaps the most romantic of areas – Sinus Iridium. Look to the lunar north where you will discover the smooth bay partially encircled by the Juras Mountains. Promentoriums Heraclides and LaPlace stand like distant lighthouses at either tip. If seeing conditions are good, you will note many graceful rilles, like frozen waves, crossing its floor.

If you don’t own a telescope, Sinus Iridium still shows quite well in binoculars. For unaided viewers? See if you can spot cool, blue Spica nearby.

Saturday, June 18 – Today in 1983, Sally Ride became the first American woman to go into orbit. Sally’s ride? The Space Shuttle!

But you won’t need the Space Shuttle to take you into orbit tonight as the lunar surface becomes a binocular hunter’s paradise. Starting in the lunar north, look for the blank, loveless eye of Plato and the dramatically brightening rays of Tycho to the south. Look for ancient Copernicus just slightly west of the mid-section and the brilliant points of light near the terminator that are Keplar to the north and Artistarchus to its south. Eroded crater Gassendi on the shore of Mare Humorum to the south will round out our lunar tour.

For North American observers, be sure to check out Saturn before it sets. Like a temporary “moon”, 7th magnitude star SAO79782 will be visible to its north.

Sunday, June 19 – If you are up just before dawn this morning, keep an eye on the sky as we pass through another portion of the Ophiuchid meteor stream. The radiant for this pass will be more near Sagittarius and the fall rate varies from 8 to 20, but can sometimes produce unexpectedly more.

No matter what time zone you live in, Jupiter will be a lively place tonight! For some viewers, you will see a very close pairing of Ganymede and Europa – and for others, Io and Europa. For viewers well positioned at 22:19 UT, the “Great Red Spot” will also transit.

If you haven’t been following the intricate dance of the evening planets, then go out just after sunset and look! Venus, Saturn, and Mercury are now within a fist width apart, sitting low in the west-northwest during. Mercury, the lowest of the three, sets about 1 1/2 hours after sunset, so don’t wait too late to observe. The planets will contine to move closer all next week, so mark your calendars for next weekend when they appear only 1.5 degrees apart. You won’t want to miss this!

Keep your eyes on the skies and may all your journeys be at Light Speed! …~Tammy Plotner

Posted on by Fraser Cain

Mmmm, Food From Mars

Spirulina Gnocchis, a recipe that could be cooked up from food grown in space. Image credit: ESA. Click to enlarge.
‘Martian bread and green tomato jam’, ‘Spirulina gnocchis’ and ‘Potato and tomato mille-feuilles’ are three delicious recipes that two French companies have created for ESA and future space explorers to Mars and other planets.

The challenge for the chefs was to offer astronauts well-flavoured food, made with only a few ingredients that could be grown on Mars. The result was 11 tasty recipes that could be used on future ESA long-duration space missions. ADF ? Alain Ducasse Formation and GEM are the two French companies that produced the recipes, and their mutual experience in creating new products and ?haute cuisine? have led to excellent results.

The menus were all based on nine main ingredients that ESA envisions could be grown in greenhouses of future colonies on Mars or other planets. The nine must comprise at least 40% of the final diet, while the remaining (up to) 60% could be additional vegetables, herbs, oil, butter, salt, pepper, sugar and other seasoning brought from Earth.

“We are aiming initially at producing 40% locally for astronauts’ food on future long-duration space missions, for example to Mars,” says Christophe Lasseur, ESA’s biological life-support coordinator responsible for recycling and production of air, water and food for long-term space missions.

“Why 40%? By growing enough plants to cover around 40% of what we eat, we also get ‘for free’ the oxygen and water needed to live”, explains Lasseur.

The nine basic ingredients that Lasseur plans to grow on other planets are: rice, onions, tomatoes, soya, potatoes, lettuce, spinach, wheat and spirulina ? all common ingredients except the last. Spirulina is a blue-green algae, a very rich source of nutrition with lots of protein (65% by weight), calcium, carbohydrates, lipids and various vitamins that cover essential nutritional needs for energy in extreme environments.

Today all the food for astronauts in space is brought from Earth, but this will not be possible for longer missions. Although still on the drawing board, ESA has already started research to see what could be grown on other planets – and what a self-supporting eco-system might look like on Mars.

“In addition to being healthy and sufficiently nutritious for survival, good food could potentially provide psychological support for the crew, away from Earth for years,” emphasises Lasseur.

ADF chef Armand Arnal, adds: “The main challenge was to create a wide panel of recipes, distinct and full-flavoured, with only nine basic products.”

“Moreover, we had absolute restrictions on using salt, but were allowed to add a bit of sugar and fat, ingredients normally essential to the elaboration of a dish and to highlight its flavours.”

Original Source: ESA News Release

Posted on by Fraser Cain

Pluto Mission Arrives at NASA for Testing

Artist illustration of New Horizons with Pluto and Charon. Image credit: JHUAPL/SwRI. Click to enlarge.
The first spacecraft designed to study Pluto, the last planet in our solar system, arrived at NASA?s Goddard Space Flight Center (GSFC) in Greenbelt, Md., today for a series of pre-launch checkouts.

“We are extremely proud to have the NASA’s New Horizons mission make Goddard the first stop in its journey to the last planet,” said Dr. Ed Weiler, GSFC Center Director. “The New Horizons mission to Pluto is an historic journey of exploration to unlock secrets from a mysterious planet so distant that the Sun is just a bright star in the sky.”

The spacecraft will be at Goddard for the next three months where team members will check New Horizons? balance and alignment in a series of spin tests; put it before wall-sized speakers that simulate the noisy vibrations of launch; and seal it for several weeks in a four-story thermal-vacuum chamber that duplicates the extreme cold and airless conditions of space. After departing Goddard in the Fall, the spacecraft will make its way to the Kennedy Space Center, Fla. for final launch preparations.

New Horizons is the first mission to Pluto and its moon, Charon. As part of an extended mission, the spacecraft would head deeper into the Kuiper Belt to study one or more of the icy mini worlds in that vast region. New Horizons is scheduled for launch in January 2006 from Cape Canaveral Air Force Station, Fla., aboard a Lockheed Martin Atlas V. New Horizons should begin its five-month-long flyby reconnaissance of Pluto-Charon in summer 2015.

New Horizons is carrying an extensive complement of science instruments. Goddard has a major role in the Southwest Research Institute?s Ralph instrument. Ralph’s main objectives are to obtain high resolution color and surface composition maps of the surfaces of Pluto and Charon. The instrument has two separate channels: the Multispectral Visible Imaging Camera (MVIC) and the Linear Etalon Imaging Spectral Array (LEISA). A single telescope with a 3-inch (6-centimeter) aperture collects and focuses the light used in both channels. MVIC, provided by Ball Aerospace in from Boulder Colo., operates at the visible wavelength to produce color maps. LEISA operates at infrared wavelengths. LEISA, provided by Goddard, will be used to map the distribution of frosts of methane, molecular nitrogen, carbon monoxide, and water over the surface of Pluto and the water frost distribution over the surface of Charon.

New Horizons is the first mission in NASA?s New Frontiers program of medium-class, high-priority solar system exploration projects. The spacecraft is managed by the John Hopkins University Applied Physics Laboratory in Laurel, Md. The Principal Investigator Dr. Alan Stern, is from the Southwest Research Institute, San Antonio, TX. The mission team includes Goddard Space Flight Center, APL, Ball Aerospace Corporation, the Boeing Company, the Jet Propulsion Laboratory, Pasadena, Calif. Stanford University, Calif. KinetX, Inc., Tempe, AZ, Lockheed Martin Corporation, University of Colorado at Boulder, the U.S. Department of Energy and a number of other firms, NASA centers and university partners.

For more information on the mission, visit: http://pluto.jhuapl.edu.

Original Source: NASA News Release

Update: Pluto is not a planet

Posted on by Fraser Cain

Spitzer View of a Dead Star

Supernova remnant Cassiopeia A. Image credit: NASA/JPL. Click to enlarge.
An enormous light echo etched in the sky by a fitful dead star was spotted by the infrared eyes of NASA’s Spitzer Space Telescope.

The surprising finding indicates Cassiopeia A, the remnant of a star that died in a supernova explosion 325 years ago, is not resting peacefully. Instead, this dead star likely shot out at least one burst of energy as recently as 50 years ago.

“We had thought the stellar remains inside Cassiopeia A were just fading away,” said Dr. Oliver Krause, University of Arizona, Tucson. “Spitzer came along and showed us this exploded star, one of the most intensively studied objects in the sky, is still undergoing death throes before heading to its final grave.”

Infrared echoes trace the dusty journeys of light waves blasted away from supernova or erupting stars. As the light waves move outward, they heat up clumps of surrounding dust, causing them to glow in infrared light. The echo from Cassiopeia A is the first witnessed around a long-dead star and the largest ever seen. It was discovered by accident during a Spitzer instrument test.

“We had no idea that Spitzer would ever see light echoes,” said Dr. George Rieke of the University of Arizona. “Sometimes you just trip over the biggest discoveries.”

To view the echoes dancing through clouds of dust surrounding Cassiopeia A, visit:
http://www.spitzer.caltech.edu/Media/releases/ssc2005-14/visuals.shtml.

A supernova remnant like Cassiopeia A typically consists of an outer, shimmering shell of expelled material and a core skeleton of a once-massive star, called a neutron star. Neutron stars come in several varieties, ranging from intensely active to silent. Typically, a star that has recently died will continue to act up. Consequently, astronomers were puzzled that the star responsible for Cassiopeia A appeared to be silent so soon after its death.

The new infrared echo indicates the Cassiopeia A neutron star is active and may even be an exotic, spastic type of object called a magnetar. Magnetars are like screaming dead stars, with eruptive surfaces that rupture and quake, pouring out tremendous amounts of high-energy gamma rays. Spitzer may have captured the “shriek” of such a star in the form of light zipping away through space and heating up its surroundings.

“Magnetars are very rare and hard to study, especially if they are no longer associated with their place of origin. If we have indeed uncovered one, then it will be just about the only one for which we know what kind of star it came from and when,” Rieke said.

Astronomers first saw hints of the infrared echo in strange, tangled dust features that showed up in the Spitzer test image. When they looked at the same dust features again a few months later using ground-based telescopes, the dust appeared to be moving outward at the speed of light. Follow-up Spitzer observations taken one year later revealed the dust was not moving, but was being lit up by passing light.

A close inspection of the Spitzer pictures revealed a blend of at least two light echoes around Cassiopeia A, one from its supernova explosion, and one from the hiccup of activity that occurred around 1953. Additional Spitzer observations of these light echoes may help pin down their enigmatic source.

Krause was lead author with Rieke of a study about the discovery appearing this week in the journal Science.

JPL manages the Spitzer Space Telescope mission for NASA’s Science Mission Directorate. Science operations are conducted at the Spitzer Science Center, California Institute of Technology, Pasadena, Calif. JPL is a division of Caltech. Spitzer’s multiband imaging photometer, which made the new observations, was built by Ball Aerospace Corporation, Boulder, Colo.; the University of Arizona; and Boeing North America, Canoga Park, Calif. Its development was led by Rieke.

For additional images and information about Spitzer on the Web, visit: http://www.spitzer.caltech.edu/Media. For information about NASA and agency programs on the Web, visit: http://www.nasa.gov/home/index.html.

Original Source: NASA/JPL News Release

Posted on by Fraser Cain

Coprates Chasma on Mars

Perspective view of Coprates Chasma and Catena. Image credit: ESA. Click to enlarge.
This image, taken by the High Resolution Stereo Camera (HRSC) on board ESA?s Mars Express spacecraft, shows Coprates Chasma, a major trough in the Valles Marineris canyon system.

The HRSC obtained this image during orbit 449 with a ground resolution of approximately 48 metres per pixel.

The scene shows the region containing the sections of Coprates Chasma and Coprates Catena, over an area centred at about 13.5? South and 300? East, roughly in the centre of the Valles Marineris canyon system.

The trough of Coprates Chasma appears in the north, and ranges from approximately 60 km to 100 km wide and extends 8-9 km below the surrounding plains.

Coprates Catena lies parallel to Coprates Chasma and can be seen in the south as three troughs, ranging from a few kilometres to 22 km wide and up to 5 km deep. These troughs have been modified by erosion, as indicated by the linear features extending from the upper edge of the trough walls.

In contrast to the relatively sharp appearance of the upper regions of the trough walls, the lower slopes and the floors of the troughs have a softer appearance, which is probably the result of atmospheric dust.

Linear features, prevalent throughout the image and running generally parallel to the major troughs, may be faults.

Scientists are unsure of the mechanism responsible for the creation of the Valles Marineris canyon system. Some suggest that the formation of the Tharsis uplift, located west of the canyon system, caused tension and fracturing of the Martian crust.

Other researchers believe that water may have removed rock material from the subsurface, which caused the surface to collapse. A related theory suggests that large quantities of subsurface ice melted, causing surface collapse. Possibly all of these processes together were active in forming the structure.

Valles Marineris provides scientists with a window into the depths of Mars and enables them to study the complex geological and climatic history of the Red Planet.

By supplying new data for Valles Marineris, including colour and stereo images, the Mars Express HRSC camera aids scientists in this endeavour, ultimately improving our understanding of this fascinating planet.

Original Source: ESA News Release

Posted on by Fraser Cain

Capturing the Fastest Events in the Universe

ULTRACAM instrument mounted on the Very Large Telescope. Image credit: ESO. Click to enlarge.
British scientists have opened a new window on the Universe with the recent commissioning of the Visitor Instrument ULTRACAM on the European Southern Observatory’s (ESO) Very Large Telescope (VLT) in Chile.

ULTRACAM is an ultra fast camera capable of capturing some of the most rapid astronomical events. It can take up to 500 pictures a second in three different colours simultaneously. It has been designed and built by scientists from the Universities of Sheffield and Warwick (United Kingdom), in collaboration with the UK Astronomy Technology Centre in Edinburgh.

ULTRACAM employs the latest in charged coupled device (CCD) detector technology in order to take, store and analyse data at the required sensitivities and speeds. CCD detectors can be found in digital cameras and camcorders, but the devices used in ULTRACAM are special because they are larger, faster and most importantly, much more sensitive to light than the detectors used in today’s consumer electronics products.

In May 2002, the instrument saw “first light” on the 4.2-m William Herschel Telescope (WHT) on La Palma. Since then the instrument has been awarded a total of 75 nights of time on the WHT to study any object in the Universe which eclipses, transits, occults, flickers, flares, pulsates, oscillates, outbursts or explodes.

These observations have produced a bonanza of new and exciting results, leading to already 11 scientific publications published or in press.

To study the very faintest stars at the very highest speeds, however, it is necessary to use the largest telescopes. Thus, work began 2 years ago preparing ULTRACAM for use on the VLT.

“Astronomers using the VLT now have an instrument specifically designed for the study of high-speed phenomena”, said Vik Dhillon, from the University of Sheffield (UK) and the ULTRACAM project scientist. “Using ULTRACAM in conjunction with the current generation of large telescopes makes it now possible to study high-speed celestial phenomena such as eclipses, oscillations and occultations in stars which are millions of times too faint to see with the unaided eye.”

Observing Black Holes
The instrument saw first light on the VLT on May 4, 2005, and was then used for 17 consecutive nights on the telescope to study extrasolar planets, black-hole binary systems, pulsars, white dwarfs, asteroseismology, cataclysmic variables, brown dwarfs, gamma-ray bursts, active-galactic nuclei and Kuiper-belt objects.

One of the faint objects studied with ULTRACAM on the VLT is GU Muscae. This object consists of a black hole in a 10-hour orbit with a normal, solar-like star. The black hole is surrounded by a disc of material transferred from the normal star. As this material falls onto the black hole, energy is released, producing large-amplitude flares visible in the light curve. This object has magnitude 21.4, that is, it is one million times fainter than what can be seen with the unaided eye. Yet, to study it in detail and detect the shortest possible pulses, it is necessary to use exposure times as short as 5 seconds. This is possible with the large aperture and great efficiency of the VLT.

These unique observations have revealed a series of sharp spikes, separated by approximately 7 minutes. Such a stable signal must be tied to a relatively stable structure in the disc of matter surrounding the black hole. The astronomers are now in the process of analysing these results in great details in order to understand the origin of this structure.

Another series of observations were dedicated to the study of extrasolar planets, more particularly those that transit in front of their host star. ULTRACAM observations have allowed the astronomers to obtain simultaneous light curves, in several colour-bands, of four known transiting exoplanets discovered by the OGLE survey, and this with a precision of a tenth of a percent and with a 4 second time resolution. This is a factor ten better than previous measurements and will provide very accurate masses and radii for these so-called “hot-Jupiters”. Because ULTRACAM makes observations in three different wavebands, such observations will also allow astronomers to establish whether the radius of the exoplanet is different at different wavelengths. This could provide crucial information on the possible exoplanets’ atmosphere.

The camera is the first instrument to make use of the Visitor Focus on Melipal (UT3), and the first UK-built instrument to be mounted at the VLT. The Visitor Focus allows innovative technologies and instrumentation to be added to the telescope for short periods of time, permitting studies to take place that are not available with the current suite of instruments.

“These few nights with ULTRACAM on the VLT have demonstrated the unique discoveries that can be made by combining an innovative technology with one of the best astronomical facilities in the world,” said Tom Marsh of the University of Warwick and member of the team. “We hope that ULTRACAM will now become a regular visitor at the VLT, giving European astronomers access to a unique new tool with which to study the Universe.”

More information
The ULTRACAM team is composed of Vik Dhillon, Stuart Littlefair, and Paul Kerry (Sheffield, UK), Tom Marsh (Warwick, UK), Andy Vick and Dave Atkinson (UKATC, Edinburgh, UK). For the installation on the VLT, they received support from Kieran O’Brien and Pascal Robert (ESO, Chile). The ULTRACAM project page can be found at http://www.shef.ac.uk/~phys/people/vdhillon/ultracam.

Original Source: ESO News Release