More at ESA.int.
Wednesday, February 28, 2007
More at ESA.int.
Global Mars 3D view + Phobos transit animation at ESA.int.
Image Credits: ESA © 2007 MPS for OSIRIS Team MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA
Tuesday, February 27, 2007
Read how precious lessons were learned for future observations.
What is the importance of ROMAP observations (which goal is to study the local magnetic field of Comet 67P/Churyumov-Gerasimenko and examine the intensity of the magnetic interaction between the comet and the solar wind in three spatial dimensions)? What might we learn in terms of future space exploration?
The visible parts of a comet, coma and tail, depend on the outgas rate of the nucleus. The gas will be ionised by UV radiation and interacts with the solar wind plasma. The outgas rate of a comet increases with its vicinity to the Sun. With Rosetta we have the unique possibility to investigate the onset of this interaction process from a very large distance (3.5AU) to near Earth distance (1AU). After landing of Philae the observation can be done in parallel on the comet and at various distance to the comet by the Orbiter. Furthermore we can investigate the magnetic properties of the comet during the descent phase of the Philae. Magnetic forces could accelerate the aggregation process of dust grains due to its large scattering cross section. If this process contributes to the formation of comets magnetisation should remains. Also this could be investigated by ROMAP for the first time.
It is always a positive surprise to get new data from a far distant place.
More at ESA.int
Monday, February 26, 2007
For future images and milestones, with a team as this and a mission like that I’d better get me a life vest...
I know that size doesn't matter but am I exagerating by saying that CIVA surpassed all the expectations we had from a camera onboard such a small lander as Philae?
As a whole, Philae is a jewel, and one has hard times to realize the level of technical and scientific treasures it incorporates, at system and instrument level. CIVA is just an example. Just one figure: when on the comet, in terribly drastic environment (full vacuum, mean temperature much below -100°C), the entire vehicle, with all systems and instruments, will have a total power to live, operate, drill samples,acquire data, transmit them, less than 10W, which is less than the small light bulb in your fridge. As for CIVA, and for the first time, we developed microcameras some tens of grams only, with performances equal to much much larger systems; data processing is within electronics more than 10 times lighter than previously flown etc. The achieved resolution and sensitivity while mapping Mars is indeed astonishing, and just equal to the "nominal" expected built-in one. However, to have such an image taken requires a fantastic combination of coupled activities, where the CIVA imaging is just one part: activities at Lander level, at Rosetta level, with cooperation of a great variety of extremely skilled and committed colleagues : this is for me the main message here.
Both during flybys and when on the comet, most observations for us will be "one shot", as we will not have the time and/or the resources to repeat them in case of malfunctioning. Consequently, all parameters have to be optimized towards their exact tuning. Observations as that of last night does provide exactly this: beyond its direct outcome, it significantly contributes to optimizing the operational mode that we will have to freeze for follow-on activities.
Can you tell me what was the nature of the data acquired with ROMAP?
Yes, ROMAP did a splendid and unique monitoring of the magnetic environment of Mars as a function of the altitude, exhibiting all major structures with a huge sensitivity and direct scientific outcomes.
What was your, and your team, reaction when seing this image that seems to be coming out directly from space exploration aficionados wildest dreams?
What will be the work done untill the next milestone?
To use all follow-on flight opportunities to upgrade, test, validate operational modes for all systems and instruments on board (and there is a huge demand on this side), to increase robustness and optimize our chance of success, for our enormously challenging adventure...
Image credits: ESA - C.Carreau
"Stunning image taken by the CIVA imaging instrument on Rosetta's Philae lander just 4 minutes before closest approach at a distance of some 1000 km from Mars."
Credits: CIVA / Philae / ESA Rosetta
ESA updatesRosetta swingby update - 22:00 CET 24 February
Rosetta swingby update - 03:13 CET 25 February
Rosetta comet-chaser takes a close look at planet Mars
Rosetta successfully swings-by Mars – next target: Earth
Rosetta lander measures Mars' magnetic environment around close approach
Beautiful new images from Rosetta’s approach to Mars: OSIRIS UPDATE
Stunning view of Rosetta skimming past Mars
Friday, February 23, 2007
Click here to access the complete Timeline of Major Activities
Thursday, February 22, 2007
Animated Gif of 1 frame per hour Swing-by
Credits: Doug Ellison using the Solar System Simulator
Philae fact sheet (.pdf)
Rosetta's closest view of Mars
This post has been edited at 16:45GMT
ESA TV Exchanges
Replay 1: 23 January 16:00-16:15 GMT
Replay 2: 24 January, 11:30-11:45 GMT
Stubbe Hviid, OSIRIS co-investigator, Max Planck Institute, Katlenburg-
Wednesday, February 21, 2007
And from the Planetary Society blog...
Includes diagram with angular diameters of Mars, Phobos, and Deimos. (Credit: Rosetta Science Operations Centre at ESA / Emily Lakdawalla)
Friday, February 16, 2007
The relation has not been perfect...
Common citizens are often unaware of the Agency’s great work and achievements and the complaints (from those interested in Space Exploration) about ESA’s outreach efforts often appear with more frequency than desired.
What is being done to get ESA's and general public's interests, tuned?
The Agency has been giving more and more importance to citizen’s awareness in its current activities and looking for more involvment in shaping tomorrow’s European space exploration.
spacEurope had access to some of the work that has recently been done and what might the general public contribution in the future be like.
Here are some of the ideas and work done so far.
Two years ago, board stakeholder consultations recommended that ESA should invest on a more fruitful relation with the general public.
As result of this, on March of 2006 was held the first Citizen’s Jury in the UK.
"One aim was to find what people think about space.
But the other equally important aim was to allow a diverse group of citizens an opportunity to contribute to the next stage of ESA’s strategy.
This experiment in public engagement cast the public as a new sort of stakeholder – not just passive recipients of the benefits of space, but as active partners in the space adventure.”
The London's Citizen’s Jury consisted on the following:
“-A randomly selected, demographically representative panel of 12 persons who met over a period of 3 days to discuss the topic of space and space exploration in particular.
-10 witnesses, from policy makers to scientists or writers presented and answered questions.
-Discussion of the issues over the course of the jury in order to develop own thoughts and ideas, and to begin laying the foundations for a common postion.
-At the final day of the jury the jurors draw up and signed a set of recommendations for ESA. The set comprises recommendations on how to involve the general public into the case for space in a better way, what is from the jury’s point of view important for a European exploration strategy, what is important regarding costs for space exploration, how to promote ESA as a brand, how to involve space in politics and what are UK specific recommendations.
-The intension is to set up a series of Citizen’s juries in most ESA member states.”
The outcomes of the Citizen Jury in the UK can be consulted here.
ESA also promoted, in the end of 2006, a public competition via Internet, from which 5 winners were selected, having the possiblity of, not only attending, but also participating at the Edinburgh Exploration Workshop that took place in January.
From the total participants, some conclusions could be achieved, people demonstrated a great interest, being, the majority, space interested people who would like to see more public engagement regarding space exploration.
European identity was also at high level among the competition participants.
The 5 winners presented, at the meeting, their own experiences regarding three main aspects:
“-Why are they interested in space exploration?
-How is ESA reflected in the public oppinion?
-What can ESA do to gain more public attention?”
Recommendations adressing general public involvment into ESA’s strategy development were also given during the discussion.
The outcomes from this presentations can be read here.
Public Consultation and Engagement Campaign > Conclusions
“After stakeholder consultation, ESA is looking for long-term sustained public engagement in space exploration.
To make sure that space exploration responds to interests and objectives of the society, the general public is invited to contribute to the development of European long-term scenario for space exploration by:
We, the citizens are here, watchful, confident, participant and working on a new adventure, an adventure that will take Europe beyond.
spacEurope thanks the Directorate for Human Spaceflight, Exploration and Microgravity' Head of Strategy and Architecture Office, Mr. Bernhard Hufenbach and, specially, Jacqueline Myrrhe for all the hard work, efficiency and energy put into Europe's Space efforts.
Thursday, February 15, 2007
From all the amazing images released so far, latest news announced what for me sounded like a dream come true.
Hiking maps...from Mars.
It will take some time untill we have the chance to glance the first human with one of these in his hands, walking a windy, dusty, rusty, martian landscape, but for now, this has been a great step towards the realisation of that dream.
Professor Gerhard Neukum, HRSC Principal Investigator, from the Freie Universität Berlin, gave some of it’s precious time to elucidate some spacEurope doubts.
One of those doubts was about how much time was spent to make this Iani Chaos maps, according to Prof. Neukum:
-It was an effort of the HRSC Science and Experiment Team to develop the tools and to produce exemplary maps. All together the efforts took several years.
...And why did the choice fell over this region of Mars?
-Because it is scientifically interesting (releases of water).
It is also one of the best large-area datasets in the course of the HRSC Mars surface mapping effort.
It is planned to do the same with others or will it have to wait for further discussion?
-It is planned but depends on a firm program and additional money.
What might be the strongest arguments to get more funds to proceed with this gigantic work?
-The international Mars exploration as such.
By doing this work can we infer that this is part of a primary, but planned, step towards human exploration?
-It will be useful and necessary for human exploration.
So, can we imagine a future manned mission walking on Mars using this maps?
Prof Neukum also informed spacEurope that there will be no maps generated from HRSC data below 1:50'000, since ground resolution of the data does not allow for more detailed maps.
Hikers...maps like the ones used on Earth’s walks (1:25000) are out of question for now...
What might be their applications in the future? And in terms of science?
-The maps are applicable for science, exploration and mission planning.
Maps of this kind are a useful tool in connection with investigations of the Geology of Mars.
HRSC accomplished recently its third anniversary.
What can we wait from future observations?
-We can expect new interesting things, while covering more and more of the Martian surface.
Right now we covered 35 percent of the Martian surface for resolutions between 10m and 20m per pixel. We are just getting a mission extension for 2008 and 2009. By the end of this extension we will be at more than 60 percent coverage of the surface of Mars at 10m to 20m resolution in stereo and color.
Further extensions are necessary to get close to 100% coverage at that resolution and that is one of the primary goals of the mission.
We’ll keep on dreaming, we’ll keep on hiking.
Mars is getting closer than ever.
A special thanks to Dirk Benkert for its precious help on making this Q’n’A possible.
Wednesday, February 14, 2007
Image credit: Image NASA/JPL/University of Arizona
Monday, February 12, 2007
"Up to now, some map sheets have been created as examples within the scope of the German HRSC experiment funding. A realization of the map series could only be carried out within a currently discussed comprehensive effort towards a planetary mapping programme at the European level."
This mission’s first phase will last approximately two months (untill the 2nd of April), then COROT will rotate 180º to keep it under the desired illumination conditions, surveying from then on, another area of the sky.
In the presented animation (composed by images obtained in the night between 31 January and 1 February 2007 by COROT's 'exo-channel') there are three star candidates that COROT will look with special attention.
Thursday, February 8, 2007
Taking advantage of this, a series of scientific operations are scheduled for the event.
Dr. Gerhard Schwehm, ESA-ESTEC Head of Solar System Science Operations Division and the mission’s Project Scientist, answers spacEurope questions and give us a full insight on what we will witness in the upcoming days.
Know more about Rosetta.
What new informations about Mars can Rosetta, in the whole of it's swing-by adventure, provide us as a must comparing with other missions actually orbiting and roving Mars?
-You have to understand that the gravity assist is for navigation not science. It is a great opportunity to cross calibrate instruments.
We will have the first close UV observation by ALICE, might see the dust environment due to the unique dynamic range and the filters of the OSIRIS camera, and make studies of the atmospheric loss processes by the RPC Plasma package.
From the orbiter which instruments will be used on the Mars swing-by?
And from the Philae Lander instruments? Some work on amino acids detection?
-OSIRIS ( Imaging), Navigation Camera, ALICE (UV Spectrometer), VIRTIS (Visual and IR Mapping Spectrometer), RPC and the cameras on the Lander and ROMAP, the plasma instrument and Magnetometer on the Lander + the Standard Radiation Monitor.
For the amino acids you have to sample and put material in furnace and than run through mass spectrometer. This you can only do when landed. I.e. COSAC will definitely not be on.
From the Lander only the CIVA imaging system and ROMAP will be on. And the Lander instruments can run through closest approach as the Lander has it own power system running on batteries.
Speaking of OSIRIS, what can we expect when compared with other imaging instruments already on Mars?
-Unfortunately we will go through an eclipse at closest approach and have to switch off, otherwise we would have got 4 m resolution as best of MEX HSRC.
And we will observe Phobos.
Phobos and Deimos also. What are the science objectives for Martian moons?
-Add to the data set in imaging and IR mapping: surface composition and morphology.
Trajectory's corrections are planned to the 9 th and the 18 th of February, are preparations following as expected?
-We still have four slots reserved before closest approach. We are very confident that we will only need the slot on 9 Feb. We are already close to the nominal trajectory, presently aim at about 286 km miss distance and as you know the nominal flyby will be at 250km on 25 Feb at 01:58 UTC.
There was a flight-test on the 7 th of January, did it surprise anyway? Were the science operations determinded to be cancelled and give full priority to spacecraft operations?
-I believe you mixing up some info. We had a very intense active payload check out from mid-November for one month where we checked all instruments and in case upgraded the on board S/W. We still have been planning small checks for some of the instruments, but now running the sequences as uploaded and concentrate on the flyby. If we would require a very late orbit update, i.e. a couple of hours before closest approach we would even cancel payload ops. You see: navigation has highest priority.
What can we earn from knowing better the relation between the martian atmosphere and solar wind? And from the radiation environment study?
-We will learn a lot of atmospheric loss processes due to the solar wind penetrating into the atmosphere. Wonderful results from ASPERA on MEX and VEX. We can learn a lot how an atmosphere is evolving through this cleaning process.
SREM provides the radiation environment at Mars and on the way to Mars, which is important for planning future human exploration.
Rosetta will be, at it's closest approach, only 250kms from Mars, which regions of the planet will be surveyed in detail?
-It is more the global aspect as we are switched off at closest approach.
This is a fenomenal mission in all it's extension.
From the Mars observations what results could outcome as a major surprise?
-Detection of dust in the Mars vicinity by OSIRIS would be exciting. we will get anyhow the first UV spectra. And last but not least new info on the plasma environment, the team is already really excited.
But again, do not forget, science here isn't the highest priority we take the opportunity to do science.
For detailed information regarding Rosetta's Mars Swing-by, please consult the Trajectory Status Presentation given by Trevor Morley from the ESOC Flight Dynamics Team for the Mars Swing-by Preparation Readiness Meeting that took place on the February the 2nd and which was kindly made accessible to spacEurope by Dr. Gerhard Schwehm.
Hard to get the picture ain’t it?
The Cassini spacecraft imaged one with that size (2400kms in diameter) on Titan’s North Pole.
Associating clouds this size with the lakes discovered in the previous year, we are closer to understand the process conducting to the filling and drying of those lakes.
Dr. Christophe Sotin, from the University of Nantes and member of the visual and infrared mapping spectrometer team (VIMS) help us drawing a portrait of what is going on Saturn’s most exciting moon.
Know more about Cassini-Huygens.
A doubt, the cloud has become visible as spring arrives but it was already there hidden from view, correct?
-Yes, this is correct. It was observed from Earth-based telescopes. But of course, it did not have the resolution we have with VIMS and we do see many more details and structure.
Could you describe what would we see on the surface of Titan below this gigantic cloud?
-With VIMS, we cannot see below the cloud. But radar saw lakes on areas below the cloud.
Is it raining over there?
-We haven't seen the rain. But theoretical work predicts rain. But it is a model.
And how would it rain? Snow-like features?
-We haven't seen the rain. But when we look at the South pole where a similar cloud was present 5 years ago, we do not see something like snow.
But we are still processing the data and this is not a definite answer.
More data are still to come.
And on the velocity this cloud is moving, any data already?
How does it interact with the almost stillness of the atmosphere nearer the surface?
We are working on models describing the dynamics of Titan's atmosphere and the relationships between the clouds at 40° latitude and the polar clouds.
25 years, that is a long period...In what is based the conclusion pointing to that cycle's duration?
-We have observations since the Voyager mission, 25 years ago. And we see the variations between the South and the North Pole.
In that 4 to 5 years period in between the lakes will get drier and drier, is that it? What is the process involved?
-Apparently, on one lake, we see a shoreline at higher elevation and it looks like the lake is drying out.
However, we will try to get another radar image at the end of the extended mission (2010) in order to compare the level of material in the lakes.
Any answer so far for the differences in lake's population from the North to the South Pole?
-Not yet. Actually, we may not have paid enough attention to the South pole and we are going back to the data in this area.
What can we expect to know more from the following 16 fly-bys?
Is there a focused search on a specific question?
-Well, the nominal tour was already designed and the sharing between instruments is not going to be changed. What we may do, is to change the pointing according to what has been discovered. Also, the findings have been important in order to choose between the options we had.
Wednesday, February 7, 2007
-It's a great feeling, being part of such a successful space mission.
It's amazing to think that a satellite that was designed in the mid-1970's and built in the early 1980's is still operating perfectly in 2007!
Obviously, a lot of people have contributed to this success over the years, but a special vote of thanks is owed to the Mission Operations Team located at the Jet Propulsion Laboratory.
These are the people from both ESA and NASA that operate the spacecraft day in, day out, making sure that we scientists have so much interesting data to work with. A great bunch of people.
From my personal perspective, when I was working on the first south polar pass in 1994, I never imagined I would be writing web stories to celebrate the third one!
What will happen from now on, regarding scientific and spacecraft operations on route to the solar north polar cap?
-As I mentioned in the ESA web story, one of the nice things about this phase of the mission is that, as Ulysses swings from south to north, we are "closer" to the Sun than at other times during the 6.2-yr orbit. This means that we don't need as much power to heat the spacecraft, and so we can have more instruments switched on.
Another thing that's nice about this pole-to-pole sweep is that Ulysses also comes relatively close to the Earth as it crosses the plane of the ecliptic at the end of August (still 0.4 AU away, but closer than on previous orbits).
This will give us opportunities to do joint studies with other spacecraft (STEREO, for example).
I’m sure those rookie STEREO spacecrafts will learn a lot from working with Ulysses... ;)
In the last days two releases indicated us that everything is going as planned and the first scientific observations already started...
Malcolm Fridlund, the Mission’s Project Scientist was, once more, kind enough to share with us what do this latest steps mean.
Regarding the transition to Fine Pointing Mode, which took place on the 30th of January I would like to ask if you could share your thoughts regarding the remarkably close results when compared to the modelled ones and what is expected from the astero-seismologic observations.
Also, from what I understood from the release it was predicted to find the Delta 1 piece, what can this mean when related with the mission's objectives?
-The fact that the performance of the instruments on board are superceeding expectations means that we will observe more in the same time which translates in better accuracy on somewhat fainter stars in the asteroseismology element and somewhat smaller planets (or which is the same thing better signal to noise for the larger planets).
The instrument will do more.
The Delta 1 was just a streak on the detector and when querying the databases keeping track on mobile objects it was identified with the spent rocket from a launch in 1984.
It was never the intention to observe it. It just passed through the field.
I've just read the latest CNES update (in French) regarding Corot's first scientific observations.
Can you provide a brief explanation about what we are seing and what can we get from those three images?
-The first science images are just examples of the data being downloaded.
In this case it is the asteroseismology camera which is displayed. In principle, an image is integrated for 30 seconds. You then measure the flux of each of the target stars.
You then repeat the process and do so for a month.
That way you can detect variations as small as 1 part in 1 million. The frames displayed just show what the individual frames look like.
Also that some stars are so bright that they saturate the detector (the streaks) and we have lost some (unknown) number of photons. You then can not measure their flux and they are lost. Likewise, to faint stars are providing poor statistics and also can not be used for accurate photometry.
In a month you get 86400 frames like the one shown and then you can interpret your data.
That is it for now, but something tells me that we are just in the beggining of a memorable mission...
Yesterday, we learned more about XMM-Newton observations,today we have the previlege of having the presence of Christoph Winkler, Project Scientist for Integral, who will feed our thoughts with some clews about how is the daily life of the Galaxy in which we live in and how is our presence in it possible.
“We're made of stars”...
That's is a beautiful premisse...
Can you describe us which elements are the ones we are trying to understand the nature?
-All chemical elements.
In particular the "heavy" ones above hydrogen are synthesized inside stars during nuclear burning and finally expelled into interstellar space through supernova explosions, stellar winds and alike.
In stars (including our sun), the energy to let them "shine" is produced by nuclear fusion. That is to start on the lowest level of the chemical periodic system that 4 hydrogen atoms will merge into one helium atom. By this there will be a gain in energy (the binding energy) which is released as radiation.
The radiation pressure is always in balance by the gravitational pressure of the gas masses of the star. if Iron is reached, there is no spontaneous fusion anymore to gain energy. In order to continue one has to add energy to the system.
The star starts to contract, temperature and pressure goes up and by force heavier elements are being formed. At some point in time (this is beyond the scope here to explain), the star will come near the end of his life by either ejecting the outer gas layers (stellar winds), the rest will cool down to a white dwarf of a bit more than one solar mass. If the star is very heavy (say 8 times the sun or so), the star will explode as a supernova. This will produce more heavier elements, and will also eject most of the stellar matter into space where new stars are being formed (using this material - this is valid of course also for the "birth" of the solar system with the Earth and the human being). What remains from the star itself after a supernova depends on the mass it remains: could become a so-called neutron star (pulsar) or a black hole.
Integral will look for answers about how this elements form.
What guidelines are being followed towards this?
-Certain elements (Al, Fe, Ni, Ti) can be observed with gamma-ray telescopes.
The yield (i.e. mass production) of certain stars is important to know for these elements.
Does a supernova critical mass follow a predictable model?
-Core collapse supernovae are from stars with many solar masses (limited by the existence of massive stars - 50 solar masses? 100 solar masses?).
Other types of supernova explosion involve so-called white dwarfs, which have a constrained mass according to theory.
Can we know the exact moment when a supernova will explode originating new building blocks?
-No, depends on what you mean by 'exact'. The next one in our Galaxy is over due.....
When I use the word “exact” it has to do with the previous question and predictable models, if we watched a supernova for enough time would it be possible to know, according to models when would it reach its end?
-Well, very massive stars are known to have a lifetime of about few million years. So they will surely become a supernova. But when (on a time scale for a human life) will this be exactly is hard to predict.
Could you explain what you mean by “over due”?
So far we have not detected these "hot spots", but the intensity can also be very weak.....
Will the elements forming us and the planets, merged into the sun, originate a supernova again?
-The sun will not end up as a supernova.
But interstellar matter elsewhere (containing elements already synthesized in previous stellar cycles) may form cool clouds out of which new stars will be born.
Those stars, if massive enough, will end their life as supernova thereby keeping the cycle of element injection on-going.
Is it confirmed the existence of Saggitarius A*?
And how big is it?
-There is very strong observational evidence that what is called as Sgr A* is a black hole at the centre of our Galaxy with the mass of about 3 Million solar masses.
What is it's influence in the galaxy?
-It will accrete close-by matter acting as a point source with high mass.
How large is the population of black holes in our galaxy's center?
-Right in the center there is one (Sgr A*). There are more black holes in our galaxy, mostly in the central bulge region and the plane.
I would have to do some research to find the exact numbers. Few dozens are known, may be?
Note that we only observe the effect of a black hole on its immediate environment (e.g. the accretion of matter), nobody has yet really seen a black hole. That's why many people prefer to call them black hole candidates.
How do they behave? Attracting?
-Yes, but some also show jet emission, which is probably coupled to instabilities in the accretion process.
Is it possible, from Integral's observations, to predict a "near" future to the center of the galaxy?
-That might be difficult -Theoriticians should know better, but we have shown recently that the centre (Sgr A*) which is currently very weak in the Integral energy range, was about 10,000 times brighter a few hundred years ago.
(For more information click here)
Has Integral found any clew regarding the strange flashes (the major explosions in the known universe) in the gamma ray sky?
-We see them at regular intervals.
One in December 2003 was very strange as it was close-by and very faint.
There should be many more of those in the Universe.
Another one (from a so-called soft gamma-repeater) showed a huge outburst, where this burst contained the same amount of energy emitted during 0.2 seconds, equivalent to what the sun produces in 250.000 years.
Photons from this burst also hit the lunar surface and were subsequently observed by INTEGRAL as a reflection.
What might be the origin of high-energy radiation at the galaxy bulge who are not related with x-ray binaries?
Are you talking about the 511 keV map of annihilation radiation?
Yes, precisely. (For more information click here)
-Ok, so the answer is we do not know what specific types of sources do produce what we observe.
That could be also due to supernovae, or microquasars, but also due to exotic dark matter particles.
But, for sure, efforts are being made to reach its closeness...
Tuesday, February 6, 2007
Where did we came from? What are we made of? Where did the bricks forming us, forming the planet where we walk, eat, sleep, procriate, and all the creatures in it came from?
The answers to this perennial questions are become clearer and clearer.
Today’s theme is the discovery that previously predicted values for calcium in the universe were one and a half times lower than the real thing...(more information about it here)
Hope you enjoy it as much as I did.
The universe contains one and a half times more calcium than previously assumed by previous models.
Where were this models' premisses obtained?
-The older models that I use in my research are supernova models that try to predict how many elements a star produces when it explodes.
I particularly focussed on supernovae that occur in binary stars: type Ia supernovae.
Previous supernova Ia models predicted that the ratio between calcium and iron should be about 0.7, while in clusters of galaxies we see a ratio of 1.0.
What are the consequences of such an high value for calcium in the Universe's composition?
-For our understanding of the universe on cosmological scales, the high value of calcium does not have big consequences.
However, it does matter for our understanding of supernova type Ia explosions that occur throughout the universe.
For the first time, abundance measurements in the largest objects in the universe appear to be accurate enough to test supernova models.
In that respect, this work is trying to bridge the gap between supernova theoreticians and cluster observers.
What about the elements, the ones referred in ESA's release, like oxygen, neon, sulphur and others?
Were they according with previous modellation?
-The other elements line up well with previous models, that's why it is striking that calcium does not follow the prediction. I compared the abundance of eight chemical elements with the models and only calcium shows different behaviour with respect to older supernova models.
Researchers have new crucial data to follow their pursuit of the Universe's elemental building blocks history.
Did it, in any manner, already changed some basic concepts concerning that search?
-Many researchers that pursue the enrichment history of the universe are using the older supernova models as a reference, but these models are not yet fully tested or gauged on a large universal scale.
In that sense this work shows that we are currently able to do so and that it will become better when new X-ray satellite missions will be launched.
Supernovae type Ia are one of the most important ingredients of the soup of chemical elements that we live in today.
We're descendants of those supernova explosions.
Do the ones from where our componants derived came from our own galaxy or from the neighborood?
Is it possible to answer this? How?
-The elements that we are made of mostly originate from supernovae that exploded in our own galaxy.
This process is still going on. One of the best examples of current-day merging are the small and large Magellanic Clouds. These are small galaxies that in some time from now will merge with our galaxy.
Some of the elements we are made of might originate from smaller galaxies that merged with our galaxy billions of years ago.
Isn't the elements distribution throughout the Universe dependent of the way they form?
-The distribution of elements in the universe is indeed dependent of the way the elements form, or actually where the supernovae occur. Even within the hot gas we find in clusters of galaxies, the elemental distributions are not homogeneous.
Of course, most of the heavier elements can be found where the galaxies are, because they contain many stars that can explode. But elements can also be blown off from a galaxy when there is a star burst or when the galaxy hits the hot gas in a cluster.
This way elements can end up in the dilute gas in between galaxies.
"Clusters are in many ways the big cities of the universe".
Following your comparison, can we establish differences between those clusters as we do with cities on Earth, let's say...between an industrial city or a city more dedicated to services?
-I am afraid that my comparison does not get that far, but there are two different types of clusters that can be compared with cities on Earth.
In the universe we know of cooling clusters and non-cooling clusters.
The cooling clusters are usually very heavy and rich (they contain many galaxies), and they have a relatively dense core. It compares well with, for example, the city of New York, where you have a very heavily populated centre (Manhattan) and less densely populated outskirts.
In non-cooling clusters the density is much more flat, like in cities without large skyscrapers in their centre.
Both types of clusters are 'polluted' with elements, because supernovae occur everywhere.
But the elemental distribution is slightly different.
How significant is the percentage of matter contained in those huge clusters?
-Unfortunately, this is not exactly known, because a lot of the matter in the universe might be missing. We think there is also a lot of mass in faint filaments of gas that connect the clusters with each other. Our galaxy is in such a filament, but the gas densities in our neighbourhood are very hard to determine.
The contribution of these filaments to the total mass of the universe might be between 20% and 50%.
Your study also concluded that supernovae in clusters resulted from (a curious comparison image...) a 'dance of death' between white dwarf and a companion star.
Which are the caractheristiques of the unfortunate one?
In a supernova type Ia the white dwarf is the one that explodes. Such a dwarf star is actually a remnant of a solar type star that already 'died' before.
Typically, a white dwarf is as large as the earth (10,000 km radius) but weighs as much as the Sun. At some point during 'the dance' the companion star dumps some of its matter onto the white dwarf which pushes the little star over a physical limit. At this point the 'stellar corpse' explodes.
Isn't, according to this scenario, possible for the dwarf to form a black hole instead of exploding in a supernova fashion?
-No, the white dwarf is not massive enough to form a black hole.
The most likely object to be formed during the explosion is a neutron star. That is an even smaller star than a white dwarf, it's only 20 km in diameter and consists of mostly neutrons and other subatomic particles.
You have indicated that half the supernovae studied in this clusters seem like to have appeared this way.
Which differs from our own galaxy estimated values which is 15%.
Might this mean that, not only Earth, but the galaxy where it lays, provided, by it's special nature, all the conditions for the eclosion of life?
-Yes. Life as we know it depends on the basic elements like carbon, nitrogen, oxygen and iron.
We find all these elements in nearly every corner of the universe.
So in that sense the ingredients for life are nearly everywhere. Also throughout our own galaxy.
Monday, February 5, 2007
Probably the planet that has, throughout time, ignited the most human imagination.
From an imagined, fantastic, channeled world to a dry, bombarded, life deprived landscape, from home of imaginary queens and cartoon creatures to a cold, though traversable world, from a world seen by the eyes of the brave tiny Sojourner to an epic journey taking place right now due to the incredible Spirit and Opportunity rovers.
From a blurry image to the sharpness of HiRise...
Mars is, definitely, “my” planet.
The one where dreams lead me to.
But from all this, fantasy and reality, what is the Red Planet revealing us today?
What are we, its neighbours, learning out from the avalanche of data that a whole fleet of spacecrafts is sending back to Earth?
What are the probabilities of finding, amongst the unique geology of Mars, our ever dreamed Martian cousins?
A recently revealed study, entitled “Modelling the surface and subsurface Martian radiation environment: Implications for astrobiology” leaded by Lewis Dartnell from the University College of London points to the need of digging deeper under the Martian surface to answer this question.
Hope on finding signs of life is not lost...just went under.
7,5 meters under.
I can only be very thankful to the author for being the first one to talk us about Mars, to take us into the heart of the quest for Martian life.
I had and, somehow, still have, more on a childhood dream manner than on a scientific approach, faith on some sort of Martian extremophile that could defy radiation and survive on the surface in some places with specific caractheristiques.
Reading the referred study’s heads-up I was somehow affraid that this might have been completely refuted...
The possiblity of any life on the surface is completely dismissed with the conclusions you have arrived?
”Not at all” (can you listen to my Deep breath of relief?...)
“The results from our radiation model help inform us as to how long a population of particular kinds of cells could survive in a dormant state before they were inactivated by the ionising radiation damage. If cells were only recently brought to the surface, such as in the gullies in crater walls that we’ve seen flow with liquid water in the last few years, then they could survive the radiation for long enough for us to sample them. The bottoms of recent impact craters may also expose cells that we could find. The problem is that such locations are very challenging targets to accurately land a probe in."
Wouldn't it be possible, within the time scale present here, for a determined organism to adapt to the actual conditions in some localized areas where radiation might be deflected?
”The fact is that even non-radiation-resistant terrestrial cells could survive the radiation levels right on the surface of Mars. The problem is that the surface of Mars is so cold that any water will be frozen solid, and so bacteria contained within it are presumed to be held dormant. Without being metabolically-active, the cells cannot repair radiation damage and it accumulates to the point that they become inactivated.”
...Are you complaining about the cold, the rain, the flu?
A season on Mars would make you want to run in a swimming suit through the warm antarctica fields...
Where are those Martian’s wildlife preservation organizations when you need one?...
“We’ve got another paper coming out soon that does model the deflection of radiation particles by the crustal magnetic anomalies in Terra Sirenum and Cimmeria, but the fields are too weak to have any effect of deflecting the energetic particles hazardous to cells on the surface.”
You made reference to the most plausible target be at Elysium Planitia (due to Mars Express finding of signs leading to a frozen sea).
Wouldn't the poles be tempting places to look for life (and no, I’m not referring to those so actually fashionable penguins...)?
"Yes, these are also very exciting places to look, as the ice here would also represent favourable preservation conditions. The reason that the ‘pack-ice’ at Elysium was selected as a particularly interesting candidate was that it is believed to have flowed out on to the martian surface only 5 million years ago, and so represents a deeper sample of water that has been exposed to the cosmic radiation for a relatively short period."
Do you find it plausible to believe that water might exist on both hemispheres, permiting the existing of several hypothetic different ecosystems on Mars, making the Red Planet a place pulsing with life?
"There is probably a lot of subsurface permafrost ice in both the southern highlands and the northern basin, and so preserved cells or biosignatures might be find across the martian globe.
As for active ecosystems, they’ll probably need to be several kilometres underground, where the temperature is high enough to melt the permafrost into liquid aquifers."
ExoMars is coming and generating great expectations.
Will the depth it can reach be enough to provide answers?
"ExoMars is planned to have a 2 m drill length. This, our research shows, is probably not deep enough to find surviving cells. However, ExoMars is not designed to perform the cell sampling experiments that our research is addressing. The probe will, however, carry an astrobiology package, called Pasteur, capable of detecting certain biosignatures, such as organic molecules, in the martian subsurface. Our research addresses only the question of surviving cells, not biosignatures, and so ExoMars could well make some ground-breaking discoveries."
When NASA released those images of gullies revealing recent water related activity on Mars, my imagination drove towards a different kind of approach.
How would you see a "vertical exploration mission"?
A vehicule that could suspend itself and drill in a fresh gullied wall?
"Yep; there are proposals of trying this with something that dangles over the side of Valles Marineris as well, or balloons that could float across the valley face and make measurements at different heights.
Are we far from finding our martian neighbours or the search has only gained a new perspective?
"The probes designed to land on Mars over the coming years and drill several meters beneath the surface could well find very exciting evidence for previous life. Finding active ecosystems on Mars, if they exist, will probably require drilling several kilometres below the surface, and this would almost certainly require human supervision of industrial-sized drilling equipment."
While we don’t have our own foreman yelling at those lazy-freezing laborers to drill faster, the time is to gather the necessary luggage for such a task: knowledge, innovation and, what really take us forward, the will to know.
That probe was Huygens and catched an eight year ride with the Cassini spacecraft untill it plunged deeply into the unknown behind Titan’s veil.
Breath was hold untill the first data delivered revealed to human eyes a whole surprising new world, an astonishing primal landscape, closer to Earth than imagined, with river-like structures and small Titanian pebbles seeded on the soil surrounding Huygens’ landing site. Now, two years passed, Cassini is still on duty and the data retrieved from Huygens preciously helps scientists to gather and convert Titan’s intriguing details on a strong building of knowledge.
As a way to celebrate the mission’s anniversary, but also the discoveries currently being achieved, fruit of the work and dedication of a whole team, spacEurope had the previlege to have some of it’s questions answered by Jean-Pierre Lebreton, the mission’s Manager and Project Scientist.
Know more about Cassini-Huygens.
"The surface must be covered with thick layer of organic goo.
“If I do understand the question here is the answer. The temperature profile was indirectly derived from accelerometry measurements during entry (from 1400 km high, may be up to 1600 kms, down to 155 kms). We see lots of structure/layers. Some were know from ground-based stellar occulations (temperature inversion just above 500 km altitude); detections of many haze layers by Cassini Camera is also indicative of a layered stratosphere which may suggest the presence of (gravity) waves propagating upwards.”
The three main elements composing the atmosphere, methane, ethane and nitrogen, how do they interact?
“Nitrogen participates to the chemistry at high altitude; nitrogen is the main constituent of the atmosphere. The thermodynamic of the atmosphere and of the rain is also controlled by nitrogen.”
But there are still many questions to be answered...
“It's contribution to chemistry in the troposphere and on the surface is to be understood.”
How will it be, according to Christophe Sotin suggestion, the approach of Cassini to study the lakes on an extended mission?
“Cassini will plan to flyover the lake region and make more observations, with the radar, to look for variation of the lakes and also for measuring the composition with the visual Infrared Mapping Spectrometer.”
Speaking of Titan's future exploration, what would be, in your oppinion, the best design for reaching the best results?
“We are studying both in Europe and in the US, mission concepts for future missions to Titan.”
If you had nightmares about a rover getting it's wheels stucked on Titan’s goo just forget it...
“Despite what I said in a press conference 6 days after the landing, rovers would most likely not be the best way to explore Titan in the future. Mobility in the atmosphere (vertical and horizontal) will be best provided by hot air balloons (montgolfiere). Dropping long-lived probes on the surface would also be exciting (composition of surface material and seismic-like activity which would require probe survival for 1 or 2 Titan days).
Is it being equationed a similar in concept mission, taking in account the success of the Cassini-Huygens one, to two of the most fascinating moons of our solar system, Europa and Io? Do you participate or are you aware if there is any advance study on how to penetrate Europa's icy secrets?
“A proposal for a Europa/Jupiter mission is expected in response to ESA's Cosmic Vision AO to be released soon.”
I just can’t wait to hear more about that...
“One of the big questions that such a mission will have to answer is how thick is the icy layer above Europa's ocean (although the presence of an ocean is still to be confirmed). Hopefully such a misison will take shape through an international collaboration scenario. Europe, US and Japan are interested in such a mission, which could be conducted the way Cassini-Huygens is so successfully conducted (US-led), but a Europa/Jupiter mission could be either led by Europe or by the US, with Japan as the third major partner.”
You can understand, by Huygens Mission Manager words, that, undoubtfuly, in spite of the time needed to have a GO on a mission of this nature, Europa is on his mind...
“A properly designed Europa Orbiter should be able to answer many questions, and prepare the ground for surface penetrators, and then surface landers in subsequent missions. Europa's future exploration will take decades.
Having still the data under study and Cassini marvelling us, where can our knowledge about Titan arrive untill one future mission?
“Titan, once thought to be a frozen early Earth, appears to be as complex as any of the terrestrial planets in the solar system that have an atmosphere; Titan is probably more like the Earth than either Mars or Venus.”
We will be here, looking closer than ever to Titan, “definitively a World worth to explore further”.