The Europlanet Interview
November 2011 - Magda Stavinschi
Europlanet's Eleni Chatzichristou interviewed the Romanian Astronomer, Magda Stavinschi, who is also acting as Europlanet's national outreach node for Romania.
Magda's original dream was to become a teacher. "After finishing high school, I enrolled at the University of Bucharest, Faculty of Mathematics."
But she was soon caught by the beauty of astronomy: "After three years of very abstract studies, I discovered a branch yielding spectacular results: celestial mechanics. I pursued this direction and graduated with a thesis on problems related to time. Soon after I was appointed by governmental decision as a researcher at the Astronomical Observatory of Bucharest, where I started working in the Department of Time, with a focus on the study of the Earth's rotation, for astrometry."
|According to Dr. Stavinschi, astrometry is very hard work: you have hardly any spectacular results even if you are working 24 hours a day. "I remember our best astrometrist (Ella Marcus). I had never met a person like her - cultivated, intelligent and very hard working. But she couldn't get promoted, because a star catalog takes several years to finish and unfortunately the number of publications is a criterion of promotion everywhere."||
Things changed dramatically after the major social reforms that took place in Romania in December 1989. "Astronomers were among the first revolutionaries. Following this trend, on the 8th of January 1990, the leadership of our institute was replaced. I was elected head of department, and on the 1st of April 1990 I became director, while Romanian astronomy returned under the patronage of the Romanian Academy". These events were followed by fifteen difficult years: everything changed and the country itself was transformed. «I first reactivated the international collaborations», she remembers."I resumed the publication of our special magazine – the Romanian Astronomical Journal, I helped young people to specialize abroad, and once they started to obtain research grants elsewhere in the world, the idea occurred to me to keep contacts with them by signing contracts for associate researchers, for the first time in Romanian research".
Dr. Stavinschi’s initiative and fresh ideas were blooming. Taking advantage of the event of a total solar eclipse over Romania on the 11th August 1999, she organized the first international workshop preceding an eclipse (1996), an ISYA (1999), a NATO Advanced Study Institute (1999), and, in the frame of the Francophony, six years of intensive courses in Astrophysics at the Faculty of Physics in Bucharest. "Because it is never easy to attract funding for astronomy, in February 1999 I tried to obtain an audience with the Prime Minister. As a result, by governmental decision, we were offered money for the restoration of old buildings and for the construction of a planetarium (8.5 m diameter, 65 seats)", Dr. Stavinschi says proudly."Unfortunately, my efforts to obtain at least a 1m telescope and a planetarium projector have not been successful". But she didn’t give up: "The desire to modernize the main instruments that dated back from the beginning of the 20th century (the great meridian telescope and the astrograph) prompted me to set up, in 2000, together with Jean Kovalevsky, the IAU WG 'Future Development of Ground based astrometry'".
Dr. Stavinschi’s great contribution as a scientist and leader were clearly demonstrated over the years. But, besides her scientific career, she pursued almost with a similar enthusiasm the challenge of science education and outreach. "My efforts to reintroduce Romanian astronomy in schools led me to accept the presidency IAU C46 "Astronomy Education and Development" (2006-2009). During this time and especially after I was director, I was determined to help address several school, mass media and astronomy outreach questions. It is not easy to do research, to manage an institute, a WG or a Commission, to care for your family, and, at the same time, to answer to the public questions, but I realized that, since there are so few astronomers in the country (about one in one million inhabitants), it is almost a duty to accept the challenge".
I asked Dr. Stavinschi what the situation of women scientists in Romania is, and whether she had faced any major challenges as a woman in her astronomy career. "I didn’t face any discrimination throughout most of my career but I felt that men found it difficult to have a woman director. In the communist countries the rules imposed equality between women and men. For instance, if a presidium was chosen for a meeting, a fixed number of persons had to be women". This is maybe the explanation why immediately after '89 Romania had the largest percentage of women per country in IAU. "All the new staff chosen at January 8, 1990 was composed only by women: director, deputy director, scientific secretary". Is this still the case? "Unfortunately progressively the situation has changed: young ladies today prefer to become top-models than scientists".
Dr. Stavinschi concluded the interview with an anecdote, a significant episode that she experienced last summer. "Since the very early stages of my career I realized that astronomy is not only a science but an important part of the world’s culture (maybe that's why I was attracted to it). The history of astronomy helps in fact to understand better the evolution of human civilization. In the past, I had searched the archives in my country and in France to write related articles, but this summer while looking for more documents regarding the history of Romanian astronomy I had the huge surprise to find, in the special collections of the National Library, twelve boxes (that is, over 5000 pages) of documents kept by the first director of the Observatory, which have not been touched by anyone in the nearly sixty years that have elapsed since his death. So my holidays turned into a feverish effort of scanning and identifying documents. Obviously, I am just at the beginning and many exiting discoveries lie ahead!".
Magda Stavinschi, together with Basarab Nicolescu have founded the “Science and Religion” series at Curtea Veche Editing House in 2006. This was at the beginning of the “Science and Orthodoxy – Research and Education” three year program financed by the renown American foundation John Templeton. They have since published several dozens of volumes, a true library aimed at the general public, scholars and students. Recently, she co-authored a book published by Bill van Altena at Cambridge University Press about Modern Astrometry.
"Astronomy has a lot of fascinating aspects hidden in the sky as well as here on Earth; you just need to look carefully, and you won’t be disappointed".
March 2011 - Christopher Go
Leading amateur astronomer, Christopher Go, talked to Europlanet's Anita Heward about using the Hubble Space Telescope, discovering impacts on Jupiter and starting a whole new field of astronomy.
AH: How long have you been doing amateur astronomy?
CG: I got interested in November 1986, during the last apparition of Halley’s Comet. I was still in high school then, and I was just using a pair of binoculars. I was also fortunate to get a copy of the August 1996 issue of Astronomy Magazine. The rest I learned from books from our school library.
AH: Was anyone in your family interested in astronomy?
CG: No. There were hardly any amateur astronomers in my city. During 1986, there was no Internet, so it wasn’t easy to communicate with other people. I had to work things out by myself. What really helped a lot were the magazines particularly Astronomy and Sky & Telescope. These periodicals give me connections with other amateur astronomers and what they are doing.
I started planetary imaging in 2003. That was during the great Mars opposition. I started imaging Jupiter and Saturn in 2004. In 2006 I discovered that Oval BA had turned red. This spot was later nicknamed the Red Spot Junior. Because of this, I was invited by Imke de Pater, of UC Berkeley, to join her team in doing Jupiter research and we’ve used the Hubble Space Telescope and the Keck Observatory. It was also during that time period that I got to know and collaborate with Glenn Orton of JPL, Amy Simon Miller of NASA GSFC, Agustin Sanchez-Lavega of IOPW and other planetary astronomers. It’s been an exciting for an amateur astronomer to link up with the professionals.
Last year in 2009, there was a quad-transit of Saturn where four moons crossed the face of Saturn. I teamed up with the Hubble Heritage Team and Mike Wong to image this event using the Hubble Space Telescope.
AH: Talk me through the last year.
CG: Early morning of June 3 (June 4 local time) last year, Australian amateur astronomer Anthony Wesley sent an e-mail that he had detected an impact in Jupiter. As I went through my own data which I got earlier that morning, I found that I too had imaged the impact. It was just great timing that we were imaging at exactly the same time.
This would turn out to be the first time an extraterrestrial fireball was observed here on earth. One thing interesting is that this probably is one of the few times that amateur astronomers have created a new field in astronomy – which is ‘small impacts on other planets’. So right now we amateurs are basically trying to build a network constantly monitoring the planets to see if there are more impacts. This is quite important because we don’t have any statistics on many small objects orbiting the Solar System.
AH: That must have been exciting.
CG: Yes indeed. We are now able to collaborate with professionals in using the Hubble Space Telescope and other earth based observatories like Keck, Gemini, IRTF and VLT. In my case, our group (with Dr Imke de Pater) have used the Hubble Space Telescope every year since 2006 with a total of probably around 40 orbits.
The impact on Jupiter
AH: That must put you ahead of a lot of professional astronomers in terms of the amount of time you’ve had on Hubble.
CG: The collaboration between amateur and professional astronomers is really very strong in Planetary Science. In our study of the outer planets, we already have an excellent system where observations by amateurs are accessible to professionals.
Unfortunately, the use of the Hubble Space Telescope and the large observatories around the world are not infinite. Professionals need to fight to get time in using these instruments. And observing planets isn’t really top priority. This is where hundreds of amateurs around the world imaging on a nightly basis can provide data. The resolution of amateur images is already approaching that of professional imaging.
There is a structure wherein professionals and amateurs collaborate and, if there’s a new phenomenon, our reaction time is very fast. For example during the impact, we were able to get Hubble in two days. It was something unbelievable, because the whole process on how to use Hubble can take weeks.
AH: In the Philippines, is there a thriving astronomy community?
CG: There are two major astronomical societies in the Philippines but these are based in Manila. Right now we are starting one here in Cebu, called the Cebu Amateur Astronomers Association.
I am fortunate to have a fellow planetary imager here in Cebu. Tomio Akutsu is a renowned Japanese planetary imager who now works here. He also co-discovered a third red spot in Jupiter in 2008.
One thing nice about Cebu island is that we are very close to the equator where the planets are very high up and we have very stable atmosphere because of its proximity to the sea. We get very high resolution up to 0.2 arcseconds per pixel. Tropical islands are ideal places to do planetary imaging.
AH: What do you do in your day job?
CG: I run a furniture factory. I sell tables, chairs and accessories to the USA and Europe.
But my background is physics. I’m a lecturer in our university part-time. When I started the furniture business, I used to teach about three units per semester. But once I got busy, I had to stop. But right now I still do some lectures for the Physics Department of the University of San Carlos.
Animation of storm in Saturn's Northern Hemisphere
AH: You make time to come to conferences?
CG: I try to make time. This is the first time I’ve been to Europlanet, but normally I frequent the DPS meeting. This is where our group present our work , our group with Imke de Pater , and it’s also the time where we can meet. Conferences are also good time to get to know other planetary astronomers and meet those that I collaborate with. It’s good timing because the week after the DPS is a furniture show in North Carolina, so it hits two birds with one stone. These are usually scheduled during the same time period, so it’s cost convenient.
The Europlanet Interview
September 2010 - Dr Mahesh Anand
Dr Mahesh Anand talked to Europlanet's Anita Heward about using diamonds as probes to explore planet Earth, looking for bio-signatures in Martian meteorites and the implications of the recent discovery of water on the Moon.
AH: What’s your background?
MA: I started at school in India and I did my Bachelors’ and Masters’ there. I did my Bachelors’ at Varanasi and then I came to what is known as IIT in Mumbai, which stands for Indian Institute of Technology. Until recently, there were seven IITs in India, which have basically accounted for the majority of Indians working in Silicon Valley for the past 20 years.
I did science there, but I was very, very fortunate to go to that school, because it opened so many doors for me. It has such good atmosphere – everyone is living a sort of LA lifestyle inside IIT, because that’s what they aspire to do as soon as they finish.
|It was very useful but I decided not to go to the US just after, because I wanted to buck the trend. I decided to do a PhD at Cambridge in the UK. Again, I was extremely fortunate, because I was given a fellowship, so I didn’t have to pay a single penny.||
After my PhD I then went to the US, because I got a very good opportunity to work on NASA Apollo samples and diamonds. I worked there for 3 years as a post-doc and then I came to the Natural History Museum [in London] and started to work with Monica [Grady] on Martian projects.
Then in 6 months time, I found that Monica had got a professorship at the OU and she would be moving. And then, in another 6 months, I found that I had a job at the OU too.
So we brought the project here and since then, I am here.
AH: And what’s your main research focus.
MA: At the moment, my main focus of research is on lunar science. But, because I have been involved in so many different projects, I work on diamonds and I work on rocks that carry diamonds from deep inside the Earth called kimberlites.
AH: What’s interesting about diamonds from a scientific point of view?
MA: Everything! Diamonds come from so deep that there are no other rocks – nothing else – that come from that deep. So they bring up the signatures that are otherwise inaccessible by other means.
We have geophysical measurements that tell us, “OK, at 150 km, this is what the Earth’s mantle is like”. But here you have something that formed at that depth. And the beauty of diamond is that it encloses certain minerals. Diamond is very strong, so once it encloses something, it doesn’t release it. If you break that diamond open, and then investigate those minerals, you learn a lot about the Earth’s composition and its evolution through time – diamonds also have been dated through these mineral inclusions and the great majority turn out to be about 3.8 billion years old! So effectively, they are time capsules.
AH: They are sort of planetary probes for Earth?
MA: Yes, planetary probes for Earth. So they are extremely interesting – and the rocks themselves that bring diamonds are interesting because they have to come sufficiently fast to preserve the diamond. Diamond is not stable on the Earth’s surface, and also it reacts with the magma that is bringing it up. Here I’m talking about a magma coming from 150 kilometres depth within a few minutes to half an hour. If diamonds stay in the magma any longer, they will be reabsorbed. On the Earth’s surface, it’s actually converting into graphite – but that process is so long that it will take place over several millions or maybe billions of years.
AH: At what depth do diamonds form?
MA: The newest finding in diamond research is that even though the kimberlites are coming from 150 km, which might be the final resting place for diamonds, diamonds are not necessarily formed at 150 km – they might be forming at 450 km, which is one of the discontinuities [between different zones in the mantle]. So now they are called ultra-deep diamonds – they might even be coming from 1000 km depth.
If we look at the deepest mine that somebody has drilled, I think the deepest mine is about 30 mile or 30 km max – so that’s how far you can go. That’s why diamonds are so interesting and exciting.
AH: What else are you working on?
MA: I have a couple of students that I am co-supervising with Prof. Charles Cockell and the work that I do [with them] involves measuring the isotopic composition of transition metals such as iron, copper and zinc. These metals get utilised in biological processes – metabolism and normal day-to-day life. What happens is that when organisms actually take these metals up, they fractionate – they actually change the ratio of one isotope to another. In the lab, we can measure those ratios and use them as a proxy for biological or non-biological processes. This is a research field that is rapidly evolving.
AH: So, for example, when you have more Mars samples returned by missions in the future, then this work will be helpful?
MA: Yes. In fact, one of the things that I came back to the UK to work on with Monica was precisely to do this: to use iron isotopes in Martian meteorites that we have and to see if there are any signatures that suggest biology. We haven’t found any, but that was the idea. Considering that we have about only about 50 or so Martian meteorites, I’m not surprised that we didn’t find any – we are barely scratching the surface of Mars through these meteorites.
AH: Tell me about Moon rocks. What fascinates you about them?
MA: It depends which angle you are looking at. I’m a geologist by training. First of all Moon rocks are so pristine. Any geologist who is used to working on Archean rocks on Earth know that they look grotty and you have to break boulders of 100 kilos or maybe 1000 kilos to get to that small piece – the freshest piece possible. You bring it to the lab and you make a thin section and, still, it’s all weathered. When you look at a Moon rock, you find no speck whatsoever of any alteration. So that’s immediately exciting – that you are going to learn about the pristine processes that have gone on in another planetary body.
The second thing is that, from a geological point of view, the origin of the Moon itself is very interesting. There have been people studying that and trying to sort it out for the last forty years. It’s throwing up new questions all the time. From oxygen isotopes point of view, it’s so closely related to Earth but from every other angle it’s so different.
So some people would say, “It just came from Earth – it was made from the same material as the Earth formed from”. But you look at the other things and it doesn’t make sense.
Then, all of a sudden in the last few years, you have the discovery of water on the Moon. Obviously, it’s not a pond or anything like that, but the top layer of soil on the lunar surface appears to be coated with water. There’s strong evidence for ice at the lunar poles and the data suggest that, actually, there’s not one source – there’s a diversity of sources that are involved in this, which I think is really exciting. It has opened up a complete new area of research.
To me, as a scientist, the most exciting problem in lunar geology at present is to really sort out how many types of water there are, what the source is, what is the quantity, the distribution, how could you extract it (if you want to extract it) and how you can use it, you know, that sort of thing is quite exciting.
AH: Was there evidence of aqueous minerals?
MA: Well, I don’t know if you’d call apatite [a type of phosphate compound] an aqueous mineral – it’s a hydrous mineral. In fact one of the areas that right now I’m pursuing is actually looking for water in lunar apatite – that’s what I presented at the Royal Astronomical Society recently. Because apatites occur in lunar basalts, formed by the solidification of molten magma, their studies give an indication of what is inside the Moon.
So far, instruments are looking from the top and you can’t rule out the possibility that all this water is actually surficial i.e. has been transported there from external sources. But if you look at the basalts that are coming from deeper levels, maybe 100 – 400 kilometre depth and they have minerals that have water in them, then that is telling you that the inside of the Moon is also wet, not just the outside.
AH: But there’s no evidence of surface water in the Apollo samples?
MA: That’s very interesting because people when they started presenting this data in the early 1970s, they were largely ignored and any signs of water in lunar samples was ascribed to terrestrial contamination. And so the party line became that there is no water in lunar samples and hence no water on the Moon.
AH: You are led to believe that it’s dry?
MA: Yes, and most of the results were suggesting that. It was also not possible at that time to detect water at the levels at which we can detect now. The sophisticated instruments such as secondary ion-mass spectrometers (SIMS) weren’t there and if they were there in prototype, they weren’t capable of detecting water at the [parts per million] levels that is observed in lunar samples. So people stopped looking at it. Sometimes, we (scientists) become like a herd and we make our opinion based on what has been said previously and then we stop looking at things. It’s only in the last year or so that people have restarted looking at the same samples and now finding that there is water. Because 30 or 40 years on we have sensitive instruments that can detect water and you now have orbital data so that you are not so scared to go out in public and say that there is water on the Moon.
Europlanet Interview: Stamatios (Tom) Krimigis
Tom Krimigis is a space scientist, of Greek origin, who has been heavily involved in most robotic missions for space exploration to almost every planet in our solar system.
Dr Krimigis is one of the very few scientists that have been invited to meet and brief world leaders about scientific achievements. These include President Reagan in 1986, President Gorbachev in 1987, and President Bush in 1990. He has often testified before Congressional Committees on issues of Space Science and Technology and has participated in many advisory committees for the US Government. Dr Krimigis has also been instrumental in setting up NASA's Discovery program for low-cost planetary missions. Eleven Discovery missions have been chosen so far, the most high profile one being NEAR, the first mission to orbit and land on an asteroid (Eros).
Dr Krimigis' research interests encompass a large variety of topics, including the Sun, the magnetospheres of the Earth and other planets, and the interplanetary medium. He has published more than 380 articles in scientific journals and books and he is one of the most cited scientists in his field. He has delivered more than 1000 talks and lectures all over the world. In parallel with his scientific achievements he has been actively involved in science outreach through several public talks and is currently serving as the Chair of the Strategic Advisory Board of Europlanet-RI.
Dr Krimigis has played a leading role in several NASA - ESA missions, including Principal Investigator on the Low Energy Charged Particle (LECP) experiments carried by Voyager 1 and 2. More than 30 years after their launch in 1977, the spacecrafts are fast approaching the heliopause, the boundary that separates the solar plasma from the interstellar medium. Voyager 1 crossed the termination shock of the solar wind, at 94 Astronomical Units (AU), on December 2004 and Voyager 2 crossed the termination shock, at 83.65 AU, on August 2007. At this point the two spacecrafts are in opposite directions, at the Solar System boundaries. The LECP instruments continue to monitor the solar plasma and to measure the energetic particle activity in the outer heliosphere, at the heliopause and in the future in the interstellar plasma, providing scientists with invaluable data for several decades now.
Dr Krimigis is PI of the Cassini spacecraft's Magnetospheric Imaging Instrument (MIMI). Recently, Dr Krimigis and collaborators have published results from Cassini in the leading journal Science that challenge the conventional view of the shape of the heliosphere.
Dr. Eleni Chatzichristou (EC) talked to Dr. Tom Krimigis (TK) about his achievements and inspirations:
EC: What does the new discovery (on the shape of the heliosphere) mean for our understanding of the solar system?
TK: The images from the Cassini/MIMI/INCA instrument have revolutionized what we thought we knew for the past fifty years; the solar system travels through the local interstellar medium not like a comet but more like a big, round bubble. More specifically, models had predicted a foreshortened "nose" in the direction of the solar system's motion, and an elongated "tail" in the opposite direction. The map we've created from INCA's images suggests that pressure from a hot population of charged particles and interaction with the interstellar medium's magnetic field strongly influence the shape of the heliosphere, and shape it into a "bubble".
EC: What are your plans for the next decade and what would be the next step(s) for NASA/ESA in planetary missions?
TK: My own plans for the next decade are to follow the data from our instruments on Voyagers 1 and 2, now in the heliosheath at 114 and ~90 AU, respectively, and find out where the heliopause, the true boundary with the interstellar medium, is located. Also, to analyze data from our instrument on Cassini and see the progress and eventual end of the Cassini Solstice Mission, scheduled to conclude in 2017. And before that, to see the New Horizons encounter with Pluto in July 2015. The planetary program has some very exciting missions in the planning stages, such as the EJSM (Europa Jupiter System Mission), and eventually TandEM (Titan and Enceladus Mission). The origin of possible biological activity looms large as a science goal, among several others. Future research can't get much better than that!
EC: Is there a competition or primarily collaboration between ESA and NASA, and where do you think ESA lags behind the American agency?
TK: I don't believe there is competition, but rather complementarity. For example, neither agency could afford EJSM or TandEM alone. Both are joint endeavors and coordinated well between ESA and NASA. Of course, NASA can have a more extensive program, since it has nearly three times the budget that ESA has.
EC: You have created your successful career all by yourself at a time when the space programs were just starting and you found yourself right in the middle of where things were happening. How easy do you think is for young talented space scientists to become equally successful today?
TK: Sometimes one can be at the right place at the right time-I was lucky enough to get to the University of Iowa only a few years after Van Allen discovered the radiation belts (Van Allen Belts). It was a very exciting time, with new discoveries coming one right after another. That's when I built my first instrument for a planetary mission, the Mariner 4 spacecraft to Mars, then another one to Venus, with Mariner 5. After that followed Voyager (by now at Johns Hopkins Applied Physics Lab), and Gallileo, and Ulysses and Cassini, MESSENGER, and New Horizons. It's a wonderful feeling, to have built instruments that have gone to all the planets. Needless-to-say, it's more difficult for a young scientist today-all the "low-hanging fruit' has been picked. But there are still plenty of opportunities for younger scientists for discoveries that could change our views on rather fundamental issues. A key example is the quest for biological activity, current or past, on solar system bodies; it has been a long-term objective and has not been answered by my generation of scientists- and there are many others!
EC: What is the major challenge in space exploration and what has been the major challenge(s) for you in your career?
TK: I'm not sure I know them all-but the search for life's origins is clearly the top.
As for me, the major challenge has always been the degree of risk one should take in designing instruments (and spacecraft). I faced that early on, when I used very thin (25 micron) totally depleted solid state detectors to search (successfully) for He and CNO in the Van Allen Belts (on Injun 4, in 1964). None knew at the time whether these would survive in space, nor their radiation susceptibility. Then I took a risk in flying a stepper motor to rotate the detector heads on the Voyager missions-the only way to obtain angular distribution information. I was told it would fail in six months, but both motors are still stepping every 192 seconds after nearly 33 years. Without stepping, we would have missed out on key discoveries at all the outer planets as well as the heliospheric termination shock.
EC: After so many years of an active successful career what is the major lesson that you have learned from life?
TK: I learned that major discoveries entail taking big (experimental) risks. Taking incremental steps rarely pays off, and it's very boring to boot!
Dr Tom Krimigis was born in the Greek island of Chios, where he spent his school years. He then moved to the University of Minnesota (USA) where he obtained his Bachelors’ degree in 1961, followed by a Masters’ in 1963 from the University of Iowa. He then became a student of J.A. van Allen, with whom he has published some of his best known works, such as the first use of a solid detector in space and the discovery of alpha particles (helium) in the radiation belts. Dr Krimigis obtained his PhD in 1965 from the University of Iowa where he was immediately employed as a faculty of the Physics and Astronomy Dept., before joining the Johns Hopkins University Applied Physics Laboratory (APL) three years later. He later headed the Space Physics and Instrumentation Group, became Chief Scientist in 1980, Head of the Space Department in 1991 until 2004, and Emeritus Head since then. The APL Space Department’s work concerns the design, construction and launching of scientific instruments, as well as of entire satellites, for space missions.
The Man Behind the Missions
Tom Krimigis has been Principal Investigator and Co-Investigator in several NASA - ESA missions: Among them are the Low Energy Charged Particle Experiment on Voyagers 1 and 2 (Jupiter, Saturn and beyond), the Mariner 3,4 (Mars) and 5 (Venus) missions, the Active Magnetospheric Particle Tracer Explorer (first man-made "comet" in space), the extremely successful Cassini-Huygens mission to Saturn and Titan. He was equally involved with other famous missions studying objects of our solar system, such as Galileo (Jupiter), Ulysses (Sun), ACE (interplanetary medium), MESSENGER (Mercury), and New Horizons (Pluto).
For his achievements he has received some twenty NASA Group Achievement Awards. He was furthermore awarded twice (in 1981 and 1986) the NASA Medal for Exceptional Scientific Achievement, the International Academy of Astronautics Basic Sciences Award and the AHEPA Academy Prize, both in 1994. In 1977 the Greek President has awarded him with the Gold Cross "Commandeur de ‘Ordre du Phoenix" and in 1998 the American Hellenic Institute has honored him with the "Hellenic Heritage Achievement Award". In 1999 the International Astronomical Union named an asteroid as "8323 Krimigis", in his honor. Since 2004 he is an elected member of the Athens Academy.
Left: The traditional paradigm of what the solar system looks like as it travels through the interstellar medium (W.I. Axford, Space. Sci. Rev. 14,582, 1973). Right: The new Cassini results indicate a very different picture for the heliosphere (T. Krimigis et al., Science 326,971, 2009). Images and animations at the European Geosciences Union (EGU) press conference webcast.
Heliosphere: The bubble in space around our solar system which is filled with the energetic particles and ions of the solar wind and its associated magnetic field (solar magnetosphere). The heliosphere extends out to about 100 AU (1 Astronomical Unit is the average distance between the Sun and the Earth, equal to 150 million kilometers) The heliosphere's boundary is considered to be the point where the interstellar medium counterbalances the solar wind pressure, and it is called the heliopause.
Interstellar Medium:The space between the stars of a galaxy, filled (even though very dilute) with gas, dust and cosmic rays. The interstellar medium gets enriched in heavier elements through stellar explosions during the stars lifecycle, and then recycles this matter through the formation of new stars in its densest regions.
Magnetosphere:All planets with intrinsic magnetic field (including the Earth) deflect the solar wind, creating around them a magnetosphere consisting of ions and electrons which come from the solar wind and the planet's ionosphere.
Radiation Belts: The Earth has two regions of trapped fast particles: The inner radiation belt, discovered by van Allen, extends about one Earth radius (6731 km) above the equator and consists of very energetic protons produced by the interaction of cosmic rays with atoms of the Earth's atmosphere. The outer radiation belt consists of ions and electrons of lower energy and is directly influenced by the magnetic storms (disturbances of the Earth's magnetosphere, related to space weather phenomena). The outer radiation belt contains also alpha particles, that is, atoms of helium which have lost their two electrons and are mainly found in the solar wind.
Solar Plasma:The solar plasma consists from protons and electrons primarily. It also contains ions of helium and heavier elements and it trains solar magnetic field lines with it as it escapes from the Sun.
Solid State Detector: The most recent class of detector developed is the solid state detector. These detectors convert the incident photons of ionizing radiation directly into electrical pulses/signal. Solid state detectors are made from a variety of semi-conducting materials, depending on the application we intend to use them for, including: germanium, silicon, cadmium telluride, mercuric iodide, and cadmium zinc telluride.The charge collected is proportional to the energy deposited in the detector and therefore these devices can also yield information about the energy of individual particles or photons of radiation.
Termination Shock:When the solar wind leaves the sun, and for several billion kilometers further in the heliosphere, it travels at very high speed (up to 800 km/sec). Further out, when it starts colliding with the interstellar medium, it slows down and becomes subsonic. The area in space where this happens is called the termination shock.
Scientist of the month
In this section, Europlanet will be profiling a leading European planetary scientist each month.