Water on the Moon from Lightcurve Films on Vimeo.
Τετάρτη 26 Σεπτεμβρίου 2012
A comet is approaching the earth: stay tuned!!!
A newly discovered comet has the potential to put on a dazzling celestial display late next year, when it will be so bright you may be able to see it briefly in the daytime sky.
The discovery of the object named Comet ISON was announced Monday (Sept. 24) by Russians Vitali Nevski and Artyom Novichonok, who detected it in photographs taken three days earlier using a 15.7-inch (0.4-meter)reflecting telescope of the International Scientific Optical Network (ISON), near Kislovodsk. The new comet is officially known as C/2012 S1.
When first sighted, Comet ISON was 625 million miles (1 billion kilometers) from Earth and 584 million miles (939 million km) from the sun, in the dim constellation of Cancer. It was shining at magnitude 18.8 on the reverse scale used by astronomers to measure the brightness of sky objects (the lower the number, the brighter the object). That makes the comet currently about 100,000 times fainter than the dimmest star that can be seen with the unaided eye.
And in Greek language...
Ένας κομήτης που εντοπίστηκε πριν από λίγες μέρες από αστρονόμους στη Ρωσία φαίνεται ότι θα γίνει τόσο λαμπρός στα τέλη του 2013 ώστε θα είναι ορατός ακόμα και στο φως της ημέρας.
Η τροχιά στην οποία κινείται η διαστημική χιονόμπαλα, επισημαίνουν οι ερευνητές, παρουσιάζει σημαντικές ομοιότητες με την τροχιά του «Μεγάλου Κομήτη του 1680», ο οποίος έγινε ορατός στη διάρκεια της ημέρα και σχημάτισε μια ουρά με φαινόμενο μήκος μεγαλύτερο από το πλάτος της Σελήνης.
Η ομοιότητα των τροχιών υποδεικνύει ότι τα δύο σώματα σχετίζονται ή ότι πρόκειται για τον ίδιο κομήτη, αναφέρει το Space.com.
O νέος κομήτης, με την ονομασία Comet ISON ή C/2012 S1, εντοπίστηκε το περασμένο Σαββατοκύριακο με τηλεσκόπιο του Διεθνούς Επιστημονικού Οπτικού Δικτύου (ISON) κοντά στο Κισλοβόντσκ στην περιοχή του Βόρειου Καυκάσου.
Βρισκόταν τότε σε απόσταση ενός δισεκατομμυρίου χιλιομέτρων από τη και 939 εκατομμύρια χιλιόμετρα από τον Ήλιο. Παραμένει εξαιρετικά δυσδιάκριτος, καθώς η λαμπρότητά του είναι 100.000 φορές μικρότερη από τη φωτεινότητα του πιο αμυδρού άστρου που μπορούμε να δούμε με γυμνό μάτι.
Το σόου θα αρχίσει όταν ο κομήτης πλησιάσει τον Ήλιο, οπότε οι πάγοι της επιφάνειάς του θα αρχίσουν να εξαερώνουν την ακτινοβολία και θα σχηματίσουν μια ουρά που εκτείνεται για χιλιάδες ή και εκατομμύρια χιλιόμετρα στο Διάστημα.
Ο C/2012 S1 θα αρχίσει να γίνεται ορατός με γυμνό μάτι τον Οκτώβριο του 2013, όταν θα φαίνεται να κινείται τις πρώτες πρωινές ώρες ανάμεσα στα άστρα του αστερισμού του Λέοντα.
Το φαινόμενο θα κορυφωθεί όταν ο κομήτης φτάσει στο περιήλιο, δηλαδή στην ελάχιστη απόστασή του από τον Ήλιο, στις 28 Νοεμβρίου 2013. Υπό την επίδραση της ακραίας βαρύτητας του Ήλιου, ο C/2012 S1 θα πραγματοποιήσει μια κλειστή στροφή πίσω από το άστρο για να εμφανιστεί και πάλι στην άλλη πλευρά του.
Κανείς δεν μπορεί να προβλέψει πόσο μακριά και φωτεινή θα είναι η ουρά του, οι αστρονόμοι πάντως ελπίζουν σε ένα από τα πιο θεαματικά περάσματα των τελευταίων δεκαετιών.
Δεδομένου ότι οι κομήτες θεωρούνται κατάλοιπα από το σχηματισμό του Ηλιακού Συστήματος πριν από 4,5 δισ. χρόνια, οι επιστήμονες θα παρακολουθούν τον C/2012 S1 αναζητώντας στοιχεία για τη σύστασή του.
Τρίτη 4 Σεπτεμβρίου 2012
Neil A. Armstrong: Join the angels
Neil A. Armstrong, the first man to walk on the moon, was born in Wapakoneta, Ohio, on August 5, 1930. He began his NASA career in Ohio.
After serving as a naval aviator from 1949 to 1952, Armstrong joined the National Advisory Committee for Aeronautics (NACA) in 1955. His first assignment was with the NACA Lewis Research Center (now NASA Glenn) in Cleveland. Over the next 17 years, he was an engineer, test pilot, astronaut and administrator for NACA and its successor agency, the National Aeronautics and Space Administration (NASA).
As a research pilot at NASA's Flight Research Center, Edwards, Calif., he was a project pilot on many pioneering high speed aircraft, including the well known, 4000-mph X-15. He has flown over 200 different models of aircraft, including jets, rockets, helicopters and gliders.
Armstrong transferred to astronaut status in 1962. He was assigned as command pilot for the Gemini 8 mission. Gemini 8 was launched on March 16, 1966, and Armstrong performed the first successful docking of two vehicles in space.
As spacecraft commander for Apollo 11, the first manned lunar landing mission, Armstrong gained the distinction of being the first man to land a craft on the moon and first to step on its surface.
Armstrong subsequently held the position of Deputy Associate Administrator for Aeronautics, NASA Headquarters, Washington, D.C. In this position, he was responsible for the coordination and management of overall NASA research and technology work related to aeronautics.
He was Professor of Aerospace Engineering at the University of Cincinnati between 1971-1979. During the years 1982-1992, Armstrong was chairman of Computing Technologies for Aviation, Inc., Charlottesville, Va.
He received a Bachelor of Science Degree in Aeronautical Engineering from Purdue University and a Master of Science in Aerospace Engineering from the University of Southern California. He holds honorary doctorates from a number of universities.
Armstrong was a Fellow of the Society of Experimental Test Pilots and the Royal Aeronautical Society; Honorary Fellow of the American Institute of Aeronautics and Astronautics, and the International Astronautics Federation.
He was a member of the National Academy of Engineering and the Academy of the Kingdom of Morocco. He served as a member of the National Commission on Space (1985-1986), as Vice-Chairman of the Presidential Commission on the Space Shuttle Challenger Accident (1986), and as Chairman of the Presidential Advisory Committee for the Peace Corps (1971-1973).
Armstrong was decorated by 17 countries. He was the recipient of many special honors, including the Presidential Medal of Freedom; the Congressional Gold Medal; the Congressional Space Medal of Honor; the Explorers Club Medal; the Robert H. Goddard Memorial Trophy; the NASA Distinguished Service Medal; the Harmon International Aviation Trophy; the Royal Geographic Society's Gold Medal; the Federation Aeronautique Internationale's Gold Space Medal; the American Astronautical Society Flight Achievement Award; the Robert J. Collier Trophy; the AIAA Astronautics Award; the Octave Chanute Award; and the John J. Montgomery Award.
Armstrong passed away on Aug. 25, 2012 following complications resulting from cardiovascular procedures. He was 82. August 2012
After serving as a naval aviator from 1949 to 1952, Armstrong joined the National Advisory Committee for Aeronautics (NACA) in 1955. His first assignment was with the NACA Lewis Research Center (now NASA Glenn) in Cleveland. Over the next 17 years, he was an engineer, test pilot, astronaut and administrator for NACA and its successor agency, the National Aeronautics and Space Administration (NASA).
As a research pilot at NASA's Flight Research Center, Edwards, Calif., he was a project pilot on many pioneering high speed aircraft, including the well known, 4000-mph X-15. He has flown over 200 different models of aircraft, including jets, rockets, helicopters and gliders.
Armstrong transferred to astronaut status in 1962. He was assigned as command pilot for the Gemini 8 mission. Gemini 8 was launched on March 16, 1966, and Armstrong performed the first successful docking of two vehicles in space.
As spacecraft commander for Apollo 11, the first manned lunar landing mission, Armstrong gained the distinction of being the first man to land a craft on the moon and first to step on its surface.
Armstrong subsequently held the position of Deputy Associate Administrator for Aeronautics, NASA Headquarters, Washington, D.C. In this position, he was responsible for the coordination and management of overall NASA research and technology work related to aeronautics.
He was Professor of Aerospace Engineering at the University of Cincinnati between 1971-1979. During the years 1982-1992, Armstrong was chairman of Computing Technologies for Aviation, Inc., Charlottesville, Va.
He received a Bachelor of Science Degree in Aeronautical Engineering from Purdue University and a Master of Science in Aerospace Engineering from the University of Southern California. He holds honorary doctorates from a number of universities.
Armstrong was a Fellow of the Society of Experimental Test Pilots and the Royal Aeronautical Society; Honorary Fellow of the American Institute of Aeronautics and Astronautics, and the International Astronautics Federation.
He was a member of the National Academy of Engineering and the Academy of the Kingdom of Morocco. He served as a member of the National Commission on Space (1985-1986), as Vice-Chairman of the Presidential Commission on the Space Shuttle Challenger Accident (1986), and as Chairman of the Presidential Advisory Committee for the Peace Corps (1971-1973).
Armstrong was decorated by 17 countries. He was the recipient of many special honors, including the Presidential Medal of Freedom; the Congressional Gold Medal; the Congressional Space Medal of Honor; the Explorers Club Medal; the Robert H. Goddard Memorial Trophy; the NASA Distinguished Service Medal; the Harmon International Aviation Trophy; the Royal Geographic Society's Gold Medal; the Federation Aeronautique Internationale's Gold Space Medal; the American Astronautical Society Flight Achievement Award; the Robert J. Collier Trophy; the AIAA Astronautics Award; the Octave Chanute Award; and the John J. Montgomery Award.
Armstrong passed away on Aug. 25, 2012 following complications resulting from cardiovascular procedures. He was 82. August 2012
Δευτέρα 13 Αυγούστου 2012
Κυριακή 5 Αυγούστου 2012
Σάββατο 4 Αυγούστου 2012
Everyone has to look at this
All the people, worldwide, should closely the story of this guy.
Especially, the Greek people, the people who suffered. They need to acquire some of his ENERGY and passion for life.
Especially, the Greek people, the people who suffered. They need to acquire some of his ENERGY and passion for life.
Mars lander Curiosity protected by largest ever heat shield
This Sunday will see one of the most dramatic events in the history of space exploration. On August 5, 2012 at 10:31 p.m. U.S. PDT (August 6, 05:31 GMT), the nuclear-powered science rover Curiosity will reach Mars and begin one of the most complex, most daring landings ever attempted. Ironically, it may end in one of two ways – a triumph for the men and women of NASA as the Curiosity lander sends back its first signals from the Red Planet or utter silence. And the key to this is a heat shield that is so new to the field of planetary exploration that it is an experiment in itself.
Mars is the Bermuda Triangle of the Solar System. Over half of all missions end in failure with probes failing to reach orbit and landers vanishing. One of the reasons for this is the atmosphere of Mars, which is one of the most hostile for explorers when it comes to landing. The Moon’s vacuum makes landing on rockets a relatively simple maneuver. And though Earth's atmosphere can burn up entering vehicles, it also helps to slow them down enough to effect a safe landing on wings or parachutes.
Entering the Martian atmosphere
The thin atmosphere of Mars is like neither of these. With a pressure of only 1/100th that of Earth’s, there’s too much of it to avoid burning up and not enough of it to slow down properly. When Curiosity's entry vehicle hits the Martian atmosphere at 13,200 mph (21,250 km/h) and suffers over 10 g’s in deceleration forces, it will be protected by the largest aeroshell ever built.
This remarkable vehicle will literally fly through the Martian sky. Tilted at an angle and protected by its heat shield, the aeroshell will use the aerodynamic characteristics of the shield and tiny thrusters to turn itself into a lifting body that can turn and even bank in lazy “S” curves to help slow it down. This principle was used on the Apollo Command Module, but this is the first time it’s been used on a planetary mission.
The key to surviving this fiery ordeal is the 14.8 ft (4.5 m) diameter heat shield. It’s of an unprecedented size for such a mission, but the Curiosity lander is itself unprecedented. At 1,982 lbs (899 kg), Curiosity is the size of a 4X4 – a robotic, nuclear-powered SUV with a laser capable of vaporizing rock. This requires a very large entry vehicle to get it to the ground with the whole thing coming in at 5,359 lbs (2,431 kg). This, in turn, has to be sealed in the largest ever aeroshell, a protective pod that looks like an upside-down bowl with a plate under it. That plate is the largest ever planetary mission heat shield.
This heat shield isn’t just big, it’s also of a new design previously used on theStardust mission to collect samples from a comet’s tail and return them to Earth. The heat and stress on the shield will be greater than any Mars probe has ever encountered, with temperatures reaching 3,800° F (2,100° C). To protect against this, the shield is made of tiles of phenolic impregnated carbon ablator (PICA) invented by the NASA Ames Research Center. Though NASA did its best to design the shield using the best models of the Martian atmosphere, models are still models, so the shield was built with a wide margin of error.
NASA hopes to learn a great deal from the shield’s performance and, in order to profit from the experience, the shield has been fitted with the Mars Science Laboratory Entry, Descent, and Landing Instrument (MEDLI) Suite. This is a pack of 14 sensors consisting of seven pressure sensors to collect atmospheric data and seven plugs fitted with multiple temperature sensors. Since the heat shield works by ablation, that is, it protects the vehicle by burning away, the temperature sensors are fitted to the shield at different depths, so material loss can be plotted. All fourteen plugs are hooked into an electronics box that feeds the data to the lander where it is combined with information about changes in velocity.
From this data, scientists and engineers hope not only to build up a profile of the Martian atmosphere, but to also evaluate the effectiveness of the shield. During the descent, measurements are taken eight times per second and this is fed back to the lander.
As to the shield, its reward is that 24 seconds after the parachute deploys at an altitude of seven miles (11 km), the heat shield separates and what’s left of it plummets to the ground. It’s job is done, though the spacecraft continues its descent with the aeroshell jettisoning and Curiosity lowered to the surface by a rocket-powered sky crane. The data collected from the MEDLI Suite will be held by Curiosity and transmitted to Earth during the first month after landing.
Assuming it’s there to do the transmitting. We'll have our answers soon enough.
In the video below, NASA team members detail some of the challenges faced in getting the Curiosity Mar's rover to the Martian surface.
CURIOSITY LIVE STREAM
For anyone who would like to follow along with the mission on
Sunday night (5th of August), here's a couple useful links:
NASA TV live feed: http://www.ustream.tv/nasa
Eyes on the solar system: http://eyes.nasa.gov/index.html
NASA TV live feed: http://www.ustream.tv/nasa
Eyes on the solar system: http://eyes.nasa.gov/index.html
Stream videos at Ustream
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