Since the dawn of intelligent man, we as a race have asked several questions pertaining to the heavens, and to the meaning of life. A NASA mission, scheduled to launch in March 2009, hopes to take us a step closer to answering one of these timeless questions: “are we alone?” The Kepler Mission is not only named after the great mathematician and astronomer, Johannes Kepler, it also celebrates the 400^th anniversary of the publication of his first two laws on planetary motion.

Some of the goals of the Kepler Mission include: determine the percentage of terrestrial planets in the habitable zone of nearby stars; determine the period and geometries of any such discoveries; discover any additional members of the planetary system to which the habitable planet belongs; and to determine the properties of the planetary systems host star.

To help celebrate this mission, and the 400^th anniversary of the publication of Kepler’s work, NASA is taking names from the public to put on a DVD which will orbit the Sun onboard the Kepler spacecraft. Anybody who wishes to submit their name must write a short essay, under 500 words, explaining why they personally believe the Kepler mission is important. So why is this mission important? There are at least three reasons why this mission is important: #1) Are we alone in the universe? Mankind has been pondering this question for centuries, and by discovering habitable planets outside of our solar system, we will be much closer to answering this question. The discovery of such a planet will dramatically affect our scientific and religious communities; the discovery of one such planet will create a montage of new questions; #2) Eternal life. If the human race wishes to outlive the life of our host star, we will eventually have to colonize a planet outside of our own solar system. The first step, in this thankfully very distant journey, is to map out the habitable planets in our galactic neighborhood. #3) Planetary evolution. By discovering Earth-like planets existing around several types of stars, in several stages of their lives, we will be able to better understand the processes which shape planetary evolution, and the development of life.

The Kepler spacecraft will not orbit the Earth, but will orbit the sun while slightly trailing the Earth with an orbital period of about 372.5 days. With this orbit the spacecraft should be able to avoid having its view blocked by the Earth, Moon, or Sun. The reason this is important is because of the methods with which the spacecraft will search for these potentially habitable planets.

The Kepler spacecraft will search for Earth-like planets using a technique known as the Transit Method of Detecting Extrasolar Planets. A transit occurs when a planet crosses in front of its host star as viewed by an observer. These transits dim the brightness of a star which allow for the detection of extrasolar planets. This change in brightness is very difficult to detect by terrestrial planets, such as Earth, because they only dim their host star by 100 parts per million, lasting only 2 to 16 hours. In order for an extrasolar transit to be observed from our solar system, the orbit must be viewed edge on. The probability of observing such a planet is less than 1%. To increase the chances of observing a transiting terrestrial planet, the Kepler spacecraft will observe 100,000 of our neighboring stars. Because any planet in the habitable zone will require an orbit close to that of one Earth year, Kepler will need to observe any transits discovered amongst these 100,000 stars for at least 3.5 years to determine if the transit is periodic enough to be a planet.

The Kepler Mission may not be able to directly determine whether or not we are alone in the universe, but it will be able to tell us if we have neighboring planetary systems, containing planets, capable of sustaining life. When compared to all the stars in the universe, even one discovery amongst the relatively small sample space of 100,000 stars will be significant enough for us to rethink our meaning and place in the universe.

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And to think some people can’t be bothered because “There wasn’t any parking at my polling place…” Actual quote.  Sigh…. Let me see if I got this straight, astronauts circling in orbit can cast their votes in the general election, but 1 parking spot too few is enough to delay your civic duty 4 more years?

I’m not trying to spin up some indignant rhetoric around patriotic duty and whatnot, but considering how many people have given their lives to obtain and protect the freedoms we enjoy – not the least of these being the right and privilege to determine our leadership through general elections – it seems a tad remiss to take a pass on casting a ballot because of a lack of convenience.

http://www.nasa.gov/mission_pages/station/expeditions/expedition18/vote_110408.html

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Two NASA scientists have found the smallest, or lightest weight, black hole ever yet discovered. The black hole is in the binary system, XTE J1650-500, which is in the constellation Ara in the southern hemisphere. The mass of the black hole is only 3.8 solar masses. This beats the previous record holder of 6.3 solar masses. The black hole was discovered earlier as part of the binary with a normal star and was known to be lightweight but its exact weight was not known until recently with the use of a new method.

This new method uses a relationship between the black hole and the inner part of the surrounding in falling gas and material. Hot gas piles up around the black hole as it falls in and heats up giving off x-rays. The x-ray’s intensity varies in a regular pattern, called the quasi-periodic oscillation, or QPC. Astronomers discovered the congestion zone is closer to smaller black holes and therefore makes the QPC change more quickly. To measure the black hole masses, astronomers used archival data from RXTE, which has made exquisitely precise measurements of QPO frequencies in at least 15 black holes. Using this method they measured the mass of XTE J1650-500 as 3.8 solar masses with a margin of error of only half a sun.

This value is well below those measured for other standard black holes. Now there is a threshold value below which a dying star will become a neutron star instead of a black hole. It is thought to be between 1.7 to 3 solar masses. However, with this new discovery and method of detection this boundary could be in question. This value is very important for fundamental astrophysics. This is because it’s hard to know exactly what happens when a star goes supernova, when a very large amount of mass is condensed to a very small size with high density. The more details we learn about this process in particular, the more we learn about physics in general. So while the study of super massive black holes may sound more exciting, studying the smallest of black holes may be more fundamental for our understanding of physics and matter.

NASA has chosen a new mission in the Mars Exploration Program to study the Martian atmosphere. The purpose of the $485 million MAVEN mission, (Mars Atmosphere and Volatile EvolutioN), is to study the Martian Atmosphere, climate history, and potential habitability. This mission is intended to take the most detailed measurements ever recorded in the Martian atmosphere.

After the launch in 2013, MAVEN will enter an elliptical orbit from 90 to 3870 miles above the Martian surface where it will take measurements for an entire Earth year. Maven will also descend to an altitude of 80 miles above the surface where it will take detailed measurements of the upper atmosphere. After the mission is complete MAVEN will be used as a communications satellite for future rovers and landers.

The Martian atmosphere is relatively thin, with pressures ranging from .03 kPa to 1.155 kPa, and an average sea-level pressure of about .6 kPa (nearly 170 times less than that of Earth). Even though the atmosphere on Mars is 4 km taller than Earths, its Mass is nearly 206 times less than Earths. The atmosphere is composed of 95% CO₂, 3% N, 1.6% Ar, with trace amounts of O₂, H₂O, and CH₄. The atmosphere has been divided into 4 subdivisions: lower atmosphere, middle atmosphere, Upper atmosphere, and exosphere. The lower atmosphere is region that is warmed from airborne dust particles. The middle atmosphere is distinguished only by a jet stream. The upper atmosphere is characterized by very high temperatures, and the atmospheric gasses are stripped apart by the sun. The exosphere, like on Earth, is the boundary-less region where the atmosphere slowly tappers out into space.

Because Mars has the only surface observable from Earth, its climate has been studied since the 17^th century. The first up-close climate observations were made in the 60’s by the Mariner missions and the Viking missions of the 70’s. Today the Mars Global Surveyor keeps up where they left off. We know that the Martian climate has some similarities with the Earth, such as changing seasons, ice-ages, and even a sublimating south-pole which could indicate a warming climate. Unlike Earth, Mars lacks water and has a low ability to resist temperature change during a full heating/cooling cycle.

Recent Missions such as the rovers, Spirit and Opportunity, have shown that large amounts of water most likely existed on the Martian surface at one time. So with any luck, MAVEN will be able to provide some insight into where this water went, and what happened to a Martian atmosphere that was once able to support water and perhaps life. Even more importantly, MAVEN will help us understand the evolution and the eventual fate of our own atmosphere.