Posts Tagged ‘mission’

Balloon Picking up Mysterious Radio Signals

Friday, January 16th, 2009 by Bellatrix

NASA’s most recent balloon trip has found something new and unexplained, don’t you just love when that happens. The ARCADE balloon mission has uncovered a new radio signal with unknown origin, which may be more of an interesting find than the balloons real mission.

The findings come from NASA’s balloon borne instrument known as Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission, or ARCADE. ARCADE was launched in July of 2006 in Palestine Texas. It flew to an altitude of 37km, 120,000 ft, where the atmosphere thins and begins to give way to space. It took data for about 4 hours before parachuting back to Earth. Balloons like this one are used for this reason, they can get above the interference caused by our atmosphere but are much cheaper to launch and build then a full blown satellite.

ARCADE’s mission was to observe and collect radio data from some of the first stars born in our universe. Since these stars are so distance their light is only observable at radio wavelengths. For the instrument to be sensitive enough to pick up this information it had to be cooled, really cooled. It was sent up with 500 gallons of liquid helium to keep it at a frosty 2.5 degrees Celsius above absolute zero. So it was all poised and ready but the data it was sent to collect was lost in a powerful radio signal of unknown origin.

This background radio signal was about 6 times larger than what they had expected to find. It was too strong, or loud, to be coming from the distant stars, and even too loud to be coming from known radio sources like gas from the halo of our galaxy. All galaxies give off some radio noise, usually just a hiss, except for those which are radio loud, usually quasars. But even with all these radio loud galaxies there isn’t enough of them to account for this noise, for the noise to be coming from just galaxies there’d have to be so many radio galaxies they’d be packed in like sardines, one right next to another, which just isn’t the case.

So obviously there’s something that we are missing, something loud making this racket that we don’t even know about; and that’s exciting. This is a great example of why astronomy is so exciting. This routine type mission that was supposed to just give a few details on a particular type of star and then BAM! There’s a mystery with possible far reaching implications. Is this a new object all together? Is it an evolutionary stage of galaxies that we didn’t know about? NASA hasn’t yet mentioned any planned follow up to try and dig deeper into this mystery but I’m sure that it is coming, I mean everyone loves a good mystery.

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Large Deposits of Water-Ice Found on Mars

Monday, November 24th, 2008 by Evan Finnes

On November 20th, 2008, NASA confirmed that the Mars Reconnaissance Orbiter has discovered ancient glaciers of water-ice preserved under a layer or dust and rock. These subsurface glaciers are located at altitudes much lower than any previously discovered layers of ice, and also contain more water-ice than any other region on Mars, including the poles.

These glaciers were discovered underneath a formation that had been puzzling geologists for years. These formations are known as “aprons” because of the way they gently slope upwards. The glaciers were discovered after ground penetrating radars were pointed at these “aprons” because the radio waves were reflected without a significant loss of energy shortly after penetrating the surface. The radio waves that are not reflected travel through these formations with an apparent velocity, which is consistent with the composition of water-ice.

Hundreds of these apron-like features are located in latitude bands between 35 and 60 degrees on either side of the Martian equator. They are also commonly located beneath cliffs and are typically tens of kilometers long, and may be the remnants of a giant ice sheet, which may have at one time engulfed these mid-altitude regions. Many scientists believe that Mars was once tilted in such a fashion that the poles pointed toward the Sun, leaving the mid-latitude regions in a much cooler climate. This discovery offers proof to this hypothesis.

Studying these ice-sheets could help us understand processes that effect climate change, which is a poorly understood phenomenon, here on Earth. Our last glacial Maximum occurred about 20,000 years ago, when much of the North American and Eurasian continents were covered in an ice sheet over 3 kilometers thick. There are many factors which are thought to cause the onset of an ice age, such as: changes in the atmosphere, tectonic geography, variation in the Earth’s orbit, and variations in solar energy. The changes in the atmosphere which effect the onset of glaciers is not well understood, although, there is some proof that CO2 levels shrink during the onset of an ice age, and increase during interglacial periods. The effects of increased CO2 on the climate have long been a subject of great debate. Tectonic geography affects the onset of ice ages by arranging the continents in such a way that they prevent the flow of warm water from the equator to the poles; this allows the formation of ice sheets. These ice-sheets increase the planets albedo, which decreases the amount of solar radiation, which is absorbed. This decrease in absorbed energy allows the ice sheets to expand. There are three known configurations which block or reduce this flow of warm water–two of which exist today. A continent sits on top of a pole, such as Antarctica. Or a polar sea, such as the Arctic Ocean, is nearly land-locked. The third configuration consists of a single mass continent which covers much of the equator. Such a mass continent existed between 850 and 635 million years ago during the Cryogenian period, and was called Rodinia. Variations in the Earth’s orbit, called Milankovitch cycles, suggests that major ice ages occur every 100,000 years due to periodic changes in Earth’s eccentricity, axial tilt, and orbital periods; however, how these variations effect the climate are not well understood.

The discovery of these large volumes of water-ice on Mars will be very important to the future colonization, and manned missions to mars. This ice will serve as drinking water, and as a source of energy, which will be used in hydrogen fueled vehicles. This will defiantly reduce costs for such future missions because fewer supplies will have to be shipped to the red planet.

On Earth, such buried glaciers in Antarctica preserve traces of ancient organisms. So these Martian glaciers might also serve as a place to look for fossil evidence of past life on Mars. In addition to fossil life, localized heating due to volcanism may have melted some ice, which could provide an environment for microorganisms to evolve.

The discovery of subsurface glaciers on Mars will help us understand the processes which evoke climate change on Earth, provide a place to gather food and fuel for future missions to Mars, and could be one of the best places to look for signs of ancient organisms. Indeed, these will be places which will be thoroughly explored by rovers, Landers, and eventually, by mankind.

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Monday, November 17th, 2008 by Evan Finnes

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 400th 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 400th 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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