Saturday, January 28, 2012

NASA's Kepler Announces 11 Planetary Systems Hosting 26 Planets

NASA's Kepler mission has discovered 11 new planetary systems hosting 26 confirmed planets. These discoveries nearly double the number of verified Kepler planets and triple the number of stars known to have more than one planet that transits, or passes in front of, its host star. Such systems will help astronomers better understand how planets form.

The planets orbit close to their host stars and range in size from 1.5 times the radius of Earth to larger than Jupiter. Fifteen of them are between Earth and Neptune in size, and further observations will be required to determine which are rocky like Earth and which have thick gaseous atmospheres like Neptune. The planets orbit their host star once every six to 143 days. All are closer to their host star than Venus is to our sun.

"Prior to the Kepler mission, we knew of perhaps 500 exoplanets across the whole sky," said Doug Hudgins, Kepler program scientist at NASA Headquarters in Washington. "Now, in just two years staring at a patch of sky not much bigger than your fist, Kepler has discovered more than 60 planets and more than 2,300 planet candidates. This tells us that our galaxy is positively loaded with planets of all sizes and orbits."

For more info, visit: http://www.nasa.gov/mission_pages/kepler/news/new-multi-systems.html

Wednesday, January 25, 2012

The Sun Flares with Activity

Following one of the longest and weakest periods of activity in many cycles, the Sun is brimming with activity again. In late January 2012, our nearest star offered a preview of what may be to come in the solar maximum of 2012–13. The storm has the potential to disrupt some communications and satellite systems and to bring auroras to high-latitude skies.

The images above show a solar flare as observed by the Atmospheric Imaging Assembly (AIA) on NASA’s Solar Dynamics Observatory (SDO) at 03:27, 03:42, and 04:12 Universal Time (Greenwich Time) on January 23. Note the brightening of the solar surface as gas was superheated and magnetically supercharged. By the third (right) image, a stream of solar material is seen flowing off into space above the hot spot, likely solar protons and a coronal mass ejection. Click on the enlarged images and movies for a wider view.

The high-latitude solar flare was measured as M8.7 in intensity, just below the most intense “X class” of flares. The eruption sent a stream of fast-moving, highly energetic protons toward Earth, provoking the most intense solar energetic particle storm—an S3 on NOAA Space Weather Prediction Center’s scale—since 2005.

The flare was accompanied by a coronal mass ejection (CME), a cloud of solar plasma that was ejected from the solar atmosphere in the direction of Earth. The CME was observed by the STEREO and SOHO spacecraft with an initial speed of more than 2,000 kilometers (1,400 miles) per second. It was estimated to reach Earth sometime on January 24 and Mars on January 25. NOAA forecasters were predicting a G2 geomagnetic storm, though a G3 was possible.

Solar flares and CMEs are not a danger to humans on Earth's surface, as the planet's magnetic field (magnetosphere) and atmosphere deflect and absorb the solar energy and particles. The sun storms can pose some risks to astronauts, and they can upset the electronics and transmissions on science, military, and communications satellites. Closer to Earth's surface, solar activity can cause disruptions of radio signals (particularly HF), provide a small dose of radiation to passengers on high-latitude flights, and provoke auroras (northern and southern lights).

Tuesday, January 24, 2012

NASA Cold Weather Airborne Campaign to Measure Falling Snow

Beginning Jan. 17, NASA will fly an airborne science laboratory above Canadian snowstorms to tackle a difficult challenge facing the upcoming Global Precipitation Measurement (GPM) satellite mission - measuring snowfall from space.

GPM is an international satellite mission that will set a new standard for precipitation measurements from space, providing next-generation observations of worldwide rain and snow every three hours. It is also the first mission designed to detect falling snow from space.

"Snow is notoriously hard to measure as it falls," said Walter Petersen, the GPM ground validation scientist at NASA's Wallops Flight Facility in Virginia. "Snowflakes contain varying amounts of air and water, and they flutter, wobble and drift as they leave the clouds."

Knowing how "wet" a snowflake is allows scientists to measure overall water content. A wet, heavy snow can shut down a city, and melted snow is a crucial source of freshwater in many areas.

Working with Environment Canada, NASA's GPM Cold-season Precipitation Experiment (GCPEx) will measure light rain and snow in Ontario from Jan. 17 to Feb. 29. The field campaign is designed to improve satellite estimates of falling snow and test ground validation capabilities in advance of the planned launch of the GPM Core satellite in 2014.

NASA's DC-8 airborne science laboratory will fly out of Bangor, Maine, carrying radar and a radiometer that will simulate the measurements to be taken from space by GPM. At an altitude of 33,000 feet (10 kilometers), the DC-8 will make multiple passes over an extensive ground network of snow gauges and sensors at Environment Canada's Center for Atmospheric Research Experiments north of Toronto.

Monday, January 23, 2012

Revisiting the 'Pillars of Creation'

In 1995, NASA's Hubble Space Telescope took an iconic image of the Eagle nebula, dubbed the "Pillars of Creation," highlighting its finger-like pillars where new stars are thought to be forming. Now, the Herschel Space Observatory has a new, expansive view of the region captured in longer-wavelength infrared light.

The Herschel mission is led by the European Space Agency, with important NASA contributions.

The Eagle nebula is 6,500 light-years away in the constellation of Serpens. It contains a young, hot star cluster, NGC6611, visible with modest backyard telescopes, which is sculpting and illuminating the surrounding gas and dust. The result is a huge, hollowed-out cavity and pillars, each several light-years long.

The new Herschel image shows the pillars and the wide field of gas and dust around them. Captured in far-infrared wavelengths, the image allows astronomers to see inside the pillars and structures in the region. Herschel's image also makes it possible to search for young stars over a much wider region, and come to a much fuller understanding of the creative and destructive forces inside the Eagle nebula.

For more info, visit: http://www.nasa.gov/mission_pages/herschel/news/herschel20120118.html

Tuesday, January 17, 2012

Two Earth Satellites Viewed From Houston


This photograph taken from Houston, Texas, juxtaposes Earth’s oldest satellite with one of its youngest. The Moon is thought to have been formed by the impact of a large body (perhaps Mars-sized) with the early Earth approximately 4.6 billion years ago. In contrast, the first components of the International Space Station (ISS) assumed orbit around the Earth in 1998, with assembly completed 13 years later—a significant period of time to us, but the merest fraction of a second in the history of the Moon.

While the ISS appears to be fairly close to the Moon’s surface in the image, it’s a trick of perspective. The Moon orbits Earth at an average distance of 384,400 kilometers (238,855 miles), while the ISS orbits at altitudes ranging from approximately 330 to 410 kilometers (205 to 255 miles).

The ISS can frequently be viewed from the Earth’s surface with the naked eye as a bright object moving rapidly across the sky. The ISS has also been photographed from Earth transiting more dramatic backdrops, such as the Sun.

As can be seen in the high-resolution version of this image, major structural elements of the Station - such as the solar panel arrays - can be resolved using high-powered binoculars or lenses. Major features of the lunar nearside surface are likewise discernable with the naked eye, the most obvious being the dark maria lowlands (mare in plural) contrasting with the bright highland regions (or terrae). With moderate magnification, other features such as impact craters become clearly visible; for example, Copernicus and Tycho Craters.

Friday, January 13, 2012

Seeing Forests for the Trees and the Carbon


Trees cool and moisten our air and fill it with oxygen. They calm the winds and shade the land from sunlight. They shelter countless species, anchor the soil, and slow the movement of water. They provide food, fuel, medicines, and building materials for human activity.

Scientists estimate that humans release about nine billion tons of carbon (mostly carbon dioxide) each year by burning fossil fuels and by changing the landscape. About four billion tons end up in the atmosphere and two billion tons dissolve in the ocean. The last three billion go into ecosystems on land, but exactly where these sinks are located remains an open question.

Forests are considered one of the world’s largest banks for all of the carbon emitted into the atmosphere through natural processes and human activities. They cover about 30 percent of Earth’s land surface, while accounting for 50 percent of plant productivity. As much as 45 percent of the carbon stored on land is tied up in forests.

Thursday, January 12, 2012

2012: Beginning of the End or Why the World Won't End?


Remember the Y2K scare? It came and went without much of a whimper because of adequate planning and analysis of the situation. Impressive movie special effects aside, Dec. 21, 2012, won't be the end of the world as we know. It will, however, be another winter solstice.

Much like Y2K, 2012 has been analyzed and the science of the end of the Earth thoroughly studied. Contrary to some of the common beliefs out there, the science behind the end of the world quickly unravels when pinned down to the 2012 timeline. Below, NASA Scientists answer several questions that we're frequently asked regarding 2012.



Question (Q): Are there any threats to the Earth in 2012? Many Internet websites say the world will end in December 2012.
Answer (A): Nothing bad will happen to the Earth in 2012. Our planet has been getting along just fine for more than 4 billion years, and credible scientists worldwide know of no threat associated with 2012.

Q: What is the origin of the prediction that the world will end in 2012?
A: The story started with claims that Nibiru, a supposed planet discovered by the Sumerians, is headed toward Earth. This catastrophe was initially predicted for May 2003, but when nothing happened the doomsday date was moved forward to December 2012. Then these two fables were linked to the end of one of the cycles in the ancient Mayan calendar at the winter solstice in 2012 -- hence the predicted doomsday date of December 21, 2012.

Source :http://www.nasa.gov/topics/earth/features/2012.html

Wednesday, January 11, 2012

Where the Trees Are

Trees are one of Earth’s largest banks for storing the carbon that gets emitted by natural processes and human activities. Forests cover about 30 percent of the planet’s surface, and as much as 45 percent of the carbon stored on land is tied up in forests.

But did global forests hold more or less carbon in the past? And could they store more in the future? Does it matter where those trees are growing? Scientists really don’t know. But before they can find out, they’ll need a reliable inventory of what is growing today.

Josef Kellndorfer and Wayne Walker of the Woods Hole Research Center (WHRC) recently worked with colleagues at the U.S. Forest Service and U.S. Geological Survey to create such an inventory for the United States. The map above was built from the National Biomass and Carbon Dataset (NBCD), released in 2011. It depicts the concentration of biomass - a measure of the amount of organic - in the trunks, limbs, and leaves of trees. The darkest greens reveal the areas with the densest, tallest, and most robust forest growth.

Over six years, researchers assembled the national forest map from space-based radar, satellite sensors, computer models, and a massive amount of ground-based data. It is possibly the highest resolution and most detailed view of forest structure and carbon storage ever assembled for any country.

Forests in the U.S. were mapped down to a scale of 30 meters, or roughly 10 computer display pixels for every hectare of land (4 pixels per acre). They divided the country into 66 mapping zones and ended up mapping 265 million segments of the American land surface. Kellndorfer estimates that their mapping database includes measurements of about five million trees.

For more info, visit: http://earthobservatory.nasa.gov/IOTD/view.php?id=76697