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Topic: Sun

NASA’s Dawn mission reveals Ceres’ Ice in Shadowed Craters related to dwarf planet’s tilt

 

Written by Elizabeth Landau
NASA’s Jet Propulsion Laboratory

NASA - National Aeronautics and Space AdministrationPasadena, CA – Dwarf planet Ceres may be hundreds of millions of miles from Jupiter, and even farther from Saturn, but the tremendous influence of gravity from these gas giants has an appreciable effect on Ceres’ orientation.

In a new study, researchers from NASA’s Dawn mission calculate that the axial tilt of Ceres — the angle at which it spins as it journeys around the sun — varies widely over the course of about 24,500 years. Astronomers consider this to be a surprisingly short period of time for such dramatic deviations.

This animation shows how the illumination of Ceres' northern hemisphere varies with the dwarf planet's axial tilt, or obliquity. Shadowed regions are highlighted for tilts of 2 degrees, 12 degrees and 20 degrees. (NASA/JPL-Caltech/UCLA/MPS/DLR/IDA)

This animation shows how the illumination of Ceres’ northern hemisphere varies with the dwarf planet’s axial tilt, or obliquity. Shadowed regions are highlighted for tilts of 2 degrees, 12 degrees and 20 degrees. (NASA/JPL-Caltech/UCLA/MPS/DLR/IDA)

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NASA says Rosetta images show active surface on Comet 67P/Churyumov-Gerasimenko

 

Written by DC Agle
NASA’s Jet Propulsion Laboratory

NASA - National Aeronautics and Space AdministrationPasadena, CA – Images returned from the European Space Agency’s Rosetta mission indicate that during its most recent trip through the inner solar system, the surface of comet 67P/Churyumov-Gerasimenko was a very active place – full of growing fractures, collapsing cliffs and massive rolling boulders.

Moving material buried some features on the comet’s surface while exhuming others. A study on 67P’s changing surface was released Tuesday, March 21st, in the journal Science.

A 100 foot-wide (30 meter), 28-million-pound (12.8-million-kilogram) boulder, was found to have moved 460 feet (140 meters) on comet 67P/Churyumov-Gerasimenko in the lead up to perihelion in August 2015, when the comet's activity was at its highest. (ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)

A 100 foot-wide (30 meter), 28-million-pound (12.8-million-kilogram) boulder, was found to have moved 460 feet (140 meters) on comet 67P/Churyumov-Gerasimenko in the lead up to perihelion in August 2015, when the comet’s activity was at its highest. (ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)

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NASA prepares Satellites for alignment of Planets and Stars

 

Written by Mara Johnson-Groh
NASA’s Goddard Space Flight Center

NASA - National Aeronautics and Space AdministrationGreenbelt, MD – The movements of the stars and the planets have almost no impact on life on Earth, but a few times per year, the alignment of celestial bodies has a visible effect.

One of these geometric events — the spring equinox — is just around the corner, and another major alignment — a total solar eclipse — will be visible across America on August 21st, with a fleet of NASA satellites viewing it from space and providing images of the event.

To understand the basics of celestial alignments, here is information on equinoxes, solstices, full moons, eclipses and transits:

During a transit, a planet passes in between us and the star it orbits. This method is commonly used to find new exoplanets in our galaxy. (NASA's Goddard Space Flight Center/Genna Duberstein)

During a transit, a planet passes in between us and the star it orbits. This method is commonly used to find new exoplanets in our galaxy. (NASA’s Goddard Space Flight Center/Genna Duberstein)

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NASA’s MAVEN spacecraft makes adjustment to avoid Mars Moon Phobos

 

Written by Nancy Neal Jones
NASA’s Goddard Space Flight Center

NASA - National Aeronautics and Space AdministrationGreenbelt, MD – NASA’s MAVEN spacecraft performed a previously unscheduled maneuver this week to avoid a collision in the near future with Mars’ moon Phobos.

The Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft has been orbiting Mars for just over two years, studying the Red Planet’s upper atmosphere, ionosphere and interactions with the sun and solar wind. On Tuesday, February 28th, the spacecraft carried out a rocket motor burn that boosted its velocity by 0.4 meters per second (less than 1 mile per hour).

This artist's sketch shows NASA's MAVEN spacecraft above Mars. (NASA)

This artist’s sketch shows NASA’s MAVEN spacecraft above Mars. (NASA)

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NASA finds Red Dwarf Star with several Earth Size Planets in Orbit

 

Written by Elizabeth Landau
NASA’s Jet Propulsion Laboratory

NASA - National Aeronautics and Space AdministrationPasadena, CA – A bumper crop of Earth-size planets huddled around an ultra-cool, red dwarf star could be little more than chunks of rock blasted by radiation, or cloud-covered worlds as broiling hot as Venus.

Or they could harbor exotic lifeforms, thriving under skies of ruddy twilight.

Scientists are pondering the possibilities after this week’s announcement: the discovery of seven worlds orbiting a small, cool star some 40 light-years away, all of them in the ballpark of our home planet in terms of their heft (mass) and size (diameter). Three of the planets reside in the “habitable zone” around their star, TRAPPIST-1, where calculations suggest that conditions might be right for liquid water to exist on their surfaces—though follow-up observations are needed to be sure.

This illustration shows the seven planets orbiting TRAPPIST-1, and ultra-cool dwarf star, as they might look as viewed from Earth using a fictional, incredibly powerful telescope. (NASA-JPL/Caltech)

This illustration shows the seven planets orbiting TRAPPIST-1, and ultra-cool dwarf star, as they might look as viewed from Earth using a fictional, incredibly powerful telescope. (NASA-JPL/Caltech)

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NASA’s Earth Science continues research from International Space Station

 

Written by Samson Reiny
NASA Earth Science News Team

NASA - National Aeronautics and Space AdministrationWashington, D.C. – The number of instruments on the International Space Station dedicated to observing Earth to increase our understanding of our home planet continues to grow.

Two new instruments are scheduled to make their way to the station on the SpaceX Dragon capsule.

The Stratospheric Aerosol and Gas Experiment (SAGE) III instrument will monitor the condition of the ozone layer, which covers an area in the stratosphere 10 to 30 miles (16 to 48 kilometers) above Earth and protects the planet from the sun’s harmful ultraviolet radiation.

The International Space Station is becoming an increasingly busy platform for studying our home planet. (NASA)

The International Space Station is becoming an increasingly busy platform for studying our home planet. (NASA)

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2017 Total Solar Eclipse will give NASA Unique Opportunity to study the Earth

 

Written by Sarah Frazier
NASA’s Goddard Space Flight Center

NASA - National Aeronautics and Space AdministrationGreenbelt, MD – The first total solar eclipse in the continental United States in nearly 40 years takes place on August 21st, 2017. Beyond providing a brilliant sight in the daytime sky, total solar eclipses provide a rare chance for scientists to collect data only available during eclipses. NASA is funding 11 scientific studies that will take advantage of this opportunity.  

“When the moon blocks out the sun during a total eclipse, those regions of Earth that are in the direct path of totality become dark as night for almost three minutes,” said Steve Clarke, director of the Heliophysics Division at NASA Headquarters in Washington, D.C. “This will be one of the best-observed eclipses to date, and we plan to take advantage of this unique opportunity to learn as much as we can about the sun and its effects on Earth.”

The total solar eclipse of Aug. 21, 2017, stretches across the U.S. from coast to coast, providing scientists with a unique opportunity to study the eclipse from different vantage points. (NASA’s Scientific Visualization Studio)

The total solar eclipse of Aug. 21, 2017, stretches across the U.S. from coast to coast, providing scientists with a unique opportunity to study the eclipse from different vantage points. (NASA’s Scientific Visualization Studio)

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NASA reports Vortex Coronagraph takes it’s first Planetary System Images

 

Written by Elizabeth Landau
NASA’s Jet Propulsion Laboratory

NASA - National Aeronautics and Space AdministrationPasadena, CA – A new device on the W.M. Keck Observatory in Hawaii has delivered its first images, showing a ring of planet-forming dust around a star, and separately, a cool, star-like body, called a brown dwarf, lying near its companion star.

The device, called a vortex coronagraph, was recently installed inside NIRC2 (Near Infrared Camera 2), the workhorse infrared imaging camera at Keck. It has the potential to image planetary systems and brown dwarfs closer to their host stars than any other instrument in the world.

The vortex mask shown at left is made out of synthetic diamond. Viewed with an scanning electron microscope, right, the "vortex" microstructure of the mask is revealed. (University of Liège/Uppsala University)

The vortex mask shown at left is made out of synthetic diamond. Viewed with an scanning electron microscope, right, the “vortex” microstructure of the mask is revealed. (University of Liège/Uppsala University)

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NASA’s Hubble Space Telescope discovers shadow moving across Young Star

 

Written by Felicia Chou
NASA Headquarters

NASA - National Aeronautics and Space AdministrationWashington, D.C. – Searching for planets around other stars is a tricky business. They’re so small and faint that it’s hard to spot them. But a possible planet in a nearby stellar system may be betraying its presence in a unique way: by a shadow that is sweeping across the face of a vast pancake-shaped gas-and-dust disk surrounding a young star.

The planet itself is not casting the shadow. But it is doing some heavy lifting by gravitationally pulling on material near the star and warping the inner part of the disk. The twisted, misaligned inner disk is casting its shadow across the surface of the outer disk.

These images, taken a year apart by NASA's Hubble Space Telescope, reveal a shadow moving counterclockwise around a gas-and-dust disk encircling the young star TW Hydrae. The two images at the top, taken by the Space Telescope Imaging Spectrograph, show an uneven brightness across the disk. Through enhanced image processing (images at bottom), the darkening becomes even more apparent. These enhanced images allowed astronomers to determine the reason for the changes in brightness. The dimmer areas of the disk, at top left, are caused by a shadow spreading across the outer disk. (NASA, ESA, and J. Debes (STScI))

These images, taken a year apart by NASA’s Hubble Space Telescope, reveal a shadow moving counterclockwise around a gas-and-dust disk encircling the young star TW Hydrae. The two images at the top, taken by the Space Telescope Imaging Spectrograph, show an uneven brightness across the disk. Through enhanced image processing (images at bottom), the darkening becomes even more apparent. These enhanced images allowed astronomers to determine the reason for the changes in brightness. The dimmer areas of the disk, at top left, are caused by a shadow spreading across the outer disk. (NASA, ESA, and J. Debes (STScI))

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NASA discovers Schizophrenic Neutron Star

 

Written by Elizabeth Landau
NASA’s Jet Propulsion Laboratory

NASA - National Aeronautics and Space AdministrationPasadena, CA – Like anthropologists piecing together the human family tree, astronomers have found that a misfit “skeleton” of a star may link two different kinds of stellar remains. The mysterious object, called PSR J1119-6127, has been caught behaving like two distinct objects — a radio pulsar and a magnetar — and could be important to understanding their evolution.

A radio pulsar is type of a neutron star — the extremely dense remnant of an exploded star — that emits radio waves in predictable pulses due to its fast rotation.

This artist's concept shows a pulsar, which is like a lighthouse, as its light appears in regular pulses as it rotates. (NASA/JPL-Caltech)

This artist’s concept shows a pulsar, which is like a lighthouse, as its light appears in regular pulses as it rotates. (NASA/JPL-Caltech)

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