Tag Archives: Corona

NASA Space Place – Solar Eclipse Provides Coronal Glimpse

Posted on February 21, 2017 12:35 pm - - Leave a Comment

Poster’s Note: One of the many under-appreciated aspects of NASA is the extent to which it publishes quality science content for children and Ph.D.’s alike. NASA Space Place has been providing general audience articles for quite some time that are freely available for download and republishing. Your tax dollars help promote science! The following article was provided for reprinting in February, 2017.

By Marcus Woo

2013february2_spaceplaceOn August 21, 2017, North Americans will enjoy a rare treat: The first total solar eclipse visible from the continent since 1979. The sky will darken and the temperature will drop, in one of the most dramatic cosmic events on Earth. It could be a once-in-a-lifetime show indeed. But it will also be an opportunity to do some science.

Only during an eclipse, when the moon blocks the light from the sun’s surface, does the sun’s corona fully reveal itself. The corona is the hot and wispy atmosphere of the sun, extending far beyond the solar disk. But it’s relatively dim, merely as bright as the full moon at night. The glaring sun, about a million times brighter, renders the corona invisible.

“The beauty of eclipse observations is that they are, at present, the only opportunity where one can observe the corona [in visible light] starting from the solar surface out to several solar radii,” says Shadia Habbal, an astronomer at the University of Hawaii. To study the corona, she’s traveled the world having experienced 14 total eclipses (she missed only five due to weather). This summer, she and her team will set up identical imaging systems and spectrometers at five locations along the path of totality, collecting data that’s normally impossible to get.

Ground-based coronagraphs, instruments designed to study the corona by blocking the sun, can’t view the full extent of the corona. Solar space-based telescopes don’t have the spectrographs needed to measure how the temperatures vary throughout the corona. These temperature variations show how the sun’s chemical composition is distributed—crucial information for solving one of long-standing mysteries about the corona: how it gets so hot.

While the sun’s surface is ~9980 Fahrenheit (~5800 Kelvin), the corona can reach several millions of degrees Fahrenheit. Researchers have proposed many explanations involving magneto-acoustic waves and the dissipation of magnetic fields, but none can account for the wide-ranging temperature distribution in the corona, Habbal says.

You too can contribute to science through one of several citizen science projects. For example, you can also help study the corona through the Citizen CATE experiment; help produce a high definition, time-expanded video of the eclipse; use your ham radio to probe how an eclipse affects the propagation of radio waves in the ionosphere; or even observe how wildlife responds to such a unique event.

Otherwise, Habbal still encourages everyone to experience the eclipse. Never look directly at the sun, of course (find more safety guidelines here: eclipse2017.nasa.gov/safety). But during the approximately 2.5 minutes of totality, you may remove your safety glasses and watch the eclipse directly—only then can you see the glorious corona. So enjoy the show. The next one visible from North America won’t be until 2024.

For more information about the upcoming eclipse, please see:

NASA Eclipse citizen science page: eclipse2017.nasa.gov/citizen-science

NASA Eclipse safety guidelines: eclipse2017.nasa.gov/safety

Want to teach kids about eclipses? Go to the NASA Space Place and see our article on solar and lunar eclipses! spaceplace.nasa.gov/eclipses/

This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

Caption: Illustration showing the United States during the total solar eclipse of August 21, 2017, with the umbra (black oval), penumbra (concentric shaded ovals), and path of totality (red) through or very near several major cities. Credit: Goddard Science Visualization Studio, NASA

About NASA Space Place

With articles, activities, crafts, games, and lesson plans, NASA Space Place encourages everyone to get excited about science and technology. Visit spaceplace.nasa.gov (facebook|twitter) to explore space and Earth science!

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NASA Space Place – Big Science In Small Packages

Posted on December 17, 2016 8:57 am - - Leave a Comment

Poster’s Note: One of the many under-appreciated aspects of NASA is the extent to which it publishes quality science content for children and Ph.D.’s alike. NASA Space Place has been providing general audience articles for quite some time that are freely available for download and republishing. Your tax dollars help promote science! The following article was provided for reprinting in December, 2016.

By Marcus Woo

2013february2_spaceplaceAbout 250 miles overhead, a satellite the size of a loaf of bread flies in orbit. It’s one of hundreds of so-called CubeSats—spacecraft that come in relatively inexpensive and compact packages—that have launched over the years. So far, most CubeSats have been commercial satellites, student projects, or technology demonstrations. But this one, dubbed MinXSS (“minks”) is NASA’s first CubeSat with a bona fide science mission.

Launched in December 2015, MinXSS has been observing the sun in X-rays with unprecedented detail. Its goal is to better understand the physics behind phenomena like solar flares – eruptions on the sun that produce dramatic bursts of energy and radiation.

Much of the newly-released radiation from solar flares is concentrated in X-rays, and, in particular, the lower energy range called soft X-rays. But other spacecraft don’t have the capability to measure this part of the sun’s spectrum at high resolution—which is where MinXSS, short for Miniature Solar X-ray Spectrometer, comes in.

Using MinXSS to monitor how the soft X-ray spectrum changes over time, scientists can track changes in the composition in the sun’s corona, the hot outermost layer of the sun. While the sun’s visible surface, the photosphere, is about 6000 Kelvin (10,000 degrees Fahrenheit), areas of the corona reach tens of millions of degrees during a solar flare. But even without a flare, the corona smolders at a million degrees—and no one knows why.

One possibility is that many small nanoflares constantly heat the corona. Or, the heat may come from certain kinds of waves that propagate through the solar plasma. By looking at how the corona’s composition changes, researchers can determine which mechanism is more important, says Tom Woods, a solar scientist at the University of Colorado at Boulder and principal investigator of MinXSS: “It’s helping address this very long-term problem that’s been around for 50 years: how is the corona heated to be so hot.”

The $1 million original mission has been gathering observations since June.

The satellite will likely burn up in Earth’s atmosphere in March. But the researchers have built a second one slated for launch in 2017. MinXSS-2 will watch long-term solar activity—related to the sun’s 11-year sunspot cycle—and how variability in the soft X-ray spectrum affects space weather, which can be a hazard for satellites. So the little-mission-that-could will continue—this time, flying at a higher, polar orbit for about five years.

If you’d like to teach kids about where the sun’s energy comes from, please visit the NASA Space Place: spaceplace.nasa.gov/sun-heat/

This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

Caption: Astronaut Tim Peake on board the International Space Station captured this image of a CubeSat deployment on May 16, 2016. The bottom-most CubeSat is the NASA-funded MinXSS CubeSat, which observes soft X-rays from the sun—such X-rays can disturb the ionosphere and thereby hamper radio and GPS signals. (The second CubeSat is CADRE — short for CubeSat investigating Atmospheric Density Response to Extreme driving – built by the University of Michigan and funded by the National Science Foundation.) Credit: ESA/NASA

About NASA Space Place

With articles, activities, crafts, games, and lesson plans, NASA Space Place encourages everyone to get excited about science and technology. Visit spaceplace.nasa.gov (facebook|twitter) to explore space and Earth science!

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NASA News Digest: Space Science For 12 October – 16 October 2014

Posted on October 20, 2014 10:00 pm - - Leave a Comment

Greetings fellow astrophiles,

The NASA News service provides up-to-date announcements of NASA policy, news events, and space science. A recent selection of space science articles are provided below, including direct links to the full announcements. Those interested in receiving these news announcements directly from NASA can subscribe to their service by sending an email to:

hqnews-request@newsletters.nasa.gov?subject=subscribe

NASA Mission Finds Widespread Evidence of Young Lunar Volcanism

RELEASE 14-284 (Click here for the full article) – 12 October 2014

2014oct20_14_284NASA’s Lunar Reconnaissance Orbiter (LRO) has provided researchers strong evidence the moon’s volcanic activity slowed gradually instead of stopping abruptly a billion years ago.

Scores of distinctive rock deposits observed by LRO are estimated to be less than 100 million years old. This time period corresponds to Earth’s Cretaceous period, the heyday of dinosaurs. Some areas may be less than 50 million years old. Details of the study are published online in Sunday’s edition of Nature Geoscience.

“This finding is the kind of science that is literally going to make geologists rewrite the textbooks about the moon,” said John Keller, LRO project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

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To access the complete collection of LROC images, visit: lroc.sese.asu.edu/

For more information about LRO, visit: www.nasa.gov/lro

NASA Mission Provides Its First Look at Martian Upper Atmosphere

RELEASE 14-285 (Click here for the full article) – 14 October 2014

2014oct20_14_285NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft has provided scientists their first look at a storm of energetic solar particles at Mars, produced unprecedented ultraviolet images of the tenuous oxygen, hydrogen, and carbon coronas surrounding the Red Planet, and yielded a comprehensive map of highly-variable ozone in the atmosphere underlying the coronas.

The spacecraft, which entered Mars’ orbit Sept. 21, now is lowering its orbit and testing its instruments. MAVEN was launched to Mars in November 2013, to help solve the mystery of how the Red Planet lost most of its atmosphere.

“All the instruments are showing data quality that is better than anticipated at this early stage of the mission,” said Bruce Jakosky, MAVEN Principal Investigator at the University of Colorado, Boulder. “All instruments have now been turned on — although not yet fully checked out — and are functioning nominally. It’s turning out to be an easy and straightforward spacecraft to fly, at least so far. It really looks as if we’re headed for an exciting science mission.”

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For more about MAVEN, visit: www.nasa.gov/maven

NASA’s Hubble Telescope Finds Potential Kuiper Belt Targets for New Horizons Pluto Mission

RELEASE 14-281 (Click here for the full article) – 15 October 2014

2014oct20_14_281Peering out to the dim, outer reaches of our solar system, NASA’s Hubble Space Telescope has uncovered three Kuiper Belt objects (KBOs) the agency’s New Horizons spacecraft could potentially visit after it flies by Pluto in July 2015.

The KBOs were detected through a dedicated Hubble observing program by a New Horizons search team that was awarded telescope time for this purpose.

“This has been a very challenging search and it’s great that in the end Hubble could accomplish a detection – one NASA mission helping another,” said Alan Stern of the Southwest Research Institute (SwRI) in Boulder, Colorado, principal investigator of the New Horizons mission.

The Kuiper Belt is a vast rim of primordial debris encircling our solar system. KBOs belong to a unique class of solar system objects that has never been visited by spacecraft and which contain clues to the origin of our solar system.

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For images of the KBOs and more information about Hubble, visit: www.nasa.gov/hubble

For information about the New Horizons mission, visit: www.nasa.gov/newhorizons

NASA’s Hubble Finds Extremely Distant Galaxy through Cosmic Magnifying Glass

RELEASE 14-283 (Click here for the full article) – 16 October 2014

2014oct20_14_283Peering through a giant cosmic magnifying glass, NASA’s Hubble Space Telescope has spotted a tiny, faint galaxy — one of the farthest galaxies ever seen. The diminutive object is estimated to be more than 13 billion light-years away.

This galaxy offers a peek back to the very early formative years of the universe and may just be the tip of the iceberg.

“This galaxy is an example of what is suspected to be an abundant, underlying population of extremely small, faint objects that existed about 500 million years after the big bang, the beginning of the universe,” explained study leader Adi Zitrin of the California Institute of Technology in Pasadena, California. “The discovery is telling us galaxies as faint as this one exist, and we should continue looking for them and even fainter objects, so that we can understand how galaxies and the universe have evolved over time.”

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For images and more information about Hubble, visit: www.nasa.gov/hubble

NASA Spacecraft Provides New Information About Sun’s Atmosphere

RELEASE 14-288 (Click here for the full article) – 16 Ocrober 2014

2014oct20_14_288NASA’s Interface Region Imaging Spectrograph (IRIS) has provided scientists with five new findings into how the sun’s atmosphere, or corona, is heated far hotter than its surface, what causes the sun’s constant outflow of particles called the solar wind, and what mechanisms accelerate particles that power solar flares.

The new information will help researchers better understand how our nearest star transfers energy through its atmosphere and track the dynamic solar activity that can impact technological infrastructure in space and on Earth. Details of the findings appear in the current edition of Science.

“These findings reveal a region of the sun more complicated than previously thought,” said Jeff Newmark, interim director for the Heliophysics Division at NASA Headquarters in Washington. “Combining IRIS data with observations from other Heliophysics missions is enabling breakthroughs in our understanding of the sun and its interactions with the solar system.”

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For more information about IRIS, visit: www.nasa.gov/iris

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NASA News Digest: Space Science For 25 July – 14 August 2014

Posted on August 30, 2014 6:49 pm - - Leave a Comment

Greetings fellow astrophiles,

The NASA News service provides up-to-date announcements of NASA policy, news events, and space science. A recent selection of space science articles are provided below, including direct links to the full announcements. Those interested in receiving these news announcements directly from NASA can subscribe to their service by sending an email to:

hqnews-request@newsletters.nasa.gov?subject=subscribe

NASA’s Mars Spacecraft Maneuvers to Prepare for Close Comet Flyby

RELEASE 14-201 (Click here for the full article) – 25 July 2014

2014august30_main_sidingspring_version07b-01_2NASA is taking steps to protect its Mars orbiters, while preserving opportunities to gather valuable scientific data, as Comet C/2013 A1 Siding Spring heads toward a close flyby of Mars on Oct. 19.

The comet’s nucleus will miss Mars by about 82,000 miles (132,000 kilometers), shedding material hurtling at about 35 miles (56 kilometers) per second, relative to Mars and Mars-orbiting spacecraft. At that velocity, even the smallest particle — estimated to be about one-fiftieth of an inch (half a millimeter) across — could cause significant damage to a spacecraft.

NASA currently operates two Mars orbiters, with a third on its way and expected to arrive in Martian orbit just a month before the comet flyby. Teams operating the orbiters plan to have all spacecraft positioned on the opposite side of the Red Planet when the comet is most likely to pass by.
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For more information about the Mars flyby of comet Siding Spring, visit: mars.nasa.gov/comets/sidingspring/

For more information about NASA’s Mars Exploration Program, visit: www.nasa.gov/mars

NASA’s Long-Lived Mars Opportunity Rover Sets Off-World Driving Record

RELEASE 14-202 (Click here for the full article) – 28 July 2014

2014august30_14_202a_0NASA’s Opportunity Mars rover, which landed on the Red Planet in 2004, now holds the off-Earth roving distance record after accruing 25 miles (40 kilometers) of driving. The previous record was held by the Soviet Union’s Lunokhod 2 rover.

“Opportunity has driven farther than any other wheeled vehicle on another world,” said Mars Exploration Rover Project Manager John Callas, of NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California. “This is so remarkable considering Opportunity was intended to drive about one kilometer and was never designed for distance. But what is really important is not how many miles the rover has racked up, but how much exploration and discovery we have accomplished over that distance.”
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For more information about NASA’s Mars rovers Spirit and Opportunity, visit: www.nasa.gov/rovers and marsrovers.jpl.nasa.gov

Follow the project on Twitter at: twitter.com/MarsRovers

On Facebook, visit: www.facebook.com/mars.rovers

An image of Lunokhod 2’s tracks, as imaged by NASA’s LRO, is available online at:
lroc.sese.asu.edu/posts/774

NASA’s Hubble Finds Supernova Star System Linked to Potential “Zombie Star”

RELEASE 14-212 (Click here for the full article) – 6 August 2014

2014august30_14-212_0Using NASA’s Hubble Space Telescope, a team of astronomers has spotted a star system that could have left behind a “zombie star” after an unusually weak supernova explosion.

A supernova typically obliterates the exploding white dwarf, or dying star. On this occasion, scientists believe this faint supernova may have left behind a surviving portion of the dwarf star — a sort of zombie star.

While examining Hubble images taken years before the stellar explosion, astronomers identified a blue companion star feeding energy to a white dwarf, a process that ignited a nuclear reaction and released this weak supernova blast. This supernova, Type Iax, is less common than its brighter cousin, Type Ia. Astronomers have identified more than 30 of these mini-supernovas that may leave behind a surviving white dwarf.
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For images and more information about Hubble, visit:
www.nasa.gov/hubble and hubblesite.org/news/2014/32

NASA’s NuSTAR Sees Rare Blurring of Black Hole Light

RELEASE 14-210 (Click here for the full article) – 12 August 2014

2014august30_14-210_0NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR) has captured an extreme and rare event in the regions immediately surrounding a supermassive black hole. A compact source of X-rays that sits near the black hole, called the corona, has moved closer to the black hole over a period of just days.

“The corona recently collapsed in toward the black hole, with the result that the black hole’s intense gravity pulled all the light down onto its surrounding disk, where material is spiraling inward,” said Michael Parker of the Institute of Astronomy in Cambridge, United Kingdom, lead author of a new paper on the findings appearing in the Monthly Notices of the Royal Astronomical Society.
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For more information on NuSTAR, visit: www.nasa.gov/nustar

NASA’s Chandra Observatory Searches for Trigger of Nearby Supernova

RELEASE 14-216 (Click here for the full article) – 14 August 2014

2014august30_14-216_0New data from NASA’s Chandra X-ray Observatory offer a glimpse into the environment of a star before it exploded earlier this year, and insight into what triggered one of the closest supernovas witnessed in decades.

The data gathered on the Jan. 21 explosion, a Type Ia supernova, allowed scientists to rule out one possible cause. These supernovas may be triggered when a white dwarf takes on too much mass from its companion star, immersing it in a cloud of gas that produces a significant source of X-rays after the explosion.

Astronomers used NASA’s Swift and Chandra telescopes to search the nearby Messier 82 galaxy, the location of the explosion, for such an X-ray source. However, no source was found, revealing the region around the site of the supernova is relatively devoid of material.
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For an additional interactive image, podcast, and video on the findings, visit: chandra.si.edu

For a preprint of the study results in The Astrophysical Journal, visit: arxiv.org/abs/1405.1488

For Chandra images, multimedia and related materials, visit: www.nasa.gov/chandra

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NASA Space Place – The Invisible Shield Of Our Sun

Posted on July 23, 2014 9:00 pm - - Leave a Comment

Poster’s Note: One of the many under-appreciated aspects of NASA is the extent to which it publishes quality science content for children and Ph.D.’s alike. NASA Space Place has been providing general audience articles for quite some time that are freely available for download and republishing. Your tax dollars help promote science! The following article was provided for reprinting in July, 2014.

By Dr. Ethan Siegel

2013february2_spaceplaceWhether you look at the planets within our solar system, the stars within our galaxy or the galaxies spread throughout the universe, it’s striking how empty outer space truly is. Even though the largest concentrations of mass are separated by huge distances, interstellar space isn’t empty: it’s filled with dilute amounts of gas, dust, radiation and ionized plasma. Although we’ve long been able to detect these components remotely, it’s only since 2012 that a man-made spacecraft — Voyager 1 — successfully entered and gave our first direct measurements of the interstellar medium (ISM).

What we found was an amazing confirmation of the idea that our Sun creates a humongous “shield” around our solar system, the heliosphere, where the outward flux of the solar wind crashes against the ISM. Over 100 AU in radius, the heliosphere prevents the ionized plasma from the ISM from nearing the planets, asteroids and Kuiper belt objects contained within it. How? In addition to various wavelengths of light, the Sun is also a tremendous source of fast-moving, charged particles (mostly protons) that move between 300 and 800 km/s, or nearly 0.3% the speed of light. To achieve these speeds, these particles originate from the Sun’s superheated corona, with temperatures in excess of 1,000,000 Kelvin!

When Voyager 1 finally left the heliosphere, it found a 40-fold increase in the density of ionized plasma particles. In addition, traveling beyond the heliopause showed a tremendous rise in the flux of intermediate-to-high energy cosmic ray protons, proving that our Sun shields our solar system quite effectively. Finally, it showed that the outer edges of the heliosheath consist of two zones, where the solar wind slows and then stagnates, and disappears altogether when you pass beyond the heliopause.

Unprotected passage through interstellar space would be life-threatening, as young stars, nebulae, and other intense energy sources pass perilously close to our solar system on ten-to-hundred-million-year timescales. Yet those objects pose no major danger to terrestrial life, as our Sun’s invisible shield protects us from all but the rarer, highest energy cosmic particles. Even if we pass through a region like the Orion Nebula, our heliosphere keeps the vast majority of those dangerous ionized particles from impacting us, shielding even the solar system’s outer worlds quite effectively. NASA spacecraft like the Voyagers, IBEX and SOHO continue to teach us more about our great cosmic shield and the ISM’s irregularities. We’re not helpless as we hurtle through it; the heliosphere gives us all the protection we need!

Want to learn more about Voyager 1’s trip into interstellar space? Check this out: www.jpl.nasa.gov/news/news.php?release=2013-278.

Kids can test their knowledge about the Sun at NASA’s Space place: spaceplace.nasa.gov/solar-tricktionary/.

This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

2014-ll_orionis.en

Caption: Image credit: Hubble Heritage Team (AURA / STScI), C. R. O’Dell (Vanderbilt), and NASA, of the star LL Orionis and its heliosphere interacting with interstellar gas and plasma near the edge of the Orion Nebula (M42). Unlike our star, LL Orionis displays a bow shock, something our Sun will regain when the ISM next collides with us at a sufficiently large relative velocity.

About NASA Space Place

The goal of the NASA Space Place is “to inform, inspire, and involve children in the excitement of science, technology, and space exploration.” More information is available at their website: http://spaceplace.nasa.gov/

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