NASA Administrator Charles Bolden, left, welcomes JAXA (Japan
Aerospace
Exploration Agency) President Naoki Okumura to NASA Headquarters
on Wednesday, July 10, 2013, in Washington. Image Credit: NASA/Bill Ingalls
Exploration Agency) President Naoki Okumura to NASA Headquarters
on Wednesday, July 10, 2013, in Washington. Image Credit: NASA/Bill Ingalls
WASHINGTON -- NASA Administrator Charles Bolden and the president of the
Japan Aerospace Exploration Agency (JAXA) met in Washington Wednesday, July 10,
to discuss the importance of international cooperation in space, especially the
continued support for the International Space Station.
Bolden and Naoki Okumura also discussed NASA's plans for a new asteroid
initiative, previously announced in President Obama's fiscal year 2014 budget
proposal. Okumura welcomed the opportunity to discuss JAXA's potential
contribution based on experience through its Hayabusa asteroid sample return
mission. This is Okumura's first bilateral meeting with NASA since being named
JAXA's president in April.
“NASA has enjoyed a long-standing, mutually beneficial relationship with
Japan in space exploration activities and we look forward to further discussions
about our asteroid initiative,” said Bolden. "We currently have more than 35
active agreements with JAXA in human spaceflight, Earth science, space science,
and aeronautics, making Japan one of the agency’s leading partners in civil
space cooperation.”
NASA's asteroid initiative involves robotically capturing a small near-Earth
asteroid and redirecting it safely to a stable lunar orbit where astronauts can
visit and explore it.
Capturing and redirecting an asteroid integrates the best of NASA's science,
technology and human exploration capabilities and draws on the innovation of
America's brightest scientists and engineers. The knowledge gained from the
initiative will help us protect our planet, advance exploration capabilities and
technologies for human spaceflight, and help us better utilize our space
resources.
For more information about NASA visit:
Composite image of planetary nebula NGC
2392.
Image Credit: X-ray: NASA/CXC/IAA-CSIC/N. Ruiz et al; Optical:
NASA/STScI
Image Token:
Stars like the Sun can become
remarkably photogenic at the end of their life. A good example is NGC 2392,
which is located about 4,200 light years from Earth. NGC 2392, nicknamed the
"Eskimo Nebula", is what astronomers call a planetary nebula. This designation,
however, is deceiving because planetary nebulas actually have nothing to do with
planets. The term is simply a historic relic since these objects looked like
planetary disks to astronomers in earlier times looking through small optical
telescopes.
Instead, planetary nebulas form when a star uses up all of the hydrogen in
its core -- an event our Sun will go through in about five billion years. When
this happens, the star begins to cool and expand, increasing its radius by tens
to hundreds of times its original size. Eventually, the outer layers of the star
are carried away by a thick 50,000 kilometer per hour wind, leaving behind a hot
core. This hot core has a surface temperature of about 50,000 degrees Celsius,
and is ejecting its outer layers in a much faster wind traveling six million
kilometers per hour. The radiation from the hot star and the interaction of its
fast wind with the slower wind creates the complex and filamentary shell of a
planetary nebula. Eventually the remnant star will collapse to form a white
dwarf star.
Now days, astronomers using space-based telescopes are able to observe
planetary nebulas such as NGC 2392 in ways their scientific ancestors probably
could never imagine. This composite image of NGC 2392 contains X-ray data from
NASA's Chandra X-ray Observatory in purple showing the location of
million-degree gas near the center of the planetary nebula. Data from the Hubble
Space Telescope show – colored red, green, and blue – the intricate pattern of
the outer layers of the star that have been ejected. The comet-shaped filaments
form when the faster wind and radiation from the central star interact with
cooler shells of dust and gas that were already ejected by the star.
The observations of NGC 2392 were part of a study of three planetary nebulas
with hot gas in their center. The Chandra data show that NGC 2392 has unusually
high levels of X-ray emission compared to the other two. This leads researchers
to deduce that there is an unseen companion to the hot central star in NGC 2392.
The interaction between a pair of binary stars could explain the elevated X-ray
emission found there. Meanwhile, the fainter X-ray emission observed in the two
other planetary nebulas in the sample – IC 418 and NGC 6826 – is likely produced
by shock fronts (like sonic booms) in the wind from the central star. A
composite image of NGC 6826 was included in a gallery of planetary nebulas
released in 2012. [http://chandra.harvard.edu/photo/2012/pne/]
A paper describing these results is available online and was
published in the April 10th, 2013 issue of The Astrophysical Journal. The first
author is Nieves Ruiz of the Instituto de Astrofísica de Andalucía (IAA-CSIC) in
Granada, Spain, and the other authors are You-Hua Chu, and Robert Gruendl from
the University of Illinois, Urbana; Martín Guerrero from the Instituto de
Astrofísica de Andalucía (IAA-CSIC) in Granada, Spain, and Ralf Jacob, Detlef
Schönberner and Matthias Steffen from the Leibniz-Institut Für Astrophysik in
Potsdam (AIP), Germany.
NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra
program for NASA's Science Mission Directorate in Washington. The Smithsonian
Astrophysical Observatory controls Chandra's science and flight operations from
Cambridge, Mass.
NASA
Guillermo Gonzalo Sánchez Achutegui
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