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Sunday, July 31, 2011

MISR Mystery Image Quiz


Welcome back to another chance to play geographical detective!

This image was taken by the Multi-angle Imaging SpectroRadiometer (MISR), and represents an area of about 1800 kilometers by 900 kilometers. Please note that due North may not be at the top of the page. These questions refer to a landmark, area or province within the pictured region. Please answer the questions below and tell us where on Earth you think the location is. You may use any reference materials you like to answer the quiz.

From the statements below, please indicate which are TRUE and which are FALSE.

1. Located within the lower third of the image is a dramatic landmark that has lain dormant for thousands of years.

2. The southwest part of the region pictured overlooks a capital city.

3. This area was once rich in biodiversity. However, urbanization over the past several decades has reduced the wealth of flora and fauna in the region by nearly 30 percent.

4. One of the seven natural wonders of the world lies to the northeast of this region, less than a week away by car.

5. The highest point in this region, located near the peninsula shown in the image, was first successfully climbed in the 16th century, according to records.

6. The country in which this region is located is home to one of the world's largest (by volume) rivers.

7. On the west coast of the region pictured lies a World Heritage Site surrounded by water.

What location is shown in this image?

Quiz Rules


Send us your answers, name (initials are acceptable if you prefer), and your hometown by the quiz deadline of Wednesday, August 3, 2011, using the Quiz answer form. Answers will be published on the MISR web site. The names and home towns of respondents who answer all questions correctly by the deadline will also be published in the order responses were received. The first 3 people on this list who are not affiliated with NASA, JPL, or MISR and who have not previously won a prize will be sent a print of the image.

A new "Where on Earth...?" mystery will appear periodically. The image also appears on the Earth Observatory, http://earthobservatory.nasa.gov/, and on the Atmospheric Sciences Data Center home pages, http://eosweb.larc.nasa.gov/, though usually with a several-hour delay.

Photo credit: NASA/GSFC/LaRC/JPL, MISR Team

Saturday, July 30, 2011

IC 342


Looking like a spider's web swirled into a spiral, the galaxy IC 342 presents its delicate pattern of dust in this image from NASA's Spitzer Space Telescope. Seen in infrared light, the faint starlight gives way to the glowing bright patterns of dust found throughout the galaxy's disk.

At a distance of about 10 million light-years, IC 342 is relatively close by galaxy standards, however our vantage point places it directly behind the disk of our own Milky Way. The intervening dust makes it difficult to see in visible light, but infrared light penetrates this veil easily. It belongs to the same group as its even more obscured galactic neighbor, Maffei 2.

IC 342 is nearly face-on to our view, giving a clear, top-down view of the structure of its disk. It has a low surface brightness compared to other spirals, indicating a lower density of stars (seen here as a blue haze). Its dust structures show up much more vividly (red). Blue dots are stars closer to us, in our own Milky Way.

New stars are forming in the disk at a healthy clip. The very center glows especially brightly in the infrared, highlighting an enormous burst of star formation occurring in this tiny region. To either side of the center, a small bar of dust and gas is helping to fuel this central star formation.

Data from Spitzer's infrared array camera (IRAC) are shown in blue (3.6 microns), green (4.5 microns) and red (5.8 and 8.0 microns).

Photo credit: NASA/JPL-Caltech

Friday, July 29, 2011

Asteroid 2010 TK7





This animation illustrates the orbit of 2010 TK7 (green dots), the first known Earth Trojan asteroid, discovered by NEOWISE, the asteroid-hunting portion of NASA's WISE mission. Trojans are asteroids that share an orbit with a planet, circling around the sun in front of or behind the planet. They circle around stable gravity wells, called Lagrange points, which circle the sun like Earth does.

The movie follows Earth as it travels along its orbit (blue dots) around the sun, so Earth remains at the front of our view. The various objects are not drawn to scale.

Asteroid 2010 TK7 has an extreme orbit that takes the asteroid far above and below the plane of Earth's orbit. The motion above and below the plane is referred to as an epicycle. In addition, the asteroid moves within the plane of Earth's orbit in what is called libration, circling horizontally around its stable point every 395 years.

Typically, Trojan asteroids, for example those that orbit with Jupiter, don't travel so far from the Lagrange points. They stay mostly near these points, located where the angle between the sun and Earth is 60 degrees. Asteroids near a comparable position with respect to Earth would be very difficult to see, because they would appear near the sun from our point of view.

WISE was able to spot 2010 TK7 because of its eccentric orbit, which takes it as far as 90 degrees away from the sun. WISE surveyed the whole sky from a polar orbit, so it had the perfect seat to find 2010 TK7. Follow-up observations with the Canada-France-Hawaii Telescope on Mauna Kea, Hawaii, helped confirm the object's Trojan nature.

The clock at upper left shows how the orbit changes over time. The asteroid's orbit is well understood -- over the next ten thousand years, 2010 TK7 will not approach Earth any closer than 20 million kilometers (12.4 million miles), which is more than 50 times the distance from Earth to the moon.


Asteroid 2010 TK7 is circled in green, in this single frame taken by NASA's Wide-field Infrared Survey Explorer, or WISE. The majority of the other dots are stars or galaxies far beyond our solar system.

Astronomers discovered this object -- the first known Earth Trojan asteroid -- after sifting through asteroid candidates identified by WISE.

This image was taken in infrared light at a wavelength of 4.6 microns in October 2010.

Photo credit: NASA/JPL-Caltech/UCLA; movie credit: Paul Wiegert, University of Western Ontario, Canada

Thursday, July 28, 2011

Enceladus Creating Saturn's E-Ring


Wispy fingers of bright, icy material reach tens of thousands of kilometers outward from Saturn's moon Enceladus into the E ring, while the moon's active south polar jets continue to fire away.

This astonishing, never-before-seen structure is made visible with the sun almost directly behind the Saturn system from Cassini's vantage point. The sun-Enceladus-spacecraft angle here is 175 degrees, a viewing geometry in which structures made of tiny particles brighten substantially.

These features are very likely the result of particles injected into Saturn orbit by the Enceladus geysers: Those injected in the direction of the moon's orbital motion end up on larger, slower orbits and trail Enceladus in its orbit, and those injected into the opposite direction end up smaller, faster orbits and lead Enceladus. (Orbital motion is counter-clockwise.) In addition, the configuration of wisps may hint at an interaction between Saturn's magnetosphere and the torrent of particles issuing from Enceladus.

In addition to the wisps, another unexpected detail is the dark gore in the center of the ring, following the moon in its orbit, likely brought about by the sweeping action of Enceladus as it orbits in the center of the E ring.

The view looks down onto Enceladus (505 kilometers, or 314 miles across) from about 15 degrees above the ringplane. Tethys (1,071 kilometers, or 665 miles across) is visible to the left of Enceladus.

The image was taken in visible light with the Cassini spacecraft wide-angle camera on Sept. 15, 2006, at a distance of approximately 2.1 million kilometers (1.3 million miles) from Enceladus. Image scale is 128 kilometers (80 miles) per pixel.

Photo credit: NASA/JPL/Space Science Institute

Note: The above image is one of several used in a recent ESA press release, Herschel Confirms Enceladus as Primary Water Supply for Saturn's Atmosphere. This story is unique in that this is the first instance where a moon is directly affecting the atmosphere of the host planet.

Wednesday, July 27, 2011

Slumping Rim of the Moon's Darwin C Crater


High incidence angle (83°) accentuates the slumping rim of Darwin C. The parallel fractures along the crater rim are slump blocks pulling away from the rim toward the interior of the crater, which is in shadow (lower right). LROC NAC M148624404R, image is 720 meters across.

Darwin C (20.5°S, 288.9°E) is one of several satellite craters associated with the crater Darwin. Compared to its sister satellite craters, this one is less degraded. However, the rim of Darwin C provides an excellent example of post-impact modification of a crater rim.

Photo credit: NASA/GSFC/Arizona State University

Note: For more information, see Slumping Rim of Darwin C.

Tuesday, July 26, 2011

Iapetus


The Cassini spacecraft takes one of its last good looks at Iapetus, a Saturnian moon known for its yin-yang-like, bright-and-dark color pattern.

This view looks toward the south pole of Iapetus (1,471 kilometers, or 914 miles across), and lit terrain seen here is in the southern latitudes of the trailing hemisphere. There is only one other planned viewing opportunity of Iapetus left in Cassini's Solstice Mission, in March 2015.

See PIA11690 to learn more about the color on Iapetus. See PIA08404 to learn more about the moon's equatorial ridge.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on June 7, 2011. The view was obtained at a distance of approximately 863,000 kilometers (536,000 miles) from Iapetus and at a Sun-Iapetus-spacecraft, or phase, angle of 98 degrees. Image scale is 5 kilometers (3 miles) per pixel.

Photo credit: NASA/JPL-Caltech/Space Science Institute

Monday, July 25, 2011

Galaxy Cluster CL J1449+0856


This image shows the X-ray emission (in purple) coming from the diffuse intra-cluster medium of the galaxy cluster CL J1449+0856 as detected by XMM-Newton.

The X-ray signal is superimposed onto a composite image of very long exposures taken at near-infrared wavelengths with ESO's Very Large Telescope in Chile and the Subaru telescope on Hawaii. Most of the objects visible in the field are very faint and distant galaxies: the galaxy cluster is visible as a clump of faint, red objects near the center.

Located at a redshift z~2, CL J1449+0856 is the most distant mature cluster ever detected.

The cluster luminosity (L) is approximately 7 × 1043 erg/s in the soft X-ray energy range (0.1-2.4 keV), and corresponds to a temperature of 2 keV (about 23 million Kelvin) and an estimated mass of 5-8 × 1013 solar masses.

The region depicted above is about 100 arc minutes on a side.

Photo credit: ESA/ESO/Subaru/R. Gobat et al.

Sunday, July 24, 2011

Daybreak at Gale Crater


This computer-generated view depicts part of Mars at the boundary between darkness and daylight, with an area including Gale Crater beginning to catch morning light.

Northward is to the left. Gale is the crater with a mound inside it near the center of the image. NASA has selected Gale as the landing site for the Mars Science Laboratory mission. The mission's rover will be placed on the ground in a northern portion of Gale crater in August 2012.

Gale crater is 96 miles (154 kilometers) in diameter and holds a layered mountain rising about 3 miles (5 kilometers) above the crater floor. The intended landing site is at 4.5 degrees south latitude, 137.4 degrees east longitude.

This view was created using three-dimensional information from the Mars Orbiter Laser Altimeter, which flew on NASA's Mars Global Surveyor orbiter. The vertical dimension is not exaggerated. Color information is based on general Mars color characteristics.

Image credit: NASA/JPL-Caltech

Saturday, July 23, 2011

Stars in the Andromeda Galaxy's Disc


This image shows NASA/ESA Hubble Space Telescope images of a small part of the disc of the Andromeda Galaxy, the closest spiral galaxy to the Milky Way. Hubble's position above the distorting effect of the atmosphere, combined with the galaxy's relative proximity, means that the galaxy can be resolved into individual stars, rather than the cloudy white wisps usually seen in observations of galaxies.

A galaxy's disc is the area made up of its spiral arms, and the darker areas between them. After the galaxy's central bulge, this is the densest part of a galaxy. However, these observations are made near the edge, where the star fields are noticeably less crowded. This lets us see glimpses through the galaxy into the distant background, where the more diffuse blobs of light are actually faraway galaxies.

These observations were made in order to observe a wide variety of stars in Andromeda, ranging from faint main sequence stars like our own Sun, to the much brighter RR Lyrae stars, which are a type of variable star. With these measurements, astronomers can determine the chemistry and ages of the stars in each part of the Andromeda Galaxy.

Photo credit: NASA, ESA and T.M. Brown (STScI)

Note: For more information and additional photos, see Four Unusual Views of the Andromeda Galaxy.

Friday, July 22, 2011

Hubble Discovers a Fourth Moon Around Pluto


Astronomers using the Hubble Space Telescope have discovered a fourth moon orbiting the icy dwarf planet Pluto. The tiny, new satellite – temporarily designated P4 -- popped up in a Hubble survey searching for rings around the dwarf planet.

The new moon is the smallest discovered around Pluto. It has an estimated diameter of 8 to 21 miles (13 to 34 km). By comparison, Charon, Pluto's largest moon, is 648 miles (1,043 km) across, and the other moons, Nix and Hydra, are in the range of 20 to 70 miles in diameter (32 to 113 km).

"I find it remarkable that Hubble's cameras enabled us to see such a tiny object so clearly from a distance of more than 3 billion miles (5 billion km)," said Mark Showalter of the SETI Institute in Mountain View, Calif., who led this observing program with Hubble.

The finding is a result of ongoing work to support NASA's New Horizons mission, scheduled to fly through the Pluto system in 2015. The mission is designed to provide new insights about worlds at the edge of our solar system. Hubble's mapping of Pluto's surface and discovery of its satellites have been invaluable to planning for New Horizons' close encounter.

"This is a fantastic discovery," said New Horizons’ principal investigator Alan Stern of the Southwest Research Institute in Boulder, Colo. "Now that we know there's another moon in the Pluto system, we can plan close-up observations of it during our flyby."

The new moon is located between the orbits of Nix and Hydra, which Hubble discovered in 2005. Charon was discovered in 1978 at the U.S. Naval Observatory and first resolved using Hubble in 1990 as a separate body from Pluto.

The dwarf planet’s entire moon system is believed to have formed by a collision between Pluto and another planet-sized body early in the history of the solar system. The smashup flung material that coalesced into the family of satellites observed around Pluto.

Lunar rocks returned to Earth from the Apollo missions led to the theory that our moon was the result of a similar collision between Earth and a Mars-sized body 4.4 billion years ago. Scientists believe material blasted off Pluto's moons by micrometeoroid impacts may form rings around the dwarf planet, but the Hubble photographs have not detected any so far.

"This surprising observation is a powerful reminder of Hubble's ability as a general purpose astronomical observatory to make astounding, unintended discoveries," said Jon Morse, astrophysics division director at NASA Headquarters in Washington.

P4 was first seen in a photo taken with Hubble's Wide Field Camera 3 on June 28. It was confirmed in subsequent Hubble pictures taken on July 3 and July 18. The moon was not seen in earlier Hubble images because the exposure times were shorter. There is a chance it appeared as a very faint smudge in 2006 images, but was overlooked because it was obscured.


Photo credit: NASA; map credit: NASA, ESA, and A. Feild (STScI)

Thursday, July 21, 2011

The Case of the Warped Galactic Ring


In a strange twist of science, astronomers using the Herschel Space Observatory have discovered that a suspected ring at the center of our galaxy is warped for reasons they cannot explain. This image from Herschel, an infrared European Space Agency-led mission with important NASA contributions, reveals the ring with greater clarity than ever before. It can be seen as the yellow loop that appears to have two lobes (Figure 1). In fact, the ring, which is a collection of very dense and cold gas and dust, is twisted so that part of it rises above and below the plane of our Milky Way galaxy.

Previous observations had revealed portions of the ring. Herschel sees long-wavelength infrared light, which can penetrate through the murky region at the center of our galaxy, allowing Herschel to get a more complete view.

Astronomers aren't sure how rings like this form in galaxies but some theories suggest they arise out of gravitational disturbances with neighboring galaxies. New stars are thought to be forming in the dense gas making up the ring.

The ring stretches across more than 600 light-years of space, and is about 15 Kelvin (minus 433 degrees Fahrenheit). The warmest material in this picture is blue, and the coldest is red.

The image was taken using two of Herschel's instruments -- the photodetector array camera and spectrometer (70-micron-light is coded blue; 160-micron light is coded green) and the spectral and photometric imaging receiver (350-micron light is red).

Photo credit: ESA/NASA/JPL-Caltech

Wednesday, July 20, 2011

Vesta


NASA's Dawn spacecraft obtained this image with its framing camera on July 17, 2011. It was taken from a distance of about 9,500 miles (15,000 kilometers) away from the protoplanet Vesta. Each pixel in the image corresponds to roughly 0.88 miles (1.4 kilometers).

Photo credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Note: For more information, see Dawn Spacecraft Snaps Close-up Image of Asteroid Vesta; also, Dawn Orbits Giant Asteroid Vesta .

Tuesday, July 19, 2011

Titan's North Polar Hood


The Cassini spacecraft examines Titan's north polar hood, the part of the atmosphere of Saturn's largest moon appearing dark at the top of this image.

See PIA09739 and PIA08137 to learn more about Titan's atmosphere. This view looks toward the anti-Saturn side of Titan. North on Titan (5,150 kilometers, or 3,200 miles across) is up. The southern pole of Titan is going into darkness, with the Sun advancing towards the north with each passing day. See PIA11603 and PIA11667 to learn more about the changing seasons in the Saturnian system. The upper layer of Titan's hazes is still illuminated by sunlight scattered off the planet.

The image was taken in visible violet light with the Cassini spacecraft wide-angle camera on April 19, 2011. The view was acquired at a distance of approximately 137,000 kilometers (85,000 miles) from Titan and at a Sun-Titan-spacecraft, or phase, angle of 18 degrees. Image scale is 8 kilometers (5 miles) per pixel.

Photo credit: NASA/JPL-Caltech/Space Science Institute

Monday, July 18, 2011

Small Mounds in Chryse Planitia


The suggested area in this observation is characterized by a group of cones, shield-like features, and round mounds. They are a few hundred meters to kilometers in diameter but their heights are unknown.

Possible explanations for their formation include sedimentary (mud) volcanism and magmatic volcanism. HiRISE data would be essential for distinguishing these hypotheses.

This caption is based on the original science rationale.

Photo credit: NASA/JPL-Caltech/University of Arizona

Sunday, July 17, 2011

Massive Solar Eruption Close-Up



On June 7, 2011 the Sun unleashed an M-2 (medium-sized) solar flare with a spectacular coronal mass ejection (CME). This video uses the full-resolution 4096 x 4096 pixel images at a 1 minute time cadence and to provide the highest quality, finest detail version possible. It also shows the event in multiple wavelengths.

Video credit: NASA

Saturday, July 16, 2011

Vesta


Note: If all has gone well, the spacecraft Dawn should have gone into orbit around the asteroid Vesta today.

NASA's Dawn spacecraft obtained this image with its framing camera on July 9, 2011. It was taken from a distance of about 26,000 miles (41,000 kilometers) away from the protoplanet Vesta. Each pixel in the image corresponds to roughly 2.4 miles (3.8 kilometers).

Photo credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Friday, July 15, 2011

A Colorful Mood


This image highlights some of the color features present on Mercury's surface, such as Low Reflectance Material (LRM) and crater rays. Visible in the top left quadrant of this image is the named crater Moody, which has a prominent orange color on its floor in this enhanced color image.

This image was acquired as part of MDIS's color base map. The color base map is composed of WAC images taken through eight different narrow-band color filters and will cover more than 90% of Mercury's surface with an average resolution of 1 kilometer/pixel (0.6 miles/pixel). The highest-quality color images are obtained for Mercury's surface when both the spacecraft and the Sun are overhead, so these images typically are taken with viewing conditions of low incidence and emission angles.

Date acquired: July 03, 2011
Image Mission Elapsed Time (MET): 218154838, 218154854, 218154834
Image ID: 456233, 456237, 456232
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 9 (1000 nanometers), 7 (750 nanometers), 6 (430 nanometers) as red-green-blue
Center Latitude: -30.86°
Center Longitude: 149.5° E
Resolution: 1712 meters/pixel
Scale: Moody crater is 83 km (~51.5 mi.) in diameter
Incidence Angle: 32.6°
Emission Angle: 0.5°
Phase Angle: 32.8°

Photo credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Thursday, July 14, 2011

The COSMOS Field


This very deep image shows the COSMOS field imaged by the Canada-France-Hawaii Telescope (CFHT). Huge numbers of very faint galaxies are visible. A new study of this field, combining data from ESO’s Very Large Telescope and ESA’s XMM-Newton X-ray space observatory has turned up a big surprise. Most of the huge black holes in the centers of active galaxies in the past 11 billion years were not turned on by mergers between galaxies, as had been previously thought. Some of the active galaxies with supermassive black holes at their centers that were used in the new study are marked with red crosses on this picture.

Photo credit: CFHT/IAP/Terapix/CNRS/ESO

Note: For more information, see What Activates a Supermassive Black Hole?

Wednesday, July 13, 2011

One Day on Neptune


On July 12, 2011 Neptune has arrived at the same location in space where it was discovered nearly 165 years ago. To commemorate the event, NASA's Hubble Space Telescope has taken these "anniversary pictures" of the blue-green giant planet.

Neptune is the most distant major planet in our solar system. German astronomer Johann Galle discovered the planet on September 23, 1846. At the time, the discovery doubled the size of the known solar system. The planet is 2.8 billion miles (4.5 billion kilometers) from the Sun, 30 times farther than Earth. Under the Sun's weak pull at that distance, Neptune plods along in its huge orbit, slowly completing one revolution approximately every 165 years.

These four Hubble images of Neptune were taken with the Wide Field Camera 3 on June 25-26, during the planet's 16-hour rotation. The snapshots were taken at roughly four-hour intervals, offering a full view of the planet. The images reveal high-altitude clouds in the northern and southern hemispheres. The clouds are composed of methane ice crystals.

Photo credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)

Note: For more information, see Neptune Completes Its First Circuit Around The Sun Since Its Discovery.

Friday, July 8, 2011

Herschel and Hubble View of Supernova 1987A


This mosaic shows the region surrounding the remnant of the famous supernova SN1987A as observed by Herschel (on the left) and the Hubble Space Telescope (on the right). SN1987A resides in the Large Magellanic Cloud, one of the dwarf galaxies orbiting the Milky Way, and it was first observed from Earth 24 years ago. At a distance of only 160 000 light years, this backyard supernova has become a 'local' laboratory for close-up studies of stellar demise. The remnant of SN1987A is visible, in the Herschel image, as a faint dot of light indicated by the white circle; the region enclosed within the circle is shown in greater detail in the Hubble image.

The detection of SN1987A with Herschel demonstrates that this object contains an amount of dust nearly equivalent to the mass of the Sun and roughly 1000 times larger than what was previously believed. At temperatures of 16–23 Kelvin, the newly discovered component is about 20 times colder than any dust detected in the past in this supernova remnant.

This result confirms that supernovae are able to produce significant quantities of dust over very short timescales and has profound implications on the understanding of how dust first formed in cosmic history.

Photo credit: ESA/Herschel/PACS/SPIRE/NASA-JPL/Caltech/UCL/STScI and the Hubble Heritage Team (AURA/STScI/NASA/ESA)

Note: For more information, see Stardust in Our Backyard Provides New Clues to Galaxy Evolution.

Friday, July 1, 2011

GRB 021125 by IBIS


INTEGRAL's IBIS instrument captured the gamma-ray burst (GRB) of 19 December 2004 that Philippe Laurent and colleagues have now analyzed in detail. It was so bright that INTEGRAL could also measure its polarization, allowing Laurent and colleagues to look for differences in the signal from different energies. The GRB shown here, on 25 November 2002, was the first captured using such a powerful gamma-ray camera as INTEGRAL's. When they occur, GRBs shine as brightly as hundreds of galaxies each containing millions upon millions of stars.

Photo credit: ESA/SPI Team/ECF

Note: For more information, see INTEGRAL Challenges Physics Beyond Einstein.