MESSENGER captured this high-resolution image of an elongated pit crater within the floor of the 355-km (220-mile) -wide crater Tolstoj on Mercury on Jan. 11, 2012. The low angle of sun illumination puts the interior of the pit crater into deep shadow, making it appear bottomless.
Pit craters are not caused by impacts, but rather by the collapse of the roof of an underground magma chamber. They are characterized by the lack of a rim or surrounding ejecta blankets, and are often not circular in shape.
Since the floor of Tolstoj crater is thought to have once been flooded by lava, a pit crater is not out of place here.
The presence of such craters on Mercury indicates past volcanic activity on Mercury contributing to the planet’s evolution.
Of course, there is no sound in space, but sonfication is a process where any kind of non-auditory data is translated as sound. “We’re transforming space data into the sonic realm such that we can gain a new perspective, and begin to ask new questions,” said Robert Alexander, a doctoral student at the University of Michigan, getting his Ph.D in Design Science, who created this great sonification video of the recent solar storm activity. Alexander used data from two spacecraft: SOHO, studying the Sun, and the MESSENGER spacecraft at Mercury, which has the University of Michigan’s Fast Imaging Plasma Spectrometer (FIPS) on board, an imaging mass spectrometer.
Mercury was recently bombarded with a solar storm, and the sound created from particles colliding with the FIPS is utterly horrifying, sounding like the worst monster you could ever imagine. Continue reading “What Does a Solar Storm Sound Like?”
MESSENGER wide-angle camera image of Mercury's southern hemisphere.
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NASA’s MESSENGER spacecraft, about to wrap up its first full year in orbit around Mercury, captured this view of the planet’s heavily-cratered southern hemisphere on August 28, 2011. Because of its orbit, MESSENGER gets particularly good panoramic views of Mercury’s underside.
Here’s why…
MESSENGER’s orbit, established on March 18, 2011 at 00:45 UTC, is not a simple circling path around the first rock from the Sun. Instead it is highly elliptical, bringing it 124 miles (200 km) above Mercury’s north pole at its closest and more than 9,420 miles (15,193 km) from its south pole at its farthest! (See diagram below.)
The close approaches over the northern hemisphere allow MESSENGER to study the Caloris basin, Mercury’s largest surface feature and, at over 960 miles (1,550 km) across, one of the largest impact craters in the entire Solar System.
The view of Mercury’s southern hemisphere above features some notable craters as well: the relatively youthful 444-mile (715-km) -wide Rembrandt basin is seen at top right, while the smaller pit-floor crater Kipling can be discerned to its left, just below the planet’s limb.
When craters are larger than 300 km in diameter, they are referred to as basins.
During its 12 months in orbit MESSENGER will have experienced only two days on Mercury! This is because Mercury rotates very slowly on its axis, completing a full solar day (sunrise to sunrise) every 176 Earth days. (And you thought your work day seemed to last forever!)
This image, acquired by NASA’s MESSENGER spacecraft on December 12, 2011, reveals the blue coloration of the 32-mile (52-km) -wide Degas crater located in Mercury’s Sobkou Planitia region.
Degas’ bright central peaks are highly reflective in this view, and may be surrounded by hollows — patches of sunken, eroded ground first identified by MESSENGER last year.
Such blue-colored material within craters has been increasingly identified as more of Mercury’s surface is revealed in detail by MESSENGER images. It is likely due to an as-yet-unspecified type of dark subsurface rock, revealed by impact events.
The slightly larger, more eroded crater that Degas abuts is named Brontë.
The image was acquired with MESSENGER’s Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS), using filters 9, 7, 6 (996, 748, 433 nanometers) in red, green, and blue, respectively.
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington.
The 68-mile (109-km) -wide Amaral crater on Mercury reveals its brightly-tipped central peaks in this image, acquired by NASA’s MESSENGER spacecraft on Feb. 4, 2012. Long shadows are cast by the crater’s peaks and rugged rim (north is to the left.)
The image was acquired as a high-resolution targeted observation with MESSENGER’s Narrow-Angle Camera (NAC) on its Mercury Dual Imaging System (MDIS).
Amaral’s bright peaks were first spotted during MESSENGER’s first flyby of Mercury in Jan. 2008. With a smooth floor, visible ejecta and small secondary craters, Amaral appeared noticeably younger than the heavily cratered surface around it.
Amaral's "blue" peaks seen in a color-enhanced global image acquired Jan. 14, 2008.
Its central peaks also attracted astronomers’ interest, as they were seen to possess a striking blue hue in color-enhanced images that likely indicates rocks with different composition from the surrounding surface.
Amaral’s peaks resemble those of the slightly larger crater Eminescu, which is now known to contain recently-discovered features called hollows. It’s not yet known if Amaral also contains hollows, but it’s suspected that they may be present on the tips of the peaks.
The crater is named after Brazilian artist Tarsila do Amaral. She lived from 1886 to 1973 and is considered to be one of the leading Latin American modernist painters.
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington.
The pale-orange coloration around the 39-mile (62-km) -wide Kuiper crater on Mercury is evident in this image, a color composition made from targeted images acquired by NASA’s MESSENGER spacecraft on September 2, 2011.
The color may be due to compositional differences in the material that was ejected during the impact that formed the crater.
Kuiper crater is named after Gerard Kuiper, a Dutch-American astronomer who was a member of the Mariner 10 team. He is regarded by many as the father of modern planetary science.
“Kuiper studied the planets… at a time when they were scarcely of interest to other astronomers. But with new telescopes and instrumentation, he showed that there were great things to discover, which is as true today as it was then.”
– Dr. Bill McKinnon, Professor of Planetary Sciences at Washington University in St. Louis
Airless worlds like Mercury are constantly bombarded with micrometeoroids and charged solar particles in an effect known as “space weathering”. Craters with bright rays — like Kuiper — are thought to be relatively young because they have had less exposure to space weathering than craters without such rays.
See the original image release on the MESSENGER site here.
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
MESSENGER captures image of curious "hollows" around a crater peak
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The latest featured image from NASA’s MESSENGER spacecraft, soon to complete its first year in orbit around Mercury, shows the central peak of the 78-mile (138-km) – wide crater Eminescu surrounded by more of those brightly-colored surface features dubbed “hollows”. Actually tinted a light blue color, hollows may be signs of an erosion process unique to Mercury because of its composition and close proximity to the Sun.
First noted in September of last year, hollows have now been identified in many areas across Mercury. They showed up in previous images as only bright spots, but once MESSENGER established orbit in March of 2011 and began high-resolution imaging of Mercury’s surface it became clear that these features were something totally new.
The lack of craters within hollows seems to indicate that they are relatively young features. In fact, they may be part of a process that continues even now.
“Analysis of the images and estimates of the rate at which the hollows may be growing led to the conclusion that they could be actively forming today,” said David Blewett of the Johns Hopkins University Applied Physics Laboratory (APL).
One hypothesis is that the hollows are formed by the sublimation of subsurface material exposed during the creation of craters, around which they are most commonly seen. Being so close to the Sun (29 million miles/46 million km at closest) and lacking a protective atmosphere like Earth’s, Mercury is constantly being scoured by the powerful solar wind. This relentless stream of charged particles may literally be “sandblasting” exposed volatile materials off the planet’s surface!
The image above shows an area approximately 41 miles (66 km) across. It has been rotated to enhance perspective; see the original image and caption here.
Image: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Popular Science magazine names NASA’s Mars Science Laboratory, Dawn and MESSENGER missions as ‘Best of What’s New’ in innovation in 2011. Artist concept shows mosaic of MESSENGER, Mars Science Laboratory and Dawn missions. Credit: NASA/JPL-Caltech
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A trio of NASA’s Planetary Science mission’s – Mars Science Laboratory (MSL), Dawn and MESSENGER – has been honored by Popular Science magazine and selected as ‘Best of What’s New’ in innovation in 2011 in the aviation and space category.
The Curiosity Mars Science Laboratory was just launched to the Red Planet on Saturday, Nov. 26 and will search for signs of life while traversing around layered terrain at Gale Crater. Dawn just arrived in orbit around Asteroid Vesta in July 2011. MESSENGER achieved orbit around Planet Mercury in March 2011.
Several of the top mission scientists and engineers provided exclusive comments about the Popular Science recognitions to Universe Today – below.
“Of course we are all very pleased by this selection,” Prof. Chris Russell, Dawn Principal Investigator, of UCLA, told Universe Today.
Dawn is the first mission ever to specifically investigate the main Asteroid Belt between Mars and Jupiter and will orbit both Vesta and Ceres – a feat enabled solely thanks to the revolutionary ion propulsion system.
“At the same time I must admit we are also not humble about it. Dawn is truly an amazing mission. A low cost mission, using NASA’s advanced technology to enormous scientific advantage. It is really, really a great mission,” Russell told me.
Vesta is the second most massive asteroid and Dawn’s discoveries of a surprisingly dichotomous and battered world has vastly exceeded the team’s expectations.
Asteroid Vesta from Dawn - Exquisite Clarity from a formerly Fuzzy Blob
NASA's Dawn spacecraft obtained this image of the giant asteroid Vesta with its framing camera on July 24, 2011. It was taken from a distance of about 3,200 miles (5,200 kilometers). Before Dawn, Vesta was just a fuzzy blob in the most powerful telescopes. Dawn entered orbit around Vesta on July 15, and will spend a year orbiting the body before firing up the ion propulsion system to break orbit and speed to Ceres, the largest Asteroid. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
“Dawn is NASA at its best: ambitious, exciting, innovative, and productive,” Dr. Marc Rayman, Dawn’s Chief Engineer from the Jet Propulsion Lab (JPL), Pasadena, Calif., told Universe Today.
“This interplanetary spaceship is exploring uncharted worlds. I’m delighted Popular Science recognizes what a marvelous undertaking this is.”
JPL manages both Dawn and Mars Science Laboratory for NASA’s Science Mission Directorate in Washington, D.C.
Dawn is an international science mission. The partners include the German Aerospace Center (DLR), the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute.
“Very cool!”, John Grotzinger, the Mars Science Laboratory Project Scientist of the California Institute of Technology, told Universe Today.
“MSL packs the most bang for the buck yet sent to Mars.”
Last View of Curiosity Mars Science Laboratory Rover - inside the Cleanroom at KSC.
Curiosity just before Encapsulation for 8 month long interplanetary Martian Journey and touchdown inside Gale Crater. Credit: Ken Kremer
Curiosity is using an unprecedented precision landing system to touch down inside the 154 km (96 miile) wide Gale Crater on Aug. 6, 2012. The crater exhibits exposures of phyllosilicates and other minerals that may have preserved evidence of ancient or extant Martian life and is dominated by a towering mountain.
“10 instruments all aimed at a mountain higher than any in the lower 48 states, whose stratigraphic layering records the major breakpoints in the history of Mars’ environments over likely hundreds of millions of years, including those that may have been habitable for life.”
“It’s like a trip down the Grand Canyon 150 years ago, with the same sense of adventure, but with a lot of high tech equipment,” Grotzinger told me.
MSL also has an international team of over 250 science investigators and instruments spread across the US, Europe and Russia. Curiosity Mars Science Laboratory rover soars to Mars atop an Atlas V rocket on Nov. 26 at 10:02 a.m. EST from Cape Canaveral, Florida. Credit: Ken Kremer
MESSENGER is the first probe to orbit Mercury and the one year primary mission was recently extended by NASA.
Sean Solomon, of the Carnegie Institution of Washington, leads the MESSENGER mission as principal investigator. The Johns Hopkins University Applied Physics Laboratory built and operates the MESSENGER spacecraft for NASA.
“Planetary has 3 missions there… Dawn, MESSENGER, and MSL,” Jim Green proudly said to Universe Today regarding the Popular Science magazine awards. Green is the director, Planetary Science Division, NASA Headquarters, Washington
“Three out of 10 [awards] is a tremendous recognition of the fact that each one of our planetary missions goes to a different environment and takes on new and unique measurements providing us new discoveries and constantly changes how we view nature, ourselves, and our place in the universe.”
The First Solar Day
After its first Mercury solar day (176 Earth days) in orbit, MESSENGER has nearly completed two of its main global imaging campaigns: a monochrome map at 250 m/pixel and an eight-color, 1-km/pixel color map. Apart from small gaps, which will be filled in during the next solar day, these global maps now provide uniform lighting conditions ideal for assessing the form of Mercury’s surface features as well as the color and compositional variations across the planet. The orthographic views seen here, centered at 75° E longitude, are each mosaics of thousands of individual images. At right, images taken through the wide-angle camera filters at 1000, 750, and 430 nm wavelength are displayed in red, green, and blue, respectively.
Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Read more about the Popular Science citations and awards here
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Read continuing features about Curiosity, Dawn and MESSENGER by Ken Kremer starting here:
A mosaic of nine oblique views from the MESSENGER spacecraft of Mercury's limb, looking towards the horizon. Click for larger, more amazing view. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
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Wow — just wow! Here’s a unique, jaw-dropping, and beautiful look at Mercury from the MESSENGER spacecraft, in a mosaic created from nine images taken by the Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS). The camera took a “sideways” or oblique view of Mercury’s limb, looking towards the horizon, providing a distinctive look at the rough terrain, ridges, craters and scarps of the Van Eyck Formation region, adjacent to the Caloris basin. Combining the images for a larger view not only provides a “you are there” feel, but it provides the science team with new ways to study Mercury’s geology.
Make sure you click on the image for a larger, even more amazing view. You can compare this image with a “straight-down” look of the same region, below.
Correlation of features between the limb mosaic and an overhead view. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Looking at any landscape in from different angles has a major impact on how terrain location and feature orientation is perceived, the MESSENGER science team explained in a detailed description of how this image was made. While single images that focus on one feature are wonderful for in-depth explorations, combining images together in a mosaic studying can provide regional or even global perspective. These mosaics are particularly important for understanding the geological context of a particular feature and for exploring Mercury’s geologic history.
The Van Eyck region was formed by ejecta from the Caloris basin. Visible in the overhead view are “ghost craters” which are impact craters that were later buried by the voluminous volcanic lavas that form the plains in this part of Mercury. What appear as rough terrain and ridges in the oblique limb view show up as lineated, distinctive features from overhead. Both views provide clues to scientists about the processes or environment that the features formed.
The ejecta blanket of Caloris basin is to the lower left of the overhead-view.
The limb mosaic is just 9 of 75,000 images the NAC has taken and will continue to take during MESSENGER’s primary mission, which goes through March of 2012. These images were taken in June of 2011, and the mosaic was released today by the imaging team.
Planet Mercury as seen from the MESSENGER spacecraft in 2008. Credit: NASA/JPL
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According to data from the The Fast Imaging Plasma Spectrometer (FIPS) onboard NASA’s MESSENGER spacecraft, the solar wind is “sandblasting” the surface of Mercury at its polar regions.
Based on findings from one of seven different papers from the MESSENGER mission to be published in the Sept. 30th edition of Science, sodium and oxygen particles are charged in a manner similar to Earth’s own Aurora Borealis.
How are the University of Michigan researchers able to detect and study this phenomenon?
Using the FISP, the scientists at the University of Michigan have taken measurements of Mercury’s exosphere and magnetosphere. The data collected has provided researchers with a better understanding of interactions between Mercury and our Sun. FIPS data has also confirmed theories regarding the composition and source of particles in Mercury’s space environment.
“We had previously observed neutral sodium from ground observations, but up close we’ve discovered that charged sodium particles are concentrated near Mercury’s polar regions where they are likely liberated by solar wind ion sputtering, effectively knocking sodium atoms off Mercury’s surface,” said FIPS project leader Thomas Zurbuchen (University of Michigan).
In a UM press release, Zurbuchen added, “We were able to observe the formation process of these ions, and it’s comparable to the manner by which auroras are generated in Earth’s atmosphere near polar regions.”
Given that Earth and Mercury are the only two magnetized planets in the inner solar system (Mars is believed to have had a magnetic field in its past), the solar wind is deflected around them. The solar wind has made recent news due to recent outbursts from the Sun causing visible aurorae, caused by the interaction of charged particles from the Sun and Earth’s relatively strong magnetosphere. While Mercury does have a magnetosphere, compared to Earth’s it is relatively weak. Given Mercury’s weak magnetosphere and close proximity to the Sun, the effects of the solar wind have a more profound effect.
The Fast Imaging Plasma Spectrometer on board MESSENGER has found that the solar wind is able to bear down on Mercury enough to blast particles from its surface into its wispy atmosphere. Image Credit: Shannon Kohlitz, Media Academica, LLC
“Our results tell us is that Mercury’s weak magnetosphere provides very little protection of the planet from the solar wind,” Zurbuchen said.
Jim Raines, FIPS operations engineer (University of Michigan) added, “We’re trying to understand how the sun, the grand-daddy of all that is life, interacts with the planets. It is Earth’s magnetosphere that keeps our atmosphere from being stripped away. And that makes it vital to the existence of life on our planet.”
A high-resolution monochrome image has been combined with a lower-resolution enhanced-color image. The hollows appear in cyan, a result of their high reflectance and bluish color relative to other parts of the planet. The large pit in the center of the crater may be a volcanic vent, from which the orange material erupted. Credit: Courtesy of Science/AAAS
The MESSENGER team also released other results from the mission, including new evidence that flood volcanism has been widespread on Mercury, the first close-up views of Mercury’s “hollows,” and the first direct measurements of the chemical composition of Mercury’s surface.
MESSENGER, as well the the Mariner 10 flyby mission saw unusual features on the floors and central mountain peaks of some impact craters which were very bright and have a blue color relative to other areas of Mercury. This type of feature is not seen on the Moon, and were nicknamed “hollows.”
Now, with the latest MESSENGER data, hollows have been found over a wide range of latitudes and longitudes, suggesting that they are fairly common across Mercury. Many of the depressions have bright interiors and halos.
“To the surprise of the science team, it turns out that the bright areas are composed of small, shallow, irregularly shaped depressions that are often found in clusters,” says David Blewett, a staff scientist at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., and lead author of one of the Science reports. “The science team adopted the term ‘hollows’ for these features to distinguish them from other types of pits seen on Mercury.”
Blewett added the hollows detected so far have a fresh appearance and have not accumulated small impact craters, indicating that they are relatively young.
