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The Dawn mission is on its way to the asteroid belt, and is on course to rendezvous with its first target, Vesta, in February 2011. As a part of that journey, Dawn received a gravity assist from Mars as it flew past the planet on February 17, 2009. During its closest approach, this framing camera image was snapped of Mars' surface near the terminator at daybreak. The Planetary Science Institute manages Dawn's Gamma-Ray and Neutron Detector (PI, Tom Prettyman), which will map the elemental composition of the surfaces of Vesta and Ceres to determine how they formed and evolved. [Read more]
PSI scientist Catherine Weitz has been working with new data from the Mars Reconnaissance Orbiter to study light-toned layered deposits and associated valleys on the plains adjacent to Valles Marineris. She and her co-workers, including PSI scientist Rebecca Williams, have determined that the layers within these deposits have unique characteristics not seen elsewhere on Mars. [Read more]
Hawaii eruption. PSI senior scientist Bill Hartmann teaches at the University of Hawaii Hilo campus each June and sends us this painting he made of the new eruption in Hawaii Volcanoes National Park. Starting Thanksgiving of 2007 the pit crater Halemaumau, in the middle of Kilauea caldera, erupted with a shower of ash and rocks. The eruption continued as a large, continuous plume of steam and vapor, with the base glowing red at night from molten material in the vent. The plume expands thermally to a wider size as it rises, and is visible from miles away. It dissipates into "vog," a blue haze of volcanic fog that hangs over parts of the "big island" of Hawaii. This view shows the plume viewed from the rim of Kilauea on a drizzly, hazy day.
PSI Research Scientist Matt Balme, along with Dan Berman, Mary Bourke, and Jim Zimbelman of the Smithsonian Institution, has begun a new study of Transverse Aeolian Ridges (TARs) on Mars that examines their distribution, orientation, and morphology. In the above image (MOC image S0700608, width=3.03 km) layered outcrops can be seen surrounded by TARs, as well as by large dark dunes. TARs are commonly found in close proximity to layered terrain, suggesting the eroded materials of the layered terrain as a sediment source for the TARs. [Read more]
The eruption of Oldoinyo Lengai, Tanzania, the only active volcano in the world that produces natrocarbonatite lava. These carbonate-rich lavas are unique in that they have low silica content and low viscosity, behaving more like a mud flow than a lava flow; in fact they can flow faster than a person can run! PSI Associate Research Scientist Dr. R. Greg Vaughan is collaborating with scientists in Africa, Europe and the US to monitor this eruption with high resolution satellite data. [Read more]
September 27, 2007. The NASA Dawn mission successfully launches towards the rising sun from Cape Canaveral. Dawn uses ion propulsion to rendezvous with the asteroid Vesta and small planet Ceres, the largest objects between Mars and Jupiter. PSI scientists Mark Sykes and Bill Feldman are Co-Investigators and members of its Science Team, Bill Feldman designed the Gamma-Ray Neutron Spectrometer instrument, Pasquale Tricarico is simulating spacecraft trajectories about Vesta and Ceres and determining asteroid flyby opportunities en route, Matt Chamberlain is characterizing the Dawn targets using groundbased thermal and microwave observations, and Bob Gaskell will be determining object shape and surface topography.
Image credit: Launch mosaic by Randy Pollock, stitching by Johan Kiviniemi, inset by NASA/Kim Shiflett.
This is Apollo 16 metric camera frame 0161, showing the area near the A16 landing site. Unknown at the time of the A16 mission, the strongest isolated magnetic anomaly on the Moon is located in this area and modeling carried out by PSI scientist Nic Richmond has shown that the source of the anomaly (red circle) correlates with a high albedo region of the Descartes Mountains (DM). Similar correlations between magnetization and albedo have been identified elsewhere on the Moon. Working in collaboration with Lon Hood at the University of Arizona and Dave Blewett at NovaSol, Nic is using the Lunar Prospector magnetometer data from 1999 to produce a global map of the crustal magnetization, with the goal of further investigating the association between crustal magnetic anomalies and albedo.
Synthetic Aperture Radar (SAR) images of Venus taken by NASA's Magellan spacecraft (science mission complete in 1994) continue to be the primary dataset for studying that planet's surface. The images here, part of Les Bleamaster's Planetary Geology and Geophysics mapping project, display some of the diversity in volcanic landforms observed. On the left (image center - 8 S, 200 E), several (>25) "small" (Hawaii for scale) volcanic constructs and associated lava flows pepper the surface. In contrast, the image on the right (center - 6 S, 205 E) shows a significant portion of a 1000 km channel-fed lava flow. Factors that contribute to different types of volcanic landforms produced include lava composition and temperature, magma production, and the rate of emplacement. New data from ESA's Venus Express spacecraft (operational orbit achieved in May 2006) may help to better characterize Venus' surface features as well as reveal surface temperature variations resulting from active volcanism.
A Japanese spacecraft has provided one of the best arguments yet in favor of a conception of asteroids pioneered over 30 years ago by scientists at PSI. The evidence comes in startling closeup pictures of the tiny asteroid 25143 Itokawa, photographed by the Japanese Hayabusa spacecraft during a two-month encounter, September-December, 2005. The scientific results, recently highlighted in the June 2, 2006 issue of the journal Science, show images unlike any seen of other asteroids, which are mostly rounded and potato-like, dotted by craters, and with a few scattered boulders on the surface. Itokawa appears to be composed of massive splinter-like boulders protruding from a larger matrix of smaller fragments and dust. The largest bolders sticking out of the body appear to be some tens of meters across. The title of the lead article from the Hayabusa team, by Fujiwara and 21 other authors, including new PSI scientists Bob Gaskell and Hirdy Miyamoto, refers to "The Rubble-Pile Asteroid Itokawa." Image courtesy ISAS/JAXA Japanese space agency.
On March 10, 2006 NASA's Mars Reconnaissance Orbiter (MRO) succesfully completed the difficult Mars Orbit Insertion maneuver in preparation for one of the most ambitious science missions ever sent to Mars. The High Resolution Imaging Science Experiment (HiRISE) instrument will return images more detailed than ever seen before. Other onboard instruments include a spectrometer to map wter-related minerals and a radar instrument to probe for underground layers of rock and water. PSI Research Scientist Cathy Weitz is a Co-Investigator on the HiRISE Team and will be responsible for coordinating images related to geologic processes on Mars. PSI Research Associate Frank Chuang will also be working with Cathy Weitz to coordinate observations. Click here for more information about the MRO HiRISE instrument. Image credit: NASA/JPL
This high-resolution MGS MOC image shows overlapping landslide deposits at the foot of the wall in the Ganges region of the Valles Marineris canyon complex on Mars. PSI's Bill Hartmann is currently collaborating with French researcher Cathy Quantin to use the landslide data to examine the time behavior of cratering on Mars, and the implications for using small craters to date landform features. The younger (overlying) debris fan has a distinctly lower crater density of small craters than the older (underlying) deposit. The relationship shown here argues against recent suggestions that crater densities of small craters are so completely dominated by statistical clustering of "secondary" ejecta craters that they are useless for dating.
On July 4, 2005, NASA's Deep Impact probe successfully impacted on the surface of comet 9P/Tempel 1, allowing scientists their first glimpse at the interior of a comet. The impact resulted in a flash and a subsequent ejecta plume which caused changes in the comet spectra, indicating an immediate enhancement of the dust and subsequent increases in gas species including CN. PSI Senior Scientists Dr. Beatrice Mueller and Dr. Nalin Samarasinha helped detect these changes using the WIYN 3.5 m telescope on Kitt Peak in Tucson, AZ. They also helped monitor the behavior of the comet before and after the impact, providing baseline observations to which the impact and post-impact data can be compared. This image, courtesy of NASA, was taken by the Deep Impact flyby spacecraft 67 seconds after the impact.
This image of the Earth's Moon was taken on September 8, 2005 by the High Resolution Imaging Science Experiment (HiRISE) instrument onboard the Mars Reconnaissance Orbiter (MRO) spacecraft on its cruise to Mars after launch on August 12, 2005. This crescent near-side view was taken from a distance of 10 million kilometers (6 million miles) using all ten red filter charge-coupled device detectors (CCDs). The dark circular feature in the center is Mare Crisium. PSI Research Scientist Cathy Weitz is a Co-Investigator on the HiRISE Team and will be responsible for coordinating images related to geologic processes on Mars. PSI Research Associate Frank Chuang will also be working with Cathy Weitz to coordinate observations. Click here for more information about the MRO HiRISE instrument. Photo Credit: NASA/JPL/University of Arizona.
The Dawn spacecraft is under construction at Orbital Sciences Corporation in Dulles, Virginia, in preparation for launch in June 2006. After a flyby of Mars, Dawn will rendezvous consecutively with Vesta and Ceres. These are the largest asteroids and are among the few remaining protoplanets surviving from the formation of the solar system. Vesta formed 'dry', subsequently melted, and experienced core formation. Volcanic basalts cover its surface. Vesta is thought to be the source of HED meteorites. Ceres formed 'wet', differentiated into a rocky core and icy mantle, and may possess a subsurface ocean. Dawn will be the first NASA science mission to use ion propulsion. PSI Senior Scientist and Director Mark Sykes is a member of the Dawn Science Team.
Hayabusa, "Falcon" in Japanese, is a Japanese Aerospace Exploration Agency (JAXA) sample-return spacecraft supported by NASA, and is scheduled to rendezvous with Itokawa this September. The spacecraft will return the first-ever sample from an asteroid to Earth in June 2007. PSI researcher Paul Abell will be part of a team working on data obtained from the spacecraft's Near-Infrared Spectrometer (NIRS) instrument, which will help investigators determine the composition of the asteroid and select possible landing sites for sample collection.
The rolling plains of Meridiani Planum are seen here as photographed by the Opportunity Rover. On the horizon is the rim of Endurance crater, which Opportunity later reached and explored. PSI researchers have worked on various aspects of this unusual region. Melissa Lane (PSI, Tempe) helped discover the unusual deposits of hematite in the sands. Bill Hartmann (PSI, Tucson) used crater counts to indicate that the area preserves very old features, but the surface has been only recently exposed. Opportunity discovered sulfate-rich sedimentary rocks, affirming that the area is probably an ancient lakebed.
(NASA image; processing by W. K. Hartmann)
Hellas Basin is the largest preserved impact structure on Mars. Over 2000 km in diameter and 8 km deep, the Hellas basin and its surroundings exhibit landforms shaped by a diversity of geologic processes. Ongoing Hellas region research at PSI includes numerous geologic mapping projects, investigations into the development of circum-Hellas canyon systems, degradation of highland terrains, emplacement of lava flows, evolution of lobate debris aprons, and the morphologies and populations of impact craters.
This perspective rendering of the northeast rim of Hellas basin and Hesperia Planum is one of many new products being produced at PSI by Varun Bhartia, an Arizona Space Grant intern from the University of Arizona. Working with PSI researchers Les Bleamaster and David Crown, Varun is helping to build a comprehensive collection of Mars Global Surveyor and Mars Odyssey image products for our Geographic Information Systems layered database.
Almost everyone has seen a rainbow, but few people are aware of the other ways in which clouds can produce colors. Most clouds consist of water droplets with a wide range of diameters, but under some circumstances, clouds can form whose water drops are all small (around 1 micron). It is these clouds which produce a colorful phenomenon known as iridescence, an example of which is shown here. PSI's Dr. David Lien has carried out a theoretical investigation of the colors and intensities of reflected sunlight produced by cloud droplets in a range of sizes. His calculations show the theoretical basis of iridescent clouds and many other cloud colors. For more about iridescent clouds, click on image.
Photo by David Lien
The surface temperature of the southern California desert can reach 120F during summer days. The top image shows temperatures of a playa at the Zyzxx Research Station near Baker, Ca., obtained with PSI's FLIR Systems thermal infrared camera. Relatively "cold" objects appear dark: vegetation, the sky. Warmer objects appear bright: the playa and gravel road. The lower image shows the visible appearance for comparison. Dr. Karl Hibbitts, a PSI research scientist, is using FLIR infrared imaging on playas to determine the extent that temperature and thermal inertia indicate a wet (and therefore treacherous) subsurface.
For more details on these animations and a description of how quasi-satellites might be captured as true satellites, follow this link.
With a telescope, a camera, and patience, you too could discover an asteroid.
The animation here represents the inaugural presentation of 'Asteroid of the Night,' a joint educational project of the Jarnac Observatory, the Planetary Science Institute, and the Flandrau Science Center. This pilot program is an attempt to take nightly astronomical observations of asteroids directly to the public through the World Wide Web. Observational data are being made available through the generous efforts of David Levy (Jarnac Observatory and member of the PSI Board of Trustees). PSI researchers, Les Bleamaster and Carol Neese, will be involved in preparing the images and ancillary information for distribution to the Flandrau Science Center, who will incorporate these exciting views into their existing asteroid exhibit.
Both Earth and Mars have atmospheres that can mobilize particles to form sand dunes. This image is from the caldera of an inactive Volcano (Nili Patera) on Mars. The steep avalanche face on the downwind side of the dunes indicates wind direction (see arrow). There are several types of sand dunes in this image, some of which have not been previously recognized on Mars.
(a) Lateral dune.
(b) Climbing dune.
(c) Linear extension from a transverse dune.
(d) Linear dune supplies sediment to barchanoid ridge (d') on the downwind
surface.
(e) Transverse aeolian ridges (they may be mega ripples) are being buried by
larger dunes.
(f) Barchan dunes.
Despite the presence of a 100 m deep double-trough, the sand transport pathway is not significantly interrupted. The march of the dunes across the trough may be aided by the tendency for wind speed to accelerate as it meets vertical obstacles. PSI's Mary Bourke and collaborators at John Hopkins University and University of Loughborough, UK, have modeled wind as it interacts with troughs on Mars and demonstrated that, under Martian conditions, wind speeds up by 30% at the downwind trough walls. (Bourke, M.C., J. Bullard, and O. Barnouin-Jha, in press.)
The Mars Orbital Camera Image is from the Malin Space Science Systems site. Image number: M17-00435, (8.99°N, 293.29°W, 5.84 m/pixel).
Mosaic by Dan Berman. MOC images credit NASA/JPL/Malin Space Science Systems.
Photo by W.K. Hartmann
Foreground is approximately 400 km, with a vertical exaggeration of 8x.
Mosaic of five individual images of the moon taken with the Robotically Controlled Telescope (RCT), a 1.3 meter telescope on Kitt Peak. The RCT has been reconfigured for automated remote operation by PSI and the RCT Consortium . These images were made through a narrow band filter, without which the moon would be too bright to image through the RCT. The combined very large image has been reduced for posting on the web.
Image © Gil Esquerdo and the RCT Consortium
Photograph taken on 1/15/03 by David A. Crown.
Temperature shading for a three-dimensional simulation of a Cretaceous/Tertiary Boundary type impact cratering event, in which an asteroid struck the Earth 65 Million years ago. The image shows the simulation five seconds after impact. Impact velocity is 20 km/sec, angle of impact is 45 degrees (impactor coming from the left). Temperature varies from about 200K (blue) to around 10000K (Red). This simulation was carried out by PSI's Elisabetta Pierazzo and colleagues (Pierazzo and Melosh 2000).
Click on the image to see the corresponding image depicting the different materials used in the model.
An object cataloged as an asteroid when it was discovered in the 1970's, Chiron was discovered to be a comet by D. Tholen, D. Cruikshank, and PSI's William K. Hartmann when they observed it brighten in 1988 during observations at Mauna Kea Observatory. Orbital studies show that it passes Saturn about every 10,000 years, which may deflect it into the inner solar system, closer to Earth.
Painting © William K. Hartmann
This image shows part of a new geologic map of the Terra Tyrrhena region of Mars that is being prepared by Scott Mest (University of Pittsburgh) and PSI's David Crown for publication as a U.S. Geological Survey Geologic Investigations Series Map. The different colors shown on the map represent different geologic units identified on the Martian surface through analyses of spacecraft images from the Viking and Mars Global Surveyor missions. The map depicts an ancient Martian surface exhibiting numerous impact craters and fluvial valleys, some of which form an extensive, integrated drainage network. The region shown (19.7-23.5°S, 271-273.9°W) is ~300 km across.
Click on the map to view a larger version, along with a photomosaic of Viking Orbiter images (from USGS Mars Transverse Mercator quadrangles -20272 and -25272) of the same area shown in the map.
Photo by NASA/JPL/Malin Space Science Systems.
Photograph © G. A. Esquerdo
This view shows the scene in the region of the earth less than a million years after the sun formed. Small grains of dust are aggregating into "planetesimals". The planets grew by collisional aggregation of these planetesimals. Scientists at PSI have developed the most advanced and detailed theoretical computer models to represent the processes by which dust and asteroid-like particles aggregated to form the planets of our solar system, and perhaps those of other solar systems as well.
Painting © William K. Hartmann