NASA held its Rover Challenge event in Huntsville, Alabama this weekend: The 2015 NASA Human Exploration Rover Challenge Rolls to a Start – NASA
This competitive international design challenge boasts 95 registered university/college and high school teams, hailing from 18 states, Puerto Rico and from as far away as Mexico, Germany, India and Russia. Each team has spent months designing, building and testing their rovers, all for this moment…to roll into the U.S. Space & Rocket Center in Huntsville, Alabama, to defend their crowns or usurp the hierarchy of previous winners.
Rover Challenge requires student teams to design, construct, test and race human-powered rovers through an obstacle course simulating terrain potentially found on distant planets, asteroids or moons. Teams race against the clock to finish the course with the fastest times, vying for prizes in competitive divisions. The event concludes with an awards ceremony where corporate sponsors will present awards for best design, rookie team and other awards and accomplishments.
The nearly three-quarter-mile-long obstacle course will have teams racing and maneuvering in, through and around full-size exhibits of rockets, space vehicles and extra-terrestrial terrain on display at the U.S. Space & Rocket Center– the official visitor center of NASA’s Marshall Space Flight Center in Huntsville.
And a video from Reuters:
A new batch of Space Pod reports from TMRO.tv:
* Neutrinos are Awesome – Space Pod 04/13/15
* The New Vulcan Rocket – Space Pod 04/14/15
* 3D printing in space and the student built Vulcan-1 Engine – Space Pod 04/15/15
* SpaceX Launches CRS-6 with a Bang – Space Pod 04/16/15
Three PhD student researchers in engineering at the University of Leuven (Belgium) founded SpaceBillboard.com. Their plan is to sell squares on a grid on the side on the side of a small CubeSat spacecraft where companies can place ads or logos and individuals can put personal messages.
SpaceBillboard sells advertisement space on a billboard that will be launched into space on board of a satellite. This will be the first advertisement platform ever to pass the boundary of space. The revenues of this project will be used to sponsor space research at the University of Leuven. But this is not just charity. This unique story will go around the world as well.
The money raised from the billboards will go for space research:
SpaceBillboard supports innovative space research. More precisely, we want to support research on CubeSats. The first CubeSats were developed as student projects in universities, but by now, space agencies such as NASA and ESA have recognized their potential. But what makes them so special?
Bonhams auction house in New York City will hold a “Space History Sale” of space collectibles and memorabilia on Tuesday, April 1st: Bonhams sale offers items that have been to the moon and back – Pittsburgh Post-Gazette.
Astronaut Kenneth Bowersox’s spacesuit used during his ride to earth from the Int. Space Station in a Russian Soyuz spacecraft in 2003:
Rare meteorites are also available:
- StarTalk – National Geographic Channel
- Tuned In: ‘StarTalk’ not so far out of this world – Pittsburgh Post-Gazette.
Here is the StarTalk Episode Guide. His first show will include an interview with George Takei of Star Trek fame. In this clip, Tyson talks about Star Trek:
Here is this week’s Space to Ground report on activities related to the Int. Space Station:
An update on the Curiosity rover:
› Curiosity has passed the mission’s 10-kilometer mark as it heads for its next science destination, called “Logan Pass”
› The rover is approaching a corrugated geological unit that overlies the layers examined by Curiosity
NASA’s Curiosity Mars rover is continuing science observations while on the move this month. On April 16, the mission passed 10 kilometers (6.214 miles) of total driving since its 2012 landing, including about a fifth of a mile (310 meters) so far this month.
NASA’s Curiosity Mars rover used its Navigation Camera (Navcam) to capture this scene toward the west just after completing a drive that took the mission’s total driving distance past 10 kilometers (6.214 miles).
The drive on April 16, 2015, during the 957th Martian day, or sol of Curiosity’s work on Mars covered 208 feet (63.5 meters). It advanced the rover westward through a sandy-floored valley. The valley is on the rover’s route toward a higher site on Mount Sharp than sites it has investigated previously.
The rover is trekking through a series of shallow valleys between the “Pahrump Hills” outcrop, which it investigated for six months, and the next science destination, “Logan Pass,” which is still about 200 yards, or meters, ahead toward the southwest.
“We’ve not only been making tracks, but also making important observations to characterize rocks we’re passing, and some farther to the south at selected viewpoints,” said John Grant of the National Air and Space Museum, Washington. Grant is a Curiosity science team member who has been the team’s long-term planner in recent days.
A drive of 208 feet (63.5 meters) during the mission’s 957th Martian day, early Thursday, took Curiosity past a cumulative 10 kilometers of total Martian ground-distance covered. This is based on mapped distance covered by each drive; by wheel odometery, the rover reached 10 kilometers last week, but the mapped tally is considered a more precise measure of distance covered, excluding wheel slippage.
A green star marks the location of NASA’s Curiosity Mars rover after a drive on the mission’s 957th Martian day, or sol, (April 16, 2015). The map covers an area about 1.25 miles (2 kilometers) wide.
Curiosity landed on Mars in August 2012. The drive on Sol 957 brought the mission’s total driving distance past the 10-kilometer mark (6.214 miles). The rover is passing through a series of shallow valleys on a path from the “Pahrump Hills” outcrop, which it investigated for six months, toward its next science destination, called “Logan Pass.”
The rover’s traverse line enters this map at the location Curiosity reached in mid-July 2014.
The base map uses imagery from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter.
Curiosity is examining the lower slopes of a layered mountain, Mount Sharp, to investigate how the region’s ancient environment evolved from lakes and rivers to much drier conditions. Sites at Pahrump Hills exposed the mountain’s basal geological layer, named the Murray formation. Nearby, high-standing buttes are examples of terrain called the Washboard unit, from its corrugated appearance as seen from orbit.
“The trough we’re driving through is bounded by exposures of the Washboard unit, with gaps at some places that allow us to see farther south to higher exposures of it,” Grant said. “At Logan Pass, we hope to investigate the relationship between the Murray formation and the Washboard unit, to help us understand the ancient depositional setting and how environmental conditions were changing. The observations we’re making now help establish the context for what we’ll see there.”
“The rover’s mobility has been crucial, because that’s what allows us to get to the best sites to investigate,” Grant said. “The ability to get to different sections of the rock record builds more confidence in your interpretation of each section.”
From observations made by NASA’s Mars Reconnaissance Orbiter, topographically ridged terrain that has beenategorized as the Washboard unit has been mapped at many locations around Mount Sharp — on the south flank of the mountain as well as the northern flank Curiosity is climbing — and on the surrounding plains.
“Understanding the Washboard unit and what processes formed it could put what we’ve been studying into a wider context,” Grant said.
Curiosity spent much of its first 12 months on Mars investigating locations close to its landing site north of Mount Sharp. Findings during that period included evidence for ancient rivers and a lakebed environment that offered conditions favorable for microbial life, if Mars has ever hosted life. After leaving the landing vicinity, Curiosity drove to reach Mount Sharp, with a few extended stops at science waypoints along the route before arriving in September 2014.
NASA’s Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, built the rover and manages the project for NASA’s Science Mission Directorate in Washington. For more information about Curiosity, visit:
You can follow the mission on Facebook and Twitter at:
The Dawn spacecraft is moving towards the sunlight side of Ceres and has begun taking images again:
This animation shows the north pole of dwarf planet Ceres as seen by the Dawn spacecraft on April 10, 2015. Dawn was at a distance of 21,000 miles (33,000 kilometers) when its framing camera took these images. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA (See larger image here.)
April 16, 2015—After spending more than a month in orbit on the dark side of dwarf planet Ceres, NASA’s Dawn spacecraft has captured several views of the sunlit north pole of this intriguing world. These images were taken on April 10 from a distance of 21,000 miles (33,000 kilometers), and they represent the highest-resolution views of Ceres to date.
An animated sequence of these images, and a still, at: www.jpl.nasa.gov/news/news.php?release=2015-133
Subsequent images of Ceres will show surface features at increasingly better resolution.
Dawn arrived at Ceres on March 6, marking the first time a spacecraft has orbited a dwarf planet. Previously, the spacecraft explored giant asteroid Vesta for 14 months from 2011 to 2012. Dawn has the distinction of being the only spacecraft to orbit two extraterrestrial targets.
Ceres, with an average diameter of about 590 miles (950 kilometers), is the largest body in the main asteroid belt between Mars and Jupiter. Dawn has been using its ion propulsion system to maneuver to its first science orbit at Ceres, which it will reach on April 23. The spacecraft will remain at a distance of 8,400 miles (13,500 kilometers) from the dwarf planet until May 9. Afterward, it will make its way to lower orbits.
Dawn’s mission is managed by NASA’s Jet Propulsion Laboratory, Pasadena, California, for NASA’s Science Mission Directorate in Washington. Dawn is a project of the directorate’s Discovery Program, managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK, Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute are international partners on the mission team. For a complete list of acknowledgements, visit: dawn.jpl.nasa.gov/mission
The US Geological Service has released two high resolution maps of the Moon based on data from the Lunar Reconnaissance Orbiter (LRO):
- USGS Scientific Investigations Map 3316: Image Mosaic and Topographic Map of the Moon
- Here Are Two New Mind-Blowing Maps of the Moon – Popular Mechanics
The image map is created from a mosaic of images taken by the LRO’s Wide Angle Camera (WAC).
All named features greater than 85 km in diameter or length were included unless they were not visible on the map. Some selected well-known features less than 85 km in size were also included.
The topographic map is derived from elevation data measured by the LRO’s Lunar Orbiter Laser Altimeter (LOLA).
The image used for the base of this map represents more than 6.5 billion measurements gathered between July 2009 and July 2013…
Here’s a funny and funky tribute to SpaceX and Elon Musk produced by Cinesaurus: SpaceX Launch You Up (Uptown Funk Parody) – YouTube (The YT caption provides details of the video including the lyrics, the performers, etc.)
HobbySpace.com was founded to make the case to the public that space was not an area only for engineers and scientists in the government and big companies but that there were many real and tangible ways for regular folk to participate in space. AMSAT and student satellite projects, rocketry, space radio, astronomy, and many other space related activities have long involved hands-on building and operation of hardware by enthusiasts and not just specialists. With the cost of access to space dropping, we will see increasing participation of the public with space activities.
Meanwhile, in the past decade the Maker Movement, in a similar spirit, has has sought to convince the public that building and modifying real, tangible things is not just for those with elite knowledge but something they can do as well. Below is an infographic sent to me that outlines what the Maker Movement is all about:
A new report from the European Southern Observatory (ESO):
For the first time dark matter may have been observed interacting with other dark matter in a way other than through the force of gravity. Observations of colliding galaxies made with ESO’s Very Large Telescope and the NASA/ESA Hubble Space Telescope have picked up the first intriguing hints about the nature of this mysterious component of the Universe.
This image from the NASA/ESA Hubble Space Telescope shows the rich galaxy cluster Abell 3827. The strange blue structures surrounding the central galaxies are gravitationally lensed views of a much more distant galaxy behind the cluster. Observations of the central four merging galaxies have provided hints that the dark matter around one of the galaxies is not moving with the galaxy itself, possibly implying dark matter-dark matter interactions of an unknown nature are occuring. Credit: ESO
Using the MUSE instrument on ESO’s VLT in Chile, along with images from Hubble in orbit, a team of astronomers studied the simultaneous collision of four galaxies in the galaxy cluster Abell 3827. The team could trace out where the mass lies within the system and compare the distribution of the dark matter with the positions of the luminous galaxies.
Although dark matter cannot be seen, the team could deduce its location using a technique called gravitational lensing. The collision happened to take place directly in front of a much more distant, unrelated source. The mass of dark matter around the colliding galaxies severely distorted spacetime, deviating the path of light rays coming from the distant background galaxy — and distorting its image into characteristic arc shapes.
Our current understanding is that all galaxies exist inside clumps of dark matter. Without the constraining effect of dark matter’s gravity, galaxies like the Milky Way would fling themselves apart as they rotate. In order to prevent this, 85 percent of the Universe’s mass  must exist as dark matter, and yet its true nature remains a mystery.
In this study, the researchers observed the four colliding galaxies and found that one dark matter clump appeared to be lagging behind the galaxy it surrounds. The dark matter is currently 5000 light-years (50 000 million million kilometres) behind the galaxy — it would take NASA’s Voyager spacecraft 90 million years to travel that far.
This video using images from the NASA/ESA Hubble Space Telescope shows the rich galaxy cluster Abell 3827. The strange blue structures surrounding the central galaxies are gravitationally lensed views of a much more distant galaxy behind the cluster. Observations of the central four merging galaxies have provided hints that the dark matter around one of the galaxies is not moving with the galaxy itself, possibly implying dark matter-dark matter interactions of an unknown nature are occuring. Credit: NASA, ESA. Music: Johan B. Monell (www.johanmonell.com)
A lag between dark matter and its associated galaxy is predicted during collisions if dark matter interacts with itself, even very slightly, through forces other than gravity . Dark matter has never before been observed interacting in any way other than through the force of gravity.
Lead author Richard Massey at Durham University, explains: “We used to think that dark matter just sits around, minding its own business, except for its gravitational pull. But if dark matter were being slowed down during this collision, it could be the first evidence for rich physics in the dark sector — the hidden Universe all around us.”
The researchers note that more investigation will be needed into other effects that could also produce a lag. Similar observations of more galaxies, and computer simulations of galaxy collisions will need to be made.
Team member Liliya Williams of the University of Minnesota adds: “We know that dark matter exists because of the way that it interacts gravitationally, helping to shape the Universe, but we still know embarrassingly little about what dark matter actually is. Our observation suggests that dark matter might interact with forces other than gravity, meaning we could rule out some key theories about what dark matter might be.”
This result follows on from a recent result from the team which observed 72 collisions between galaxy clusters  and found that dark matter interacts very little with itself. The new work however concerns the motion of individual galaxies, rather than clusters of galaxies. Researchers say that the collision between these galaxies could have lasted longer than the collisions observed in the previous study — allowing the effects of even a tiny frictional force to build up over time and create a measurable lag .
Taken together, the two results bracket the behaviour of dark matter for the first time. Dark matter interacts more than this, but less than that. Massey added: “We are finally homing in on dark matter from above and below — squeezing our knowledge from two directions.”
The New Horizons spacecraft moves ever closer to Pluto for its fly-by in July. Today there were two panel discussions about the mission. The first panel focused on the science:
Here’s the second panel, which focuses on the spacecraft:
NASA’s New Horizons spacecraft is three months from returning to humanity the first-ever close up images and scientific observations of distant Pluto and its system of large and small moons.
Pluto-Charon in Color: This image of Pluto and its largest moon, Charon, was taken by the Ralph color imager aboard New Horizons on April 9, 2015, from a distance of about 71 million miles (115 million kilometers). It is the first color image ever made of the Pluto system by a spacecraft on approach. (full caption)
“Scientific literature is filled with papers on the characteristics of Pluto and its moons from ground based and Earth orbiting space observations, but we’ve never studied Pluto up close and personal,” said John Grunsfeld, astronaut, and associate administrator of the NASA Science Mission Directorate at the agency’s Headquarters in Washington. “In an unprecedented flyby this July, our knowledge of what the Pluto systems is really like will expand exponentially and I have no doubt there will be exciting discoveries.”
The fastest spacecraft ever launched, New Horizons has traveled a longer time and farther away – more than nine years and three billion miles – than any space mission in history to reach its primary target. Its flyby of Pluto and its system of at least five moons on July 14 will complete the initial reconnaissance of the classical solar system. This mission also opens the door to an entirely new “third” zone of mysterious small planets and planetary building blocks in the Kuiper Belt, a large area with numerous objects beyond Neptune’s orbit.
The flyby caps a five-decade-long era of reconnaissance that began with Venus and Mars in the early 1960s, and continued through first looks at Mercury, Jupiter and Saturn in the 1970s and Uranus and Neptune in the 1980s.
Reaching this third zone of our solar system – beyond the inner, rocky planets and outer gas giants – has been a space science priority for years. In the early 2000s the National Academy of Sciences ranked the exploration of the Kuiper Belt – and particularly Pluto and its largest moon, Charon – as its top priority planetary mission for the coming decade.
New Horizons – a compact, lightweight, powerfully equipped probe packing the most advanced suite of cameras and spectrometers ever sent on a first reconnaissance mission – is NASA’s answer to that call.
“This is pure exploration; we’re going to turn points of light into a planet and a system of moons before your eyes!” said Alan Stern, New Horizons principal investigator from Southwest Research Institute (SwRI) in Boulder, Colorado. “New Horizons is flying to Pluto — the biggest, brightest and most complex of the dwarf planets in the Kuiper Belt. This 21st century encounter is going to be an exploration bonanza unparalleled in anticipation since the storied missions of Voyager in the 1980s.”
Pluto, the largest known body in the Kuiper Belt, offers a nitrogen atmosphere, complex seasons, distinct surface markings, an ice-rock interior that may harbor an ocean, and at least five moons. Among these moons, the largest – Charon – may itself sport an atmosphere or an interior ocean, and possibly even evidence of recent surface activity.
“There’s no doubt, Charon is a rising star in terms of scientific interest, and we can’t wait to reveal it in detail in July,” said Leslie Young, deputy project scientist at SwRI.
Pluto’s smaller moons also are likely to present scientific opportunities. When New Horizons was started in 2001, it was a mission to just Pluto and Charon, before the four smaller moons were discovered.
The spacecraft’s suite of seven science instruments – which includes cameras, spectrometers, and plasma and dust detectors – will map the geology of Pluto and Charon and map their surface compositions and temperatures; examine Pluto’s atmosphere, and search for an atmosphere around Charon; study Pluto’s smaller satellites; and look for rings and additional satellites around Pluto.
Currently, even with New Horizons closer to Pluto than the Earth is to the Sun, the Pluto system resembles little more than bright dots in the distance. But teams operating the spacecraft are using these views to refine their knowledge of Pluto’s location, and skillfully navigate New Horizons toward a precise target point 7,750 miles (12,500 kilometers) from Pluto’s surface. That targeting is critical, since the computer commands that will orient the spacecraft and point its science instruments are based on knowing the exact time and location that New Horizons passes Pluto.
“Our team has worked hard to get to this point, and we know we have just one shot to make this work,” said Alice Bowman, New Horizons mission operations manager at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, which built and operates the spacecraft. “We’ve plotted out each step of the Pluto encounter, practiced it over and over, and we’re excited the ‘real deal’ is finally here.”
The spacecraft’s work doesn’t end with the July flyby. Because it gets one shot at its target, New Horizons is designed to gather as much data as it can, as quickly as it can, taking about 100 times as much data on close approach as it can send home before flying away. And although the spacecraft will send select, high-priority datasets home in the days just before and after close approach, the mission will continue returning the data stored in onboard memory for a full 16 months.
“New Horizons is one of the great explorations of our time,” said New Horizons Project Scientist Hal Weaver at APL. “There’s so much we don’t know, not just about Pluto, but other worlds like it. We’re not rewriting textbooks with this historic mission – we’ll be writing them from scratch.”
APL manages the New Horizons mission for NASA’s Science Mission Directorate in Washington. Alan Stern of SwRI is the principal investigator. SwRI leads the science team, payload operations and encounter science planning. New Horizons is part of the New Frontiers Program, managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama.
The extremely low atmosphere on Mars (about 1% the pressure on earth) means that liquid water will quickly evaporate. However, it appears from the Curiosity humidty and temperature measurements that there are conditions at night where brine moisture (i.e. water with salts dissolved in it) can form on the surface even in the warmer climes of the equatorial latitudes:
- Conditions that might produce liquid brine in Martian soil extend closer to the equator than expected
- Perchlorate salt in soil can pull water molecules from the atmosphere and act as anti-freeze
- Presence of brine would not make Curiosity’s vicinity favorable for microbes
Martian weather and soil conditions that NASA’s Curiosity rover has measured, together with a type of salt found in Martian soil, could put liquid brine in the soil at night.
Perchlorate identified in Martian soil by the Curiosity mission, and previously by NASA’s Phoenix Mars Lander mission, has properties of absorbing water vapor from the atmosphere and lowering the freezing temperature of water. This has been proposed for years as a mechanism for possible existence of transient liquid brines at higher latitudes on modern Mars, despite the Red Planet’s cold and dry conditions.
New calculations were based on more than a full Mars year of temperature and humidity measurements by Curiosity. They indicate that conditions at the rover’s near-equatorial location were favorable for small quantities of brine to form during some nights throughout the year, drying out again after sunrise. Conditions should be even more favorable at higher latitudes, where colder temperatures and more water vapor can result in higher relative humidity more often.
“Liquid water is a requirement for life as we know it, and a target for Mars exploration missions,” said the report’s lead author, Javier Martin-Torres of the Spanish Research Council, Spain, and Lulea University of Technology, Sweden, and a member of Curiosity’s science team. “Conditions near the surface of present-day Mars are hardly favorable for microbial life as we know it, but the possibility for liquid brines on Mars has wider implications for habitability and geological water-related processes.”
The weather data in the report published today in Nature Geosciences come from the Cuirosity’s Rover Environmental Monitoring Station (REMS), which was provided by Spain and includes a relative-humidity sensor and a ground-temperature sensor. NASA’s Mars Science Laboratory Project is using Curiosity to investigate both ancient and modern environmental conditions in Mars’ Gale Crater region. The report also draws on measurements of hydrogen in the ground by the rover’s Dynamic Albedo of Neutrons (DAN) instrument, from Russia.
“We have not detected brines, but calculating the possibility that they might exist in Gale Crater during some nights testifies to the value of the round-the-clock and year-round measurements REMS is providing,” said Curiosity Project Scientist Ashwin Vasavada of NASA’s Jet Propulsion Laboratory, Pasadena, California, one of the new report’s co-authors.
Curiosity is the first mission to measure relative humidity in the Martian atmosphere close to the surface and ground temperature through all times of day and all seasons of the Martian year. Relative humidity depends on the temperature of the air, as well as the amount of water vapor in it. Curiosity’s measurements of relative humidity range from about five percent on summer afternoons to 100 percent on autumn and winter nights.
Air filling pores in the soil interacts with air just above the ground. When its relative humidity gets above a threshold level, salts can absorb enough water molecules to become dissolved in liquid, a process called deliquescence. Perchlorate salts are especially good at this. Since perchlorate has been identified both at near-polar and near-equatorial sites, it may be present in soils all over the planet.
Researchers using the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter have in recent years documented numerous sites on Mars where dark flows appear and extend on slopes during warm seasons. These features are called recurring slope lineae, or RSL. A leading hypothesis for how they occur involves brines formed by deliquesence.
“Gale Crater is one of the least likely places on Mars to have conditions for brines to form, compared to sites at higher latitudes or with more shading. So if brines can exist there, that strengthens the case they could form and persist even longer at many other locations, perhaps enough to explain RSL activity,” said HiRISE Principal Investigator Alfred McEwen of the University of Arizona, Tucson, also a co-author of the new report.
In the 12 months following its August 2012 landing, Curiosity found evidence for ancient streambeds and a lakebed environment more than 3 billion years ago that offered conditions favorable for microbial life. Now, the rover is examining a layered mountain inside Gale Crater for evidence about how ancient environmental conditions evolved. JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Science Laboratory and Mars Reconnaissance Projects for NASA’s Science Mission Directorate, Washington.
This view from the Navigation Camera (Navcam) on NASA’s Curiosity Mars rover shows the terrain ahead of the rover as it makes its way westward through a valley called “Artist’s Drive.”
The Navcam recorded the component images of this mosaic on April 10, 2015, during the 951st Martian Day, or sol, of Curiosity’s work on Mars. The valley is on the rover’s route toward a higher site on Mount Sharp than the “Pahrump Hills” area the mission investigated at the base of the layered mountain.
NASA’s Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, manages the Mars Science Laboratory Project for NASA’s Science Mission Directorate, Washington. JPL designed and built the project’s Curiosity rover and the rover’s Navcam.
The ESA Rosetta mission releases a new set of images of Comet 67P/Churyumov-Gerasimenko:
Four months from today, on 13 August, Comet 67P/Churyumov-Gerasimenko will reach perihelion – a moment that defines its closest point to the Sun along its orbit.
For 67P/Churyumov-Gerasimenko, this takes place at a distance of about 185 million km from the Sun, between the orbits of Earth and Mars.
Rosetta is along for the ride, and has been watching the gradual evolution of the comet since arriving in August 2014.
As the comet’s surface layers are gently warmed, frozen ices sublimate. The escaping gas carries streams of dust out into space, and together these slowly expand to create the comet’s fuzzy atmosphere, or coma.
As the comet continues to move closer to the Sun, the warming continues and activity rises, and pressure from the solar wind causes some of the materials to stream out into long tails, one made of gas, the other of dust. The comet’s coma will eventually span tens of thousands of kilometres, while the tails may extend hundreds of thousands of kilometres, and both will be visible through large telescopes on Earth.
But it is Rosetta’s close study of the comet, from just a few tens of kilometres above its surface, which enables the source of the comet’s activity to be studied in great detail, providing context to the more distant ground-based observations.
This spectacular montage of 18 images shows off the comet’s activity from many different angles as seen between 31 January (top left) and 25 March (bottom right), when the spacecraft was at distances of about 30 to 100 km from the comet. At the same time, Comet 67P/Churyumov-Gerasimenko was at distances between 363 million and 300 million km from the Sun.
After perihelion, Rosetta will continue to follow the comet, watching how the activity subsides as it moves away from the Sun and back to the outer Solar System again.
The Dawn spacecraft continues to move towards a close orbit of Ceres, the largest object in the asteroid belt. (See recent report here on Dawn’s status.) The spacecraft has not yet begun making new images of the dwarf planet. Here is a report on analysis of the planet’s surface using imaging data obtained on the approach to Ceres.
A new color map of dwarf planet Ceres, which NASA’s Dawn spacecraft has been orbiting since March, reveals the diversity of the surface of this planetary body. Differences in morphology and color across the surface suggest Ceres was once an active body, Dawn researchers said today at the 2015 General Assembly of the European Geosciences Union in Vienna.
This map-projected view of Ceres was created from images taken by NASA’s Dawn spacecraft during its initial approach to the dwarf planet, prior to being captured into orbit in March 2015.
The map is an enhanced color view that offers an expanded range of the colors visible to human eyes. Scientists use this technique in order to highlight subtle color differences across Ceres. This can provide valuable insights into the physical properties and composition of materials on the surface. For example, scientists have not established clear connections between impact craters and the different colors visible here, but they are investigating this possibility.
Images taken using blue (440 nanometers), green (550 nanometers) and infrared (920 nanometers) spectral filters were combined to create the map. The filters were assigned to color channels in reverse order, compared to natural color; in other words, the short-wavelength blue images were assigned to the red color channel and the long-wavelength infrared images are assigned to the blue color channel.
“This dwarf planet was not just an inert rock throughout its history. It was active, with processes that resulted in different materials in different regions. We are beginning to capture that diversity in our color images,” said Chris Russell, principal investigator for the Dawn mission, based at the University of California, Los Angeles.
The Dawn mission made history on March 6 as the first spacecraft to reach a dwarf planet, and the first spacecraft to orbit two extraterrestrial targets. Previously, Dawn studied giant asteroid Vesta from 2011 to 2012, uncovering numerous insights about its geology and history. While Vesta is a dry body, Ceres is believed to be 25 percent water ice by mass. By comparing Vesta and Ceres, scientists hope to gain a better understanding of the formation of the solar system.
Ceres’ surface is heavily cratered, as expected, but appears to have fewer large craters than scientists anticipated. It also has a pair of very bright neighboring spots in its northern hemisphere. More detail will emerge after the spacecraft begins its first intensive science phase on April 23, from a distance of 8,400 miles (13,500 kilometers) from the surface, said Martin Hoffmann, investigator on the Dawn framing camera team, based at the Max Planck Institute for Solar System Research, Göttingen, Germany.
The visible and infrared mapping spectrometer (VIR), an imaging spectrometer that examines Ceres in visible and infrared light, has been examining the relative temperatures of features on Ceres’ surface. Preliminary examination suggests that different bright regions on Ceres’ surface behave differently, said Federico Tosi, investigator from the VIR instrument team at the Institute for Space Astrophysics and Planetology, and the Italian National Institute for Astrophysics, Rome.
These images, from Dawn’s visible and infrared mapping spectrometer (VIR), highlight two regions on Ceres containing bright spots. The top images show a region scientists have labeled “1” and the bottom images show the region labeled “5.” Region 5 contains the brightest spots on Ceres.
VIR has been examining the relative temperatures of features on Ceres’ surface. Preliminary examination suggests that region 1 is cooler than the rest of Ceres’ surface, but region 5 appears to be located in a region that is similar in temperature to its surroundings.
Based on observations from NASA’s Hubble Space Telescope, planetary scientists have identified 10 bright regions on Ceres’ surface. One pair of bright spots, by far the brightest visible marks on Ceres, appears to be located in a region that is similar in temperature to its surroundings. But a different bright feature corresponds to a region that is cooler than the rest of Ceres’ surface.
The origins of Ceres’ bright spots, which have captivated the attention of scientists and the public alike, remain unknown. It appears the brightest pair is located in a crater 57 miles (92 kilometers) wide. As Dawn gets closer to the surface of Ceres, better-resolution images will become available.
“The bright spots continue to fascinate the science team, but we will have to wait until we get closer and are able to resolve them before we can determine their source,” Russell said.
Both Vesta and Ceres are located in the main asteroid belt between Mars and Jupiter. The Dawn spacecraft will continue studying Ceres through June 2016.
Dawn’s mission is managed by NASA’s Jet Propulsion Laboratory, Pasadena, California, for NASA’s Science Mission Directorate in Washington. Dawn is a project of the directorate’s Discovery Program, managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team. For a complete list of mission participants, visit: dawn.jpl.nasa.gov/mission/
For more information about Dawn, visit: dawn.jpl.nasa.gov
1. Monday, April 13, 2015: 2-3:30 PM PDT (5-6:30 PM EDT; 4-5:30 PM CDT): We welcome ERIK CONWAY, the JPL Historian regarding his new book, Exploration and Engineering: The Jet Propulsion Laboratory and the Quest for Mars (New Series in NASA History).
2. Tuesday, April 14,, 2015:,7-8:30 PM PDT (10-11:30 PM EST, 9-10:30 PM CDT): We welcome back RAND SIMBERG for his take on space news and policy events of recent times.
4. Sunday, April 19, 2015: 12-1:30 PM PDT (3-4:30 PM EDT, 2-3:30 PM CDT): We welcome DR. JOHN JURIST AND KOBI HUDSON regarding the recent ATK 5 Segment booster test and Kobi’s ISS project.
The Space Show is a project of the One Giant Leap Foundation.
is a global celebration of humanity’s past, present, and future in space. Yuri’s Night parties and events are held around the world every April in commemoration of Yuri Gagarin becoming the first human to venture into space on April 12, 1961, and the inaugural launch of the first Space Shuttle on April 12, 1981.
Yuri’s Night events combine space-themed partying with education and outreach. These events can range from an all-night mix of techno and technology at a NASA Center, to a movie showing and stargazing at your local college, to a gathering of friends at a bar or barbecue.
Check for a party in your area at Find a Yuri’s Night event.
Or have a party of your own. Find space-inspired tunes to play in the HobbySpace music section.