Scanning the sky in microwaves, the Planck mission has obtained its very first images of galaxy clusters, and found a previously unknown supercluster which is among one of the largest objects in the Universe. The supercluster is having an effect on the Cosmic Microwave Background, and the observed distortions of the CMB spectrum are used to detect the density perturbations of the universe, using what is called the Sunyaev–Zel’dovich effect (SZE). This is the first time that a supercluster has been discovered using the SZE. In a collaborative effort, the XMM Newton spacecraft has confirmed the find in X-rays.
Sunyaev-Zel’dovich Effect (SZE) effect describes the change of energy experienced by CMB photons when they encounter a galaxy cluster as they travel towards us, in the process imprinting a distinctive signature on the CMB itself. The SZE represents a unique tool to detect galaxy clusters, even at high redshift. Planck is able to look across nine different microwave frequencies (from 30 to 857 GHz) to remove all sources of contamination from the CMB, and over time, will provide what is hoped to be the sharpest image of the early Universe ever.
“As the fossil photons from the Big Bang cross the Universe, they interact with the matter that they encounter: when travelling through a galaxy cluster, for example, the CMB photons scatter off free electrons present in the hot gas that fills the cluster,” said Nabila Aghanim of the Institut d’Astrophysique Spatiale in Orsay, France, a leading member of the group of Planck scientists investigating SZE clusters and secondary anisotropies. “These collisions redistribute the frequencies of photons in a particular way that enables us to isolate the intervening cluster from the CMB signal.”
Since the hot electrons in the cluster are much more energetic than the CMB photons, interactions between the two typically result in the photons being scattered to higher energies. This means that, when looking at the CMB in the direction of a galaxy cluster, a deficit of low-energy photons and a surplus of more energetic ones is observed.
The SZE signal from the newly discovered supercluster arises from the sum of the signal from the three individual clusters, with a possible additional contribution from an inter-cluster filamentary structure. This provides important clues about the distribution of gas on very large scales which is, in turn, crucial also for tracing the underlying distribution of dark matter.
“The XMM-Newton observations have shown that one of the candidate clusters is in fact a supercluster composed of at least three individual, massive clusters of galaxies, which Planck alone could not have resolved,” said Monique Arnaud, who leads the Planck group following up sources with XMM-Newton.
“This is the first time that a supercluster has been discovered via the SZE,” said Aghanim. “This important discovery opens a brand new window on superclusters, one which complements the observations of the individual galaxies therein.”
Superclusters are large assemblies of galaxy groups and clusters, located at the intersections of sheets and filaments in the wispy cosmic web. As clusters and superclusters trace the distribution of both luminous and dark matter throughout the Universe, their observation is crucial to probe how cosmic structures formed and evolved.
The first Planck all-sky survey began in mid-August 2009 and was completed in June 2010. Planck will continue to gather data until the end of 2011, during which time it will complete over four all-sky scans.
The Planck team is currently analyzing the data from the first all-sky survey to identify both known and new galaxy clusters for the early Sunyaev-Zel’dovich catalogue, which will be released in January of 2011.
This is one of the strangest looking craters ever found on Mars, and this platypus-tail-shaped depression, called Orcus Patera, is an enigma. The term ‘patera’ is used for complex or irregularly shaped volcanic craters, but planetary scientists aren’t sure if this landform is volcanic in origin. Orcus Patera lies between the volcanoes of Elysium Mons and Olympus Mons, but its formation remains a mystery. This is the latest image of the object, taken by ESA’s Mars Express.
It could be an impact crater that originally was round, but then subsequently deformed by compressional forces. Or, it could have formed from two craters next to each where the adjoining rims eroded. However, the most likely explanation is that it was made in an oblique impact, when a small body struck the surface at a very shallow angle.
It is 380 km long by by 140 km wide, and has a rim that rises up to 1,800 meters above the surrounding plains, while the floor of the depression lies 400–600 m below the surroundings. The floor of the depression is unusually smooth.
The image above was created using a Digital Terrain Model (DTM) obtained from the High Resolution Stereo Camera on ESA’s Mars Express spacecraft. Elevation data from the DTM are color-coded: purple indicates the lowest-lying regions, and beige the higher elevations. The scale is in meters.
NASA and the European Space Agency (ESA) are working on a joint program to explore Mars in the coming decades and announced today they have selected five science instruments for the first mission. The ExoMars Trace Gas Orbiter, scheduled to launch in 2016, is the first of three joint robotic missions to the Red Planet. It will study the chemical makeup of the Martian atmosphere with a 1000-fold increase in sensitivity over previous Mars orbiters. The mission will focus on trace gases, including methane, which could be potentially geochemical or biological in origin and be indicators for the existence of life on Mars. The mission also will serve as an additional communications relay for Mars surface missions beginning in 2018.
“Independently, NASA and ESA have made amazing discoveries up to this point,” said Ed Weiler, associate administrator of NASA’s Science Mission Directorate in Washington. “Working together, we’ll reduce duplication of effort, expand our capabilities and see results neither ever could have achieved alone.”
The selection of the instruments begins the first phase of the new NASA-ESA alliance for future ventures to Mars. The instruments and the principal investigators are:
— Mars Atmosphere Trace Molecule Occultation Spectrometer — A spectrometer designed to detect very low concentrations of the molecular components of the Martian atmosphere: Paul Wennberg, California Institute of Technology, Pasadena Calif.
— High Resolution Solar Occultation and Nadir Spectrometer — A spectrometer designed to detect traces of the components of the Martian atmosphere and to map where they are on the surface: Ann C. Vandaele, Belgian Institute for Space Aeronomy, Brussels, Belgium.
— ExoMars Climate Sounder — An infrared radiometer that provides daily global data on dust, water vapor and other materials to provide the context for data analysis from the spectrometers: John Schofield, NASA’s Jet Propulsion Laboratory (JPL), Pasadena, Calif.
— High Resolution Color Stereo Imager — A camera that provides four-color stereo imaging at a resolution of two million pixels over an 8.5 km swath: Alfred McEwen, University of Arizona.
— Mars Atmospheric Global Imaging Experiment — A wide-angle, multi-spectral camera to provide global images of Mars in support of the other instruments: Bruce Cantor, Malin Space Science Systems, San Diego, Calif.
The science teams on all the instruments have broad international participation from Europe and the United States, with important hardware contributions from Canada and Switzerland.
“To fully explore Mars, we want to marshal all the talents we can on Earth,” said David Southwood, ESA director for Science and Robotic Exploration. “Now NASA and ESA are combining forces for the joint ExoMars Trace Gas Orbiter mission. Mapping methane allows us to investigate further that most important of questions: Is Mars a living planet, and if not, can or will it become so in the future?”
The plan consists of two Mars cooperative missions in 2016 and 2018, and a later joint sample return mission. The 2016 mission features the European-built ExoMars Trace Gas Orbiter, a European-built small lander demonstrator, a primarily-U.S. international science payload, and NASA-provided launch vehicle and communications components. ESA member states will provide additional instrument support.
The 2018 mission consists of a European rover with a drilling capability, a NASA rover capable of caching selected samples for potential future return to Earth, a NASA landing system, and a NASA launch vehicle. These activities are designed to serve as the foundation of a cooperative program to increase science returns and move the agencies toward a joint Mars sample return mission in the 2020s.
The ESA has scheduled the launch of Cryosat-2 for February 25th aboard a Russian Dnepr rocket from the Baikonur Cosmodrome in Kazakhstan. This is the second attempt at launching the Earth-observing satellite that’s tasked with monitoring global ice thickness. The initial launch of Cryosat on October 8th, 2005 failed due to an anomaly of the launch sequence.
Other Earth-observing satellites have taken measurements of the ice thickness near the poles, but Cryosat-2 will be the first such satellite completely dedicated to monitoring ice thickness variations, and will keep tabs on the decline of sea ice, which in the Arctic has been shown to have shrunk 2.7% per decade since 1978.
Cryosat-2 will have a highly inclined polar orbit, and will reach 88 degrees north and south, so as to maximize the amount of observations of the Earth’s poles. The instruments aboard the satellite will be able to monitor the thickness changes in both sea ice and land ice with an accuracy of one centimeter. This will give scientists an unprecedented amount of data to work with to study how Arctic and Antarctic ice changes impact climate change, and vice versa.
The instrument aboard Cryosat-2 that will be measuring ice thickness is the SAR/Interferometric Radar Altimeter (SIRAL). This is a an altimeter and interferometer that operates in the Ku-band (13.575 GHz), and uses radar signals bounced off the ice to measure its thickness variations.
Cryosat-2 also has two other instruments to determine its position with a high amount of accuracy, the Doppler Orbit and Radio Positioning Integration by Satellite (DORIS) and Laser Retro-Reflector (LRR). DORIS detects and measures the Doppler shift of signals broadcast from a network of radio beacons spread around the world to give the velocity of the satellite relative to the Earth.
The LRR instrument will complement and help calibrate DORIS. The LRR is a small laser retroreflector that is attached to the underside of the satellite, and lasers from a network of tracking stations will be fired at the satellite. By measuring the interval between the firing of the laser and the return of the pulse, the position of the satellite can be measured very accurately.
The mission has a three-year lifespan, with a potential for a two-year extension. Cryosat-2 is currently nestled safely inside the Dnepr rocket’s protective fairing, and in the next nine days the satellite will be integrated into the rest of the launcher and moved out to the launch pad.
The new joint Mars exploration program of NASA and ESA is quickly pushing forward to implement an agreed upon framework to construct an ambitious new generation of red planet orbiters and landers starting with the 2016 and 2018 launch windows.
The European-led ExoMars Trace Gas Mission Orbiter (TGM) has been selected as the first spacecraft of the joint initiative and is set to launch in January 2016 aboard a NASA supplied Atlas 5 rocket for a 9 month cruise to Mars. The purpose is to study trace gases in the martian atmosphere, in particular the sources and concentration of methane which has significant biological implications. Variable amounts of methane have been detected by a martian orbiter and ground based telescopes on earth. The orbiter will likely be accompanied by a small static lander provided by ESA and dubbed the Entry, Descent and Landing Demonstrator Module (EDM).
The NASA Mars Program is shifting its science strategy to coincide with the new joint venture with ESA and also to build upon recent discoveries from the current international fleet of martian orbiters and surface explorers Spirit, Opportunity and Phoenix (see my earlier mars mosaics). Doug McCuiston, NASA’s director of Mars Exploration at NASA HQ told me in an interview that, “NASA is progressing quickly from ‘Follow the Water’ through assessing habitability and on to a theme of ‘Seeking the Signs of Life’. Looking directly for life is probably a needle in the haystack, but the signatures of past or present life may be more wide spread through organics, methane sources, etc”.
NASA and ESA will issue an “Announcement of Opportunity for the orbiter in January 2010” soliciting proposals for a suite of science instruments according to McCuiston. “The science instruments will be competitively selected. They are open to participation by US scientists who can also serve as the Principal Investigators (PI’s)”. Proposals are due in 3 months and will be jointly evaluated by NASA and ESA. Instrument selections are targeted for announcement in July 2010 and the entire cost of the NASA funded instruments is cost capped at $100 million.
“The 2016 mission must still be formally approved by NASA after a Preliminary Design Review, which will occur either in late 2010 or early 2011. Funding until then is covered in the Mars Program’s Next Decade wedge, where all new-start missions reside until approved, or not, by the Agency”, McCuiston told me. ESA’s Council of Ministers just gave the “green light” and formally approved an initial budget of 850 million euros ($1.2 Billion) to start implementing their ExoMars program for the 2016 and 2018 missions on 17 December at ESA Headquarters in Paris, France. Another 150 million euros will be requested within two years to complete the funding requirement for both missions.
ESA has had to repeatedly delay its own ExoMars spacecraft program since it was announced several years ago due to growing complexity, insufficient budgets and technical challenges resulting in a de-scoping of the science objectives and a reduction in weight of the landed science payload. The ExoMars rover was originally scheduled to launch in 2009 and is now set for 2018 as part of the new architecture.
The Trace Gas orbiter combines elements of ESA’s earlier proposed ExoMars orbiter and NASA’s proposed Mars Science Orbiter. As currently envisioned the spacecraft will have a mass of about 1100 kg and carry a roughly 115 kg science payload, the minimum deemed necessary to accomplish its goals. The instruments must be highly sensitive in order to be capable of detecting the identity and extremely low concentration of atmospheric trace gases, characterizing the spatial and temporal variation of methane and other important species, locating the source origin of the trace gases and determining if they are caused by biologic or geologic processes. Current photochemical models cannot explain the presence of methane in the martain atmosphere nor its rapid appearance and destruction in space, time or quantity.
Among the instruments planned are a trace gas detector and mapper, a thermal infrared imager and both a wide angle camera and a high resolution stereo color camera (1 – 2 meter resolution). “All the data will be jointly shared and will comply with NASA’s policies on fully open access and posting into the Planetary Data System”, said McCuiston.
Another key objective of the orbiter will be to establish a data relay capability for all surface missions up to 2022, starting with 2016 lander and two rovers slotted for 2018. This timeframe could potentially coincide with Mars Sample Return missions, a long sought goal of many scientists.
If the budget allows, ESA plans to piggyback a small companion lander (EDM) which would test critical technologies for future missions. McCuiston informed me that, “The objective of this ESA Technology Demonstrator is validating the ability to land moderate payloads, so the landing site selection will not be science-driven. So expect something like Meridiani or Gusev—large, flat and safe. NASA will assist ESA engineering as requested, and within ITAR constraints.” EDM will use parachutes, radar and clusters of pulsing liquid propulsion thrusters to land.
“ESA plans a competitive call for instruments on their 3-4 kg payload”, McCuiston explained. “The Announcement of Opportunity will be open to US proposers as well so there may be some US PI’s. ESA wants a camera to ‘prove’ they got to the ground. Otherwise there is no significant role planned for NASA in the EDM”.
The lander would likely function as a weather station and be relatively short lived, perhaps 8 Sols or martian days, depending on the capacity of the batteries. ESA is not including a long term power source, such as from solar arrays, so the surface science will thus be limited in duration.
The orbiter and lander would separate upon arrival at Mars. The orbiter will use a series of aerobraking maneuvers to eventually settle into a 400 km high circular science orbit inclined at about 74 degrees.
The joint Mars architecture was formally agreed upon last summer at a bilateral meeting between Ed Weiler (NASA) and David Southwood (ESA) in Plymouth, UK. Weiler is NASA’s Associate Administrator for the Science Mission Directorate and Southwood is ESA’s Director of Science and Robotic Exploration. They signed an agreement creating the Mars Exploration Joint Initiative (MEJI) which essentially weds the Mars programs of NASA and ESA and delineates their respective program responsibilities and goals.
“The key to moving forward on Mars exploration is international collaboration with Europe”, Weiler said to me in an interview. “We don’t have enough money to do these missions separately. The easy things have been done and the new ones are more complex and expensive. Cost overruns on Mars Science Lab (MSL) have created budgetary problems for future mars missions”. To pay for the MSL overrun, funds have to be taken from future mars budget allocations from fiscal years 2010 to 2014.
“2016 is a logical starting point to work together. NASA can have a 2016 mission if we work with Europe but not if we work alone. We can do so much more by working together since we both have the same objectives scientifically and want to carry out the same types of mission”. Weiler and Southwood instructed their respective science teams to meet and lay out a realistic and scientifically justifiable approach. Weiler explained to me that his goal and hope was to reinstate an exciting Mars architecture with new spacecraft launching at every opportunity which occurs every 26 months and which advance the state of the art for science. “It’s very important to demonstrate a critical new technology on each succeeding mission”.
More on the 2018 mission plan and beyond in a follow up report.
If you’re looking for some superb space and astronomy vodcasts, ESA has produced a series of informative video podcasts that explore our Universe as seen through the “eyes” of ESA’s fleet of science spacecraft. “The [email protected] podcast series was started as part of an education and public outreach project for the International Year of Astronomy,” said Dr. Salim Ansari, from ESA’s Directorate of Science and Robotic Exploration, “but it will continue on past IYA, continuing to cover more missions and discoveries.”
The series is a high quality video podcast with HD graphics and stunning visuals. Ansari said the production all done in house.
“One of my favorites is actually the first podcast that shows how with our eyes we see just a small portion of the electromagnetic spectrum,” Ansari said. “But we demonstrate how the different spacecraft can provide insight across the whole spectrum.”
Other podcasts delve into specifics of the electromagnetic spectrum that will be explored by the new Planck (microwave) and Herschel (infrared) spacecraft, to learning about the Gaia galaxy mapper mission that will determine the position of a billion stars.
A new 7th podcast will be released next week that introduces the solar system as seen by the Venus Express, Mars Express, Rosetta, Cassini-Huygens, SoHO and Cluster.
NASA and the European Space Agency (ESA) have officially agreed to combine their efforts in the exploration and study of Mars. The heads of both agencies, NASA administrator Charles Boden and ESA director-general Jean-Jacques Dordain signed an agreement that officially binds the two agencies together for upcoming orbiter and rover missions. Discussions of this cooperation began in December of 2008, and culminated in a meeting in June 2009, out of which came the official agreement signed last week.
The new “letter of intent” outlines the Mars Exploration Joint Initiative (MEJI), under which mission engineers will cooperate in the design and launch of rovers, orbiters and landers into the 2020s, with the ultimate goal of returning rocks from Mars to Earth for study. The first collaborative mission is a European-led orbiter that will also place a meteorological station on Mars planned for 2016. This will be followed by surface rovers to keep Spirit and Opportunity company (c’mon, you know they’ll still be ticking!) in 2018, and possibly a network of landers shortly after in 2018, one of which will include the ESA’s ExoMars Lander.
NASA will take care of the launching rockets for 2016 and 2018, and the ESA will cover the entry, descent and landing for the first mission in 2016.
The signing of this document makes official the talks held in Plymouth, UK this past June. Since the talks, most of the fine print has been worked out on the collaboration – this signing just seals the deal.
The ESA and NASA, both under financial constraints in their Mars exploration programs, envision this new union to allow both to to launch vehicles in the window that opens every 26 months for missions to Mars. NASA’s most recently planned mission to the Red Planet, the Mars Science Laboratory, missed the October 2009 window because of technical problems, so will have to be launched in 2011 instead. The same fate befell the ESA ExoMars lander, which has been postponed three times – until 2018 – from the initial launch date of 2009. This joint initiative aims at preventing such delays by sharing both engineering and financial responsibilities.
NASA’s associate administrator for science, Dr Ed Weiler, told the BBC back in July,”We have very similar scientific goals, maybe we ought to consider working together jointly on all our future Mars missions, so that we can do more than either one of us can do by ourselves.”
Hopefully, this collaboration will provide both administrations with the opportunity to get more science done for cheaper, and extend further the already amazing capabilities of proposed missions to the Red Planet.
The comet chasing spacecraft Rosetta will make its third and final swing by the Earth on November 13th to pick up more speed for the last part of a 10-year journey that lies ahead. Its mission is to place a lander on comet 67P/Churyumov-Gerasimenko and chase the comet for an entire year on its orbit around the Sun. The spacecraft will be visible to observers from the ground in certain locations on the Earth. This last flyby will increase the spacecraft’s speed by 3.6 km/s (2.2 miles/s) with respect to the Sun, giving Rosetta the energy it needs to boost it to the outer regions of the Solar System.
Rosetta was launched March 2nd, 2004, and will visit a host of targets on its way to comet 67P/Churyumov-Gerasimenko. Rosetta already paid a visit to asteroid 2867 Steins in September 2008. It will visit comet 21 Lutetia 10 June 2010, after which it will go into hibernation until it reaches its final destination in May 2014.
Once Rosetta arrives at 67P/Churyumov-Gerasimenko, it will deploy its Philae lander on the comet’s nucleus, and continue to orbit and study the comet for an entire year during its closest orbit of the Sun. This is the first mission ever to orbit and land on a comet, and promises to return a wealth of data on cometary interaction with the Sun. Comets also contain mostly undisturbed materials from the formation of the Solar System in their nuclei, so studying their composition gives scientists an look into how our Solar System developed.
During the flyby of Earth in November of 2007, Rosetta took the breathtaking image of the Earth pictured here. This next flyby will give observers on the ground a chance to take a look back at Rosetta. The closest approach will occur on November 13th at 8:45 Central European Time (07:45 UT).
Unfortunately, the spacecraft will only be visible from parts of Europe, South America and Africa, as can be seen in the image below. If you are in these regions during the approach, and have favorable conditions, there is a wealth of observing information on the Rosetta blog, specifically on the posts Tips for Sky Junkies I and Tips for Sky Junkies II. They will also be closely following the flyby on the blog, so you can check there for updates on the eve of the event if you are outside the observable range of the spacecraft.
As always, you can check back with us on Universe Today for more coverage of Rosetta’s journey!
NASA’s Mars Exploration Rovers (MER) have been an outstanding success in their longevity and helping us to understand the role of water in Mars’ past. But Spirit and Opportunity don’t have the instruments on board to answer the question foremost in many people’s minds: Is there, or was there ever life on Mars?
A new spacecraft being readied by the European Space Agency (ESA) will have that ability. The rover for the ExoMars 2013 mission will have an on-board subsurface radar, a drill, and life-detection equipment as part of the scientific payload.
To help prepare for the mission, scientists at Aberystwyth University in Wales have simulated the surface of Mars in their lab to test the “roving” capabilities of the vehicle. Also being tested are the robotic arm for collecting samples and a panoramic camera.
The ExoMars mission will also have an orbiter that will scan for the best landing site for the rover. The rover is slated to travel to ten different locations in 6 months. The rover will use a radar system that can scan the surface and subsurface, a drill that can dig down 1-2 meters below the surface and gather a sample that will be brought to the onboard instruments that will look for life, past or present, in the Mars landscape.
A robotic arm that is part of this system is similar to arm that was part of the ill-fated Beagle 2 lander, that crashed on Mars surface in 2003. But the new arm has been improved, and it is hoped the arm will work with on-board cameras and to be able to acquire rock samples autonomously.
The rover will weigh about 140-180 kg, comparable to the NASA’s MER. The main scientific objectives of the ExoMars mission are to study the biological environment of Mars surface, to characterize the Mars geochemistry and water distribution and to identify possible surface hazards to future human missions.
The mission is scheduled to launch in 2013 and land on Mars in 2014.
The International Space Station (ISS) depends on regular deliveries of food, air and water, as well as equipment and spare parts to keep the station and its occupants happy and in peak operating condition. Of course, the space shuttle brings supplies on its visits for construction and crew exchange missions, and the Russian Progress spacecraft faithfully brings supplies and equipment to the station approximately every six months. But beginning in February 2008 the ISS will have a new supply ship: Europe’s Automated Transfer Vehicle (ATV). The first of seven planned ships, known as the “Jules Verne,” is currently undergoing fueling to ready the craft for its journey to the space station. Launch is tentatively scheduled for February 22.
The ATV pressurized cargo carrier is based on the Italian-built Multi-Purpose Logistics Module (MPLM), (aka Leonardo, Donatello and Raffaello) which has already been carried to the station via the space shuttle as a “space barge,” transporting equipment to and from the station. The ATV, which is equipped with its own propulsion and navigation systems combines full automatic capabilities of an unmanned vehicle with human spacecraft safety requirements. Its mission in space will resemble the combination of a tugboat and a river barge.
Every 12 months or so, the ATV will haul 7.5 tons of cargo to the Station 400 km above the Earth. The ATV will launch on board a Arianne 5 rocket from Kourou, French Guiana. An automatic navigation system will guide the ATV on a rendezvous trajectory towards ISS, to automatically dock with the station’s Russian service module. The ATV will remain docked to the station as a pressurized “waste basket” for up to six months until its final mission: a fiery one-way trip into the Earth’s atmosphere to dispose of up to 6.5 tons of station waste.
The ATV is a cylinder 10.3 meters long and 4.5 meters in diameter. The exterior is covered with an insulating foil layer on top of anti-meteorite Whipple Shields. The X-shaped extended solar arrays look like a metallic blue wings. Inside, the ATV consists of two modules, the propulsion spacecraft and the integrated cargo carrier which docks with the ISS.
The ATV’s will become especially important during the time period between after the shuttles are retired and before the next generation of US space craft, can bring supplies and crew to the station. The ESA also sees the ATVs as a way for Europe to pay its share in ISS running costs. Depending on the operational lifetime of the Space Station, ESA will build at least 7 ATVs.