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High Resolution Solar Imaging from the Moon F. Berrilli - Tor Vergata University / INAF & A. Bigazzi - CE Consulting Altran Group / INAF F.Manni - SRS Engineering Design Srl A. Egidi - Tor Vergata University / INAF Contribution: V. Carbone (UNICAL) and S. Fineschi (INAF/TO) Observation of the Universe from the Moon - LNF INFN May 7, 2007 1 The Sun as active star Observation of the Universe from the Moon - LNF INFN May 7, 2007 2 Observation of the Universe from the Moon - LNF INFN May 7, 2007 3 Space weather refers to violent transfers of matter and energy from the sun to the Earth. CME blast and subsequent impact at Earth This illustration shows a CME blasting off the Sun's surface in the direction of Earth. Two to four days later, the CME cloud is shown striking and beginning to be mostly deflected around the Earth's magnetosphere. The blue paths emanating from the Earth's poles represent some of its magnetic field lines. The magnetic cloud of plasma can extend to 30 million miles wide by the time it reaches earth. These storms, which occur frequently, can disrupt communications and navigational equipment, damage satellites, and even cause blackouts. Courtesy of SOHO/LASCO consortium. SOHO is a project of international cooperation between ESA and NASA University of Colorado at Boulder Observation of the Universe from the Moon - LNF INFN May 7, 2007 4 A massive flare take place 1972 August 7th, between 1972 Apollo 16 (April) and Apollo 17 (December) human missions on the Moon. Observation of the Universe from the Moon - LNF INFN May 7, 2007 5 Solar surface magnetism consists of an amazing hierarchy of discrete strongfield structures. The basic element is the flux tube, a key concept of MHD astrophysics. Solar flux tubes have tiny cross-sections (~0.1 arcsec) corresponding to ~70km on the solar surface. Observation of the Universe from the Moon - LNF INFN May 7, 2007 6 Magnetic fields and flows interaction on solar surface Observation of the Universe from the Moon - LNF INFN May 7, 2007 7 Science: Local and Global Helioseismology. • Subsurface flows and MF dynamics Observation of the Universe from the Moon - LNF INFN May 7, 2007 8 The Moon as a platform for Solar Observations Observation of the Universe from the Moon - LNF INFN May 7, 2007 9 Attractive features • Achieving the highest resolutions on the photosphere and large FOVs with a small the telescope working at the diffraction limit • A 1m telescope may achieve limit resolution of a photon’s mean free path (also, the physical limit) About 50 km on the photosphere ,that is 0.05” - 0.1” (UV - visible). •On ground, high-res Adaptive Optics system have an isoplanatic patch of a few arcsec. • Extended spectral coverage, from NIR to UV (400-200nm) •UV chromospheric network and Solar UV Variability (Climate Drive) • Multi-layer imaging from deep Photosphere to the Chromosphere Observation of the Universe from the Moon - LNF INFN May 7, 2007 10 Attractive features (cont’d) • • Continuous visibility to few Ground Stations on Earth No need for a Satellite Control Center (orbit maintenance. Compare e.g. to L2 S-E orbiting S/Cs such as SOHO) • Continuous, high-rate download link to few Earth stations. • Little on-board processing and storage needed when a relaying orbiting telecom infrastructure is present. • Daylight operations - Power availability! greater flexibility in Mission design, as far as mass and power budget, landing site determination, telescope’s housekeeping and communications framework are concerned. • Extended (14 days), continuous observation capability. • monitoring evolution of long-living magnetic field complexes • global helioseismology Observation of the Universe from the Moon - LNF INFN May 7, 2007 11 Observation of the Universe from the Moon - LNF INFN May 7, 2007 12 ESA “Cosmic Vision” 2015-2025 “The varying magnetic field of the Sun is directly responsible for changes in the solar ultraviolet and Xray emission, and is also closely related to the […] possible forcing role in climatic variations. […] The solar magnetic field is continuously generated and destroyed on timescales ranging from fractions of a second to decades. These topics will remain major scientific challenges in the Cosmic Vision 2015-2025 timeframe.” Observation of the Universe from the Moon - LNF INFN May 7, 2007 Cosmic Vision: Space Science for Europe 2015-2025 – Executive Summary – May 2006 13 INAF/Piano Lungo Termine 2007-2017 The solar output, and associated fluctuations due to the solar activity, is the indispensable mechanism that sustains life on the Earth and generates the complex dynamics of the Heliosphere. For these reasons a task of primary interest for Science and for astrophysics is to understand our star: the Sun. The paragraphs is derived from the scientific road map for the next 10 years of Italian solar physics presented by the National Institute for Astrophysics-INAF. Observation of the Universe from the Moon - LNF INFN May 7, 2007 14 Telescope Design Telescope prototype for other astronomical instruments Primary Mirror Diameter: 1000 [mm] System Focal Ratio: 25 System Focal Length: 25000 Obstruction Ratio: 8.4% Angular Field: 0.12 Deg Observation of the Universe from the Moon - LNF INFN May 7, 2007 15 SiC Foam Technology (INAF/OAB – Off. Galileo) •31cm mirror •15 Kg/m2 •19 nm rms error Foamed primary mirror substrate in SiC ( 310 mm dia.) • Two SiC face sheets deposited on a foam core of the same material • Very light and stiff mirrors for space applications • Ion beam figuring polishing (final few microns) New process: foam generation, skin deposition, cladding. Courtesy O.Citterio, OAB, Brera Observatory Observation of the Universe from the Moon - LNF INFN May 7, 2007 16 Environmental challenges: dust 1. The average dust grain size is about 70 µm, with a percentage of 1020% below 10 µm. The dust is very pervasive, penetrates easily everywhere (problems with spacesuits and with moving mechanisms). 2. The shape of the grains is variable from spherical to very angular (see photo). 3. Low electrical conductivity The dust keeps the charge acquired through light exposure or charge deposition by the solar wind. 4. It thus adheres to surfaces both electrically and mechanically. The lunar dayside charges positive, as photo electron currents dominate; and the lunar nightside charges negative, since plasma electron currents dominate. Electric fields must thus exist near the terminator. Optical measurements suggest that dust particles of 5-6 µm might electrically levitate within a few meters, and that sporadically particles having much smaller size (0.1 µm) can levitate with a scale height of 10 km. IMPACT OF LUNAR DUST ON THE EXPLORATION INITIATIVE. T. J. Stubbs, R. R. Vondrak and W. M. Farrell, NASA Goddard Space Flight Center, 17 Observation of the Universe from the Greenbelt, MD 20771, USA, Lunar and Planetary Science XXXVI (2005) Moon - LNF INFN May 7, 2007 Weights Carbon Fiber 0.7 x 6 2.1 [kg] 4.2 4.7 8.4 3.1 5.0 27.5 Al 25.5 Steel, Al, Cu,.. 27.5 1.5 15.0 69.5 [kg] Observation of the Universe from the Moon - LNF INFN May 7, 2007 18 Technology Challenges Primary mirror building technology Landing! Control system for post-landing telescope alignment and focus Image stabilisation – Secondary mirror high frequency adaptation Unassisted Operation in hostile environment • Mechanic (dust, rigid interface with lunar surface) • Thermal (night-day 250°K ) • Radiation (unshielded Solar Wind and Cosmic Rays- electronic hazards). Observation of the Universe from the Moon - LNF INFN May 7, 2007 19 Summary High scientific output Possible use as terrestrial or astronomical telescope Lunar environment characterization for astronomical telescope Technologically stimulating Small, relatively simple instrument “affordable” budget Observation of the Universe from the Moon - LNF INFN May 7, 2007 20 Observation of the Universe from the Moon - LNF INFN May 7, 2007 21 However (some argue): The Apollo instrument complexes operated for years with little if any problem from dust. The laser retroreflectors left there are still reflective. The instrument complexes included a dust-detector experiment on Apollos 11, 12, 14, and 15 to measure possible accumulation from the lunar module liftoff. The accumulation proved much lower than expected. The Surveyor 3 TV camera, returned after 31 months on the Moon, showed some dust deposited by the module, but investigators concluded that natural dust transport was "relatively insignificant, if evident at all." The long survival of natural lunar albedo features, such as the 100-million-year-old Tycho ray system, bears out the same conclusion Observation of the Universe from the Paul Lowman Jr, (NASA GSFC), Nov 2006 Moon Physics - LNF INFN Today, May 7, 2007 22 Mass Evaluation Physical evaluation parameters for various candidate mirror materials. The best two values for each property are highlighted Design and optimization of silicon carbide(SiC) mirrors for the Canadian Large Optical Telescope (LOT) Joeleff Fitzsimmons, Scott Roberts National Research Council Canada, Herzberg Institute of Astrophysics Observation of the Universe from the Moon - LNF INFN May 7, 2007 23 To solve the problem of Coronal heating: • How the structure of the small-scale solar magnetic field changes when we progress from the photosphere through the chromosphere up to the corona • How is energy that gives rise to coronal heating channelled? • Is the field braided? Is energy transported via waves, and if so what kind of waves? Or is magnetic energy stored in the coronal field by continuous footpoint motions and released by reconnection? • Can we explain the vertical peristence of the magnetic network? Observation of the Universe from the Moon - LNF INFN May 7, 2007 24