Observation of the Universe from the Moon - LNF INFN May 7, 2007 1 High Resolution Solar Imaging...

Observation of the Universe from the MooObservation of the Universe from the Moon - LNF INFN May 7, 2007n - LNF INFN May 7, 2007

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High Resolution Solar High Resolution Solar Imaging from the Moon Imaging from the Moon

F. Berrilli - Tor Vergata University / INAFF. Berrilli - Tor Vergata University / INAF &

A. Bigazzi - CE Consulting Altran Group / INAFF.Manni - SRS Engineering Design SrlA. Egidi - Tor Vergata University / INAF

Contribution: V. Carbone (UNICAL) and S. Fineschi (INAF/TO)


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The Sun as active starThe Sun as active star


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Space weather refers to violent transfers of matter Space weather refers to violent transfers of matter and energy from the sun to the Earth.and energy from the sun to the Earth.

University of Colorado at Boulder

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


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A massive flare take place 1972 August 7th, between 1972 Apollo 16 (April) and Apollo 17 (December) human missions on the Moon.


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Solar surface magnetism consists of an amazing hierarchy of discrete strong-field 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.


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Magnetic fields and flows interaction on Magnetic fields and flows interaction on solar surfacesolar surface


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Science: Local and Global Science: Local and Global Helioseismology.Helioseismology.

• Subsurface flows and MF dynamics


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The Moon as a platform for Solar The Moon as a platform for Solar ObservationsObservations


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Attractive featuresAttractive 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


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Attractive features (cont’d)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.

• Extended (14 days), continuous observation capability.• monitoring evolution of long-living magnetic field complexes • global helioseismology

• 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.


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““The varying magnetic field of the Sun is directly The varying magnetic field of the Sun is directly responsible for changes in the responsible for changes in the solar ultraviolet solar ultraviolet and X-and X-ray emissionray emission, and is also closely related to the […] , and is also closely related to the […] possible forcing role in climatic variations.possible forcing role in climatic variations.

[…] The solar […] The solar magnetic field is continuously magnetic field is continuously generatedgenerated and destroyedand destroyed on timescales ranging from on timescales ranging from fractions of a second to decades.fractions of a second to decades.

These topics will remain major scientific challenges in These topics will remain major scientific challenges in the Cosmic Vision 2015-2025 timeframethe Cosmic Vision 2015-2025 timeframe.”.”

ESA “Cosmic Vision” 2015-2025

Cosmic Vision: Space Science for Europe 2015-2025 – Executive Summary – May 2006


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The solar output, and associated The solar output, and associated fluctuations due to the solar activity, fluctuations due to the solar activity, is the indispensable mechanism that is the indispensable mechanism that sustains life on the Earth and sustains life on the Earth and generates the complex dynamics of generates the complex dynamics of the Heliosphere. For these reasons the Heliosphere. For these reasons a task of primary interest for a task of primary interest for Science and for astrophysics is to Science and for astrophysics is to understand our star: the Sun. understand our star: the Sun.

INAF/Piano Lungo Termine 2007-2017

The paragraphs is derived from the The paragraphs is derived from the scientific road map for the next 10 scientific road map for the next 10 years of Italian solar physics presented by the National Institute for years of Italian solar physics presented by the National Institute for Astrophysics-INAF.Astrophysics-INAF.


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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

Telescope DesignTelescope Design


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SiC Foam Technology (INAF/OAB – Off. Galileo)SiC Foam Technology (INAF/OAB – Off. Galileo)

Courtesy O.Citterio, OAB, Brera Observatory

• 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)

Foamed primary mirror substrate in SiC ( 310 mm dia.)

•31cm mirror •15 Kg/m2 •19 nm rms error

New process: foam generation, skin deposition, cladding.


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1. The average dust grain size is about 70 µm, with a percentage of 10-20% 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.

IMPACT OF LUNAR DUST ON THE EXPLORATION INITIATIVE. T. J. Stubbs, R. R. Vondrak and W. M. Farrell, NASA Goddard Space Flight Center,Greenbelt, MD 20771, USA, Lunar and Planetary Science XXXVI (2005)

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.

Environmental challenges: dustEnvironmental challenges: dust


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2.1 [kg]

4.7

3.18.4

0.7 x 6

25.5

4.2

27.5

5.0

15.0

27.5

69.5 [kg]

Carbon Fiber

Steel, Al, Cu,..

Al

1.5

WeightsWeights


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Technology ChallengesTechnology Challenges Primary mirror building technology Primary mirror building technology Landing!Landing! Control system for post-landing telescope Control system for post-landing telescope

alignment and focusalignment and focus Image stabilisation – Secondary mirror high Image stabilisation – Secondary mirror high

frequency adaptationfrequency adaptation Unassisted Operation in hostile environment Unassisted Operation in hostile environment

• Mechanic (dust, Mechanic (dust, rigid interface with lunar rigid interface with lunar surfacesurface) )

• Thermal (night-day 250°K ) Thermal (night-day 250°K ) • Radiation (unshielded Solar Wind and Cosmic Radiation (unshielded Solar Wind and Cosmic

Rays- electronic hazards).Rays- electronic hazards).


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SummarySummary High scientific outputHigh scientific output Possible use as terrestrial or astronomical Possible use as terrestrial or astronomical

telescopetelescope Lunar environment characterization for Lunar environment characterization for

astronomical telescopeastronomical telescope Technologically stimulatingTechnologically stimulating Small, relatively simple instrument Small, relatively simple instrument

“affordable” budget“affordable” budget


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However (some argue):However (some argue):

The long survival of natural lunar albedo features, such as the 100-million-year-old Tycho ray system, bears out the same conclusion

Paul Lowman Jr, (NASA GSFC), Physics Today, Nov 2006

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 Apollo instrument complexes operated for years with little if any problem from dust.

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."


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Design and optimization of silicon carbide(SiC) mirrors for the Canadian Large Optical Telescope (LOT)

Joeleff Fitzsimmons, Scott RobertsNational Research Council Canada, Herzberg Institute of Astrophysics

Physical evaluation parameters for various candidate mirror materials. The best two values for each property are highlighted

Mass EvaluationMass Evaluation


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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 1 High Resolution Solar Imaging...

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