The Beagle 2 microscope provides optical images of the Martian surface at a resolution 5x higher than any other experiment currently planned. By using a novel illumination system it images in three colors and can also detect fluorescent materials

Beauvivre, S.

Blümchen, T.

Hofmann, B.

Hviid, S. F.

Josset, J.-L.

Keller, H. U.

Lüthi, B. S.

Markiewicz, W. J.

Oquest, C.

Pillinger, Colin

Reynolds, R.

Rüffer, P.

Smith, P. H.

Tanner, R.

Thomas, N.

English

Open Research Online (The Open University)

Open Research OnlineThe Open University’s repository of research publicationsand other research outputsThe Beagle 2 microscopeConference or Workshop ItemHow to cite:Lu¨thi, B. S.; Thomas, N.; Hviid, S. F.; Keller, H. U.; Markiewicz, W. J.; Blu¨mchen, T.; Smith, P. H.; Tanner, R.;Oquest, C.; Reynolds, R.; Josset, J.-L.; Beauvivre, S.; Hofmann, B.; Ru¨ffer, P. and Pillinger, Colin (2004). The Beagle2 microscope. In: 35th Lunar and Planetary Science Conference, 15-19 Mar 2004, Houston, Texas, USA.For guidance on citations see FAQs.c© [not recorded]Version: [not recorded]Link(s) to article on publisher’s website:http://www.lpi.usra.edu/meetings/lpsc2004/pdf/1238.pdfCopyright and Moral Rights for the articles on this site are retained by the individual authors and/or other copyrightowners. For more information on Open Research Online’s data policy on reuse of materials please consult the policiespage.oro.open.ac.ukTHE BEAGLE 2 MICROSCOPE. B. S. Lüthi, N. Thomas, Physikalisches Institut, University of Bern, Sidlerstr. 5, 3012 Bern,Switzerland, (luethi@phim.unibe.ch), S. F. Hviid, H. U. Keller, W. J. Markiewicz, T. Blümchen, Max-Planck-Institut für Aeronomie,Katlenburg-Lindau, Germany, P. H. Smith, R. Tanner, C. Oquest, R. Reynolds, Lunar and Planetary Laboratory, University ofArizona, Tucson, Arizona, U.S.A., J.-L. Josset, S. Beauvivre, SPACE-X, Neuchâtel, Switzerland, B. Hofmann, Natural HistoryMuseum of Bern, Switzerland, P. Rüffer, Institut für Datentechnik und Kommunikationsnetze, TU Braunschweig, Braunschweig,Germany, C. T. Pillinger, Dept. of Earth and Planetary Sciences, Open University, Milton Keynes, U.K.Introduction: The microscope for the Beagle 2 lander,which was launched as part of the European Space Agency’sMars Express mission on 2 June 2003, is able to provide imagesof the Martian surface at around 6 microns resolution. Itprovides optical images of the surface of Mars at a resolution5 times higher than any other experiment currently planned.The device has a working distance of 12 mm and uses a set of12 light-emitting diodes which surround the optical apertureto illuminate the sample in 4 colors. The target is brought intofocus using a translation stage.We describe the scientific objectives and present measure-ments of terrestrial samples for illustration. We also give abrief summary of the design of the microscope. For a detaileddescription of the instrument and initial results from groundcalibration exercises which were designed to validate the sys-tem see [1].Figure 1: The Beagle 2 microscope with light-emitting diodessurrounding the optics aperture (in the front) and detector andread-out electronics (behind).Scientific Objectives: A microscope has four distinctlydifferent tasks in a lander package. It can be used to...1. ...study the physical and structural properties of rockand soil surfaces and hence make a good geophysicalanalysis and contribute to the overall geological andmineralogical interpretation of the landing site.Figure 2 shows two images of samples of radicallydifferent origin. The left image is a layered limestone(cave sediment) from Piz Alv in Switzerland. The fine-grained crystalline appearance and the layering are bothstrongly evident at this resolution. On the other hand,Figure 2: Microscope images from a layered limestone (left)and a basaltic volcanic rock (right).the basaltic volcanic rock (from the Cady Mountains,Mojave, California) in the right image is not stratifiedand highly irregular. These examples show, that themicroscope can provide a preliminary assessment ofthe origin of observed material.2. ...assist studies of the atmosphere of Mars. Specifi-cally, dust particles are continuously precipitating outof the dusty atmosphere and hence a microscope can beused to constrain the sizes and shapes of particles forinput into atmospheric scattering and radiative transfermodels of Martian atmosphere.The microscope resolution is high enough to resolveindividual dust particles from the higher end of the sizedistribution. In Figure 3 we show an image of theMartian regolith simulant JSC Mars-1 [2]. Informationabout the morphology of dust particles can be extracted,which in turn can give indications to the soil formingprocesses active on the surface of Mars.Figure 3: Microscope image of the Martian regolith simu-lant JSC Mars-1 (left) and its reconstructed elevation model(right).Lunar and Planetary Science XXXV (2004) 1238.pdf3. ...investigate the morphology of a potentially biologi-cal sample and hence identify structures which may becharacteristic of past or present biological activity.The UV illumination can be used to look for the pres-ence of fluorescent rocks (Figure 4), which are indica-tive (but not proof) of rocks with a biological origin. Toeliminate reflected UV from the incoming beam a filterhas been introduced into the optics.Figure 4: Image of a fluorescent rock illuminated with the UVLEDs of the microscope.On Earth living organisms create many characteristicshapes in the 10 - 1000 micron range. If such corre-sponding shapes exist at the landing site, they will beresolved by the microscope.4. ...characterize and/ or select a sample before it is passedto another analytical instrument. It is used therefore toassist the chemical analysis.Instrument Design: The microscope consists of severalnatural elements (see Figure 1): the optics with the surroundingillumination system, the micro-camera element and (to join thetwo elements) a light-tight tube providing a strong mechanicalinterface and baffling. The translation stage for microscopefocussing forms a fourth work package. The properties ofthese elements are summarized in Table 1.Table 1: Design properties of the Beagle 2 microscope.Optics magnification: 3.5:1lens design: Cook tripletfocal length: 15.75 mmdepth of focus: 40 micronfilter: 400 nm (rejects UV)Illumination 12 LEDs: 3 red, 3 green, 3 blue,System 3 UV (fluorescence)Micro- Detector: 1024× 1024 frameCamera transfer CCDpixel pitch: 14 microntypical QE: 15% at 640 nmADC resolution: 10 bitprovided by: SPACE-X, SwitzerlandInterface material: carbon-fibreTube baffle: reduces straylight2 microfilters: for system-ventingTranslation fine focus: using a stepper motorStage step size: 0.1 micronComplete pixel resolution: 4 micronSystem dimensions: ∼ 111× 52× 22 mm3mass: ∼ 245 gpower: 1.5 W (average)Summary: The microscope for Beagle 2 provides opticalimages of the surface of Mars at a resolution 5 times higher thanany other experiment currently planned. The device achievesthis in three colors by using a novel illumination system. Inaddition, the system will be able to excite and detect fluorescentmaterials.There are several distinctively different science objectivesand the instrument can provide a wealth of interesting results.In a forthcoming paper [3], images of rock and soil sam-ples acquired with the microscope will be compared to imagesacquired with a standard laboratory microscope at similar spa-tial resolution.References: [1] N. Thomas et al. (2003) Planet. SpaceSci., submitted. [2] C. C. Allen et al. (1998) Lunar & Planet.Sci. Conf. XXIX. [3] A. T. Basilevsky et al. (2003) Planet.Space Sci., submitted.Lunar and Planetary Science XXXV (2004) 1238.pdf

The Beagle 2 microscope

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The Beagle 2 microscope

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