7 research outputs found
Planetary protection: an international concern and responsibility
Planetary protection is a set of measures agreed upon at an international level to ensure the protection of scientific investigation during space exploration. As space becomes more accessible with traditional and new actors launching complex and innovative projects that involve robotics (including sample return) and human exploration, we have the responsibility to protect the pristine environments that we explore and our own biosphere. In this sense, the Committee on Space Research (COSPAR) provides the international standard for planetary protection as well as a forum for international consultation. COSPAR has formulated a Planetary Protection Policy with associated requirements for responsible space exploration. Although not legally binding under international law, the standard offered by the Policy with its associated requirements is internationally endorsed along with implementation guidelines supplied for reference in support States’ compliance with Article IX of the United Nations Outer Space Treaty of 1967. Indeed, States parties to the Outer Space Treaty (under Article VI) are responsible for any space activities in their countries, governmental and non-governmental. The main goal of this Policy is to avoid compromising the search for any lifeforms on other celestial bodies and to protect the Earth from a potential threat posed by extraterrestrial samples returned by an interplanetary mission. The COSPAR Planetary Protection Policy has defined five categories, depending on the target and objective of the specific space mission. Associated to these categories are requirements are various degrees of rigor in the contamination control applied. The Policy is assessed regularly and updated with input from new scientific findings and in conjunction with the fast-evolving space exploration milieu. The COSPAR Panel on Planetary Protection (PPP) is a designated international committee composed of scientists, agency representatives and space experts. Its role is to support and revise the COSPAR Policy and its related requirements (https://cosparhq.cnes.fr/scientific-structure/panels/panel-on-planetary-protection-ppp/). The Panel’s activities deal with the individual needs of a space mission while exercising swift care and expertise to ensure sustainable exploration of the Solar System
Origin of rutile-bearing ilmenite Fe-Ti deposits in Proterozoic anorthosite massifs of the Grenville Province
The Saint-Urbain and Big Island rutile-bearing ilmenite Fe-Ti oxide deposits are located
in the composite 450 km² Saint-Urbain anorthosite (1055-1046 Ma, U-Pb zircon) and in
the Lac Allard intrusion (1057-1062 Ma, U-Pb zircon) of the 11,000 km² Havre-Saint
Pierre anorthosite suite, respectively, in the Grenville Province of Eastern Canada. Slow
cooling rates of 3-4°C/m.y. are estimated for both anorthosites, based on combined U-Pb
zircon/rutile/apatite and ⁴⁰Ar/³⁹ Ar biotite/plagioclase geochronology, and resulted from
emplacement during the active Ottawan Orogeny. Slow cooling facilitated (1) diffusion
of Zr from ilmenite and rutile, producing thin (10-100 microns) zircon rims on these
minerals, and (2) formation of sapphirine via sub-so lidus reactions of the type: spinel +
orthopyroxene + rutile ± corundum → sapphirine + ilmenite. New chemical and
analytical methods were developed to determine the trace element concentrations and Hf
isotopic compositions of Ti-based oxides. Rutile is a magmatic phase in the deposits
with minimum crystallization temperatures of 781°C to 1016°C, calculated by Zr-in
rutile thermometry. Ilmenite present in rutile-free samples has higher Xhem (hematite
proportion in ilmenite), higher high field strength element concentrations (Xhem = 30-17;
Nb = 16.1-30.5 ppm; Ta 1.28-1.70 ppm), and crystallized at higher temperatures than
ilmenite with more fractionated compositions (Xhem = 21-11; Nb = 1.36-3.11 ppm; Ta =
<0.18 ppm) from rutile-bearing rocks. The oxide deposits formed by density segregation
and accumulation at the bottom of magma reservoirs, in conditions closed to oxygen,
from magmas enriched in Fe and Ti. The initial ¹⁷⁶Hf/¹⁷⁷ Hf of rutile and ilmenite (Saint
Urbain [SU] = 0.28219-0.28227, Big Island [BI] = 0.28218-0.28222), and the initial Pb
isotopic ratios (e.g.²⁰⁶Pb/²⁰⁴ Pb: SU = 17.134-17.164, BI = 17.012-17.036) and ⁸⁷Sr/⁸⁶ Sr
(SU = 0.70399-0.70532, BI = 0.70412-0.70427) of plagioclase from the deposits overlap
with the initial isotopic ratios of ilmenite and plagioclase from each host anorthosite,
which indicates that they have common parent magmas and sources. The parent magmas
were derived from a relatively depleted mantle reservoir that appears to be the primary
source of all Grenvillian anorthosite massifs and existed for --600 m.y. along the margin
of Laurentia during the Proterozoic.Science, Faculty ofEarth, Ocean and Atmospheric Sciences, Department ofGraduat
Mineralogical and lithological unmixing with radiative transfer modelling in the open-pit context of Mine Canadian Malartic
International audienceIn this study, Hapke's radiative transfer model is used to verify the feasibility of retrieving the composition and grain-size of the ground in an open-pit mine, seen as a regolith. Such a tool could be useful for dust surveys and thus preventing potential environmental risks such as acid mine drainage. As the true compositional endmembers of the medium are not retrieved but rather chosen from spectral libraries and the range of grain sizes (a few to hundreds of micrometers) and porosities (0.22 to 0.52 for the filling factor) vary greatly in an open-pit mine, we show that the mineralogical unmixing results are not reliable. Too many combinations of different relative abundances, grain sizes and porosities lead to fits between modelled and measured spectra under 0.3% in reflectance. To tackle this issue, we explore a lithological unmixing approach. Considering lithologies as endmembers, as opposed to considering minerals, reduces the variability in the solutions as fewer endmembers are used. The results show that the studied samples with multi-component grains behave spectrally as expected for mono-mineral grains. With no root mean square errors higher than 5%, the relative abundances retrieved are sufficiently precise to consider mapping lithologies with this method
Planetary protection: Updates and challenges for a sustainable space exploration
Planetary protection enables scientific return from solar system bodies investigations and at the same time protects life on Earth. As we continue to explore our solar system by landing machines and humans on other planets, we need to ascertain that we do not bring potentially dangerous material home to Earth or carry anything from Earth that may contaminate another planetary body and prevent scientific investigations.
A Planetary Protection Policy has been developed by the Committee on Space Research (COSPAR), which provides a forum for international consultation in the area of space research. The COSPAR Planetary Protection Policy, and its associated requirements, is not legally binding under international law but is an agreed standard with implementation guidelines for compliance with Article IX of the Outer Space Treaty. States Parties to the Outer Space Treaty are responsible for national space activities under Article VI, including the activities of governmental and non-governmental entities.
The current members of the COSPAR Panel on Planetary Protection are representatives from national space agencies and thematic experts from the science community of different countries (https://cosparhq.cnes.fr/scientific-structure/ppp). Other stakeholders, including the private sector, are invited to attend and present at the PPP meetings.
The COSPAR PPP maintains and updates the COSPAR Planetary Protection Policy regularly, always reviewing all available scientific knowledge leading to updates to the policy, in particular as concerns the outer solar system and lunar exploration. Such updates are performed in a careful and balanced way to ensure that the right measures are envisaged to fulfil the rationales for planetary protection
A New Era For Planetary Protection: The Probabilistic Approach
The primary aims of planetary protection are to ensure that: 1) scientific
investigations of possible extra-terrestrial life forms, precursors, and remnants are
not jeopardised during planetary space missions; 2) Earth is protected from the potential hazard posed by extra-terrestrial matter carried by spacecraft returning
from an interplanetary mission. The concept of planetary protection has received
increased attention over recent years due to the emergence of new spacefaring
countries and the growing involvement of commercial actors. The international
standards for planetary protection have been developed through consultation with
the scientific community and the space agencies by the Committee on Space
Research's Panel on Planetary Protection, which provides guidance for compliance
with the Outer Space Treaty of 1967. To date, there are five categories of
requirements, which are defined based on the mission's target, type, and scientific
rationale. The categories outline the recommended measures to be applied to a
mission.
As the mission target increases in relevance to habitability and/or the origins of
life, the stringency in hardware cleanliness requirements increases. Initial
guidelines were guided by a probabilistic approach. This approach uses
mathematical models to calculate the probability of the initial microbial
contamination from a spacecraft contaminating a target body. Post-Viking,
bioburden limits/ spore counts were introduced to the policy for target bodies like
Mars, as it was concluded that Mars was less hospitable than initially believed. Yet,
the probabilistic approach is still applied to Category III and IV (e.g., Europa
Clipper) and Category V (e.g., Mars sample return) missions. This approach could
benefit more complex missions where there is a need for a more advanced
approach to planetary protection. For this to be reliable, further scientific
knowledge is required, e.g., our understanding of cleanroom contaminants and the
biocidal impact of the mission environment, and the mathematical models need to
be constrained. Ongoing research by space agencies and the scientific community
is working towards addressing these knowledge gaps. The COSPAR Panel on
Planetary Protection will continue to review this approach as a plausible alternative
to bioburden limits to enable the next generation of missions