NASA has proposed to make a hardware contribution to the European Space Agency’s (ESA’s) Euclid mission in exchange for U.S. membership on the Euclid Science Team and science data access.
The Euclid mission will employ a space telescope that will make potentially important contributions to probing dark energy and to the measurement of cosmological parameters. Euclid will image a large fraction of the extragalactic sky at unprecedented resolution and measure spectra for millions of galaxies.
This report responds to a request from NASA to evaluate whether a small investment in Euclid (around $20 million in hardware) is a viable part of an overall strategy to pursue the science goals of the New Worlds, New Horizons (NWNH) report’s top-ranked large-scale, space-based priority: the Wide-Field Infrared Survey Telescope (WFIRST). WFIRST has a broad, wide-field, near-infrared capability that will serve a wide variety of science programs of U.S. astronomers, including exoplanet research, near-infrared sky surveys, a guest observer program, and dark energy research. In carrying out this study the committee’s intent has been to be clear that this report does not alter NWNH’s plans for the implementation of the survey’s priorities.
The Committee on the Assessment of a Plan for U.S. Participation in Euclid concludes that the NASA proposal would represent a valuable first step toward meeting one of the science goals (furthering dark energy research) of WFIRST.
While WFIRST dark energy measurements are expected to be superior to Euclid’s, U.S. participation in Euclid will have clear scientific, technical, and programmatic benefits to the U.S. community as WFIRST and Euclid go forward.
NASA should make a hardware contribution of approximately $20 million1 to the Euclid mission to enable U.S. participation. This investment should be made in the context of a strong U.S. commitment to move forward with the full implementation of WFIRST in order to fully realize the decadal science priorities of the NWNH report.
In exchange for this small, but crucial contribution, NASA should secure through negotiation with the European Space Agency both a U.S. position on the Euclid Science Team with full data access and the inclusion of a team of U.S. scientists in the Euclid Consortium that would be selected by a peer-reviewed process with full data access as well as authorship rights consistent with Euclid policies still to be formulated.
NASA should seek independent community review of any financial commitment for hardware expenditures beyond $30 million for Euclid.
