NASA should conduct a large, direct imaging mission to study Earth-like exoplanets, according to a new report

To answer important questions about planetary systems, such as the scarcity of our solar system or the existence of planets other than Earth, NASA should conduct a vast mission of direct imaging – an advanced space telescope – able to study exoplanets The stars look like the sun, says a new report mandated by the Congress by the National Academies of Science, Engineering and Medicine.

The study of exoplanets – planets outside our solar system that revolve around a star – has seen remarkable discoveries over the past decade. The report identifies two overriding objectives in this scientific area:

• Understand the formation and evolution of planetary systems as products of star formation and characterize the diversity of their architectures, compositions and environments.
• Learn enough about exoplanets to identify potentially habitable environments and search for scientific evidence of life on worlds revolving around other stars.

On the basis of these objectives, the report's committee found that our current knowledge of the range of planetary characteristics outside the solar system is largely incomplete. A holistic approach to studying habitability in exoplanets, using both theory and observations, will ultimately be needed to look for evidence of past and present life elsewhere in the universe.

Although the committee recognized that the development of a direct imaging capability would require significant financial investments and a long period of time to achieve results, the effort will foster the development of the scientific community and the technological capacity to develop. understand a multitude of areas. To detect a system analogous to our Earth-Sun system, the report recommends using instruments that allow direct imaging of an exoplanet by blocking the light emitted by parent stars, such as a coronagraph or star.

In addition, according to the report, ground-based astronomy, made possible by two United States-led telescopes, will play a central role in studying the formation of planets and potentially terrestrial worlds. The future giant Magellan telescope (GMT) and the proposed Thirty Meter telescope (TMT) would allow significant advances in imaging and spectroscopy – absorption and light emission – of entire planetary systems. According to the report, they could also detect molecular oxygen in temperate terrestrial planets in transit around small stars.

The commission stressed that the technology roadmap to enable the full potential of TMGs and TMTs in the study of exoplanets requires investment and should take advantage of the existing network of US centers and laboratories. To this end, the report recommends that the National Science Foundation invest in both telescopes and their exoplanet instrumentation to allow unrestricted access to the American community.

While missions such as Kepler's spacecraft have characterized a remarkable population of planets relatively close to their stars, our knowledge of the worlds in the far reaches of the universe is sorely lacking. The report states that WFIRST, the major space mission that received the highest priority in the 2010 Academies Decennial Survey, will play two extremely valuable roles: first, it will allow a study of planets further away from their missionary stars. Second, this will allow a large direct imaging mission.

Although the radial velocity method – which measures the shift of the star in orbit around the center of gravity of the planetary system – continues to provide essential information about mass and orbit, its measurements are currently limited by variations calibration of instruments, indicates the report. New instruments installed on large telescopes, large allocations of observation time and collaboration between observers and theoreticians are some of the prerequisites for progress. To develop these methods and facilities to measure the masses of terrestrial planets in orbiting sun-like stars, NASA and the NSF should put in place a strategic initiative in extremely precise radial velocities.

In addition, NASA should create a mechanism to systematically collect data on exoplanet atmospheres at the beginning of the James Webb Space Telescope mission. The committee also recommended relying on the NASA-Nexus Interdisciplinary Collaborative Initiative for the Exoplanet Science System – supporting an interdivisional research effort that invites interdisciplinary research proposals.

The committee called on NASA to support a robust individual investigator program including grants for theoretical, laboratory and ground telescopic surveys to fully realize the scientific benefits of exoplanet missions. The report also recognizes that discrimination and harassment exist in the scientific workforce and can affect the exoplanet research community, which hampers the participation of people belonging to certain demographic groups. To maximize scientific potential and opportunities for excellence, institutions and organizations should take concrete action to eliminate discrimination and harassment and proactively recruit and retain scientists from under-represented groups.

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