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For the first time in history, humans have reached the point where it is possible to construct a revolutionary space-based observatory that has the capability to find dozens of Earth-like worlds, and possibly some with signs of life. This same telescope, designed as a long-lived facility, would also produce transformational scientific advances in every area of astronomy and astrophysics from black hole physics to galaxy formation, from star and planet formation to the origins of the Solar System. The Association of Universities for Research in Astronomy (AURA) commissioned a study on a next-generation UVOIR space observatory with the highest possible scientific impact in the era following JWST. This community-based study focuses on the future space-based options for UV and optical astronomy that significantly advance our understanding of the origin and evolution of the cosmos and the life within it. The committee concludes that a space telescope equipped with a 12-meter class primary mirror can find and characterize dozens of Earth-like planets and make fundamental advances across nearly all fields of astrophysics. The concept is called the High Definition Space Telescope (HDST). The telescope would be located at the Sun-Earth L2 point and would cover a spectral range that, at a minimum, runs from 0.1 to 2 microns. Unlike JWST, HDST will not need to operate at cryogenic temperatures. HDST can be made to be serviceable on orbit but does not require servicing to complete its primary scientific objectives. We present the scientific and technical requirements for HDST and show that it could allow us to determine whether or not life is common outside the Solar System. We do not propose a specific design for such a telescope, but show that designing, building and funding such a facility is feasible beginning in the next decade - if the necessary strategic investments in technology begin now.
The global climate crisis poses new risks to humanity, and with them, new challenges to the practices of professional astronomy. Avoiding the more catastrophic consequences of global warming by more than 1.5 degrees requires an immediate reduction of
For astronomers to make a significant contribution to the reduction of climate change-inducing greenhouse gas emissions, we first must quantify our sources of emissions and review the most effective approaches for reducing them. Here we estimate that
Laboratory astrophysics and complementary theoretical calculations are the foundations of astronomy and astrophysics and will remain so into the foreseeable future. The impact of laboratory astrophysics ranges from the scientific conception stage for
An updated Science Vision for the SOFIA project is presented, including an overview of the characteristics and capabilities of the observatory and first generation instruments. A primary focus is placed on four science themes: The Formation of Stars
Recent studies of the effects on the Earths atmosphere by astrophysical sources, such as nearby gamma-ray bursts or supernovae, have shown that these events could lead to severe changes in atmospheric composition. Depletion of ozone, the most notable