What's Ahead for Astronomy in the Next Decade?

The universe is vast and interesting and full of things to discover. How do astronomers manage to study it all at once? Well, we can’t with limited time, human power and resources. So, astronomers get together every 10 years to assess the field as a whole and recommend what projects should be funded for the next decade. This “decadal review” was the first since I’ve been hanging out the field, so let me introduce what the next 10 years of U.S. astronomy will be like.

Hundreds of scientific proposals, “state of the profession,” and technology development papers were submitted by the community to a committee of distinguished astronomers from various parts of the field. The long-awaited findings were introduced via a webcast to 80 different institutions on Friday. A pre-publication copy of the 270-page report is available now from National Academies Press.
The committee highlighted three main areas of science, none of which should be too surprising to those who follow the field: Cosmic Dawn, New Worlds and the Physics of the Universe. Or, how did all of this get here, are there planets like Earth nearby, and what makes up the universe? Projects that are well suited to answer these questions, as well as technologically feasible, were given high recommendations.

The high-priority missions include a space telescope called WFIRST, or the Wide-Field InfraRed Survey Telescope. This mission would cover two of the key science goals, first by investigating the nature of dark energy, and second by detecting exoplanets.

On the ground, the Large Synoptic Survey Telescope got a lot of attention. This 8-meter survey telescope will contribute to a host of science objectives with its deep surveys, making the data available to anyone. The production and distribution of such surveys, such as the Sloan Digital Sky Survey, has signaled a new era in astronomy where spending long nights at the telescope has been replaced for many researchers by data-mining public archives.

Next on the priority list, the committee highly recommended a funding boost to the Explorer program, which is responsible for medium-sized and highly productive missions such as WMAP, which carefully measured various cosmological parameters, and WISE, which has surveyed the sky in infrared, detecting near-Earth asteroids and capturing stunning images of newborn stars. Such versatile instruments can target key science questions in a timely manner.

The committee likes the Explorer program so much, in fact, that it recommended creating a similar program for ground-based astronomy. They received so many good proposals for ground-based telescopes of this scale, and it is likely that several can be funded in the coming decade. Some really fantastic experiments were mentioned, such as HERA which would survey hydrogen from the very early universe, telling us a bit about how stars were formed, and NanoGRAV, which will monitor pulsars in order to detect gravitational waves.
Some other interesting projects were recommended at a lower level, often citing the need for more technological development and a desire for international partnership. These include LISA, a space-borne gravitational wave experiment, an X-ray telescope, a giant segmented mirror telescope (GSMT), and telescopes to detect high-energy cosmic rays that hit the Earth’s atmosphere. Sadly, it looks as though the X-ray sky may have a gap in exploration, with no new project firmly on the table.

Some other recommendations caught my attention. For example, there was a strong plea for better career mentoring of young astronomers. It was realized that there are more graduate students coming out with PhDs than there are tenure-track faculty positions, and that institutions should be preparing students for a diversity of careers in astronomy. However, without specific plans or recommendations, it is hard to see how this will come about in the coming years.

Also, the Square Kilometer Array, the next generation of meter and centimeter wave radio telescope, was mostly left out. Although room is left for pathfinder opportunities, the committee did not feel that it would be technologically ready in the next decade. It will be interesting to see how the international consortium working on the project responds to that.

Altogether, choices have to be made with limited resources, and the committee seemed confident that its recommendations were realistic, given budget expectations. And I think there will be exciting discoveries to come very soon.