A 2008 Astronet road map called for the Extremely Large Telescope. Some astronomers are upset by the group’s latest effort.

ESO

For more than 1 year, Astronet, a group of more than 50 astronomers, has labored to draw up priorities for the next 2 decades of European astronomy. A partial draft plan, released in February, lists the field’s most pressing scientific questions, such as how primordial gases coalesced into the first stars and galaxies and whether the atmospheres of exoplanets betray signs of life. To answer them, the plan calls for new facilities including the Einstein Telescope, a gravitational wave detector to be built in a network of underground tunnels; antennas installed on the radio-quiet far side of the Moon; and a fleet of orbiting telescopes to probe exoplanet atmospheres.

But some are unhappy with what the draft plan left out—particularly in radio and gamma ray astronomy, as well as the study of high-energy particles from space. “Something went wrong,” says Leonid Gurvits, a radio astronomer at the Delft University of Technology. “It’s not anyone’s intention, it just happened in this unfortunate way.” Astronet organizers say the drafts were not intended to be exhaustive and later revisions will reflect the roughly 200 comments received before a 1 May deadline.  

 Astronet mirrors the U.S. decadal survey of astrophysics, which since the 1960s has provided funding agencies and legislators with infrastructure priorities—essentially a wish list of big telescopes and space missions. The current iteration in the United States, known as Astro2020, is expected to release its report in the coming months. It was put together by more than 150 committee and panel members with input from hundreds of submitted white papers as well as dozens of virtual meetings and town halls.

In its first incarnation, Astronet aimed for something similarly comprehensive, producing a science vision in 2007 and the following year, a road map of facilities and missions. It endorsed efforts now under construction including the Extremely Large Telescope, the Square Kilometre Array, and several space missions.

Astronet was set up under the auspices of the European Union in 2005 with a 4-year budget of €2.5 million. After updating its vision and road map in 2015, the European Union cut off funding. But the group continued with support of a few tens of thousands of euros per year from funding bodies in eight nations plus the European Southern Observatory (ESO). The Astronet board, made up of funding agency representatives, decided this time to produce “something more precise, direct, and to the point,” says board chair Colin Vincent of the United Kingdom’s Science and Technology Facilities Council. The new report, he says, aimed to answer, “What are the science questions, where are we now, and what do we need to progress over the next 20 years?”

Astronet formed panels of as many as 12 researchers in each of five fields, ranging from the origin and evolution of the universe to understanding the Solar System and conditions for life. It also formed a panel covering computing and another for outreach, education, and diversity. COVID-19 thwarted plans to gather input at town hall meetings. The panels did not solicit white papers but instead drafted reports from their own experience. Drafts reports from the five subject panels were posted on the Astronet website for comments; the computing and workforce reports are still being drafted. The plan was to “throw them out there and see what the community makes of them,” Vincent says. After the comment period closed, Astronet planned virtual town halls and revisions before final release before the end of the year.

Not everyone was impressed by this approach. Although Astronet tried to get the word out to astronomers across Europe, some complained they only heard about the draft reports 1 month or less before the deadline for comments. “It came totally out of the blue. Most people didn’t know about it,” says radio astronomer Heino Falcke of Radboud University. “Everyone’s screaming: ‘What’s going on?’” Gurvits says. RadioNet, a network representing radio astronomy, requested an extension to the comments deadline but was declined.

Others have complained about what they see as glaring omissions in the draft reports. According to Andreas Haungs of the Karlsruhe Institute of Technology, who heads the Astroparticle Physics European Consortium, the drafts don’t sufficiently credit the work done by astronomers using high-energy gamma rays, neutrinos, or gravitational waves. “I don’t think it really worked,” he says. Falcke says the report contains “not a single word” on the Event Horizon Telescope, which in 2019 produced the first image of a black hole’s shadow. “This is almost an embarrassment,” he says.

Gerry Gilmore of the University of Cambridge’s Institute of Astronomy, head of the OPTICON network of optical and infrared astronomers, counters that the Astronet reports are “discussion documents, the start of a conversation.” Vincent also defends the process. “The important thing was to get people to respond. That’s the point of the consultation,” he says, acknowledging that the drafts may have appeared parochial to some. He says the subject panels are revising their drafts, and in June, the European Astronomical Society will hold an open meeting to discuss those revisions, with further iterations continuing over the summer.

Astronet has a difficult task. Europe already has the European Space Agency (ESA), which launches many space telescopes, and the ESO, which manages a group of top optical telescopes in Chile. With independent budgets, funded directly by national governments, those agencies autonomously work out their own long-term strategies. Linda Tacconi of the Max Planck Institute for Extraterrestrial Physics, who is leading Voyage 2050, ESA’s latest science planning process, says it has been slowed by COVID-19. “Therefore, Voyage 2050 could not be included in the Astronet report,” she says. 

That leaves Astronet to bring some order to the disconnected groups of astronomers who aren’t covered by those two agencies. Dealing with so many national funders isn’t easy either, Vincent says. “A prescriptive approach wouldn’t be as successful,” he says. “We need a common understanding on what is needed and [national agencies] can make a variety of responses on what to bring to the party.”