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Written by: Daniel Apai, University of Arizona and Jeremy Dietrich, University of Arizona

Published: 14 November 2020

 

Only 12 light years from Earth, Tau Ceti is the closest single star similar to the Sun and an all-time favorite in sci-fi stories. Habitable worlds orbiting Tau Ceti were destinations of fictional starships like “The Expanse”‘s Nauvoo and “Barbarella”’s vessel. “Star Trek”’s Captain Picard also frequented an exotic bar in the system. Now, thanks to a new approach to analyzing nearby planetary systems, we have a deeper understanding of the actual worlds that orbit Tau Ceti and many other nearby stars.

Exoplanets – worlds around other stars – have long been staples of science fiction but remained mostly inaccessible to scientific investigations. This all changed over the past decade, when NASA’s Kepler and TESS exoplanet hunter space telescopes added thousands of new planets to the previously short tally of alien worlds.

We, astrophysicists and exoplanet researchers at the University of Arizona’s Steward Observatory and Lunar and Planetary Laboratory, and members of NASA’s NExSS exoplanet research coordination network, have long been fascinated by the secrets nearby unexplored planetary systems may hold.

We have now developed a novel way to figure out whether there are yet-undiscovered planets in these systems. We realized that by combining what is known about a given planetary system with simple statistical rules, we can predict where yet-undetected planets may reside and how large they may be – just like guessing what pieces are missing from a partially completed puzzle. The new analysis can guide discoveries of new planets, help complete maps of planetary systems in the solar neighborhood and inform future searches for life.

Building up systems with Dynamite

Our model, nicknamed Dynamite, combines four ingredients to predict hidden worlds. First, Dynamite considers the locations and sizes of all currently known planets in a given system. In general, the more planets that are known in the system, the easier it is to predict whether any are missing. The second consideration is knowing that planets are more likely to be closer to the star than farther out. Dynamite uses a mathematical description – built up through statistical studies of thousands of known exoplanets – of how far from their host star planets are likely to be.

Although planets are likely to be closer to their host stars, they cannot all be jammed together. Planets all attract each other via gravity, which is much stronger when the planets are closer. Thus, planets that are too close will distort each others orbits, often leading to chaotic interactions and even the ejection of one of the planets from their birth systems. This criterion for stability is the third important element that Dynamite uses to predict the architecture of the planetary system.

The fourth component is a mathematical pattern in the lengths of the orbits of adjacent planets (some configurations are more likely than others). Put together, Dynamite tries to build model planetary systems that are similar to actual planetary systems, with a compact and stable collection of planets orbiting their host stars.

We were not sure whether such a relatively simple recipe could be used to successfully predict missing planets. To test Dynamite, we gave it some known multi-planet systems with a twist: In each system we hid one or two of the known planets from the algorithm. In the cases tested, Dynamite successfully predicted whether one or two planets are missing and where those planets could be, and could even guess their sizes correctly.

Today, Dynamite can be tested only on systems with planetary orbits similar to that of Earth’s or smaller. That’s because we lack data on outer planetary systems, so we cannot yet detect far-flung planets – the equivalent of Neptune. More data will allow Dynamite’s four rules of building a planetary system to be refined and its predictions improved. Still, our predictions for over 50 partially explored planetary systems, discovered by NASA’s TESS space telescope, are already guiding the search for hidden worlds.

Searching for life in nearby systems

The most exciting planets to predict and hunt for will be the closest ones to us – the worlds we will likely target in future searches for signatures of extraterrestrial life.

In our newest study, we applied Dynamite to the partially explored Tau Ceti system, where four planets are already known. Weak signals indicating the potential presence of several other planet candidates have also been reported, but their presence hasn’t been verified.

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Based on our model, we predict that three of the planet candidates are real planets. What’s more, we predict that another, yet unseen world exists. This new planet, which we call Tau Ceti PxP-4, is particularly exciting as it is within the temperate zone of Tau Ceti – the region around the star where a planet similar to Earth would be habitable. Our analysis shows that PxP-4 may be a gaseous planet, akin to our Neptune, but smaller and warmer. We find, however, that PxP-4 is more likely to be a rocky planet, although larger than Earth.

Such a world may be detectable in the coming years with the newest planet-hunting instruments and, if confirmed, would be a prime target for future searches for life. And, perhaps – one day in the distant future – Tau Ceti’s PxP-4 may even be home to an exotic bar popular among Starfleet officers.

Daniel Apai, Associate Professor of Astronomy and Planetary Sciences, University of Arizona and Jeremy Dietrich, Graduate Student in Astronomy, University of Arizona

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Written by: Elizabeth Larson

Published: 13 November 2020

LAKE COUNTY, Calif. – After years of work and collaboration by local agencies and organizations, Lake County’s first permanent housing facility dedicated to addressing homelessness officially opened on Thursday.

Hope Center, a project of Hope Rising Lake County in partnership with numerous local agencies and the city of Clearlake, is located at 3400 Emerson St. in Clearlake.

It was celebrated during a small, socially-distanced ceremony on Thursday afternoon, witnessed by local officials, partners and the center’s eight new employees.

The building, which formerly housed medical offices, was purchased by Adventist Health. It’s now been remodeled into a 20-bed transitional housing facility, with a kitchen, conference and meeting rooms, and other amenities.

The project has been the work of years by a number of dedicated partners, but earlier this year it looked like it had stalled, as construction halted and grant funding “vaporized,” according to Hope Rising Executive Director Allison Panella.

But big ideas have a way of overcoming even the greatest of obstacles.

Shelly Trumbo, Adventist Health’s vice president of community integration who was Hope Rising’s interim executive director at its founding, suggested that central to the Hope Center is a “love ethic,” and quoting the definition of love in 1 Corinthians Chapter 13, Trumbo added, “Love never gives up.”

In January, Panella and Shannon Kimbell-Auth, Adventist Health’s manager for community integration who will now head up the staff at Hope Center, went to the Clearlake City Council to request financial assistance to get the center’s doors opened.

The council was open to the proposal and followed up in April by approving a memorandum of understanding with Adventist Health Clear Lake and Hope Rising Lake County in which the city contributed $500,000 in bond funds for the Hope Center.

Then, in September, Gov. Gavin Newsom announced that Lake County had received funding as part of the third round of awards for Project Homekey, a program administered by the California Department of Housing and Community Development that is making $600 million available to local public entities to provide long-term housing for people experiencing homelessness.

The Hope Center received $3.38 million from that Project Homekey funding round.

Assemblywoman Cecilia Aguiar-Curry, on hand in person for the Thursday ceremony, said the Project Homekey grant was “significant,” and will fund Lake County’s first permanent housing center for the homeless.

Aguiar-Curry recognized the strong efforts of local officials and the resulting partnerships in creating the center.

Congressman Mike Thompson, in a video shown at the ceremony, also heralded the work of the public and private partners whose work has made the Hope Center a reality.

Trumbo noted during the ceremony that while love is the motivator for the work, “There’s nothing soft about standing alongside a human being and supporting them through their journey of transformation. That’s the work that’s going to be happening here, and that’s love, and it’s strong and it’s solid.”

She added, “Revolutions don’t just happen in big moments in public view, they happen in small ways of people coming together.”

One of the key partners in creating the Hope Center is Adventist Health Clear Lake.

The hospital’s president and CEO, David Santos, recalled arriving in Lake County in 2009 and seeing the county’s needs, which set him on a path to addressing addiction and mental illness. That, in turn, led to focusing on “high utilizers,” those who frequently use hospital and other services in the community. He said his goal was to instill hope in both patients and health care providers.

“Today, I declare, we’ve reached a tipping point,” said Santos, who believes that Lake County is creating a rural health model not just for California but for the rest of the nation.

Panella said the Hope Center is unique; it exists because of a network of agencies that worked together.

Those agencies include the city of Clearlake, Lake County Behavioral Health Services, Lake County Continuum of Care, Partnership HealthPlan, the Lake County Health Department, the Department of Social Services, North Coast Opportunities, Adventist Health and Redwood Community Services.

Panella recounted earlier this year meeting at the site with Kimbell-Auth, City Manager Alan Flora, City Councilman Russell Perdock, who also is an Adventist Health staffer. At that point, construction had stalled and grant funding – along with their dreams – had depleted.

At the same time, they found the Hope Center sign had been vandalized, with the “Hope” turned to “Nope.”

But the woman who vandalized the sign came to them that day, admitted what she did, then asked to make amends by cleaning the sign. She then asked to help weed the property, which Panella said she did.

Panella said everybody needs the opportunity to go from “nope to hope.”

Following a ribbon-cutting in front of the building, Kimbell-Auth and other staff led an in-person and virtual tour of the facility and invited people to plant flower seeds and bulbs in the flower beds around the building.

Kimbell-Auth said the people who will live at the center will be called “participants” rather than “clients.”

“They’re participating in their own housing navigation plan,” she explained.

As part of their responsibilities, participants will have access to Alcoholics Anonymous or Narcotics Anonymous meetings, and do daily chores like mopping floors, emptying trash and cleaning bathrooms.

To become a sponsor, volunteer or provide a meal for Hope Center participants, visit www.hoperisinglc.org.

Email Elizabeth Larson at This email address is being protected from spambots. You need JavaScript enabled to view it.. Follow her on Twitter, @ERLarson, or Lake County News, @LakeCoNews.l

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Written by: Elizabeth Larson

Published: 13 November 2020

The Institute for Health Metrics and Evaluation this week issued new projections for COVID-19 deaths in the United States, anticipating another 200,000 fatalities by March unless mask-wearing increases substantially.

The institute, an independent global health research center at the University of Washington, has issued key forecasts of how the virus will impact the nation and the world throughout the pandemic.

In its latest report issued on Thursday, the institute reported that daily cases are increasing at an accelerating rate with deaths also increasing but at a slower rate.

“Given the experience in Europe, we expect that the increase in deaths will soon begin
to match the increase in cases,” the institute’s latest briefing notes.

That’s because the fall/winter surge is evident in nearly all 50 states at this time, the institute reported.

The updated forecast issued this week takes into account evidence from hospital studies showing that the infection-fatality rate has declined 30-percent since April due to improved treatment.

“Despite this, we expect 439,000 cumulative deaths by March 1 and a peak of daily deaths in mid January at 2,200 a day. Although mask use has increased to 67 percent, further increases to 95 percent could save a further 68,000 lives by March 1,” the institute reported.

The projection puts California’s deaths by March 1 at 27,073. Currently, the state has reported more than 18,100 deaths due to the virus.

The institute also estimated that, as of Nov. 9, 12 percent of the people in the United States have been infected with COVID-19. That ranges from 1 percent in Vermont to 24 percent in New Jersey. California’s infection rate is reported as between 7.5 and 9.9 percent.

To see projection charts, click here.

Email Elizabeth Larson at This email address is being protected from spambots. You need JavaScript enabled to view it.. Follow her on Twitter, @ERLarson, or Lake County News, @LakeCoNews.