Please update your Flash Player to view content.

Earthlike ‘Star Wars’ Tatooines may be common

Simulations dispute dogma: rocky planets may orbit many double stars


In this acrylic painting, University of Utah astrophysicist Ben Bromley envisions the view of a double sunset from an uninhabited Earthlike planet orbiting a pair of binary stars. In a new study, Bromley and Scott Kenyon of the Smithsonian Astrophysical Observatory performed mathematical analysis and simulations showing that it is possible for a rocky planet to form around binary stars, like Luke Skywalker’s home planet Tatooine in the “Star Wars” films. So far, NASA’s Kepler space telescope has found only gas-giant planets like Saturn or Neptune orbiting binary stars. Photo Credit: Ben Bromley, University of Utah

Luke Skywalker’s home in “Star Wars” is the desert planet Tatooine, with twin sunsets because it orbits two stars. So far, only uninhabitable gas-giant planets have been identified circling such binary stars, and many researchers believe rocky planets cannot form there. Now, mathematical simulations show that Earthlike, solid planets such as Tatooine likely exist and may be widespread.

“Tatooine sunsets may be common after all,” concludes the study by astrophysicists Ben Bromley of the University of Utah and Scott Kenyon of the Smithsonian Astrophysical Observatory.

“Our main result is that outside a small region near a binary star, [either rocky or gas-giant] planet formation can proceed in much the same way as around a single star,” they write. “In our scenario, planets are as prevalent around binaries as around single stars.”

The study has been submitted to Astrophysical Journal for review, but as is the custom in the field, the authors have posted the unreviewed paper on the scientific preprint website ArXiv (pronounced archive).

With “Star Wars: Episode VII – The Force Awakens” due to hit movie screens Dec. 18, fans of the epic series may be cheered at the possible reality of planets like Tatooine, home planet of both Luke and Anakin Skywalker, meeting place of Obi Wan Kenobi and Han Solo and the domain ruled (until his death in battle) by crime lord Jabba the Hutt. Luke stares at Tatooine’s double suns setting in a classic film moment.

The title of the new study is “Planet formation around binary stars: Tatooine made easy,” but the paper looks anything but easy: it is filled with mathematical formulas describing how binary stars can be orbited by planetesimals – asteroid-sized rocks that clump together to form planets.

“We took our sweet numerical time to show that the ride around a pair of stars can be just as smooth as around one,” when it comes to the early steps of planet formation, Bromley says. “The ‘made easy’ part is really saying the same recipe that works around the sun will work around Tatooine’s host stars.”

The study was funded by NASA’s Outer Planets Program and was a spinoff of Bromley’s and Kenyon’s research into how dwarf planet Pluto and its major moon, Charon, act like a binary system. Both are orbited by four other moons.

The study may be found at: http://arxiv.org/abs/1503.03876

Full Press Release.

More…

Ebola Virus May Replicate in an Exotic Way

Study Indicates Target for Future Drugs for Measles, Ebola, RSV


University of Utah physics doctoral student Xiaolin Tang and virologist Saveez Saffarian in the lab where they identified an exotic mechanism that may explain how a group of viruses that includes Ebola replicate or make copies of themselves to make people sick. Photo Credit: Lee J. Siegel, University of Utah

Dec. 11, 2014 – University of Utah researchers ran biochemical analysis and computer simulations of a livestock virus to discover a likely and exotic mechanism to explain the replication of related viruses such as Ebola, measles and rabies. The mechanism may be a possible target for new treatments within a decade.

“This is fundamental science. It creates new targets for potential antiviral drugs in the next five to 10 years, but unfortunately would not have an impact on the current Ebola epidemic” in West Africa, says Saveez Saffarian, senior author of a new study published today by the Public Library of Science journal PLOS Computational Biology.

Saffarian, a virologist and assistant professor of physics and astronomy, and his colleagues studied a horse, cattle and pig virus named VSV – vesicular stomatitis virus – which is a member of family called NNS RNA viruses. That family also includes closely related viruses responsible for Ebola, measles, rabies and the common, childhood respiratory syncytial virus, or RSV. The genetic blueprint in these viruses is an RNA strand that is covered by protein like beads on a necklace.

By conducting 20,000 computer simulations of the VSV starting to replicate in different possible ways, the study found a “fundamental mechanism” used by VSV and related viruses like Ebola to make copies of themselves or replicate, Saffarian says.

The mechanism: Once the virus infects a cell, enzymes called polymerases literally slide along the protein “bead”-covered viral RNA strand until they reach the correct end of the strand. Then the polymerases can read and “transcribe” the RNA code to synthesize messenger RNA, or mRNA. Once one polymerase starts doing that, it collides with other sliding polymerases, kicking them loose within the cell until they, too, attach to the correct end of the RNA and start making copies. That lets the virus replicate and take over the infected host cell.

“The proposed sliding mechanism is a fundamental new mechanism specific to the NNS RNA viruses that can be a target for antiviral drugs in the future,” Saffarian says – something he hopes pharmaceutical scientists will pursue.

The sliding contrasts with replication in many other viruses, in which the polymerases easily detach from the virus inside an infected cell and then find the right end of the RNA so replication begins.

The mechanism was discovered by computer simulations, so “we are working now on demonstrating evidence of the sliding mechanism in VSV,” Saffarian says.

He believes the discovery is “as fundamental as understanding the workings of HIV protease” – an enzyme essential for replication of the AIDS virus and that became a target of protease inhibitors, which first made it possible for AIDS patients to live with AIDS as a chronic rather than deadly disease.

Saffarian conducted the study with first author and physics doctoral student Xiaolin Tang, and with research scientist Mourad Bendjennat. The National Science Foundation funded the study.

Full Press Release.

More…

Science Night Live with Brian Saam

Wednesday, Nov. 19 @ 5:30 p.m. - Science Night Live! with Brian Saam. "A History of the Second: From Grains of Sand to Atomic Clocks" at Keys on Main (242 South Main Street, Salt Lake City, UT).

SCIENCE NIGHT LIVE

with Dr. Brian Saam,
Professor of Physics & Astronomy

A History of the Second: From Grains of Sand to Atomic Clocks

Date & Time: Wednesday, Nov. 19, 2014. 5:30 - 7:00 PM

Location: Keys on Main (242 South Main Street, Salt Lake City, UT)
View Map

Without getting too deep into existential philosophy,we can begin a discussion of time with an operational definition: time separates cause from effect; more precisely, time delineates the order of events. Our earliest human ancestors recognized that to measure time, one needs a periodic event that is easily, reliably, and universally observed in exactly the same way. Both the rotation of the Earth on its axis and revolution of the Earth about the Sun satisfy these requirements and have been universally accepted time standards throughout most of recorded history. Every timepiece ever invented prior to 1967—sundials, water clocks, hourglasses, and mechanical clocks—traced its calibration in some way back to the apparent motion of the sun in the sky. However, as robust and reliable as this standard appears (the Earth’s rate of rotation slows by about 1 second in 60,000 years), it is inadequate for the modern frontiers of scientific discovery, as well as for the needs of a global telecommunications and geo-positioning infrastructure. A much more stable standard was developed starting in the 1960s that is based on a transition that occurs between two specific energy levels in atomic cesium. These “atomic clocks” are stable to about 1 second in 30 million years. Work on even more stable clocks (1 second in 30 billion years) is at the frontier of modern atomic physics.

Frontiers of Science is free and open to the public. Must be 21 or older to attend.

Learn More.

More…

Solar Eclipse Viewing Party at NHMU: 10/23/2014

From the Natural History Museum of Utah's website.

Solar Eclipse Viewing Party!

Natural History Museum of Utah (map & parking)
Sky Gallery, The Canyon & Outside Terraces at the Museum

Thursday, October 23, 2014
1:00 - 5:00 pm

Join us and spot it from from the best spot in the Salt Lake Valley!

  • Meet some of our knowledgeable and local astronomy experts and view the eclipse through professional solar telescopes brought by Salt Lake Astronomy Society.
  • Check out the newest robotic system, COLE mrk 5, built by RoboUtes, recently back from NASA robo-ops competition.
  • Create your own pinhole viewer that will help you safetly view the eclipse.
  • Build your own Mars rover, soda bottle rocket, and more!

For more information on what we'll see on October 23, click here!

First 200 guests get a FREE pair of solar glasses!
*Solar glasses can also be purchased in the Museum Store.

Maximum Eclipse will occur at 4:26 pm
Best times to view the eclipse are from 4:15 to 4:40 pm.

More…

Follow Us

Support Us

Make A Difference

Outreach: The Department of Physics & Astronomy at the U

Community Outreach

Scholarships: The Department of Physics & Astronomy at the U

Academic Scholarships

General_Development: The Department of Physics & Astronomy at the U

Other Areas
of Support

 

Our Newest Program:

Crimson Laureate Society

Posters

Click to download full size.

The Department of Physics & Astronomy at the U

 

Science, it makes us all go

 

Even Our English Majors Study Physics

 

The Formula For The Perfect Pass

 

  • Department of Physics & Astronomy • 201 James Fletcher Bldg. 115 South 1400 East, Salt Lake City, UT 84112-0830
  • PHONE 801-581-6901
  • Fax 801-581-4801
  • ©2018 The University of Utah