UW News

planetary science

December 8, 2021

‘Would you like a little ice with your exoplanet?’ For Earth-like worlds, that may be a tall order

An artistic rendering showing an exoplanet with polar ice caps.

A team at the University of Washington and the University of Bern has computationally simulated more than 200,000 hypothetical Earth-like worlds all in orbit of stars like our sun. As they report in a paper accepted to the Planetary Science Journal and submitted Dec. 6 to the preprint site arXiv, on these simulated exoplanets, one common feature of present-day Earth was often lacking: partial ice coverage. About 90% of these potentially habitable hypothetical worlds lacked partial surface ice like polar caps.

January 27, 2021

On nights before a full moon, people go to bed later and sleep less, study shows

picture of the moon

Sleep cycles in people oscillate during the 29.5-day lunar cycle: In the days leading up to a full moon, people go to sleep later in the evening and sleep for shorter periods of time. The team, led by researchers at the University of Washington, observed these variations in both the time of sleep onset and the duration of sleep in urban and rural settings — from Indigenous communities in northern Argentina to college students in Seattle, a city of more than 750,000. They saw the oscillations regardless of an individual’s access to electricity, though the variations are less pronounced in individuals living in urban environments.

Purported phosphine on Venus more likely to be ordinary sulfur dioxide, new study shows

An image of the planet Venus, showing its thick atmosphere.

A University of Washington-led team has revisited and comprehensively reinterpreted the radio telescope observations underlying a widely reported 2019 claim that phosphine gas was present in the atmosphere of Venus. In a paper accepted to the Astrophysical Journal, they report that sulfur dioxide, a common gas in the atmosphere of Venus, is likely what was detected instead of phosphine.

January 22, 2021

The 7 rocky planets orbiting TRAPPIST-1 may be made of similar stuff

An image showing three illustrations of potential interiors of the exoplanets in the TRAPPIST-1 star system.

A study accepted by the Planetary Science Journal shows that the planets of the TRAPPIST-1 system share similar densities. That could mean they all contain roughly the same ratio of materials thought to be common to rocky planets, such as iron, oxygen, magnesium and silicon — though they appear to differ notably from Earth.

June 19, 2019

Abundance of gases in Enceladus’s ocean are a potential fuel — if life is there to consume it

This illustration shows NASA's Cassini spacecraft diving through the plume of Saturn's moon Enceladus, in 2015. New research from the University of Washington, to be presented at the coming AbSciCon2019 conference, indicates that the moon's subsurface ocean of probably has higher than previously known concentrations of carbon dioxide and hydrogen and a more Earthlike pH level, possibly providing conditions favorable to life.

The subsurface ocean of Saturn’s moon Enceladus probably has higher than previously known concentrations of carbon dioxide and hydrogen and a more Earthlike pH level, possibly providing conditions favorable to life, according to new research from planetary scientists at the UW.

July 6, 2015

In a cosmic ‘call to arms,’ UW astronomer proposes new deep-space telescope to scan the sky for signs of life

Artist's rendition of the planet Kepler-69c.

On July 6, a team of astronomers proposed a new type of mission to crack some of the universe’s most intriguing mysteries and search for life on distant worlds.

June 22, 2015

Spectrum of life: Nonphotosynthetic pigments could be biosignatures of life on other worlds

Laguna Colorada is a shallow salt lake in the southwest of Bolivia. One of several places on Earth whose colors are dominated by nonphotosynthetic pigments. Eddie Schwieterman of the University of Washington has research on how such nonphotosynthetic biosignatures might appear on exoplanets, or those outside our solar system.

To find life in the universe, it helps to know what it might look like. If there are organisms on other planets that do not rely wholly on photosynthesis — as some on Earth do not — how might those worlds appear from light-years away?

June 8, 2015

Atmospheric signs of volcanic activity could aid search for life

An eruption of the Calbuco Volcano in southern Chile. A team led by the UW's Amit Misra used data from volcanic eruptions on Earth to predict what an Earth-like exoplanet might look like during such eruptions.

Planets with volcanic activity are considered better candidates for life than worlds without such heated internal goings-on.
Now, graduate students at the UW have found a way to detect volcanic activity in the atmospheres of faraway planets when they transit, or pass in front of their host stars.

April 13, 2015

Violent methane storms on Titan may solve dune direction mystery

A view of Titan. Saturn's largest moon, with its ringed host in the background. New research from the University of Washington may solve a riddle of the direction of sand dunes on the moon's surface.

Titan, Saturn’s largest moon, has a hazy atmosphere and surface rivers, mountains, lakes and sand dunes. But the dunes and prevailing surface winds don’t point in the same direction. New research from UW astronomer Benjamin Charnay may have solved this mystery.

December 2, 2014

‘Mirage Earth’ exoplanets may have burned away chances for life

Illustration of a low-mass, M dwarf star, seen from an orbiting rocky planet.

Planets orbiting close to low-mass stars are prime targets in the search for life. But new research led by an astronomy graduate student at the UW indicates some such planets may have long since lost their chance at hosting life because of intense heat during their formative years.

July 31, 2014

Companion planets can increase old worlds’ chance at life

For certain ancient planets orbiting smaller, older stars, the gravitational influence of an outer companion planet might generate enough energy to keep the inner world habitable even when its own internal fires burn out. This is an illustration of a planet in the habitable zone of a star about the size of the sun. But what would such a world look like at its surface? Here, UW astronomy Rory Barnes provides a speculative illustration. "The star would appear about 10 times larger in the sky than our Sun. The sky is mostly dark because cool stars don't emit much blue light, so the atmosphere doesn't scatter it."

Having a companion in old age is good for people — and, it turns out, might extend the chance for life on certain Earth-sized planets in the cosmos as well.

April 15, 2014

Astronomers: ‘Tilt-a-worlds’ could harbor life

Tilted orbits such as those shown might make some planets wobble like a top that's almost done spinning, an effect that could maintain liquid water on the surface, thus giving life a chance -- according to new research by UW astronomer Rory Barnes.

A fluctuating tilt in a planet’s orbit does not preclude the possibility of life, according to new research by astronomers at the University of Washington, Utah’s Weber State University and NASA. In fact, sometimes it helps.

March 4, 2014

‘Dimer molecules’ aid study of exoplanet pressure, hunt for life

An artist's concept of an exoplanet, or planet outside the solar system.

UW astronomers have developed a new method of gauging the atmospheric pressure of exoplanets, or worlds beyond the solar system, by looking for a certain type of molecule. And if there is life out in space, it may one day be revealed by this method.

March 3, 2014

UW astronomer Eric Agol’s seven-planet system part of major NASA discovery

An artist's illustration of multiple-transiting planet systems. The planets eclipse or transit their host star from the vantage point of the observer.

UW astronomer Eric Agol played a key role in the windfall of 715 new exoplanets recently announced by NASA. Agol was on a team that found seven of those worlds, all in orbit around the same star.

November 25, 2013

Study: Greenhouse gas might have warmed early Mars enough to allow liquid water

The mystery of how the surface of Mars, long dead and dry, could have flowed with water billions of years ago may have been solved by research that included a University of Washington astronomer.

July 29, 2013

Planetary ‘runaway greenhouse’ more easily triggered, research shows

A view of the surface of Venus from NASA's Magellan mapping spacecraft.

It might be easier than previously thought for a planet to overheat into the uninhabitable “runaway greenhouse” stage, according to new research.

July 18, 2013

A warmer planetary haven around cool stars, as ice warms rather than cools

This artist's concept illustrates a planet orbiting a red dwarf star.

In a bit of cosmic irony, planets orbiting cooler stars may be more likely to remain ice-free than planets around hotter stars. This is due to the interaction of a star’s light with ice and snow on the planet’s surface.

April 25, 2013

Astronomer studies far-off worlds through ‘characterization by proxy’

A dwarf galaxy.

A UW astronomer is using Earth’s interstellar neighbors to learn the nature of certain stars too far away to be directly measured or observed, and the planets they may host.

November 19, 2012

Can life emerge on planets around cooling stars?

UW astronomers find that planets orbiting white and brown dwarfs are unlikely to be good candidates for sustaining life.

August 29, 2012

From UW to Mars, sundial has an important role

With the recent landing of NASA’s Curiosity rover on Mars, for the third time a timepiece assembled at the University of Washington has found a home on the Red Planet.