Pluto's 'Ice Dunes' Are Proof It Has 'Earth-like Characteristics'
Pluto is an ice world billions of miles away from Earth, yet scientists discover that the two share similar characteristics, including an impressive dunes system.
Dunes are formed when the wind blows grains of sand into a sheltered area, where it accumulates over time and develops into an increasingly larger mound.
With Pluto's extremely thin air, it seemed very unlikely that dunes will be able to form in the dwarf planet.
"It turns out that even though there is so little atmosphere, and the surface temperature is around -230 degrees Celsius, we still get dunes forming," lead study author Dr. Matt Telfer, a lecturer in physical geography at the University of Plymouth, says in a statement.
How Are Dunes Possible In Pluto?
The study, published in the journal Science, reveals the findings of an international team of scientists who analyzed images of Pluto snapped in July 2015. These images show a smattering of ice dunes in a roughly 47-mile area by the Sputnik Planitia ice plain boundary where there is also a mountain range located.
By analyzing the dunes and wind streaks and then combining the data with spectral and numerical modelling, the researchers found that sublimation — the process of turning solids to gas — creates sand-like grains of methane.
These sandy methane particles are then transported by the winds to the plains and mountain range, where dunes eventually form.
Dr. Eric Parteli of the University of Cologne explains that Pluto's low gravity and atmospheric pressure means that the wind strength necessary for sediment transport can be 100,000 times lower than on Earth.
The researchers suggest that Pluto's winds could actually be strong enough to transport the grains and create the dunes but only if the grains are already airborne. This is only possible with sublimation resulting in sand-like particles that are most likely methane, but scientists say it could also be nitrogen ice.
The dunes have reportedly formed in the last 500,000 years.
Doubts, Future Studies
The new findings are significant, as it shows how even the barely there atmosphere of Pluto can influence and shape the geological processes on the dwarf planet's surface greatly.
However, there are other scientists who cast doubt on the team's findings.
Alex Hayes, an astronomer from Cornell University who wasn't part of the study, points out that the movement of the sediments and the dunes can't actually be seen.
"The whole paper sees this interesting feature and tries to interpret what they could be ... The authors make a convincing argument, but without higher-resolution images, it's hard to know for sure," he tells Gizmodo.
For their part, the researchers are planning to continue studying the dunes using computer simulations, which will help them learn more about how Pluto's wispy winds are affecting their geology.