The National Aeronautics and Space Administration (NASA) has revealed several new scientific discoveries made by its New Horizons team, including the latest images of Pluto's icy mountains and its nitrogen-rich atmosphere.
NASA scientists report that these new features of the Pluto system were discovered after the first flyby of the New Horizons spacecraft around the planet.
NASA associate administrator John Grunsfeld of the Science Mission Directorate said that the New Horizons mission on Pluto demonstrates the importance of basic research in science.
He explained that the mission planners were able to build expectations for the past nine years on what could possibly be seen during the space probe's closest approach to the Pluto system as well as its moon Charon.
Grunsfeld added that the recent discoveries of the New Horizons team are the first sampling of the multitude of information that was gathered during those crucial moments, and that these findings significantly surpassed the expectations they set.
Pluto's Icy Mountain Range
The latest flyby image provided by the New Horizons spacecraft shows several tall mountains that feature peaks as high as 3,500 meters, or 11,000 feet, above the dwarf planet's icy surface.
Scientists believe that Pluto's mountains were most likely formed around 100 million years ago, making them still considerably young compared to the age of the solar system, which is estimate at 4.56 billion years old. This finding suggests that the region shown in the image, which occupies around 1 percent of the planet's surface, may very well be active geologically even today.
New Horizons researcher Jeff Moore said that the surface of Pluto is one of the youngest that they have observed in the solar system.
Compared to the icy moons of massive planets, Pluto does not heat up through gravitational interactions with other larger planetary bodies. Experts speculate that the mountainous landscape on the dwarf planet could be caused by another process.
John Spencer, deputy team leader of the Geology, Geophysics and Imaging Team (GGI), said that the findings lead scientists to ponder on what could potentially generate the geological activity on other icy planets.
Pluto's Nitrogen-filled Atmosphere
New Horizons researchers also discovered the nitrogen-rich atmosphere that covers a large area of Pluto's surface. Images from the spacecraft reveal that this atmosphere extends as much as 1,600 kilometers, or around 1,000 miles.
NASA said that the data was gathered during an event known as solar occultation, wherein the New Horizons probe had to pass through the dwarf planet's shadow while the sun backlit its atmosphere.
New Horizons scientist Randy Gladstone said that the mission's atmospheres team was forced to wait until the space probe successfully passed by Pluto in order to collect the best set of data.
Gladstone pointed out that Pluto's atmosphere was symmetric on both of its sides, and while it would possibly take another couple of months before additional data is received, the sluggish nature of the atmosphere rules out the possibility of using certain models for their observation.
Pluto's Plasma Tail
The Solar Wind Around Pluto (SWAP) instrument used by NASA scientists detected a cavity in Pluto's solar wind around an hour and a half after the space probe made its closest approach.
The cavity was discovered from 77,000 to 109,000 kilometers, or 48,000 and 68,000 miles, downstream of Pluto, and it was filled with nitrogen ions that created some form of plasma tail. The measurements of the plasma tail, however, are yet to be fully determined.
Despite similar plasma tails seen on other planets, such as Mars and Venus, the one observed on Pluto features molecules of nitrogen that are ionized by ultraviolet (UV) rays from the sun. These molecules are then carried by solar wind beyond the boundaries of the dwarf planet to produce the phenomenon recorded by the New Horizons probe.
Researcher Fran Bagenal, head of the Particles and Plasma team of New Horizons, said that they need further information from the space probe before they could produce an accurate assessment of the escaping atmosphere. Current estimates show that the atmosphere blown in the phenomenon by the hour amounts to around 500 tons.
"This is just a first tantalizing look at Pluto's plasma environment," Bagenal said.
