In a recent NASA blog post, Kelsi Singer, a researcher at Southwest Research Institute working on NASA’s New Horizons, goes over an interesting discovery made about Pluto: It seems to have a near infinite supply of nitrogen.
Pluto is Gassy
The most recent images returned by New Horizons shows that Pluto’s surface is mostly composed of nitrogen, just like Earth’s. There is; however, about a 20 percent difference in composition. Earth’s atmosphere is around ~78 percent nitrogen while Pluto’s is ~98 percent. Another interesting fact is that the nitrogen in Pluto’s atmosphere is actually leaving, and at a pretty alarming rate. According to Singer, the nitrogen is escaping at an estimated rate of “hundreds of tons per hour.”
Other pictures also show that Pluto’s surface is full of ice (duh), but there is also evidence that some of this ice is actually flowing. According to Singer, normal water ice (H20) would be essentially frozen stiff, but ice composed of nitrogen would still be able to flow.
Being a dwarf planet, this phenomenon begs an answer for one question: How can Pluto still be full of nitrogen?
Maybe It’s Comets
Comets take the blame for a lot of stuff. Maybe comets brought bacteria to Earth where it flourished and evolved. Maybe it was (probably) an asteroid or comet that wiped out the dinosaurs. Now it might be comets that are bringing the necessary nitrogen into Pluto’s atmosphere, says Singer.
For this hypothesis the team tried to answer two questions: “Could comets hitting Pluto directly deliver enough nitrogen to Pluto’s surface and atmosphere? Could these comets excavate or expose enough nitrogen ice from the near-surface layers on Pluto by forming impact craters?”
Ultimately, Singer says that it’s just not possible for comets to bring in enough nitrogen to replace the amount escaping from the atmosphere. That leads the team to a perhaps more direct hypothesis: maybe the dwarf planet is creating a huge amount of nitrogen all by itself.
Taking The Direct Approach
In the team’s prediction paper, they go over how Pluto is more likely making nitrogen through the planet’s “heat and geologic activity.” Unfortunately, the team doesn’t have enough data from New Horizons to verify what exactly is the cause of all the nitrogen.
More and more data is expected to reach us over the next few months, so the team will have more clues about what’s going on with Pluto and its interesting nitrogen phenomenon then.