NASA’s New Horizons probe uncovers Pluto.
By: Jonathan Kettle, Staff Writer.
The planet-turned- dwarf planet has been shrouded in mystery since Clyde Tombaugh painstakingly compared still photographs of the night sky in 1930 to discover the small Kuiper Belt object. Now, 85 years later, Pluto is slowly revealing its secrets.
Data from New Horizons should be fully retrieved by October 2016, but NASA scientists are eagerly analyzing the data that has already been received, and are shocked at what they are finding.
“It’s better than the Pluto I imagined […] the range of geological expression that we are seeing, the number of different surface features that tell us that, as small as it is, it is perhaps as complicated as the Earth or Mars is blowing our minds” – Alan Stern, principal investigator of the New Horizons mission.
As predicted, Pluto’s atmosphere is nitrogen-based with minor concentrations of methane and carbon monoxide like Earth’s, but that’s where the similarities end. The dwarf planet’s atmosphere varies between only one hundred thousandth and a millionth of the surface density of our own, and it’s seasons are determined by an elongated elliptical orbit. According to Ivan Linscott of Stanford University, “This crucial measurement may be telling us that Pluto is undergoing long-anticipated global change.” The nitrogen glaciers on Pluto tend to sublimate (that is, transition straight from solid to gaseous phase) and add more gas to the atmosphere. During the planet’s aphelion phases (farther away from the Sun) some of the gases condense and turn back into ice at the surface, which completes Pluto’s semi-annual season.
Looking past the atmosphere revealed mountain ranges akin to our Canadian Rockies in both height and variability. The jagged structures most likely consist of water ice, which behaves like rock at minus 230 degrees Celsius. These mountains are very young in comparison to the 4.5 billion year old solar system, which “cause[s] us to rethink what powers geological activity on many other icy worlds,” says John Spencer of the Southwest Research Institute.
On route to Pluto, New Horizons received a speed-boost of roughly 14,000 km/h when it slingshotted around Jupiter. While in the system, the probe discovered a volcano violently erupting in the Northern hemisphere of the Galilean moon Io.
When New Horizons left Earth on January 19, 2006, it was the fastest object ever to leave the planet’s atmosphere. At 16,000 m/s, or 57,600 km/h, it reached the lunar orbit in less than nine hours (which, for comparison, took the Apollo missions three full days to accomplish).
The celestial exploration craft is one of a kind in many ways. Many other probes that have been fired into space rely on solar winds to get their power; but where New Horizons is headed, the sun’s rays are too weak to power the spacecraft. Somewhat fittingly, the spacecraft runs on a plutonium energy supply and uses less than half the power than that of a 60-watt light bulb.
The probe narrowly avoided disaster when just one week before the flyby New Horizons fell silent to NASA’s scanners. A flaw in the software caused the computer to become overloaded with information and resulted in a systems crash. After an intensive and stressful hour, the spacecraft came back online in safe mode. The CPU of the probe is a radiation-hardened version of the same processor used in the original Playstation, but running at less than one third the speed. Stability, durability, and endurance are the main goals of probe computers; not quickness.
Some less mission-critical effects onboard the craft include some of Clyde Tombaugh’s ashes, a CD, Florida and Maryland state quarters, two U.S. Flags, an engraved piece of another space-craft, and a 1991 U.S. Stamp proclaiming “Pluto: Not Yet Explored.”
New Horizons will still be exploring Kuiper belt objects until the remainder of its fuel supply is gone. Two potential bodies of interest lie about 1.6 billion km beyond Pluto. To minimize fuel usage, the craft will likely have to be aimed towards a target before official channels and funding support the extended mission.
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