New Horizons artist's rendition. (Image credit: NASA)

New Horizons—the first mission to Pluto and the Kuiper Belt—will explore the controversial dwarf planet with seven science instruments that include advanced imaging infrared and ultraviolet spectrometers, a compact multi-color camera, a high-resolution telescopic camera, two powerful particle spectrometers and a space-dust detector.

The closest approach to Pluto was supposed to go down on the 14th July, however a hiccup presented itself yesterday. From NASA

Highlights From Our Journey to Pluto:

A look at the origin of New Horizons, what scientists hope to find, what we've learned thus far, and how the Pluto-Charon system could revolutionize our understanding of our own solar system:

The Controversy: 

Pluto was originally thought to be much larger than Earth and was easily accepted as the ninth planet—a title Pluto kept even when scientists realized it was much smaller. Even though theories trying to explain Pluto’s existence ranged from comet to discarded Neptunian moon, Pluto was widely accepted as a planet until the late 20th century.

Following the discovery of similar, yet smaller, objects in the Kuiper belt, along with Pluto’s moon (which is about half of Pluto’s size), a growing number of scientists were arguing in favor of Pluto’s declassification. The discovery of Eris, a Kuiper belt object 27% more massive than Pluto, in 2005 lead the IAU to set an official definition of what a planet is. As we all know, Pluto was reclassified a dwarf-planet, a title it now shares with four other bodies in our solar system.

The scientists on the New Horizons mission were also personally attached to Pluto’s status as a planet. Earlier in 2006, they had launched the billion-dollar spacecraft to go visit the last of the planets—the only planet Voyager didn’t see.  Even though the IAU has dutifully stuck to its definition of a planet, some scientists believe it won’t stand the test of time. They argue that the IAU definition will fall in 2015 when New Horizons reaches Pluto, revealing the objects in question to be new and dynamic worlds.

“New Horizons is on a journey to a new class of planets we’ve never seen, in a place we’ve never been before,” says New Horizons Project Scientist Hal Weaver, of APL. “For decades we thought Pluto was this odd little body on the planetary outskirts; now we know it’s really a gateway to an entire region of new worlds in the Kuiper Belt, and New Horizons is going to provide the first close-up look at them.”


Pluto lies in the Kuiper Belt, a region of icy bodies orbiting the sun that are believed to be remnants from the formation of our solar system 4.6 billion years ago. All of the dwarf planets—Pluto, Eris, Makemake and Haumea—except for one can be found within this part of our solar system. The other—called Ceres, which is currently being explored by Dawn—can be found between Mars and Jupiter in the asteroid belt.

Astronomers hope that the Pluto-Charon system could shed light on the earliest moments of our solar system.


New Horizons, at the end of a 9 and a half year journey, will pass by the dwarf planet and its moons (Charon, Nix, Hydra, Kerberos, and Styx) travelling at a staggering speed of 26,7000 mph (43,000 km/h). It will then continue its path into the Kuiper belt, a disc-shaped region of volatile icy compounds such as methane, ammonia and water located past Neptune’s orbit.

“New Horizons” first woke up from its 1873-day hibernation on Saturday, December 6th of 2014, finally on the last leg of its journey to Pluto and its largest moon, Charon. At the time, the probe was 2.9 billion miles (about 4.7 billion kilometers) away from Earth, and was preparing to initiate it’s pre-programmed commands. In the following month, it began making the first stage of its encounter. Then, In february, it was close enough to make out Pluto and it smaller moons (Nix and Hydra).

Tentative Findings:

Now, the system is so close, the space probe has beamed back the first colored images of Pluto, which revealed some anomalies—including a mysterious bright spot, one that looks much like the spots that we’ve seen on Ceres.

This blurry image shows the two hemispheres of Pluto, taken on June 27, 2015. (Image Credit: NASA/JHUAPL/SWRI)

The spots, while notable from a scientific perspective, aren’t terribly unexpected. Pluto is some 3.67 billion miles (5.9 billion km) from the sun. For comparison, Earth has an average orbit of just 92 million miles (150 million km). Ultimately, Pluto is so far out into our solar system, it takes more than 247 Earth-years for it to complete one orbit. And with a temperature reaching -387º Fahrenheit (-233º Celsius), vast amounts of frozen material is anticipated.

If you were to take up residence on any one of Pluto’s moons, you would have a difficult time adjusting to your new daylight hours, among other variables. Some days, the sun would rise in the east and set in the north. Other days, it could be the opposite, or you might not even see it rise at all.

The reason for the extreme variation is that two of Pluto’s moons, Nix and Hydra, “wobble unpredictably," perhaps because they are embedded in a gravitational field that shifts constantly, which appears to stem from interactions between Pluto and its largest moon, Charon (collectively, they are so strange, astronomers believe Charon may not be Pluto’s moon. Rather, they may comprise a double planet system).




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