What’s Going to Happen During Tomorrow’s #PlutoFlyby?

posted: 07/13/15
by: Danny Clemens
Pluto as of July 11
NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

The world is watching as New Horizons' decade-long, 3 billion-mile journey to Pluto nears it climax. Since awakening from nearly 1,900 days of hibernation in December 2014, the spacecraft has been sending back increasingly detailed images of the dwarf planet and its largest moon, Charon.

The flyby is more nuanced than you might think. According to press materials provided by NASA, "New Horizons must thread a celestial needle by flying through a target circle only 300 kilometers (about 200 miles) in diameter -- and with less than 100 seconds in timing error -- to accomplish its science objectives."

At its closest point, New Horizons will be a mere 7,750 miles (12,500 kilometers) from Pluto. During that approach, the spacecraft will map the sunlit faces and surface composition of Pluto and Charon; New Horizons will then continue past Pluto, eventually mapping its nightside.

While New Horizons is on the nightside, astronomers on Earth will beam a powerful radio signal to the spacecraft through Pluto's atmosphere. "By measuring the effects of atmospheric refraction on the radio beam as it travels to the spacecraft [...] scientists will be able to map the temperature, density and composition profile of the atmosphere all the way to the surface," NASA explains.

Additional science objectives include searching for an atmosphere around Charon; detecting unknown rings, satellites or magnetic fields; determining surface temperatures on Pluto and Charon; and mapping the day-night boundary of Pluto in high resolution.

"The data that we're going to produce, the data that we are already producing, is a gift for the ages," teased New Horizons principal scientist Alan Stern during a media briefing.

"We are already seeing complex and nuanced surfaces that tell us of a history of these two bodies that is probably beyond our wildest dreams on the science team. Pluto has not disappointed."

Learn more about space exploration:

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