As NASA’s New Horizons continues to approach Pluto for the closest ever flyby on July 14, scientists have finally cleared up a long-standing debate about the dwarf planet. Thanks to fresh data collected by the enterprising spacecraft, scientists have found that Pluto is 1,473 miles in diameter, which is actually larger than most prior estimates.
Although it’s just a fraction of the size of our moon, Pluto is considered to be the largest known solar system object beyond the orbit of Neptune, NASA said. With the question of size finally put to rest, it gives scientists more concrete information about what the dwarf planet is actually like. For example, scientists say Pluto’s density is lower than previously thought, while its lowest layer of atmosphere, known as troposphere, is shallower than early estimates.
The image of Pluto you see above was taken during New Horizons’ final approach, at a distance of about 1.5 million miles.
“Pluto’s bright, mysterious “heart” is rotating into view, ready for its close-up on close approach,” NASA explained. “It is the target of the highest-resolution images that will be taken during the spacecraft’s closest approach to Pluto on July 14. The intriguing “bulls-eye” feature at right is rotating out of view, and will not be seen in greater detail.”
New Horizons has traveled more than 3 billion miles over a 9-year period to get to Pluto, so July 14’s flyby will be a momentous occasion. The dwarf planet has remained a mystery over the past several decades, but the flyby on Tuesday will finally provide the answers scientists have been looking for.
“The next time we see this part of Pluto at closest approach, a portion of this region will be imaged at about 500 times better resolution than we see today,” said Jeff Moore, team leader of NASA’s Ames Research Center.