25 Jan 2015

New images of Pluto are about to reveal the true face of the dwarf planet

Pluto is a long, long, way away.

Depending on where it is on its journey around the sun it’s between 2.6 and 4.7 billion miles from earth. That’s 30 to 50 times further from the sun than our planet.

And that’s what makes Nasa’s New Horizon’s mission to visit it so significant. Though one of the most familiar sounding objects in the Solar System Pluto is nothing but a fuzzy blob. The best pictures of it are mainly guess work, what it is made of, no body knows.

If it hadn’t been the first object of its size and distance to have been discovered it would never have been in school textbooks as one of the “nine” classical planets in our Solar System.

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Pluto orbited by its moon Charon. Snapped by New Horizons last year

Starting in the late seventies new telescopes and techniques revealed large numbers of objects orbiting at the same distance from the sun and some nearly as big as Pluto. Its an area of the Solar System now known as the Kuiper belt. It’s why in 2006, Pluto officially lost its planetary stripes and was busted down to “dwarf ” status.

But its relegation doesn’t make it any less interesting. Scientists know next to nothing about what objects in the Kuiper belt look like, or what they’re made of, and how they came to be there. As the biggest known, a trip to Pluto has been on scientists’ wish list for a long time.

They would have liked the New Horizons probe to go into orbit around Pluto. But in order to get there in anything less than decades New Horizons has had to travel faster than any spacecraft launched at the time. And because Pluto is so small it can’t use the planetoid’s gravity to slow it down. So it’s simply going to fly past at 14 km per second and hope it can gather as much data as possible.

The first pictures of the probe’s approach to Pluto will start emerging this week. But it is still 200 million kilometres away so they won’t be very good. But by July – it makes its closest approach on July 14th – the true face of Pluto will finally be revealed.

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One reader comment

  1. Laurel Kornfeld says:

    Pluto’s demotion or “relegation” should not be treated as fact but as what it is–one view in an ongoing debate. Only four percent of the IAU voted on this, and most were not planetary scientists. Their decision was immediately rejected by hundreds of planetary scientists in a formal petition led by New Horizons Principal Investigator Dr. Alan Stern. These astronomers reject the notion that an object must “clear its orbit” to be a planet and instead favor the geophysical planet definition, under which a planet is a non-self-luminous spheroidal body orbiting a star, free floating in space, or even orbiting another planet. Under this definition, dwarf planets are a subclass of planets, as Dr. Stern intended. The only size threshold that matters according to the geophysical planet definition is an object being large enough and massive enough to be squeezed into a spherical shape by its own gravity. Pluto well exceeds that threshold and is therefore a full-fledged planet.

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