Pluto-Bound Probe Passes Mars’ Orbit

New Horizons Pluto Probe Readied For Launch
To be dispatched early 2006, the outward bound New Horizons spacecraft will throw new light on distant Pluto and its moon, Charon, as well as Kuiper Belt objects. Image (Image credit: Dan Durda)

NASA's NewHorizons probe has left the inner planets of the Solar System behind as it streakstoward a rendezvous with Pluto and its moons.

The spacecraft, billed as NASA'sfastest-flying probe, hurtled past the orbit of Mars - though not the planetitself - Friday on its way towards a Jupiter flyby and its more distant target Pluto.

"It'spretty amazing," New Horizons principal investigator AlanStern told "It'sa straight line across the Solar System. There are hardly any curves becausethis is so fast."

New Horizons sped past Mars'orbit some 151 million miles (243 million kilometers) from the Sun at a rate ofabout 13 miles (21 kilometers) per second. The red planet, however, trailedbehind the spacecraft at a distance of about 186 million miles (299 millionkilometers), mission managers said, adding that New Horizons was closer toEarth than Mars.

NASA launchedNew Horizons, a piano-sized spacecraft weighing about 1,054 pounds (478 kilogram),atop a Lockheed Martin-built Atlas 5 rocket - its most powerful booster - to flingthe Pluto-probe spaceward on Jan. 19, 2006.

Six of the probe's seven scienceinstruments have already been checkedfor their health as the spacecraft heads towards Jupiter, where it will usethe giant planet's gravity to boost its way on to Pluto and the icyobject-filled Kuiper Belt.

But first, the spacecraft must passthrough the AsteroidBelt, which despite its reputation is primarily made up of empty spacerather than a teeming rock field, mission managers said.

"We won't be hit," said Stern, theexecutive director of the space science and engineering division at theSouthwest Research Institute in Boulder, Colorado. "We won't even come closeenough to make any useful science observations of asteroids. They're reallyvery far apart."

New Horizons is expected to fly pastPluto and its moons July 2015. The spacecraft is due to make its closestapproach to Jupiter on Feb. 28, 2007.

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Tariq Malik

Tariq is the Editor-in-Chief of and joined the team in 2001, first as an intern and staff writer, and later as an editor. He covers human spaceflight, exploration and space science, as well as skywatching and entertainment. He became's Managing Editor in 2009 and Editor-in-Chief in 2019. Before joining, Tariq was a staff reporter for The Los Angeles Times covering education and city beats in La Habra, Fullerton and Huntington Beach. In October 2022, Tariq received the Harry Kolcum Award for excellence in space reporting from the National Space Club Florida Committee. He is also an Eagle Scout (yes, he has the Space Exploration merit badge) and went to Space Camp four times as a kid and a fifth time as an adult. He has journalism degrees from the University of Southern California and New York University. You can find Tariq at and as the co-host to the This Week In Space podcast with space historian Rod Pyle on the TWiT network. To see his latest project, you can follow Tariq on Twitter @tariqjmalik.