NASA launched the New Horizons probe today on an express ride to the Solar System’s last outpost, Pluto.
While most recent interplanetary probes have taken the slow and easy way to their destinations, taking long, looping trips around way-station planets, New Horizons is taking the Metroliner approach — short and fast.
The probe’s launch vehicle, an Atlas 5 rocket, will accelerate the Pluto probe to almost 16 km/s (36,000 mph), quick enough to pass the moon’s orbit (384,000 km or 240,000 miles) in just nine hours. In contrast, the Apollo missions, with a top speed of 11 km/s (25,000 mph) took a week to reach the moon.
New Horizons will reach its icy, remote destination, 30 times farther from the sun than the earth is, in 2015, just nine years from now. That’s about 500,000,000,000 km/year!
Pluto remains the last known planet in the solar system to be visited by an interplanetary probe. Its physical properties resemble a comet’s more than the rest of the planets, leading some astronomers to say it should no longer be classifed as a planet. IMHO, it’s a planet, so I’m going to call it that.
For more details about New Horizon, visit the official NASA website.