Those of you with a soft spot for Pluto probably know that February was a big month for this far-flung world.
First came the unveiling, on February 4th, of a new surface map painstakingly constructed from Hubble Space Telescope images. Then, on the 18th, we celebrated the 80th anniversary of Pluto's discovery by Clyde Tombaugh at Lowell Observatory.To these you can add one more event of note: on February 25th, the New Horizons spacecraft reached the point in its trajectory that places it closer to Pluto than it is to the Sun. As the mission's website touts, the craft's approach to Pluto has begun.
New Horizons has been coasting ever since its launch on January 19, 2006. So it's taken just four years to reach this halfway point. But the Sun's gravity has gradually slowed the craft, enough so that it will require another 5½ years to reach the
outermost planet second-largest dwarf planet.
No matter how you slice it, the trip has been a long and basically boring one for both New Horizons and its science team. Like a long overnight flight from Tokyo to New York, there hasn't been much to look at since a dash past Jupiter for a gravity boost and some target practice exactly three years ago today (another February date of note). So New Horizons has been in electronic hibernation since last August; it'll be roused for a checkup in a few months.
(Watch Stern and others defend Pluto's planetary status this week on "The Pluto Files," a PBS special hosted by Neil deGrasse Tyson.)