ESA Calls on Skywatchers to Track Rosetta Probe's Earth Flyby
An artist's illustration of Rosetta's Philae lander on the surface of Comet 67P/Churyumov-Gerasimenko.
Credit: ESA

The European Space Agency (ESA) is looking to amateur skywatchers for help tracking its Rosetta spacecraft, a comet-hunting probe set to swing past Earth next week.

Rosetta – and its attached lander Philae – is expected to fly by our planet on March 4, though ESA officials expect the spacecraft will be visible via telescopes and binoculars as soon as Feb. 26. and have announced a photography contest dubbed “Rossetta Up Close” for homegrown astronomers hoping to catch the spacecraft in their camera crosshairs.

Launched in March 2004, Rosetta has spent about one year in space – about one-tenth of its ultimate journey – playing catch-up to the Comet 67P/Churyumov-Gerasimenko. Rosetta itself is bound to orbit the comet and study the object as it nears the Sun and begins to outgas material. Later, the Philae lander is designed to harpoon the comet and anchor itself to the surface for further study.

It appears the best view for Rosetta fans – weather providing – will be in Mexico. The comet probe will fly over the region as it makes its closest approach to Earth at about 5:10 p.m. EST (2210 GMT) coming within 1,180 miles (1,900 kilometers).

Because of its current trajectory, the Rosetta-Philae spacecraft combo should appear from a patch of sky between the constellations Leo and Sextans.

While observers in Europe are not expected to be able to spot Rosetta with the naked eye, they may be able to use video and photo imaging together with telescopes to catch the approaching spacecraft. The probe’s high gain antenna and solar panels, which extend out to 104 feet (32 meters), may also be visible via imaging equipment.

Rosetta will not be silent as it swings past Earth during the upcoming flyby maneuver. Just a few hours before the spacecraft makes its closest approach, the probe will be pointed toward the moon in order to use the natural satellites to calibrate its onboard instruments.

After the flyby, two navigation cameras will be switched on to check Rosetta’s asteroid tracking ability using the moon as a ‘dummy’ asteroid. They will be used to verify Rosetta’s position once the spacecraft drifts past two asteroids, Steins in September 2008 and Lutetia in July 2010.

After its March 4 approach, Rosetta will move faster as it heads west on to its next planetary encounter, a flyby with the planet Mars on Feb. 27, 2007. Following that Mars boost, the probe will return to swing past Earth twice more to build up enough acceleration to reach its target comet in 2014.

Observers hoping to learn more about ESA’s “Rosetta Up Close” contest should visit the space agency’s website here for details as they become available.