A spacecraft landed on the surface of a comet for the first time ever today, the European Space Agency confirms. The 220-pound Philae lander successfully made its way to the surface of 67P/Churyumov-Gerasimenko, as part of the agency's 10 years in the making Rosetta mission.

ESA lander system engineer Laurence O'Rourke told CNN that the lander is not "steered" toward the comet—rather, the lander must be positioned and detached from the Rosetta at just the right time to "free fall" onto the comet.

According to the New York Times, Philae's 10 instruments are designed to study the comet for 64 hours before its battery runs out. After its battery drains, the Times reports, solar panels will allow for one hour of observation from the lander "every couple of days." Philae is expected to survive until March, when heat will likely incinerate the lander.

Philae's landing marks a potential turning point in the study of comets. From the Times:

Previous spacecraft missions have zoomed by comets at high speeds, providing only brief examinations. By contrast, Rosetta will be a constant companion as Comet 67P approaches the sun, swings around and heads out again, its instruments potentially providing more than two years of data.

“We will watch this comet evolve,” Matt Taylor, the project's scientist, said at a press conference last week. “It’s never been done before.”

As Philae detached from Rosetta and made its way to the comet, the lander's Twitter account live-tweeted its journey:

[Image of lander and comet model via AP]