Scientists at the European Space Agency (ESA) are trying to make contact with the Philae lander, which made a dramatic landing on the comet 67P/Churyumov-Gerasimenko in November last year, but soon went to sleep after losing power.

After touching down on comet 67P, the lander's harpoons designed to anchor it to the surface failed to fire, making it bounce across the comet and miss its original landing spot. The lander ended up in a shady spot on the comet without sufficient sunlight to keep it powered and exhausted its batteries soon after.

But with the days now becoming warmer and brighter, Philae is receiving twice as much solar energy as it did in November that could revive its solar panels. Mission controllers have commanded the ESA's Rosetta spacecraft, which has been circling comet 67P, to start sending signals to Philae and see if the lander responds. Rosetta's orbit is currently aligned with Philae to allow them to communicate with each other, provided that the lander is generating sufficient power and warmth from the limited sunlight it is now receiving.

Engineers estimate that Philae is receiving just 1.3 hours of sunlight for each 12.4-hour day on the comet. In order for Philae to wake up, the lander's solar panels must convert those limited hours of sunlight into 5.5 watts of power and it will need 19 watts to send and receive signals from Rosetta. On August 13, the comet will reach its closest point to the sun and if Philae revives by then, scientists will be able to view an amazing show from up close.

Rosetta will continue to send signals to Philae until March 20, when the space craft changes its orbit and goes out of position. In May and June, mission scientists will again try to wake up Philae by commanding Rosetta to signal the lander. If Philae fails to respond by August 13, when the comet reaches its closest point to the sun, then the scientists will have to finally give up.