NASA's LADEE spacecraft is working to get in as many last-minute discoveries as possible before it self-destructs by crashing into the surface of the moon later this month. NASA has invited the public to guess when the craft will make impact. 

The craft is expected to make contact with the lunar surface on April 21, a NASA news release reported.

The craft's final orbital maintenance maneuver will take place when the Earth's shadow passes over the moon. The four-hour-long eclipse will expose LADEE to conditions that push its survival limits.

This final maneuver will make it so that the craft's final impact hits the far side of the moon, which is not visible from Earth.

"The moon's gravity field is so lumpy, and the terrain is so highly variable with crater ridges and valleys that frequent maneuvers are required or the LADEE spacecraft will impact the moon's surface," Butler Hine, LADEE project manager at Ames said in the news release. "Even if we perform all maneuvers perfectly, there's still a chance LADEE could impact the moon sometime before April 21, which is when we expect LADEE's orbit to naturally decay after using all the fuel onboard."

NASA has issued a challenge to the public titled "Take the Plunge: LADEE Impact Challenge." Participants are urged to make their best guess as to when the spacecraft will crash into the moon.

Enter the challenge here. Winners will recieve a commemorative, personalized certificate from the LADEE program, the news release reported. 

"We want to thank all those that watched LADEE launch and have followed the mission these past months," Jim Green, NASA's Director for Planetary Science at NASA Headquarters in Washington, said in the news release. "Our Moon holds a special place in so many cultures, and because of LADEE, we'll know more than ever before about our nearest neighbor."

LADEE was the first to demonstrate Optical Laser Communications from space; the craft has been orbiting the moon since Oct. 6 and has been working to gain insight into the lunar atmosphere. The researchers hope to determine if lunar dust that was electrically charged through sunlight was responsible for the eerie glow seen on the moon's horizon during the Apollo mission.