NASA’s Lunar Atmosphere and Dust Environment Explorer (LADEE) is wrapping up its scientific mission and will crash into the moon at the end of the month. The space agency is not sure when the lunar probe will cause a new crater and is asking the public to take part in a “Take the Plunge” challenge with winners receiving a special LADEE certificate.

As reported by NASA, LADEE is entering the final stages of its lunar mission and is lowering its altitude in preparation of the lunar impact scheduled for later this month. The space agency believes LADEE will crash into the moon sometime around April 21. The total lunar eclipse on April 15 will push the lunar probe to the edge of what it was prepared to withstand but it should survive the four-hour event. Ahead of the eclipse, LADEE will perform its last orbital maintenance maneuver which positions the probe for a targeted impact on the far side of the moon.

Butler Hine, LADEE project manager, explains that the reason why there is some uncertainty about precisely when LADEE will crash into the moon is due to the lunar atmosphere. Hine said in a statement, "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."

For those wanting to guess when LADEE will crash into the moon, NASA has set up the "Take the Plunge" challenge with the submission deadline set for April 11 at 6 p.m. EDT. You can submit your guess here and winners will receive a commemorative LADEE certificate.

LADEE launched on Sept. 6, 2013, and entered the lunar orbit on Oct. 6. The lunar probe has spent more than 100 days observing the moon’s atmosphere and lunar dust. LADEE also tested the effectiveness of the Lunar Laser Communications Demonstration, achieving record-breaking transfer speeds. LADEE was equipped with three specialized instruments, the Ultraviolet/Visible Spectrometer (UVS); the Neutral Mass Spectrometer; and the Lunar Dust Experiment (LDEX).

The UVS and NMS are used to observe the lunar atmosphere, with the former analyzing its composition and the latter measuring variations of the elements that comprise it. LDEX has collected dust samples and observed variations in lunar-dust density in regard to location, with more dust being observed in the lower altitudes of the atmosphere as well as the sunrise sector of the moon, notes NASA. The space agency says the LADEE mission has been successful, completing the 100-day main science objectives and collecting even more data than expected. While NASA is not targeting a specific lunar impact location for LADEE, it will search for the spot using the Lunar Reconnaissance Orbiter (LRO).

An animation of the LADEE lunar impact, courtesy of NASA Ames Research Center, can be viewed below.