Mega Sigra learning media is a learning media that was developed for the purpose to supporting the achievement of learning objectives on eclipse material, Natural Science subjects for Grade VI Elementary Schools. Mega Sigra development through four phases (4D), they are: define phase, design phase, develop phase and disseminate phase. The difference and uniqueness of Mega Sigra compared to the eclipse simulation media that existed previously, namely the globe and the moon can rotate and evolve automatically due to being driven by a wall clock. In addition, it is also equipped with a camera that can record images and video simulations of solar and lunar eclipses. Images and videos can be printed or watched through a display on a computer screen. The overall validity test results were 87.5%, indicating that Mega Sigra was very valid for use. The practicality of the observer test results of 78.91% shows that Mega Sigra is practically used, while the practicality test through student responses of 92.50% shows that Mega Sigra is very practical to use. In the effectiveness test, Mega Sigra showed very effective results of its use. This is based on the average value of learning outcomes achieved by students in posttest activities, reaching a value of 83.7. This value is much increased from the pretest value which only reached 37.5. It also far exceeds the expected KKM of 70.00. Posttest scores also greatly increased from the average learning outcomes obtained by class IV students in 206 at 63.5 and in 2017 at 67.5, on the same learning material..