Every February, a magical event happens at Yosemite National Park. Horsetail Fall starts to glow, looking like fire or molten lava flowing down the cliff. This event is called the Firefall and it lasts just a few minutes. Around mid- to late February, if the weather and sunlight are just right, the setting sun shines on Horsetail Fall and lights it up in bright orange and red colors. Horsetail Fall is a narrow stream running off El Capitan’s east side. Most of the year, it looks plain and quiet. But in February, the sun hits it at a special angle. This makes the water glow like flames or even smoke, creating a fiery display. Photographers and nature lovers travel from all over to catch this stunning sight. The Firefall only happens under certain conditions. There must be enough water flowing, clear or rainy skies, and the perfect angle of sunlight. If the sky is cloudy, the Firefall does not appear, and the fall looks normal. Experts say it is a delicate balance of weather, timing, and luck. Sometimes people wait and see nothing. Other times, they witness the fall blazing in brilliant fire-like colors. The glowing effect happens because of light refraction. When the sun is low in the sky in mid-February, the light bends and scatters inside the falling water. This shifts the colors and creates the bright flames seen on the rocks. It's a rare natural show that combines science and beauty in perfect harmony.