Highlights. 1  Acute myocardial infarction is the medical name for a heart attack. 2  A number of different factors may increase your risk for a heart attack, including high blood pressure, high cholesterol, and diabetes.  Call 911 immediately if you believe you or someone you know may have had a heart attack.
The blue color of the sky is due to Rayleigh scattering. As light moves through the atmosphere, most of the longer wavelengths pass straight through. Little of the red, orange and yellow light is affected by the air. However, much of the shorter wavelength light is absorbed by the gas molecules.
Each planet reflects the light of the sun differently. Know what color youâre looking for in the night sky. 1  Mercury: this planet twinkles, flashing a bright yellow color. 2  Venus: Venus is often mistaken for a UFO because it is large and silver. 3  Mars: look for a reddish planet in the night sky for Mars.