At dusk, Mercury is low in west, with faint Mars 5 degrees below and Saturn 7 degrees upper left. Although the spring equinox is still three days away, the length of day today, from sunrise to sunset, is already 12 hours. Second, refraction by the Earth's atmosphere bends light and makes the rising or setting Sun appear about one solar diameter higher than it actually is. The combination of the two effects lengthens the day by about 9 minutes in middle latitudes. Find Mercury low in W at dusk, with faint Mars 6 degrees below, and Saturn 5 degrees upper left.
Spring begins in our northern hemisphere.
At sunrise, note the Moon's left half is illuminated. Saturday, March 21 Low in west at dusk, Mercury is 5 degrees right of Saturn, their least separation. Faint Mars is 7 degrees below. On Sunday evening, the three planets form an isosceles triangle, with Mars, lowest, at the apex. By Monday, Mercury is expected to fade to equal Saturn.