A lunar eclipse on May 15 tops the list of events worthy of attention in the night sky this month.
The eclipse will begin about 8:05 p.m. MDT, as the earth's shadow begins to move across the face of the moon. The moon will be completely eclipsed about 9:15 p.m. and will remain in the earth's shadow for nearly an hour. The moon then will reappear gradually, and the eclipse will end about 11:15 p.m.
The eclipse occurs the night of the full moon, as all lunar eclipses must: It is only then that the moon, earth and sun form a straight line with the earth in the middle, which allows the sun's light to illuminate the entire face of the moon, which creates the full moon from our perspective. And it is only then that, because of its position in the middle, the earth's shadow can fall on the moon.
Because it is opposite the sun's position in our sky at this time, the moon rises as the sun sets and remains in the sky all night, setting as the sun comes up.
Because the eclipse will occur about halfway through the night, the moon will be high in the southern sky.
All solar eclipses must occur with a new moon, when the moon passes directly between the earth and the sun. A solar eclipse occurs with the new moon this month, but it will be total only from Iceland and parts of Greenland.
Although the lunar eclipse may be the most unusual event in the night skies this month, Jupiter and Saturn may be more consistent, appearing in the western sky every evening.
Saturn is lower in the sky and not as bright as Jupiter, which outshines all the stars as well.