Stretching across more than half the sky we can see three planets and the Moon this week. Mercury is visible right after sunset, very low on the northwest horizon. Mars is next--red, though dim, about 15° east of Castor and Pollux (the two bright 'twin' stars of Gemini). Saturn is only 2° away from the bright Regulus, in Leo. These three planets, coupled with the Moon, give us a clear view of the ecliptic.

The ecliptic is the imaginary line across the sky that marks the plane of the solar system. It is formally defined in two ways: 1) the path of the Sun against the background stars, and 2) the plane generated by Earth's orbit around the Sun. What we also know is that all the major planets orbit the Sun pretty close to the ecliptic plane. They will always be visible near the ecliptic. The Moon also orbits Earth near the ecliptic.

The twelve constellations of the zodiac are those constellations that cross the ecliptic.

• Feb 20 -- Lunar eclipse visible from western USA.
• 1/29; 7/9; 9/21; 11/12 -- These events may appear on calendars as occurring on the following date due to the time of the event occurring near midnight. Therefore, time zone changes will result in date changes.
• Aug 1 & 30 -- Two New Moon events in the same month.

Data about bright passes of the International Space Station can be found on our Night Sky Calendar.

Click the "Night Sky Calendar" link above to see calendar information on the Moon, seasons, and other interesting events.

Clark Planetarium, in cooperation with Stardate, has produced a short video segment, 2 minutes long, on black holes called, "Escaping Oblivion." This video clip is available in may formats/sizes. Please choose one below.