Space exploration has left dozens of functioning and dead spacecraft and associated debris wandering about the solar system, and nowhere is it more evident than at Mars. Depending upon whether you count lost or missing space probes, there have been between 43 and 70 missions earmarked for the Red Planet between the year 1960 and the present. Many never came near Mars, failed to achieve orbit, crashed on the planet’s surface or simply vanished.

The first successful landing on Mars came with the Viking 1 orbiter in 1975. This was the first attempt to detect signs of life on Mars. Today three orbiters and two rovers are studying Mars, and even more are in the planning stages.

Focus on the planets

Mercury transits, or passes across the face of the sun, on May 9 for the first time since Nov. 8, 2006. Otherwise Mercury will remain hidden for much of the month, barely peeking above the eastern horizon the last two or three days of the month.

Venus is on the far side of the sun from Earth and is not visible during May.

Mars is at its peak visibility at midmonth but is visible all month. Mars rises in the southeast about two hours after sunset on May 1 but rises in conjunction with sunset by midmonth and stays in view all night. Mars will be at its brightest since 2005 and comes closest to Earth on May 30. Good conditions and a powerful telescope will reveal many surface features of the Red Planet.

Jupiter is prominent high in the south at nightfall. The giant planet is the brightest object in its section of the sky as May opens but will gradually fade as the month progresses. Still, telescopes will reveal surface features and the incessant dance of the four major moons about the planet.

Saturn trails Mars into the sky by about a half-hour, and the two remain neighbors all month. A large tilt to the ring system offers excellent viewing, and the major moon Titan also is very much in evidence.

Uranus and Neptune are both lost in the Sun during May.

May events

1: Sunrise, 5:26 a.m.; sunset, 7:40 p.m. This is May Day or Beltane, a cross-quarter day marking the midpoint between the spring equinox and summer solstice.

5: This is the peak night for the Eta Aquarid meteor shower. The new moon makes for an excellent viewing opportunity. You can expect an average of 10 to 20 meteors per hour out of the vicinity of Aquarius.

6: The moon is at perigee or closest approach to Earth. New moon, 3:31 p.m.

7: Looking to the southwest an hour before sunrise will reveal Saturn forming a triangle with Mars to its lower right and Antares to the latter’s lower left.

8: The thin crescent moon is in the west about an hour after sunset with Betelgeuse to its immediate left and Aldebaran well to the lower right of the moon.

9: Mercury will transit the sun appearing as a tiny black dot. Caution: Don’t look directly at the sun. The safest bet is to watch the event on the Internet or at a local observatory.

13: First-quarter moon, 1:03 p.m. The sun enters Taurus on the ecliptic. Look for Regulus of Leo to the upper left of the moon around 10 p.m.

18: The moon is at apogee or farthest distance from Earth. The sun enters the astrological sign of Gemini.

21: Full moon, 5:14 p.m. The full moon of May is known as the Flower Moon, Milk Moon or Corn Moon. Look for Mars, Saturn and Antares congregating about the moon tonight.

29: Last-quarter moon, 8:12 a.m.

30: Mars is at its nearest approach to Earth and will appear particularly large and bright tonight.

31: Sunrise, 4:53 a.m.; sunset, 8:13 p.m.

Send astronomical queries to Clair Wood at cgmewood@aol.com or care of the Bangor Daily News, Features Desk, P.O. Box 1329, Bangor, Maine 04402.