Phoenix’s landing on Mars brings exciting surprises

The $420 million Phoenix spacecraft touched down on the Martian surface May 26 and inadvertently began to pay dividends at once. Its thrusters had blown away a thin layer of topsoil and revealed a patch of white shiny material directly beneath the craft.

Was it water ice, dry ice (frozen carbon dioxide) or salt? The answer seems to be water ice as it disappeared through sublimation or direct conversion to vapor from solid form. The Martian surface is too warm for dry ice to exist and salt would not have sublimed at all.

This means the Phoenix immediately can embark on its primary goal of looking for organic molecules, the precursors of primitive life, in the water-containing soil. The search site has been named “Holy Cow” after an excited exclamation from a woman with the Planetary Society as the first pictures of the ice patch were transmitted to NASA.

Focus on the planets

Mercury can be found in the east-northeast about three-quarters of an hour before sunrise where it lies to the lower left of Aldebaran. Mercury will drop from sight around midmonth.

Venus begins a gradual return to the evening sky as the month opens. By July 26, look for Venus low in the northwest about 15 minutes after sunset. It will be another month before Venus, the jewel of the fall and winter sky, affords decent viewing by telescope.

Mars starts the month in the west at nightfall where it is just above brighter Regulus. Binoculars will afford a good contrast between orange Mars and blue-white Regulus. Saturn is to the upper left of Mars.

Jupiter rises around sunset and is high in the south by midnight. Surface features such as the dark equatorial bands are visible, as is the dance of Jupiter’s moons around and across the face of the giant planet.

Saturn is high in the west an hour after sunset and spends the month in intricate maneuverings with Mars and Regulus. The fabled ring system is closing but is still worth a look as this is Saturn’s last month of visibility before being swallowed in the sun’s glare.

Uranus and Neptune are high in the south during morning twilight in Aquarius and Capricornus respectively. Go online at skyandtelescope.com/uranusneptune for finder’s charts for these two distant planets.

July events

1 Sunrise, 4:53 a.m.; sunset, 8:25 p.m. The moon is at perigee, its closest approach to Earth, today.

2 The midpoint of the year occurs at 1 a.m.

3 New moon, 10:19 p.m.

4 Earth is at aphelion, or greatest distance from the sun, today. We are 3.4 percent more distant than at perihelion, which occurs on Jan. 3.

6 Saturn, Mars and Regulus are lined up in descending order on the western horizon at twilight with the crescent moon to their lower left. It may be possible to see Venus far to the trio’s lower right.

10 Moon in first quarter, 12:34 a.m. Mars is less than 1 degree to the lower left of Saturn shortly after sunset on the western horizon. Regulus is some distance away to the pair’s lower right.

14 The moon is at apogee, or greatest distance from Earth, today.

18 Full moon, 3:59 a.m. The full moon of July is known as the Thunder Moon, Hay Moon or Buck Moon.

20 The sun enters Cancer on the ecliptic.

22 The sun enters the astrological sign of Leo; however, it has just entered Cancer astronomically.

25 Moon in last quarter, 2:42 p.m.

27 This is the peak night for the Delta Aquarid meteor shower. Expect 10 to 20 fast and somewhat faint meteors an hour originating out of Aquarius in the early morning hours.

29 The moon is at perigee for the second time this month.

31 Sunrise, 5:19 a.m.; sunset, 8:03 p.m.