Indirect evidence of water on Mars excites researchers

Not long after the Phoenix landed on Mars, it found indirect evidence for the existence of water. A few small pellets found in a trench dug by Phoenix’s robotic arm vanished two days after they were exposed, leading researchers to believe they were ice that vaporized in the thin Martian atmosphere.

But when attempts were made to place samples in one of the eight ovens aboard the spacecraft, they clumped together and failed to enter the chamber. After several further unsuccessful attempts, the scientists used a looser sample even though the chances of ice samples in it were less.

The chambers, called Thermal-Evolved Gas Analyzers, were heated slowly until they reached 32 degrees Fahrenheit, the melting point of water ice. The sample then showed a minuscule slowing in warming and extra energy was needed to continue the process. It was believed the extra energy went into melting ice and this was confirmed when the analyzers showed the presence of water vapor.

William Boyington of the University of Arizona, and the team leader for the project, said: “This is the first time that Martian water has been touched and tasted.” The Phoenix will continue its search for both water and carbon-based compounds until the end of September when the sunlight begins to fade and it loses its operating power.

Focus on the planets

September features Venus, Mercury and Mars in a close-knit triangle on the western horizon for most of the month. Likely the only naked-eye planet of the three will be Venus.

Mercury is low in the west-southwest shortly after sunset as the month opens. Look for Mercury to the lower left of Venus on Sept. 1 and directly beneath its much brighter neighbor by midmonth shortly before being lost in the glow of twilight.

Venus is by far the brightest of the three close planets but never rises far above the western horizon after nightfall.

Mars is the third – and dimmest – of the three planets gracing the western horizon at dusk. Mars is to the upper left of Venus as September opens and to its lower right by midmonth. You will need binoculars to have any chance of seeing the faint Red Planet.

Jupiter is high in the south at dusk and is second only to Venus in brightness among the planets. On the evening of Sept. 7 viewers with telescopes can watch the shadows of two of Jupiter’s moons as they transit the giant planet.

Saturn emerges into the morning sky during the last week of the month. Look for Saturn just before sunrise low on the eastern horizon. Saturn’s fabled ring system is now only 4 degrees from being edge-on.

Neptune in Capricornus and Uranus in Aquarius are both good telescope subjects but you will need finder’s charts to locate them.

September events

1 Sunrise, 5:57 a.m.; sunset, 7:13 p.m.

7 Moon in first quarter, 10:04 a.m. The moon is also at apogee, or farthest distance from Earth, today.

9 The peak night for the Perseid meteor shower, however, this year’s display will likely be no more than up to five swift, fairly faint meteors per hour.

10 Mercury, Venus and Mars lie in a circle small enough that they all fit into the eyepiece of a telescope. Unfortunately they lie so low on the horizon that the view may be obscured.

15 Full moon, 5:14 a.m. The full moon of September is the Harvest Moon as it lies closest to the autumnal equinox.

16 The sun is entering Virgo on the ecliptic.

20 The moon is at perigee, or its closest approach to Earth.

22 Moon in last quarter, 1:05 a.m. Fall or autumnal equinox, 11:44 a.m. This marks the point where the sun crosses the celestial equator into the Southern Hemisphere. The sun is entering the astrological sign of Libra but astronomically is still in Virgo.

27 The “golden star” appearing on the eastern horizon to the lower left of the crescent moon at dawn is Saturn.

29 New moon, 4:12 a.m.

30 Sunrise, 6:31 a.m.; sunset, 6:18 p.m.

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