SJAA Ephemeris September 2007 | SJAA Home | Contents | Previous | Next

The Shallow Sky

The Phoenix Rises

Akkana Peck


Did you manage to get through August without reading any “WILL MARS BE AS BIG AS THE MOON?” emails? I thought I was going to skate through, but I did get some of them after all. Not as many as in past years - maybe Mars not even being up in the evening helped that a little.Well, it’s up, just barely - it rises a bit before midnight and transits near dawn, so you can get a look at it if you stay up late or rise very early.

NASA’s Mars-bound Phoenix probe launched last month, for a scheduled arrival in late May of next year. It almost missed its launch window due to weather at Cape Canaveral, so I’m sure it was a relief when it finally lifted off. Phoenix will land in Mars’ far north, where it will dig in the ice looking for evidence of organic molecules. It will also study the composition of the Martian dust and look for clues about the red planet’s atmosphere and climate.

Back on Earth, we can still see Jupiter low in the southwestern sky throughout the early evening. Catch it as early as you can, before it gets any lower.

Uranus reaches opposition on September 9, so this month and next are a great time to look for the small green disk, just barely visible to the naked eye from a dark site but easy in a telescope. It sits just west of the head (phi) of Aquarius. Neptune, a smaller, fainter and bluer disk, is running nearly two hours ahead of Uranus now, in northeast Capricornus. Pluto is getting tough this year: it’s already past its fairly low transit by the time the sky is dark enough to start looking, so it’ll take some dedication to find it this month.

Mercury is visible in the evening sky throughout the month, with a gibbous phase. Venus, on the other hand, displays a nice crescent to early morning observers.

Saturn is emerging into the morning sky. If you’re a morning person, check out the close pass of Saturn with Regulus in the first few days of the month. They’re close to the same brightness, so this is a great chance to see how different a planet looks from a star. Try a naked eye or binocular view first: see if you can tell which is which.

(I bet you’ll have no trouble telling.) Using a telescope is cheating, of course (hint: the one with the big wide rings is the planet), but after you’ve made your guess, you can use a telescope to reward yourself with views of this beautiful planet.

The last two weeks of the month are a good time for morning observers (or those who stay up all night) to look for the zodiacal light, a faint band of light extending upward from sunset or sunrise along the ecliptic. It’s caused by the reflection of sunlight off tiny bits of debris left over from the formation of the planets.

Only one problem: the moon is near full for most of that time, so try it around mid-month, before the brightening moon interferes too much, if you find yourself up before dawn in a place with very dark or clear skies.


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