Sky at a Glance | March 7th, 2008

By: Alan MacRobert March 7, 2008 0

Some daily events in the changing sky for March 7 – 15.

Comet Holmes is passing the big California Nebula in Perseus through about Wednesday the 12th. See photo and story.

When the Moon reaches first quarter late in the week, it will shine near Beta Tauri on Thursday the 13th and Mars on Friday the 14th. (The scene is drawn for the middle of North America. European observers: move each Moon symbol a quarter of the way toward the one for the previous date.)

Sky & Telescope diagram

Friday, March 7

New Moon (exact at 12:14 p.m. EST).

As the stars come out this week, the Big Dipper stands high in the northeast balancing upright on its handle. As night advances, the Dipper climbs even higher and tips leftward. Look far down to its lower right for bright Arcturus, the "Spring Star," rising in the east. Arcturus is a little more than a Dipper-length from the end of the Dipper's handle.

Saturday, March 8

Daylight Saving Time begins for most of North America at 2 a.m. Sunday morning. Clocks "spring ahead" an hour. Be sure to make this change in our online almanac (check the Daylight Saving Time box). Daylight time for North America now runs from the second Sunday in March to the first Sunday in November; the rules changed in 2007. Daylight time is not used in Hawaii, Saskatchewan, Puerto Rico, or most of Arizona.

From now through Wednesday, Mars is within 2° north of the star cluster M35 in Gemini. Use binoculars.

Sunday, March 9

Right after dark in late winter, the high northern sky is remarkably barren from Polaris all the way up to Auriga overhead. This is the realm of the huge but dim constellation Camelopardalis, the Giraffe. If you have a dark sky and are looking for a constellation-spotting challenge, try piecing out its 4th-magnitude stick figure using the fold-out evening sky map in Sky & Telescope.

Camelopardalis is home to the big, 9th-magnitude galaxy NGC 2403, which would be better known to backyard observers if it weren't in such an obscure constellation. The galaxy isn't hard to find, however. It's a fairly straightforward star-hop 8° from the nose of Ursa Major. See chart.

Monday, March 10

Tonight the 10th-magnitude asteroid 7 Iris passes close by a 6.6-magnitude star in Virgo south of Spica. The asteroid appears only about 18 arcseconds due south of the star around 4:39 a.m. EDT (1:39 a.m. PDT) Tuesday morning. A smallish scope will show them as a very unequal "double star." Real double stars this wide take millennia to change — but this one will change visibly in just minutes! See the finder chart in the March Sky & Telescope, page 72.

Tuesday, March 11

Southern Hemisphere observers will find the red variable star S Carinae at its brightest (5th or 6th magnitude) this week.

Wednesday, March 12

This evening the waxing Moon in the west makes a pretty picture with the Pleiades to its lower right, and Aldebaran and the Hyades farther to its left.

Thursday, March 13

A small telescope will always show Titan, Saturn's largest and wildest moon. Tonight Titan is four ring-lengths to Saturn's west. A 6-inch telescope will begin to show the orange color of its upper-atmosphere haze. (A guide to identifying all six of Saturn's satellites visible in amateur scopes is in the March Sky & Telescope, page 62.)

Friday, March 14

First-quarter Moon (exact at 6:46 a.m. EDT).

Around midnight tonight Eastern Daylight Time, the Moon passes 1° south of Mars.

Saturday, March 15

The Moon shines dead center in Gemini high overhead after dark.

Want to become a better amateur astronomer? Learn your way around the constellations. They're the key to locating everything fainter and deeper to hunt with binoculars or a telescope. For an easy-to-use constellation guide covering the whole evening sky, use the big monthly foldout map in each issue of Sky & Telescope, the essential magazine of astronomy. Or download our free Getting Started in Astronomy booklet (which only has bimonthly maps).

Once you get a telescope, to put it to good use you'll need a detailed, large-scale sky atlas (set of maps; the standards are Sky Atlas 2000.0 or the smaller Pocket Sky Atlas) and good deep-sky guidebooks (such as Sky Atlas 2000.0 Companion by Strong and Sinnott, the even more detailed Night Sky Observer's Guide by Kepple and Sanner, or the enchanting though increasingly dated Burnham's Celestial Handbook). Read how to use them effectively.

More beginners' tips: "How to Start Right in Astronomy".

This Week's Planet Roundup

Mars is now a featureless little gibbous blob in most telescopes, but Sean Walker recorded its major features well on the evening of March 2nd using a 12.5-inch scope, stacked video frames, and some fairly intense image processing. North is up. Syrtis Major pokes upward on the right, and Sinus Sabaeus runs leftward to Sinus Meridiani on the sunrise terminator. Mars was 8.9 arcseconds in diameter at the time. The central-meridian longitude was 320°.

S&T: Sean Walker

Mercury (magnitude +0.0) remains within 3° of brilliant Venus low before sunrise. It's dozens of times fainter, so bring binoculars. Look for it just to Venus's right.

Venus (magnitude –3.8) is getting lower every morning. Look for it just above the east-southeast horizon about 30 minutes before sunrise.

Mars (about magnitude +0.4, near the feet of Gemini) shines very high in the south to southwest during evening, high over Orion. It fits in the same binocular field with the open star cluster M35. In a telescope, Mars dwindles from 8.5 to 8.0 arcseconds wide this week — quite tiny.

Jupiter (magnitude –2.0, in Sagittarius) shines low in the southeast before and during dawn. The best time to examine it with a telescope is actually during dawn, when Jupiter is highest and when the atmospheric seeing may become steadiest. The farther south you live, the higher Jupiter will be.

Jupiter often changes its face from year to year and sometimes from week to week. Currently, the North Equatorial Belt (brown band just above center) remains wide and very dark. Can your scope split the thinner, doubled North Temperate Belt just above it? The South Equatorial Belt (just below center) has divided into a dark northern half and a lighter southern half. Mike Salway took this image from Australia (where Jupiter rises high before dawn) on March 2nd. North is up, and the System II central-meridian longitude was 216°. Little yellow Io is at right (celestial west). The Great Red Spot is on Jupiter's other side.

Mike Salway

Saturn (magnitude +0.2, close to Regulus in Leo) glows in the east-southeast as twilight fades. It rises higher all evening, and stands highest in the south around midnight daylight saving time.

Regulus (magnitude +1.4) is now just 4° from Saturn: to its upper right in early evening, and directly right of it later. Only a little dimmer than Regulus is Gamma (γ) Leonis (magnitude +2.1), located 8° to Saturn's north. The three make a narrow, eye-catching triangle. Watch the triangle get even narrower in the coming weeks.

Uranus and Neptune are hidden in the glare of the Sun. (Neptune is near Venus and Mercury, but it's too dim to see through the bright dawn even with a telescope.)

Pluto (magnitude 14.0, in Sagittarius) is in the southeast before dawn's first light.

All descriptions that relate to your horizon or zenith — including the words up, down, right, and left — are written for the world's mid-northern latitudes. Descriptions that also depend on longitude (mainly Moon positions) are for North America. Eastern Standard Time (EST) equals Universal Time (UT, UTC, or GMT) minus 5 hours. Eastern Daylight Time (EDT) is UT minus 4 hours.

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About Alan MacRobert

Alan M. MacRobert became an avid Sky & Telescope subscriber in 1966 at age 14, joined the editorial staff in 1982, and is now a senior contributing editor, semi-retired. He played a role in practically every part of the magazine and the company's other products for more than a generation, both on the amateur-observing side and the science-reporting side. In 1994 a book collection of his observing how-tos and telescopic sky tours was published as Star Hopping for Backyard Astronomers. He has produced This Week's Sky at a Glance online every week since 1989.