Sky at a Glance, April 11-19

Moon, Mars and Spica

The full Moon passes between Mars and Spica in the evening before its total eclipse.

Friday, April 11

The waxing gibbous Moon shines under Leo tonight. Leo is where you get if you follow the pointer stars of the Big Dipper far enough backward.

Saturday, April 12

This evening, look far lower left of the waxing gibbous Moon for fiery, glary Mars. By about midnight they're lined up horizontally in the south.

Sunday, April 13
Vesta, the brightest asteroid, is at opposition. Ceres, the biggest asteroid, is just 2½° from Vesta and only 2 days from opposition. They're in Virgo, easy in binoculars at magnitudes 5.8 and 7.0, respectively. Use our finder chart for Ceres and Vesta (click the link in the text for printable finder chart for "Ceres and Vesta in 2014").

Monday, April 14

A total lunar eclipse happens very late tonight for the Americas! See April's Total Eclipse of the Moon with map and timetable (also in the April Sky & Telescope, page 60).

Total lunar eclipse

Aligning his camera on the same star for nine successive exposures, Sky & Telescope contributing photographer Akira Fujii captured this record of the Moon’s progress through Earth’s shadow for several hours around the eclipse of July 16, 2000.

Meanwhile Mars shines near the Moon all night, and Mars is at its closest to Earth tonight. And in addition, Spica shines much closer to the Moon than Mars does (for the Americas).

Tuesday, April 15

After dark, look east for the lineup of Mars, Spica, and the just-past-full Moon, in that order from top down.

Wednesday, April 16

The waning gibbous Moon rises soon after dark with Saturn hanging right close by. Watch them cross the sky together for the rest of the night. The Moon occults (covers) Saturn for southern South America; map and timetable.

Thursday, April 17

Ganymede, the largest satellite of Jupiter, emerges from behind Jupiter's eastern limb around 10:18 p.m. Eastern Daylight Time. It disappears into eclipse by Jupiter's shadow around 12:06 a.m. EDT, then reappears around 3:29 a.m. EDT.

Friday, April 18

Jupiter shines right under the big Arch of Spring this year. The Arch spans much of the western sky. Pollux and Castor form its top (as seen from mid-northern latitudes). To their lower left is one end of the Arch, Procyon, and farther to their lower right is the other end, Capella.

Saturday, April 19

Have you said hello to Vega yet this year? The "Summer Star" is now sparkling low in the northeast at nightfall. By dawn it's high overhead.


Want to become a better astronomer? Learn your way around the constellations. They're the key to locating everything fainter and deeper to hunt with binoculars or a telescope.

This is an outdoor nature hobby. For an easy-to-use constellation guide covering the whole evening sky, use the big monthly map in the center of each issue of Sky & Telescope, the essential guide to astronomy. Or download our free Getting Started in Astronomy booklet (which only has bimonthly maps).

Pocket Sky Atlas

The Pocket Sky Atlas plots 30,796 stars to magnitude 7.6 — which may sound like a lot, but it's still less than one per square degree on the sky. Also plotted are many hundreds of telescopic galaxies, star clusters, and nebulae.

Once you get a telescope, to put it to good use you'll need a detailed, large-scale sky atlas (set of charts). The standards are the little Pocket Sky Atlas, which shows stars to magnitude 7.6; the larger and deeper Sky Atlas 2000.0 (stars to magnitude 8.5); and once you know your way around, the even larger Uranometria 2000.0 (stars to magnitude 9.75). And read how to use sky charts with a telescope.

You'll also want a good deep-sky guidebook, such as Sue French's Deep-Sky Wonders collection (which includes its own charts), Sky Atlas 2000.0 Companion by Strong and Sinnott, the bigger Night Sky Observer's Guide by Kepple and Sanner, or the beloved if dated Burnham's Celestial Handbook.

Can a computerized telescope replace charts? Not for beginners, I don't think, and not on mounts and tripods that are less than top-quality mechanically (able to point with better than 0.2° repeatability, which means fairly heavy and expensive). As Terence Dickinson and Alan Dyer say in their invaluable Backyard Astronomer's Guide, "A full appreciation of the universe cannot come without developing the skills to find things in the sky and understanding how the sky works. This knowledge comes only by spending time under the stars with star maps in hand."


This Week's Planet Roundup

Mars on April 8th, imaged by Anthony Wesley

Mars on April 8th, imaged by Anthony Wesley in Australia. South is up. Syrtis Major is the dark downward "peninsula" near center. Clouds cover Hellas at top and Elysium at left. The North Polar cap has shrunk, exposing the dark band around it.
Anthony Wesley

Mercury is hidden deep in the glow of sunrise.

Venus (magnitude –4.3) is the bright "Morning Star" shining in the east-southeast during early dawn.

Mars this week is at its nearest to Earth in six years, blazing at magnitude –1.5 in Virgo. It was at opposition on the 8th. It glares low in the east-southeast in twilight, and dominates the southeast after dark. Fainter Spica shines from 8° to 10° below it during evening. They're highest in the south around midnight or 1 a.m. daylight-saving time.

Now's the time for Mars in a telescope! It's 15.1 arcseconds wide this week and into next week, its largest apparent diameter until 2016. See the telescopic Mars map and observing guide in the March Sky & Telescope, page 50. Use our Mars Profiler to find which side of the planet will be facing you when you plan to observe it.

Jupiter (magnitude –2.1, in Gemini) shines even brighter than Mars, in the high southwest in twilight. It sinks westward through the evening and sets around 2 a.m. In a telescope it has shrunk to 37″ across its equator. See Jupiter: Big, Bright, and Beautiful.

Saturn (magnitude +0.2, in the center of Libra) rises around 9 or 10 p.m. and is highest in the south around 3 a.m. By then it's far left of Mars, and half as far to the upper right of Antares.

Uranus and Neptune are still buried in the glow of sunrise.


Like This Week's Sky at a Glance? Watch our SkyWeek TV short.


"We may be little guys, but we don’t think small. It’s the courage of questions, of grasping our true circumstances, and not pretending we are at the center of it all, that is adulthood."
— Ann Druyan, 2014. The remade Cosmos series continues on Sunday nights. Watch online anytime.


All descriptions that relate to your horizon — 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 Daylight Time (EDT) is Universal Time (UT, UTC, or GMT) minus 4 hours.


10 thoughts on “Sky at a Glance, April 11-19

  1. Pingback: First Contact Radio – April 11, 2014 | First Contact Radio

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  9. David-Flock

    4/17/14 – My 2 kids got to see 2 of the Ganymede events tonight. My 13 year old son watched Ganymede emerge from behind Jupiter. Then
    my 8 year old daughter witnessed Ganymede being eclipsed by Jupiter’s shadow. Thanks to S&T for an enjoyable family evening with the
    telescope !

  10. Pingback: First Contact Radio – April 18, 2014 | First Contact Radio

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