This Week’s Sky at a Glance

Update on Comet PanSTARRS: The incoming comet that we once hoped would make a fine showing in March now seems unlikely to brighten past 3rd magnitude. It will be low in the western evening twilight, so even peaking at 2nd magnitude might not be quite bright enough to be visible to the unaided eye. But PanSTARRS should be in range of binoculars and wide-field telescopes. See our updates and finder charts at SkyandTelescope.com/panstarrs.

Friday, February 22

  • Look to the right of the gibbous Moon this evening for Procyon, and above the Moon for Pollux and (higher) Castor. The Moon is 1.3 light-seconds from Earth; Procyon, Pollux, and Castor are 11, 34, and 52 light-years in the background, respectively.

    The Moon passes Regulus a day before it turns full on the 25th.

    Saturday, February 23

  • At this time of year, the Big Dipper stands on its handle in the northeast during evening. The top of the Dipper — the two Pointer stars, pointing left to Polaris — are now at exactly Polaris's height around 8 p.m. (depending on where you live in your time zone).

    Sunday, February 24

  • After dinnertime at this time of year, four carnivore constellations stand in a row from the northeast to south. They're all seen in profile with their noses pointed up and their feet (if any) to the right: Ursa Major in the northeast (with the Big Dipper as its brightest part), Leo in the east (with the Moon by his forefoot tonight), Hydra the Sea Serpent in the southeast, and Canis Major in the south.

  • Telescope users in eastern North America can watch Jupiter's moon Europa reappear out of eclipse from Jupiter's shadow around 6:59 p.m. EST. Then Io reappears out of eclipse around 8:55 p.m. EST. Both events happen just east of the planet.

    Monday, February 25

  • Full Moon this evening (exactly full at 3:26 p.m. EST). The Moon is south of Leo: in the dim constellation Sextans for part of the night.

    As the waning Moon marches later into the night, it passes Spica and Saturn.
    Leo announces spring... or at least spring's approach.
    On the nights when the Moon rises with Spica and Saturn, the pairings shift to the high southwest by dawn.
    Sky & Telescope

    Tuesday, February 26

  • With spring less than a month away, Orion is starting to tip over toward the southwest fairly early in the evening now.

    Wednesday, February 27

  • The seasons are turning; by 8 or 9 p.m. the Big Dipper has climbed as high in the northeast as Cassiopeia has sunk in the northwest.

    Thursday, February 28

  • Look for Spica very close to the waning gibbous Moon late this evening, as seen from North America. The Moon occults (hides) Spica for viewers from southeastern Mexico through central South America; map and timetables (date and times are in Universal Time).

    Friday, March 1

  • Around 11 p.m. this evening (depending on where you live), the waning Moon rises with Saturn glowing a few degrees to its left, as shown above. The pair remain close for the rest of the night.

    Saturday, March 2

  • Now that March has begun, it's Sirius's turn to stand at its highest in the south soon after nightfall.


    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 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).

    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 the even larger Uranometria 2000.0 (stars to magnitude 9.75). And read how to use sky charts with a telescope effectively.

    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.


    This Week's Planet Roundup

    The shadow of Ganymede was passing the Great Red Spot when Christopher Go took this image of Jupiter at 10:59 UT February 6th. South is up. Note the white outbreaks in the South Equatorial Belt downstream from the Great Red Spot. Another is below them in the North Equatorial Belt.

    Mercury is low in the western twilight and rapidly fading: from magnitude +0.8 on February 22nd to +4 on March 1st! Catch it early in the week before it's gone.

    Venus is hidden in the glare of the Sun.

    Mars is lost in the glow of sunset, even lower than Mercury.

    Jupiter (bright at magnitude –2.4, in Taurus) comes into view very high in the south after sunset and dominates the southwest later in the evening. To its left is orange Aldebaran; farther to its right are the Pleiades. The whole group sets in the west-northwest around 1 a.m. local time.

    In a telescope, Jupiter is shrinking as Earth pulls farther ahead of it in our faster orbit around the Sun. This week it shrinks from 40 to 39 arcseconds wide.

    This extraordinary amateur image of Saturn was captured by Darryl Pfitzner Milika in Australia on January 26th. He used a 14-inch Celestron Schmidt-Cassegrain scope and an ASI120MM planetary video camera for frame-stacking. Just visible is the hexagonal shape of the storm that surrounds Saturn's north pole. The hexagon shape was first discovered by the Cassini spacecraft in 2007. South is up.

    Also visible in his image are four of Saturn's moons. From left: Dione, Enceladus, Mimas (!), and Tethys. Click for larger view.

    Darryl Pfitzner Milika

    Saturn (magnitude +0.5, in Libra) rises in the east-southeast around 11 p.m. Watch for it to come up well to the lower left of Spica and farther to the lower right of brighter Arcturus. Saturn shines highest in the south before dawn — more or less between Spica to its right and Antares farther to its lower left.

    Uranus (magnitude 5.9, in Pisces) is getting low in the west after dusk. But after I said last week that Uranus is "disappearing," Trond Larsen in Norway wrote to say that Uranus "is still easily observable; it's closing in on [the similarly bright star] 44 Piscium." Based on past experience, he says, "I think the duo Uranus/44 Psc will remain visible until about March 5." You will, however, need clear air and a good low western view. But you've already been scouting out good low western views for Comet PanSTARRS, right?

    Neptune is in conjunction with Sun.


    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 Standard Time (EST) equals Universal Time (also known as UT, UTC, or GMT) minus 5 hours.


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