Friday, January 10
The waxing gibbous Moon passes 5° north of Jupiter in Taurus at 6 P.M. EST. This evening, our satellite appears to Jupiter’s upper left in the sky, forming the apex of a triangle with the magnitude 1.7 star Elnath to Luna’s lower left. Jupiter is still extremely bright and easy to find, shining at magnitude –2.7 following its opposition last month.
To the Moon’s far upper right is the famous open star cluster M45, also called the Pleiades. Our satellite occulted these stars just yesterday, appearing to pass in front of them from our point of view. And in just three more days, the Moon is at it again, occulting Mars in an event visible across the U.S.
Below the scene splayed out in Taurus is one of the sky’s most recognizable constellations, Orion the Hunter. The three stars that form Orion’s Belt are, from east to west, magnitude 1.7 Alnitak, magnitude 1.7 Alnilam, and magnitude 2.3 Mintaka. That first star, Alnitak, is a hot, blue-white O-type star that is the brightest of its type in the sky. The middle star, Alnilam, is just slightly brighter than its neighbor, though this difference is likely invisible to the naked eye. It is also a hot, blue-white star, although its type is B, not O. And finally, fainter Mintaka is itself a binary star with components too close to separate with a telescope. Additionally, it is part of a multiple-star system with a companion shining at 7th magnitude nearly an arcminute away, and a 14th-magnitude component between them.
Sunrise: 7:22 A.M.
Sunset: 4:54 P.M.
Moonrise: 1:32 P.M.
Moonset: 4:24 A.M.
Moon Phase: Waxing gibbous (88%)
*Times for sunrise, sunset, moonrise, and moonset are given in local time from 40° N 90° W. The Moon’s illumination is given at 12 P.M. local time from the same location.
Saturday, January 11
Today is the date Venus is predicted to reach dichotomy, when its face appears exactly half-lit from Earth.
You can spot Venus in the evening sky, lingering in the southwest for nearly four hours after sunset. At magnitude –4.5, it’s a blazing point of light you can’t miss, hanging amid the much fainter stars of Aquarius. First-magnitude Saturn is also visible, some 6.5° to Venus’ upper left (east), while similarly bright Fomalhaut, the alpha star in Piscis Austrinus, will appear to the planetary pair’s far lower left once the sky grows dark.
But Venus is definitely the target for our attention tonight. Use any size telescope to zoom in on the planet, whose disk spans an impressive 25”. Look carefully at the phase — it should be exactly 50 percent lit, with the terminator separating night from day appearing as a straight line. However, Venus’ appearance can sometimes differ from predictions, thanks to effects from its thick atmosphere. So, sketch or photograph the planet to bring out detail for comparison later.
Earth’s sister world will remain prominent in the evening sky, allowing for additional observations over the coming days to watch its apparent size and phase evolve.
Sunrise: 7:21 A.M.
Sunset: 4:55 P.M.
Moonrise: 2:25 P.M.
Moonset: 5:36 A.M.
Moon Phase: Waxing gibbous (94%)
MiraChartPH.png
Sunday, January 12
Mars comes closest to Earth this morning at at 9 A.M. EST. At that time, the Red Planet will lie 59.7 million miles (96.1 million kilometers) away. In just a few days, the Sun, Earth, and Mars will line up exactly, bringing the world to opposition in our sky. But first, the Moon will occult the Red Planet tomorrow evening, so stay tuned for more details on that exciting event shortly.
Tonight, let’s look south in the early evening to spot Orion aiming his bow at two huge creatures in the sky: Taurus the Bull, immediately to the Hunter’s right; and Cetus the Whale, on the other side of Taurus.
Cetus is “helmed” by an alpha star named Menkar, near its eastern border with Taurus. This magnitude 2.5 red giant is actually Cetus’ second-brightest star, after magnitude 2 Diphda (also known as Deneb Kaitos) in the southwestern region of the constellation. In between these two suns, about one-third of the way on a line drawn from Menkar to Diphda, is Mira, a well-known variable star — or, at least, its position, as it is not currently visible to the naked eye.
This red giant has a period of just under a year — 332 days — and spends about half the year as a visible part of the constellation, while the other half of the time, as now, it’s too faint to pick up without optical aid. It swings between 2nd and 10th magnitude — a huge variation — and has been most recently been observed around magnitude 8, meaning you will need binoculars or a small scope to find it. But once you do, note down its position; in a few months, you won’t need any help to see this star shining in the sky!
Sunrise: 7:21 A.M.
Sunset: 4:56 P.M.
Moonrise: 3:29 P.M.
Moonset: 6:39 A.M.
Moon Phase: Waxing gibbous (98%)
Monday, January 13
Full Moon occurs at 5:27 P.M. EST. January’s Full Moon is also called the Wolf Moon.
Look east after sunset, and you’ll see that Full Moon rising in the constellation Gemini, close to the small red point of light marking the position of Mars. The Moon will draw closer to the planet as time passes, covering it in an occultation this evening visible for observers across the U.S., Mexico, southeastern Canada, and western Africa.
The timing of the event depends on your location. Additionally, those on the Pacific Coast will see the occultation occur during evening twilight. You’ll need binoculars or a small telescope to watch Mars slide behind the Moon, as the Moon’s bright light will overwhelm that of the planet once it gets close.
On the East Coast, the event starts around 9:20 P.M. EST; Kansas City and similar cities in the Midwest will see Mars disappear around 8 P.M. CST. Denver residents will see the occultation begin just a few minutes before 7 P.M. MST, while on the West Coast, the Moon will slide in front of Mars some 10 minutes before 6 P.M. PST. You can check out the International Occultation Timing Association’s webpage for the occultation for the precise timing of the event near your location, though note dates and times are given in Universal Time and will require conversion to local time.
Following the occultation, the Moon passes 0.2° north of Mars at 11 P.M. EST.
Sunrise: 7:21 A.M.
Sunset: 4:57 P.M.
Moonrise: 4:38 P.M.
Moonset: 7:32 A.M.
Moon Phase: Full
Tuesday, January 14
Even as it’s headed for conjunction with the Sun and a ring-plane crossing in just a few months, Saturn remains visible for several hours after sunset this month. The magnitude 1.1 planet lies in Aquarius, made easy to find by bright Venus, which blazes in the southwest as a magnitude –4.5 evening star long after the Sun has gone down.
Tonight, Saturn sits just 4° to the upper left of Venus; the ringed planet is the second-brightest object in the region, after Venus. Pull out your telescope and you’re in for a treat, as the rings appear thin but still easily visible, tilted just under 3.7° to our line of sight, their northern face on display.
Also visible is Saturn’s largest and brightest moon, mid-8th-magnitude Titan, located some 40” from the center of the planet this evening, to its west. Tenth-magnitude Dione and Tethys may also be visible in larger scopes, located just east of Saturn, while Rhea disappears behind the planet’s northwestern limb in an occultation around 6:50 P.M. EST, passing behind the gas giant and through its dark shadow to finally reappear around 8:27 PST, visible only to observers in the western U.S.
Come back tomorrow night and you’ll find Titan still nearby, located roughly the same distance from Saturn but on the other side of the planet, now to the east.
Sunrise: 7:20 A.M.
Sunset: 4:59 P.M.
Moonrise: 5:49 P.M.
Moonset: 8:13 A.M.
Moon Phase: Waning gibbous (99%)
Wednesday, January 15
Mars opposition is finally here! The Red Planet officially reaches opposition at 10 P.M. EST, when it is visible in the east beneath the heads of Gemini the Twins, Castor and Pollux. At magnitude –1.4, Mars far outshines them, rivaling the brightest star in the sky, Sirius in Canis Major.
But of course, let’s focus on Mars, which is now at its very best for the year. The planet’s disk spans 14.6” and even shows off some surface features in larger scopes. Central on the disk around 9 P.M. in the mid-U.S. is Sinus Meridiani, a dark feature running east-west just south of the martian equator. The north polar cap may also be on display. These are best captured with high-speed video under good seeing conditions.
Even without a telescope, Mars should stand out as a bright, reddish point of light in the star-studded sky. Compared to the planet’s ruddy hue, nearby Castor appears blue-white and Pollux more golden. Because it is at opposition, Mars will rise around sunset and set around sunrise, meaning it’s visible all night. The now-waning Moon also makes an appearance two constellations over in Leo, near the Sickle asterism. You can try to catch Mars a bit earlier in the evening before the Moon rises if you want a truly dark sky, though the planet will sit lower to the horizon and your view through Earth’s turbulent atmosphere may not be as clear. The very best views will come around local midnight, when Mars is highest in the sky, about 75° above the southern horizon.
Sunrise: 7:20 A.M.
Sunset: 5:00 P.M.
Moonrise: 6:58 P.M.
Moonset: 8:45 A.M.
Moon Phase: Waning gibbous (96%)
Thursday, January 16
This evening we’re visiting the fifth planet from the Sun, the mighty gas giant Jupiter. Shining at magnitude –2.7 in Taurus, the planet gives the Bull’s face the appearance of two bright eyes, rather than just the one (magnitude 0.9 Aldebaran, the Bull’s right eye as it faces us in the sky).
Fix your telescope on Jupiter to catch its innermost moon, Io, beginning a transit of the disk around 8:36 P.M. EST, moving from east to west. About an hour later, at 9:32 P.M., Io’s shadow joins it, trailing behind. The moon’s transit lasts until 10:48 P.M. EST, while the shadow ends its journey just before midnight, slipping off the cloud tops around 11:44 EST.
But that’s not all — you may have noticed during this time that Ganymede has been drawing closer from the west, approaching Jupiter’s northwestern limb. Right around the time Io’s shadow is finishing its transit, Ganymede is slipping behind the planet’s limb, taking several minutes to fully disappear. It crosses behind the planet over the next two hours, reappearing at the northeastern limb at 1:51 A.M. EST (now the 17th in the Eastern and Central time zones).
Keep watching into the early morning hours of Friday, and you’ll see Ganymede wink out of sight some 90 minutes later, now passing into Jupiter’s long, dark shadow — some 15” from the limb — around 3:30 A.M. EST. The large moon will begin to fade just moments before this time.
Sunrise: 7:20 A.M.
Sunset: 5:01 P.M.
Moonrise: 8:04 P.M.
Moonset: 9:12 A.M.
Moon Phase: Waning gibbous (92%)
Friday, January 17
Today could be one of your last chances to see Mercury in the early-morning sky, as the tiny planet is quickly lost in twilight as it approaches the Sun.
At magnitude –0.5 Mercury is quite bright, but stands only 2° high in the southeast 30 minutes before sunrise. It’s likely the only point of light in this part of the sky you’ll see, though bright Antares to its far upper right and Altair to its far upper left may also be visible if you’ve got sharp eyes.
Through a telescope, the planet’s disk appears nearly full, some 92 percent lit. But it is only 5” across, as Mercury currently sits some 125.5 million miles (202 million km) from Earth.
Mercury will continue to sink in the morning sky until it’s invisible from our point of view. It will reappear in the evening sky in late February, so we’ll make sure to catch up with it then!
Sunrise: 7:19 A.M.
Sunset: 5:02 P.M.
Moonrise: 9:06 P.M.
Moonset: 9:35 A.M.
Moon Phase: Waning gibbous (85%)
Sky This Week is brought to you in part by Celestron.
