The Sky This Week from Oct. 10 to 17: The Moon meets Jupiter

The Moon and Jupiter are seen beginning round midnight; they proceed to rise larger within the early morning. Credit: Stellarium/Noctua Software (Landscape: Fabien Chereau)

Sky This Week is dropped at you partially by Celestron.

Friday, October 10
The Moon passes 5° north of Uranus at 5 A.M. EDT. The pair is seen within the southwest within the hours main as much as dawn, though you’ll want binoculars to view the distant ice large, because it glows a faint magnitude 5.6. Look for Uranus simply over 4° south of Pleiades.

There’s a brief darkish window this night earlier than the Moon rises. Use it to see for those who can spot the small, often-overlooked constellation Triangulum, which lies between Andromeda and Aries. You’ll discover this star sample some 20° excessive within the east round 8 P.M. native daylight time, about 40 minutes earlier than moonrise. 

As its title suggests, three brilliant stars in Triangulum type a triangle. Beta (β) Trianguli is definitely the brightest of those, shining at magnitude 3.0. You’ll discover it 7.5° south-southeast of 2nd-magnitude Almach in Andromeda. Magnitude 3.4 Alpha (α) Tri lies about 6.5° southwest of Beta, whereas magnitude 4.0 Gamma (γ) Tri is simply 2° east-southeast of Beta. The Triangle’s small dimension is usually what aids observers to find it.

Triangulum is probably most well-known for internet hosting M33, additionally known as the Pinwheel Galaxy. This deep-sky treasure is situated on the constellation’s far western border, about 4.3° northwest of Alpha Tri. Despite shining at magnitude 5.7, M33’s floor brightness is sort of low, making it troublesome to identify below brilliant situations. Give it a strive with binoculars or a telescope earlier than the Moon rises, however don’t be discouraged if our satellite tv for pc’s brilliant mild makes the view troublesome. We’ll revisit this area sooner or later, when the sky is darker and your chances are high higher. 

Sunrise: 7:06 A.M.
Sunset: 6:27 P.M.
Moonrise: 8:39 P.M.
Moonset: 11:37 A.M.
Moon Phase: Waning gibbous (82%)
*Times for dawn, sundown, moonrise, and moonset are given in native time from 40° N 90° W. The Moon’s illumination is given at 12 P.M. native time from the identical location.

Saturday, October 11
Last week, Io and Europa took a visit collectively throughout Jupiter, transiting the planet with their shadows. The moons’ resonant orbits imply comparable occasions usually repeat, and this morning is your likelihood to catch one other one. 

Bright Jupiter stands excessive above the japanese horizon through the early-morning predawn hours. By 4:30 A.M. EDT, Europa’s shadow is already seen on Jupiter’s massive disk, whereas Io and Europa sit off to the planet’s east. Note that though it’s Europa’s shadow on the cloud tops, Io seems bodily nearer to the planet, with Europa to Io’s east. Io’s shadow seems at 4:43 A.M. EDT, and by 4:50 A.M. EDT, each are readily seen. 

The two moons proceed approaching Jupiter’s japanese limb, with Io reaching it first simply over an hour later, at 5:58 A.M. EDT. The shadows are a bit greater than midway throughout the disk by this level, Europa’s shadow nonetheless main. Europa’s transit begins at 6:43 A.M. EDT, because the shadows are approaching the western limb. The shadow transits finish simply three minutes aside, beginning at 6:53 A.M. EDT. 

If you’ve cloudy skies or just aren’t capable of catch the transit, don’t fear — there shall be one other on the morning of the 18th, though the view shall be higher for these within the western half of the U.S.

Sunrise: 7:07 A.M.
Sunset: 6:26 P.M.
Moonrise: 9:38 P.M.
Moonset: 12:50 P.M.
Moon Phase: Waning gibbous (73%)

Sunday, October 12
Now that spooky season is upon us, let’s chase some cosmic ghosts. Tonight we’re searching for the Saturn Nebula (NGC 7009), a planetary nebula that, as its title implies, seems to be like a ghostly model of the ringed planet. 

You’ll discover this nebula in western Aquarius, highest within the southern sky round 8 or 9 P.M. native daylight time. As a bonus, that is earlier than the Moon rises and the sky must be darkish, aiding the view. 

NGC 7009 glows at eighth magnitude; snagging it via a telescope is comparatively straightforward, although the bigger your scope, the higher the view. Once you’ve discovered it — simply over  1° west of magnitude 4.5 Nu (ν) Aquarii — swap to excessive magnification to convey out particulars. In explicit, this nebula includes a spherical bubble in addition to two projections, known as ansae, which lend it the likeness of Saturn and earn it the widespread title. 

NGC 7009 is a planetary nebula, however it has nothing to do with planets. Instead, it has fashioned because the getting old star inside it dies, blowing off materials into house and lighting it up from inside. That central star shines at magnitude 11.5, additionally seen in a telescope. 

Sunrise: 7:08 A.M.
Sunset: 6:24 P.M.
Moonrise: 10:45 P.M.
Moonset: 1:52 P.M.
Moon Phase: Waning gibbous (62%)

Monday, October 13
Last Quarter Moon happens this afternoon at 2:13 P.M. EDT. Just a few hours later, the Moon passes 4° north of Jupiter at 6 P.M. EDT. The pair rises round midnight and are seen into the early-morning hours of October 14. 

The Moon lies simply to the decrease left of brilliant Jupiter; the planet is now magnitude –2.2, the brightest level of sunshine in that area of the sky, far outshining the celebs. To Jupiter’s higher left are Castor and Pollux, the brightest stars in Gemini the Twins. Pollux is barely brighter (magnitude 1.2) and glows a golden yellow. Castor (magnitude 1.6) is a blue-white star that simply splits into two via a telescope, revealing almost twin stars some 5” aside.

Turning a telescope on Jupiter will present all 4 of its Galilean moons seen earlier than daybreak. Callisto is farthest east, with Io closest to the planet on that facet and Europa between them. Ganymede lies alone to Jupiter’s west. 

Sunrise: 7:09 A.M.
Sunset: 6:23 P.M.
Moonrise: 11:56 P.M.
Moonset: 2:41 P.M.
Moon Phase: Waning gibbous (51%)

Tuesday, October 14
Pluto is stationary in Capricornus at 4 A.M. EDT. If you need to strive your luck with the distant dwarf planet, this night shall be an excellent alternative, because the Moon dominates the predawn sky. 

Pluto is highest round 7:30 P.M. native daylight time, when it stands about 25° excessive within the south. It is situated in southwestern Capricornus about 7° northwest of 4th-magnitude Psi (ψ) Capricorni. However, the tiny world glows an extremely faint magnitude 15.3, so that you’ll want a big scope and darkish observing web site to identify it. A go-to drive is your finest guess, as it could actually take you proper to the right subject. Pluto’s disk is simply 0.1” vast; it would seem like a really dim, “flat” star. 

If you don’t have a big scope, there’s nonetheless loads on this area of the sky to take pleasure in. Nearby is Sagittarius, a constellation rife with deep-sky wonders akin to M75, a globular cluster proper over the border from Capricornus. It is situated simply 3° northwest of Pluto’s place, and once more a go-to scope will land you proper on it. Glowing at magnitude 8.5, this historic ball of stars covers about 6’ on the sky. It seems so faint and compact as a result of it’s fairly distant — some 67,500 light-years from Earth. 

Sunrise: 7:10 A.M.
Sunset: 6:21 P.M.
Moonrise: —
Moonset: 3:20 P.M.
Moon Phase: Waning crescent (40%)

Wednesday, October 15
Comet C/2025 A6 (Lemmon) is at the moment making a splash throughout the sky, not too long ago noticed at magnitude 5.7 and visual within the predawn sky about an hour and a half earlier than the Sun rises. 

This morning the comet is in Canes Venatici and reaches some 25° excessive an hour earlier than dawn. Step outdoors and look northeast to find the Big Dipper, now standing on the tip of its deal with. To the suitable of the deal with is Canes Venatici, and Lemmon is slightly below 1.5° southeast of the constellation’s beta star, 4th-magnitude Chara, this morning. 

You’ll want at the very least binoculars to identify Lemmon. If you’re utilizing a telescope, Astronomy Associate Editor Michael Bakich recommends beginning with a low-power eyepiece and dealing your method up when you’ve discovered the comet. Taking an extended sky publicity with a smartphone may additionally pull the comet out of the background, so give {that a} strive for those who’re aware of the evening pictures settings in your cellphone. Deeper astrophotography utilizing a digital camera hooked up to your telescope might present the coma’s inexperienced glow, generated by diatomic carbon, which glows inexperienced when excited by daylight. 

Comet Lemmon shall be closest to Earth on the twenty first and sure shine brightest at the moment. You can discover further finder charts and extra recommendations on learn how to observe it right here, and we’ll be sure to revisit it on this column all through the month.

Sunrise: 7:11 A.M.
Sunset: 6:20 P.M.
Moonrise: 1:07 A.M. 
Moonset: 3:51 P.M.
Moon Phase: Waning crescent (30%)

Thursday, October 16
The waning Moon has moved into Leo and stands near Regulus, the Lion’s brilliant coronary heart, within the early-morning sky at the moment. An hour earlier than dawn, they’re 40° excessive within the east, with the crescent Moon simply to the higher proper of Regulus. 

Magnitude 1.4 Regulus shines some 150 occasions brighter than the Sun. It will not be one star however a four-star system; the best companion to identify in a telescope lies 175” away and shines at eighth magnitude. This is itself a double, although the faint companion right here requires a really massive scope to view (it’s magnitude 13.5). The fourth star within the system is a white dwarf companion to the brighter Regulus A and can’t be seen.  

Regulus anchors the asterism often known as the Sickle, which outlines Leo the Lion’s regal head. This group of stars seems to be like a backwards query mark within the sky; see for those who can spot it this morning as nicely, even with the Moon close by. 

The Moon will go 1.2° due north of Regulus at 2 P.M. EDT. If you view the pair on the similar time tomorrow morning, you’ll observe the Moon has moved to the far decrease left of Regulus. 

Sunrise: 7:12 A.M.
Sunset: 6:18 P.M.
Moonrise: 2:16 A.M. 
Moonset: 4:15 P.M.
Moon Phase: Waning crescent (21%)

Friday, October 17
Rising larger because the night progresses is the constellation Perseus, maybe most well-known for its so-called Demon Star, the variable star Algol. But the Hero hosts many different treasures, together with M34, a brilliant open cluster of younger stars that ought to draw your gaze tonight. 

You’ll discover M34 already 40° excessive within the east by 9 P.M. native daylight time. It’s situated in southwestern Perseus, simply over 5° west-northwest of Algol and close to Perseus’ border with neighboring Andromeda. 

Glowing a brilliant magnitude 5.5, M34 is technically seen to the bare eye from a transparent, darkish web site. You can view this cluster simply with binoculars or any telescope. It spans about the identical dimension because the Full Moon in most optics, so it’s fairly massive; decrease powers will present the cluster’s full extent, whereas larger powers will help you zoom in on a smaller area of the group however reveal fainter stars there. In all M34 incorporates about 100 stars and is about 180 million years outdated. 

Sunrise: 7:13 A.M.
Sunset: 6:17 P.M.
Moonrise: 3:22 A.M. 
Moonset: 4:37 P.M.
Moon Phase: Waning crescent (13%)