See All Eight Planets in One Night

Four planets are great, but how about eight? You can see them all in a single night in the next couple weeks — if you play your cards right.

Eight planets await

All eight planets are visible across the evening and morning sky from now through early September.
NASA

Four bright planets have charmed us all summer: Venus, Jupiter, Saturn, and Mars. Strung across the southern sky like a string of pearls, they've coaxed us outdoors every clear night in spite of the mosquitoes. The quartet has also provided great opportunities for sidewalk astronomy; planets are bright and easy to see through a telescope no matter your experience level.

I'll miss them when they reshuffle in the months ahead. In less than month, Venus departs for the morning sky. One year from now both Venus and Mars will be lost in the solar glare with only Jupiter and Saturn left to hold up the southern sky. But before any of this gets underway, skywatchers have a brief opportunity to do better than four planets. Or five if you include the Earth. How would you like to see all eight?

Splendor at dusk

The easiest planets to view are visible across the early evening sky from west to southeast. Look for Venus first, then Jupiter, Saturn, and Mars as twilight gives way to nightfall. Click here for a lovely photo of the quartet and Moon taken by over the Rome skyline by astronomer Gianluca Masi. 
Stellarium

Mercury joins the gang later this week as it heads into an excellent morning apparition for observers in the Northern Hemispheres. Watch for the swiftest planet to make its first appearance below the Gemini twins low in the northeastern sky at magnitude 0 about 45 minutes before sunrise this week. Mercury remains visible through the first week of September while brightening to magnitude –1.

Sweet Mercury swings low

Mercury returns to the dawn sky this week and remains visible through early September. The planet is best and highest about 45 minutes before sunrise in the eastern sky in the constellation Cancer. You can use Orion and Gemini's "Twin Stars," Castor and Pollux, to guide you there. Click here to find your local sunrise time.
Stellarium

So that makes six planets, one at dawn and four (plus Earth) at dusk. The other two, Uranus and Neptune, come into good view a little before midnight. Fortunately, both are located near relatively bright stars, with Neptune 3.5° east of Lambda (λ) Aquarii and Uranus 4.5° northeast of Omicron (ο) Piscium. If you're using binoculars, you can point directly at those stars, position them to the right side of the field of view, and use the charts provided to pinpoint both planets.

Find all eight and it will be the last time you'll see them over the course of a single night till next June, assuming you live in mid-northern latitudes.

Starhopping to the ice giants

Although the Moon will soon become a bit of a bother, Uranus and Neptune both lie near ~4th-magnitude stars Lambda (λ) Aquarii (Neptune) and Omicron (ο) Piscium (Uranus). Locate the stars with this map and then use the more detailed maps below along with a pair of binoculars or small telescope to spot these remote outer planets.
Stellarium

Time is somewhat of the essence in spotting all eight because the Moon is waxing toward full this week, brightening the sky and making it harder to see the remote planets, at least in binoculars. While it's possible to see Uranus and Neptune almost anytime in a  3-inch or 4-inch telescope, binocular views will only be possible when the Moon gets out of the picture.

This Neptune finder map is suitable for use with binoculars. North is up and times are 0h UT on the dates shown. To convert UT to local time, click here. Neptune shines at magnitude 7.8. For a large version, click, save, and print out.
Chris Marriott's SkyMap with additions by the author

That narrows down the best times to see the planetary octet to the following dates, give or take:

  • August 22–24 before full Moon when 50-mm binoculars will still show magnitude-7.8 Neptune and Mercury first becomes visible in the dawn sky
  • August 30–September 9 after the Moon has moved east of Uranus and before Mercury gets swallowed up again in the solar glow
Planet #7 beckons

Uranus is bright at magnitude 5.7 and easy to find in Aries near the border with Pisces. North is up and stars are plotted to magnitude 7. Times are 0h UT on the dates shown.
Chris Marriott's SkyMap with additions by the author

Make a plan to see them all much like you might stay up late for a spring Messier marathon. If you start in early twilight, you'll have your best shot at Venus. Because the planet is only about 10° high (one fist) a half hour after sunset, find a spot with a wide open view to the west for the best view. Timing isn't as critical for Jupiter, Saturn, and Mars, all of which appear in the sky together from an hour to more than two hours after sunset.

For Uranus and Neptune you'll have to be out around 11:30 p.m. local time or later. Then, set your alarm for an hour before sunrise and get some sleep! Hopefully, you've scouted out a location with a great view of the eastern horizon earlier in the day. When you arise, Mercury will await your gaze some 6° to 9° high 45 minutes before sunrise.

Solar system at a glance

The positions of the planets on August 22, 2018. Not to scale. <brtheplanetstoday.com

Once you've seen all eight, try to picture them in 3D using the diagram above. You're not just a world traveler — you've graduated to interplanetary! Happy trails.

12 thoughts on “See All Eight Planets in One Night

  1. Tom-Reiland

    Another good project, Bob. I did this back in early July on the nights of the 6th, 7th (My 72 birthday) and the 8th. I also observed Pluto on July 7 & 8 and Vesta and the Moon on all three nights and, of course, Planet Earth. Along with these Solar System objects I spotted Comets G-Z and PanSTARRS 2017 S3, plus Nova Scuti.
    I have a question. Do you remember or know of the last time the four brightest planets were lined up across the sky from the Western horizon to the East or SE? Also, when has this happened in the morning from the East to the West? Mercury was visible in the evening in early July, but it always set before Mars rose in the SE during early July. In my 45 plus years of observing, I don’t remember seeing this alignment. I remember seeing groupings with at least 3 planets in the West after Sunset and also in the morning sky. This is so unusual and it has been a great way to educate people who attend our Star Parties at Wagman Observatory about the plane of the Ecliptic.

      1. Tom-Reiland

        Bob, I just checked my daily observing log that I keep for casual, non-telescopic observations and I observed the five planets and the Moon on the mornings of Jan 30 and Feb 2 from the local fire hall, about a mile from my house, using my 10 X 50 binoculars and nude-eyes. Thanks for the info. I started keeping various observing log books in Nov 1973. This is one of many things that one of my mentors and one of the finest variable star observers, the late George Lindbloom, taught when I was just starting out.

  2. Anthony BarreiroAnthony Barreiro

    Thanks Bob. Once you’ve seen all eight, be sure to call out “bingo!” But why not add a minor planet to your card? At magnitude 6.8, Asteroid 4 Vesta is a full magnitude brighter than Neptune. Vesta is easy to find with binoculars 2.5 degrees east-northeast of third-magnitude theta Ophiuchi. Theta Oph is halfway between Antares and Saturn.

    (By the way, in the Uranus finder chart, north is up.)

  3. RodRod

    Bob, I did enjoy some Venus viewing 19-Aug using my trusty 90-mm refractor. Tonight with waxing gibbous Moon in Sagittarius, I enjoyed viewing Jupiter and Alpha Librae double star in same field of view (40x and 1.3 degree true field of view). I have been tracking Jupiter’s eastward motion in Libra since it stopped retrograding on 11-Jul. Also viewed Saturn and Mars along with the Moon at 180x views tonight. Mars is distinct gibbous shape now at 96% illuminated. You said “Four bright planets have charmed us all summer: Venus, Jupiter, Saturn, and Mars. Strung across the southern sky like a string of pearls, they’ve coaxed us outdoors every clear night in spite of the mosquitoes.” Yes sir, those mosquitoes are indeed pesky, bats fly around where I observe, eating as many as they can but never enough 🙂 I will setup the 10-inch scope when the nights get cooler and less trouble with pesky mosquitoes. Fall skies are coming and cooler nights too.

  4. Joe StieberJoe Stieber

    I spotted all eight major planets (including earth), plus the Moon and (4) Vesta on five (5) different nights during Mercury’s last evening elongation, They were the nights of June 14-15, June 19-20, July 8-9, July 14-15 and July 19-20, 2018. On the final night, I added comet C/2017 S3 (PANSTARRS). To make it a little more challenging on the last night, I saw them all in my 85 mm spotting scope (which has no finder). I started out just hoping to see Mercury’s crescent (it was sort of an oval shape, but tough to see at the low altitude), then I just continued on. For the other nights, it was unaided eyes and/or binoculars.

    I wasn’t too worried about Pluto, although I hope to catch it before the season ends. Until a couple of weeks ago, my 12.5-inch dob had been in the shed during a 2+ year hiatus. I finally got it out and cleaned the filthy mirror so I could get a good look at comet 21P/Giacobini-Zinner with it.

    Since the forecast looks favorable for a change, I’m hoping to get my first sighting of Mercury for this elongation later this morning, August 23, 2018, which would make it 49 elongation in a row.

  5. Joe StieberJoe Stieber

    There were some pesky clouds in the east on the morning of August 23, so instead, I spotted Mercury on the morning of August 24, 2018, about 5:10 am EDT with 15×56 binoculars, then glimpsed it with unaided eyes at 5:15 am when it was at 3.7 deg altitude. That was just before the start of nautical twilight at 5:18 am.

  6. plutogirlplutogirl

    Our solar system does NOT have only eight planets. Please do not treat the controversial demotion of Pluto by four percent of the IAU, most of whom are not planetary scientists but other types of astronomers, as gospel truth and/or as the only legitimate planet definition currently in use. Within days of the IAU ruling, hundreds of professional planetary scientists signed a formal petition rejecting the decision. They continue to reject it to this day, favoring a geophysical definition instead that does not require an object to clear its orbit to be a planet. Alan Stern, the person who first coined the term dwarf planet, did so with the intention of designating a third class of planets in addition to terrestrials and jovians, not to create a class of non-planets. The four percent of the IAU who voted on this misused his term. In 2017 and 2018, planetary scientist Kirby Runyon presented an alternate, geophysical planet definition to the Lunar and Planetary Sciences Conference. To the many planetary scientists who hold to that definition, dwarf planets are planets too, meaning our solar system has a minimum of 13 planets and counting. Please at lest acknowledge the continued existence of this debate.

    1. Bob KingBob King Post author

      Hi Laurel,
      Thanks for writing. I understand that the definition of a planet may be a poor one and could potentially change, but it is what it is for now. I didn’t bring it up because I didn’t want to bog down the article by re-iterating the argument.

  7. Greg-Bloomhuff

    Today is my father’s birthday. If he were alive, he would be 101 years old. He gave me a nice little reflector telescope for Christmas in my 7th year of age. I saw the moon up close for the first time and felt like that I could reach out and touch it! It was so bright. Dad was a navigator/gunner on a B-17 in the SW Pacific theater under General MacArthur out of New Guinea. Dad told me stories about using his compass to shoot the stars at night to plot his courses. Dad taught me how to find most of the big boy stars to help find my way. It was so exciting listening to dad as he explained the locations of the stars as if they belonged to him and me. He rarely spoke of the war. The was was too painful for him to discuss with me. He retired from the Air Force in 1963 as a Lt. Colonel. He sould have been a general but spent too many years in SAC fling spy missions over Russia out of Alaska. Dad passed away in 1988. I still look up to the night sky and hear my dad’s kind, loving voice showing me the stars as if it were the first time all over again.

    1. Bob KingBob King Post author

      Greg,

      It was sad to read your father passed, but what a wonderful treasure he left you — hearing his voice when you look up at the stars. Your story was very touching, and I (and other the readers) appreciate you sharing it. My mother recently passed, and I’ll always remember her goodness and try to emulate it in my life.

All comments must follow the Sky & Telescope Terms of Use and will be moderated prior to posting. Please be civil in your comments. Sky & Telescope reserves the right to use the comments we receive, in whole or in part, and to use the commenter’s username, in any medium. See also the Terms of Use and Privacy Policy.

COMMENT

This site uses Akismet to reduce spam. Learn how your comment data is processed.