Sky · Tonight and the year ahead
Everything above you, tonight.
Point at anything overhead and this section will name it, time it, and tell you whether it is worth the cold. The pages that need your coordinates compute for them live, from the Sky Map's any-night planetarium to tonight's ranked observing list.
The Moon's phase, every rise and set and each eclipse circumstance is computed rather than looked up, from the same vendored astronomy engine, and every figure states its convention. The event calendars are recomputed by a daily build instead; both are ways of not guessing. How this is computed →
- MoonTonight's phase and how much is lit
- Next eventThe next eclipse or turn of the season
- Dark tonightWhen astronomical dark begins
- Planets upWhich planets clear your horizon
The last two rows need to know where you are standing.
- 8,404stars charted to magnitude 6.5
- 88constellations, each with a finder
- 110Messier objects with observing notes
- 1700 to 2200the years the engine computes
The year ahead
- Full moons, each one named and timed to the minute
- Eclipses, solar and lunar, each with its own page and local circumstances
- Meteor shower peaks, with the moonlight verdict that decides the night
- Equinoxes and solstices, the four instants that turn the year
Start here
Three pages do most of the work. Each one wants your coordinates and the current instant, and each answers about the sky in front of you rather than about a date on a calendar.
Every page in the section
The rest of the Sky section, grouped by the job it does rather than by the object it is about. The left column says what scale each page works at: how often the thing happens, or how many of them there are.
The Moon
One body, four jobs: the shape it is tonight, the year's full moons and their traditional names, the distance extremes behind the supermoon headlines, and a printed year computed for coordinates you choose.
- nightly Moon Phase CalendarWhat shape is the Moon tonight, and when does it clear my horizon?
- monthly Full Moon CalendarWhen is the next full moon, and what is it called?
- 3 years Supermoons and MicromoonsIs that supermoon actually going to look any bigger?
- printable Moon Calendar 2027Can I get a printed moon calendar with my own moonrise times, not New York's?
- any night The Moon That NightWhat did the Moon look like from my town on one particular night?
Eclipses
The deepest cluster here, because an eclipse is the one event people travel for. A live console for the day itself, an on-demand computer for any eclipse in range, and the calendar of what is coming with a page for each.
- live Eclipse Control CenterWhere will the shadow be at 11:42, and will I see totality from my spot?
- any eclipse Eclipse and Saros ExplorerWhen is the next eclipse I can actually see from here?
- to 2028 Eclipse CalendarWhich eclipses are coming, and who on Earth gets to see each one?
Dated events to plan for
Things that happen on a date you have to be ready for. Each of these answers when, and then answers the question that actually decides the night: whether the Moon, the horizon or the twilight will ruin it.
- 13 a year Meteor ShowersIs the Perseid peak going to be washed out by the Moon this year?
- 4 a year Equinoxes and SolsticesWhat minute does summer actually start, and why is my earliest sunset not on the solstice?
- next parade Planet Parade TrackerIs the next planet parade visible from my back garden, and where do I look?
- 7 pairings Planet ConjunctionsWhen do Venus and Jupiter next sit side by side, and how close do they get?
- subscribe Calendar FeedsCan these dates just show up in my own calendar without me checking back?
Where a planet is in its round
Four pages built on one mechanic: a planet's place inside its synodic period, read as a status now plus the dated stations and transitions on either side of it. Two answer "can I see it", two answer "is it backing up".
- tonight Retrograde Right NowWhich planets are backing up against the stars tonight?
- 3 a year Mercury RetrogradeWhen is the next Mercury retrograde, exactly, and why do other sites say a different day?
- 584 days Venus Morning Star TrackerIs that brilliant point at dawn Venus, or have I got the wrong side of the Sun?
- 116 days Mercury Morning Star TrackerIs Mercury far enough from the Sun this week for me to catch it at all?
The solar system from outside
Two views that leave your horizon behind. One measures and one flies, both run on real positions, and both say plainly where they exaggerate scale rather than letting you assume they do not.
- any date Live OrreryWhy does Mars appear to loop backwards if it never actually stops?
- flight Voyage: Fly the Solar SystemWhat does the solar system look like from out there, right now?
Catalogs of the fixed sky
Three complete reference works about the things that do not move from one night to the next. These are browsed rather than consulted for a date, and each pairs a whole-sky map with a sortable table.
- 88 The 88 ConstellationsWhich of these star patterns is actually a constellation, and how do I find it?
- 626 Star NamesThat bright one has a name. What does it mean, and who named it?
- 110 The Messier CatalogWill M31 actually look like anything through my binoculars?
A few close relatives live elsewhere on the site: every world has its own page under Sun, Moon and Planets, rise and set times with the moonless dark window are in the Sunrise, Sunset and Dark Window calculator, navigators will want the Nautical Almanac and the celestial navigation explainer, the rhythms behind all of this are in the Cycles section, and you can put these tools on your own site with the embeddable widgets.
How these pages compute
The pages here work in one of two ways, and it is worth knowing which you are reading. The interactive ones load a vendored copy of the same open-source astronomy engine and compute in your browser for the date and coordinates you give: that is the Sky Map, Today in the Sky, the identifier, the Moon phase calendar, both eclipse tools, the trackers, the orrery, Voyage and the three catalogs. They work for any night from 1700 to 2200 because nothing is being looked up.
The event calendars carry their answers already computed. The full moon and supermoon tables, the eclipse, meteor, season and conjunction calendars are rebuilt by a daily job running the same engine, so the page you get is static and fast, and never more than a day old. Where such a page also offers a per-location figure, that part is computed live in your browser like everything else.
Two habits run through both, and they are deliberate. Every figure states its convention, because a rise time means nothing until you know the refraction model and the horizon it assumes. And where a page offers "use my location" to compute a figure for you, the coordinates stay on your device: place names are resolved against an index shipped with the page rather than a geocoding service. The one exception is deliberate and obvious, the printed Moon Calendar 2027, which is an order: it has to send the coordinates you choose, because a calendar computed for your own moonrise times is the thing being made. The details are on the methodology page.
Something missing from this section, or a figure worth arguing about? Write to info@cyclecalcs.com.