Your sky, right now
Discover the cycles that govern the sky.
Tonight's Moon and the visible planets, at their places in the sky. The next eclipses, conjunctions and meteor showers, and the cycles behind them.
Free, computed live in your browser, no account or sign-up. How this is computed →
What's next in the sky
- Next Moon phaseMoon calendar
- Next eclipseFeb 6: annular solar
- Planets meetingConjunctions
- Meteor showerShower calendar
- Highest naked-eye planet tonightTonight's sky
Tonight's planets for your area.
The Eclipse Window
Total solar eclipse, August 2, 2027
6 minutes 23 seconds of totality at greatest duration, in Egypt. The path of totality crosses southern Spain, North Africa and the Arabian Peninsula.
The cosmic clock
Every cycle in the sky is somewhere in its turn at this moment. These six dials follow the great ones, from the Moon's month to the Sun's 230-million-year lap of the galaxy.
Moon phase
the synodic month, new Moon back to new Moon
365.24 daysThe solar year
the year of the seasons, March equinox to March equinox
Twice a yearEclipse season
eclipses can only happen in the weeks when the Sun is near a lunar node
19.9 yearsGreat conjunction
the wait between Jupiter-Saturn meetings, the longest of the naked-eye conjunction cycles
Pole: PolarisThe Great Year state
precession swings Earth's axis once around in about 25,800 years; Vega takes the pole in roughly 12,000
~20 lapsThe galactic year state
about 20 orbits of the Milky Way since the Sun formed; where we sit in the current lap is not known
The rings and the small diagrams inside them fill with positions computed live in your browser. A lighter arc tagged "countdown" counts down to the next event, and the two dashed dials show deep time as a known state rather than a live phase.
Explore the sky, live
Interactive, always-current views of the night sky and the solar system, each computed live for this moment.
Live Sky Map
A planetarium of the sky over your exact spot, right now. Tap any of about 9,000 real stars, a planet, or a Messier showpiece to identify it, scrub through time, and look through the Earth to what lies below the horizon.
Open the sky map →
Eclipse Control Center
Your own contact times, computed for where you are standing, and a plain go or no-go. One clock drives four live views of the Sun, Earth and Moon.
Open the Eclipse Control Center →
SkyShare
Your night photo, the sky it caught and how rare the pairing was, on one free card.
Open the sky map, then tap the camera →
The Live Orrery
Scrub time and watch the real planets orbit, Sun-centered or Earth-centered, from Mercury out to Pluto.
LiveToday in the Sky
Tonight's Moon phase, the planets' places in the zodiac, and the next sky events.
NewWhat Is That in the Sky?
Saw a bright light, star or planet? Give the direction, height and time and it ranks what it most likely was, for tonight or a past night.
NewSun, Moon & Planets
A page for every world: where it is tonight, how to see it, cited facts, and its next oppositions, phases and eclipses.
CalendarMoon Phase Calendar
Tonight's Moon and a month grid of the new, quarter and full moons, plus each full moon's traditional name.
EclipsesEclipse Explorer
The next solar and lunar eclipses, their dates and types, and the Saros family each belongs to.
NewRetrograde Right Now
Which planets are retrograde at this moment, every station date through next year, and every Mercury retrograde ahead, with the honest astronomy.
Your locationPlanet Parade Tracker
The next planet parade from your spot, where to look and when, with a live countdown.
GuidesPlanet Conjunctions
When two planets meet in the sky: live dates and how close they pass, pair by pair.
3D flightVoyage
Fly the real solar system with the planets at their true positions: thread Saturn's rings, weave past Jupiter's moons, or play a quick stardust-collecting game.
Field kit
Print-ready PDFs, each computed for the place you choose.
Your Eclipse Day
$9
August 2, 2027: a plan with your contact times to the second, a field card and a calendar file with alarms. A watermarked sample for your spot is free.
Check your spot →
Print-ready PDF
Moon Calendar 2027
$9
Every Moon of 2027 drawn at its real illumination, each full moon named. Any month is free to sample before you pay.
See a month of it →
Print-ready PDF
The Moon That Night
$9, or $19 with your heading and dedication
The Moon's phase, moonrise and distance over any town on any night from 1700 to 2200, as a print-ready sheet. Your own night is drawn on the page before you pay.
Draw your night →
Posted on Instagram
Follow @cyclecalcs →Frames from the account as they were posted. Each one opens its post.
The 500 rule allows 25 seconds. Your pixels do not.
Where the 2027 eclipse shadow falls
What was the Moon doing over Houston when Apollo 11 landed?
The Sun you are looking at is eight minutes out of date
Take the sky with you
Free calendar feeds put every full moon, eclipse and season in your calendar app, and they stay current on their own. The newsletter is an occasional note on what is worth looking up at.
Calendar feeds: subscribe (webcal) · download the .ics · all feeds and setup
Calculators and the concepts
Calculate
Built to show their work, with the method behind every number.
- Synodic Period Calculatorthe average time between two bodies' alignments
- Planetary Alignment Calculatorreal dates of conjunctions and oppositions
- Celestial Return Calculatorwhen the Sun, Moon or a planet returns to a spot
- Sunrise & Sunsetrise, set, twilight and the dark observing window
- All calculators →
The concepts
Hands-on, plain-language explainers, each built around a visual you can move.
- Moon Phaseswhy the Moon waxes and wanes over 29.5 days
- Eclipseswhy they happen only near the lunar nodes
- Tidestwo bulges, two highs a day, spring and neap
- Seasons & the Sunhow Earth's tilt makes the solstices and equinoxes
- Precessionthe roughly 25,800-year wobble of Earth's axis
- All concepts explained →
Cycles, gear, the API and widgets
Astronomical cycles, end to end
Where every cycle stands right now, a search across all of them, and an in-depth profile of the major ones.
Open the Cycle Explorer →Stargazing gear
Certified eclipse glasses, a first telescope, binoculars and star atlases, kept current.
See the gear →A free astronomy API
No key, no signup, 5,000 requests a day free, with paid tiers from $5 a month for higher volume.
Explore the API →The sky on your own site
Free widgets: a live moon phase card, a next-eclipse countdown and a planet parade tracker.
Get the widgets →Sources and method
The live tools compute in your browser from Astronomy Engine, the open-source library behind the sky pages. See the methodology for the sources and models behind every calculation.