Know what to shoot tonight.
Plan the night, find the moon-free nights, set your subs, space the optics and beat the dew. Free calculators for astrophotographers, running entirely in your browser.
Six tools
Every number between you and a clean stack. Worked out in real time.
Imaging planner
Dark window, moon and altitude for 272 targets, ranked for your sky every night.
→Open the plannerExposure
The sub length where sky noise buries read noise.
→Open exposureDark sky calendar
Moon-free dark hours for every night this month.
→Open the calendarBack focus
Add up the train, account for filter glass, and close the gap to 55 mm.
→Open back focusUntracked exposure
How long before stars trail on a tripod. Every pixel shown.
→Open untracked exposureDew point
When your optics will dew up, and when to switch the heaters on.
→Open dew pointWhat to shoot this month
The best-placed targets for your hemisphere.
→See the full list272 targets
Messier, Caldwell and the favorites. A guide for every one.
Photos: ESA/Hubble, CC BY 4.0. Browse all targets
Whirlpool GalaxyCredit: NASA, ESA, S. Beckwith (STScI), and The Hubble Heritage Team (STScI/AURA)
Orion NebulaCredit: NASA, ESA, M. Robberto (Space Telescope Science Institute/ESA) and the Hubble Space Telescope Orion Treasury Project Team
Crab NebulaCredit: NASA, ESA and Allison Loll/Jeff Hester (Arizona State University). Acknowledgement: Davide De Martin (ESA/Hubble)
Pillars of Creation, Eagle NebulaCredit: NASA, ESA/Hubble and the Hubble Heritage Team
Carina NebulaCredit: NASA, ESA, N. Smith (University of California, Berkeley), and The Hubble Heritage Team (STScI/AURA)
Andromeda Galaxy, a sectionCredit: NASA, ESA, J. Dalcanton (University of Washington, USA), B. F. Williams (University of Washington, USA), L. C. Johnson (University of Washington, USA), the PHAT team, and R. Gendler.
Horsehead NebulaCredit: NASA, ESA, and the Hubble Heritage Team (AURA/STScI)
Ring NebulaCredit: NASA, ESA, and C. Robert O’Dell (Vanderbilt University).
Lagoon NebulaCredit: NASA, ESA, STScI
Veil Nebula, a sectionCredit: NASA, ESA, and the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration. Acknowledgment: J. Hester (Arizona State University)
Bubble NebulaCredit: NASA, ESA, Hubble Heritage TeamBest target tonight
Working out tonight's sky.
Guides
Know the sky before you set up. Month by month.
Written guides
Sub length, back focus, untracked exposure and dew, explained with worked numbers.
→Best targets by month
The galaxies, nebulae and clusters worth your clear nights, north and south.
→New moon calendar
Every new moon and dark week for this year and the next two.
→Daily sky quiz
Five new questions a day on targets, the moon, exposure and framing.
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