夜空ガイド

すべてのガイド

• How to see Jupiter without a telescope Jupiter is the third-brightest object in the night sky after the Moon and Venus, and you can find it with just your eyes.
• What is an ISS pass and how do I spot it? The International Space Station is the brightest human-made object in the sky. You can see it tonight without any equipment.
• The Kp index, explained — your aurora forecast One number tells you whether the Northern Lights might reach where you live tonight. What it means, and how to read it.
• The Bortle scale — how dark is your sky? A nine-point scale from pristine wilderness to inner city, and what you can actually see at each.
• How to find the North Star (Polaris) Polaris isn't the brightest star. It's the one that doesn't move. The five-second technique that has worked for navigators since antiquity.
• The best meteor showers of the year When the big ones peak, how many to expect, and which are worth setting an alarm for.
• Moon phases, explained simply New, crescent, quarter, gibbous, full. What's happening, and why it matters for everything else you'd want to see in the sky.
• How to spot planets without a telescope Five planets are visible to the naked eye, and they look different from stars in ways you can learn in an evening.
• Light pollution and stargazing Why you can't see the Milky Way from a city, and what it would take to bring it back.
• Dark sky parks, and the trip worth taking Designated places where outdoor lighting is restricted, so the night sky stays the way it was before electricity.
• Astrophotography without equipment Modern phones can capture stars, the Milky Way, and even nebulae. What's possible with the camera you already have.
• Star hopping for beginners Using bright stars as stepping stones to find dimmer objects. The skill astronomers used for centuries before motorized mounts.
• Civil, nautical, astronomical — types of twilight When is it actually dark? Three official transitions between day and night, each with practical meaning.
• Meteor shower viewing — getting the most from peak night A practical guide to actually seeing what's promised. Field-tested, no fluff.
• The night walk — a stargazing checklist Going out after dark is its own small adventure. A practical list of things to bring, and a few you wouldn't think of.