The Wonders of Astronomy | Knowledge and Spots for Enjoying Starry Skies in Japan

The Allure of Starry Skies | Why Do People Gaze Up at the Night Sky?

Since ancient times, humanity has looked up at the starry sky and woven stories within it. In Japan, poems praising the "Milky Way" remain in the Man'yōshū, reflecting a deep history between stars and humans. However, in modern Japan, approximately 93% of the population lives in areas where light pollution prevents them from seeing the Milky Way, and a truly starry sky has become something you must "go out of your way to see."

Precisely because of this, the sight of authentic stars beneath a dark sky is extraordinary. Under a truly dark sky where about 6,000 stars are visible to the naked eye, the Milky Way shines brilliantly white as if dividing the heavens in two, leaving one speechless at its grandeur. Astronomy is not only an act of touching such primordial wonder but also an intellectual pursuit of understanding the mechanisms of the universe.

The number of people who enjoy astronomy as a hobby continues to grow each year, with Japan's domestic telescope market estimated at an annual scale of approximately 5 billion yen. Combined with the outdoor boom following 2020, "star camping," which combines camping with stargazing, has become increasingly popular. We invite you to explore the world of astronomy, which is easy to start for beginners and enjoyable regardless of age.

Fundamentals of Astronomy | Essential Knowledge to Know First

Before starting astronomy, let's cover some basic knowledge. First, there's "magnitude," an index of a star's brightness. A 1st-magnitude star is the brightest star classification, with the naked eye limit at approximately 6th magnitude. For each increment of one magnitude number, brightness decreases by about 2.5 times. The brightest star visible in Japan is Sirius in Canis Major (magnitude -1.5).

The basic method for finding constellations is to trace from "landmark stars." In spring, extend the handle of the Big Dipper to trace Arcturus (Boötes) and Spica (Virgo) along the "Spring Arc." In summer, Deneb in Cygnus, Vega in Lyra, and Altair in Aquila form the "Summer Triangle," which commands an overwhelming presence. Winter, centered on Orion's three stars, displays many 1st-magnitude stars including Betelgeuse, Rigel, and Sirius, creating the most brilliant night sky of the year.

Utilizing astronomy apps is also recommended. Smartphone apps like "Stellarium" and "Star Walk 2" display constellations and planets in real-time simply by pointing your camera at the sky. However, looking at your smartphone screen while observing resets dark adaptation (the eyes becoming accustomed to darkness). Set the screen to red display mode or cover it with red cellophane. Dark adaptation takes approximately 20-30 minutes.

Starry Sky Spots in Japan | Premium Stargazing Locations

Japan has multiple "starry sky towns" and "dark sky reserves" selected by the Ministry of the Environment, featuring world-class dark skies.

Bisei in Ibara, Okayama Prefecture, is known as the "Town of Stars," having enacted Japan's first light pollution prevention ordinance. The Bisei Observatory features a 101-centimeter reflective telescope; during Friday and Saturday evening public viewings, Jupiter's cloud bands and Saturn's rings can be observed with remarkable clarity. The entrance fee is a reasonable 300 yen.

Iriomote-Ishigaki National Park in Taketomi, Okinawa Prefecture, was designated as Japan's first "Dark Sky Reserve" (certified by the International Dark-Sky Association) in 2018. A premier low-latitude spot where the Southern Cross is visible, from June to July, the densest portion of the Milky Way passes directly overhead—a spectacular sight. Stargazing tours on Ishigaki Island are available for around 3,000-5,000 yen.

Achi Village in Nagano Prefecture gained fame when the Ministry of the Environment's nationwide star sky survey certified it as "Japan's village with the most beautiful starry skies." The Heaven's Sohara night tour (2,200 yen for adults) takes visitors 1,400 meters above sea level by gondola, where stargazing commentary is enjoyed with all lights extinguished. The location attracts approximately 120,000 visitors annually.

In the Tōhoku region, Tanesanakogen in Iwate Prefecture and Masuda in Yokote, Akita Prefecture are well known. Tanesanakogen is said to be where Kenji Miyazawa conceived "Night on the Galactic Railroad," adding literary romance to the stargazing experience.

Selecting a Telescope and Binoculars

Expensive equipment is not essential to begin stargazing. A natural progression is to first learn constellations with the naked eye, then advance to binoculars, and finally to a telescope.

Binoculars are the finest beginner's tool for astronomy. Recommended specifications are 40-50mm objective lens diameter with 7-10x magnification. For example, binoculars marked "7×50" indicate 7x magnification with 50mm objective lens diameter. With approximately 50 times the light-gathering power of the naked eye, they beautifully reveal the star densities of the Milky Way, the Andromeda Galaxy, the Pleiades (Subaru), and the Orion Nebula. Vixen and Kenko products are highly reliable, and sufficient performance can be obtained for 10,000-20,000 yen.

When purchasing a telescope, beginners are advised to choose a refractor telescope with 80-100mm objective diameter. Maintenance is simple, and the performance is sufficient for enjoying lunar craters, Jupiter's moons, and Saturn's rings. The Vixen "PortaII A80Mf" (approximately 45,000 yen) and ScopeTrack "Raptor 60" (approximately 12,000 yen) are popular beginner models. An altazimuth mount is user-friendly for beginners, while an equatorial mount is better suited for intermediate users wishing to photograph celestial bodies.

Astronomical Event Calendar and Observation Tips

One of the pleasures of astronomy is the variety of celestial events occurring throughout the year. The "Three Major Meteor Showers" that can be reliably enjoyed each year are the Quadrantids (January), the Perseids (August), and the Geminids (December). The Perseid meteor shower is particularly abundant, with favorable conditions producing 50-80 meteors per hour.

Lunar and solar eclipses are among the most dramatic celestial shows. A total lunar eclipse reveals the fantastical sight of the moon dyed copper-red, while a partial solar eclipse can be safely observed using the pinhole projection method. The National Astronomical Observatory of Japan publishes annual schedules for these events on their website, so plan ahead.

Several tips for comfortable observation. Even in summer, mountain areas cool significantly at night—always bring warm clothing. A picnic sheet or folding chair makes looking up more comfortable. A red LED headlamp is an essential item for illuminating your hands without disrupting dark adaptation. Insect repellent is also indispensable during summer months.

The 3-4 days before and after the new moon offer the darkest skies for stargazing. Check the lunar calendar and aim for nights with minimal moonlight. SOROU.JP regularly updates astronomical event information and stargazing spot guides throughout the region. The next clear night, gaze upward into the sky. Countless stars will surely move your heart as they tell the grand story of the cosmos.