Additional projection devices are used for depicting such phenomena as eclipses, auroras, or meteors, and for showing such aids to instruction as the system of celestial coordinates or outlines of the constellations. The planetarium can also show the appearance of the heavens from any given place on Earth at any given time far into the past or future.

By means of various sets of gears and electric motors, the planetarium can show the rising and setting of the stars and the motion of the moon and planets along the ecliptic.

The images of the moon and planets are produced by separate projection devices mounted on a frame between the two star spheres. The plates are positioned around two spherical structures, one for Northern Hemisphere stars and the other for Southern Hemisphere stars. The room or building in which such an instrument is housed is also called a planetarium.Ī typical planetarium forms images of the stars by focusing light from one or more bright lamps through thousands of tiny holes drilled through metal plates.

It projects images of the planets, moon, and stars onto a domed ceiling, creating an accurate representation of the nighttime sky. A modern planetarium is a complex optical instrument. Planetarium, is an educational device for showing the locations and movements of the planets and other objects in the universe. Discs include the stunning Jabbah and Associates disc, Nebulae disk, The Solar System, and Galaxies disc, some other fun options like hot air balloons and jellyfish are available too, read more about them over at planetarium is an educational device that shows the locations and movements of the planets and other objects in the universe. 17 other Sega-branded disks are available to purchase separately for approximately $18 each and disks from the Homestar Original will work too. The Homestar Flux is provided with two discs, the Northern Hemisphere and the Northern Hemisphere Constellations. If you don’t set a timer it will automatically turn off after four hours to save power. No need to wake up from your slumber if using it to drift off to sleep as many do. The timer on the Flux can be set for 15, 30 or 60 minutes by moving a slider. If it’s staying in one place I’m not sure how important this is but it’s nice to have the option. The unit uses a USB cable for its power supply, I have run it from a wall socket and plugged it into my laptop to use, it could also be powered by a power bank making it super portable. Shooting star function is a little lackluster.The packaging for the Homestar Flux itself is attractive and certainly feels like you’re opening a premium product. It has a nice satin black finish that looks sleek and modern, although does highlight dust and sticky fingerprint marks more than I’d like. The compact projector is made from plastic and has metal feet to aid stability. The actual words are not lit or visible in the dark, but there aren't that many to forget which button does what, and you won’t do any damage if you accidentally press the wrong one. There are buttons to turn the device on, activate the timer, turn the rotation on (North or South) and activate the ‘shooting star’. The focus ring around the glass helps ensure the stars look sharp regardless of the distance of the surface from the projector. Pop a disc into the top-loading disc slot, plug it in and switch the power on and that’s all there is to it. After un-boxing it takes mere minutes to plug in and get up and running. The Sega Homestar Flux has an intuitive design. (Image credit: Future, via Tantse Walter)

Planet projector