ROTATION PERIOD / REVOLUTION PERIOD = 1.00000 = 1:1
1 SOLAR DAY = 1 SOLAR YEAR

A habitable terrestrial exoplanet in the system of the star HD90751, Janus 5 is what's called a "quiet rock" — a planet suitable for colonization, but with no sentient life forms or established civilization.

Similar to Earth in mass and surface gravity, Janus has a metallic core, a mantle dominated by silicon compounds and an active hydrosphere.

Because of Janus' perfectly circular orbital path around its sun, tidal forces between the two have, over millions of years, synchronized the planet's rotation rate and orbital speed.

As a result, Janus exhibits what astronomers call a 1:1 spin-orbit coupling — or synchronous orbital resonance — meaning the planet rotates on its axis exactly once for each time it revolves around HD90751.

As our moon always shows the same face to Earth, Janus always directs the same hemisphere toward its sun.

It is a world of extremes — one half in perpetual daylight, the other in eternal night.

Recent satellite remote sensing yielded anomalous readings from a dormant volcanic region on the planet's nightside, where the first samples of remedium were collected.

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