Hestia (Alternis)

INDEX / LEXICA / TIMELINE

Hestia is the innermost planet in the Solar System. The planet orbits so close to Sol that its atmosphere is continually blasted off, and its temperature is so high that its size is inflated to gargantuan proportions. Transits of Hestia are visible from throughout the Solar System.

Physical Characteristics

If it existed in the prime timeline, Hestia would be considered a hot Neptune, being a massive gaseous planet orbiting very close to its parent star, but it is considered as the prototypical member of a class named after itself in this timeline. Because of its enormous size, it has a major effect on the inner solar system. If it was absent, the Handmaiden belt would likely extend to the surface of the Sun, but its presence carves great gaps and shepherds groups of asteroids into more confined orbits.

Hestia's atmosphere is filled with clouds of vaporized silicates, one of the few compounds that can exist at these temperatures and form clouds. Its tidal lock creates extreme temperature and pressure differentials, driving hypersonic winds traversing between the day and night sides. On the day side, the atmosphere reaches temperatures necessary to create ionized plasma. Meanwhile, the gases on the nightside radiate this heat away and condense back into cooler gases, causing the worldwide pressure gradient that drives the vicious atmospheric winds.

Discovery & History

The planet, being 252 arcseconds in size in the sky, was clearly visible immediately after sunset or before sunrise on most days, and was thus known to the ancients. The Mariner 12 probe was first to survey it, after several flybys of Earth, Venus, and Vulcan, confirming predictions of a hellish gaseous world. The Tantalus atmospheric probe confirmed that the atmosphere is composed primarily of vaporized silicates as well. After the expansion into space, Hestia continued to be uninhabited save various scientific outposts in high orbit studying the planet. During the homeworld wars, the planet's inhabitants refused to take part in or assist either side, erupting in outrage when the UNH fleet used Hestia's position to attack the Loriset-controlled dwarf planet Praxis.

Orbit & Rotation

In the distant past, Hestia orbited Sol in a much wider orbit, likely past the current orbit of Phaeton. Over time, gravitational exchange and drag within the protoplanetary disk forced it downwards, alongside a very unlucky resonance with Savis accelerating the process enough to push it past the inner system before too much material could be stolen. It landed almost at the very inner edge of possibility, and if it had drifted any closer, it would likely no longer exist.

Not all scientists are convinced by this explanation, as many say that any migration through the inner system would have disrupted the formation of the inner rocky planets like Venus and Earth. It is possible that Hestian worlds can form very close to their stars, but this not a popular theory among scientists as of yet. Hestia is tidally locked to the sun.