Mikko Tuomi<p>Lava <a href="https://scicomm.xyz/tags/planets" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>planets</span></a> orbit their <a href="https://scicomm.xyz/tags/stars" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>stars</span></a> at remarkable speeds, completing an <a href="https://scicomm.xyz/tags/orbit" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>orbit</span></a> in as little as a few hours.</p><p>This proximity generates intense tidal locking, a gravitational phenomenon where one side of the <a href="https://scicomm.xyz/tags/planet" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>planet</span></a> always faces the <a href="https://scicomm.xyz/tags/star" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>star</span></a>.</p><p>The day side is perpetually exposed to stellar radiation, while the night side remains in darkness and is much colder.</p><p>Because these orbits are too hot for planet formation, such planets must have migrated inward after forming farther from their stars.</p><p>Some may even be the exposed rocky cores of former sub-Neptunes—planets that once held thick hydrogen-helium atmospheres that were later stripped away by intense stellar radiation.</p><p>Their densities, measured through precise transit and radial velocity data, confirm that these worlds are primarily rocky rather than gaseous.</p><p><a href="https://scicomm.xyz/tags/astronomy" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>astronomy</span></a> <a href="https://scicomm.xyz/tags/exoplanets" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>exoplanets</span></a> <br><a href="https://www.seti.org/news/worlds-of-fire-what-molten-exoplanets-teach-us-about-planet-formation/" rel="nofollow noopener" translate="no" target="_blank"><span class="invisible">https://www.</span><span class="ellipsis">seti.org/news/worlds-of-fire-w</span><span class="invisible">hat-molten-exoplanets-teach-us-about-planet-formation/</span></a></p>