This page contains information regarding Star Trek: Discovery, and thus may contain spoilers.
Kwejian was a class M planet with one moon in the Kwejian system. It was inhabited by the Kwejian people, who resided in a shielded area called the Sanctuary on one of the continents. The planet was destroyed by the Dark Matter Anomaly in 3190. (DIS: "The Sanctuary", "Kobayashi Maru", "Anomaly (DIS)")
The planet's orbit had a semi-major axis of 108.208 million kilometers (0.723332 au), an aphelion of 108.939 million kilometers (0.728213 au), and a perihelion of 107.477 million kilometers (0.718440 au). Its orbital eccentricity was 0.006772, and its average orbital speed was 35.02 kilometers per second. Its orbit was inclined 3.39458 degrees to the ecliptic, 3.68 degrees to its sun's equator, and 2.19 degrees to the invariable plane. Its orbital period was 23.549 hours and its year was 583.92 days long. The planet had a diameter of 11,480 kilometers and a surface gravity of 9.8. (DIS: "The Sanctuary", "There Is A Tide...")
Described as "one of the most beautiful planets in the known galaxy" by Hugh Culber, Kwejian contained oceans and forests, including the World Root, a network of tree roots that spanned the entire planet. Its native lifeforms included birds, trance worms, and sea locusts. (DIS: "The Sanctuary", "Kobayashi Maru", "All Is Possible")
Kwejian's atmosphere was composed of 75% nitrogen, 23% oxygen, and 2% water vapor. The Great Storms of Naillem'kwai were a significant weather phenomenon on the planet. The mean surface temperature was 15 degrees Celsius. (DIS: "There Is A Tide...", "All Is Possible")
In the late 31st century, subspace damage caused by the the Burn shifted the orbit of Kwejian's moon, which in turn changed the tides on the surface. As a result, vast numbers of sea locusts emerged from the ocean and devoured the Kwejian harvest, leading to millions starving. The Emerald Chain offered them repellent to drive the locusts away, in exchange for the planet's trance worms.
In 3189, Osyraa withheld the sea locust repellent from Kwejian, threatening them again with famine, as leverage for her demand that Steward of the Sanctuary Kyheem deliver Booker to her. In response to Kyheem's message, the USS Discovery arrived and, after a brief standoff with Osyraa's flagship Viridian, forced her to withdraw. The Discovery crew then devised a means to amplify the electromagnetic connection between the sea locusts, allowing Kyheem and Booker to combine their empathic abilities and persuade the creatures to return to the ocean. (DIS: "The Sanctuary")
In 3190, Kwejian and its moon were struck by gravitational waves from what was later termed the Dark Matter Anomaly. Kwejian experienced catastrophic gravitational shear as it passed within twelve AU of the anomaly's ergosphere. All life on the surface was extinguished, and the remnants of the planet were thrown hundreds of thousands of kilometers from its previous position. The only known survivor of the disaster was Booker, who was aboard his ship at the time. Debris from the planet was later found in the anomaly's accretion disk. (DIS: "Kobayashi Maru", "Anomaly (DIS)", "Choose to Live")