Doctor Jane Foster was one of the world's leading astrophysicists, the world's foremost astronomer, the creator of the Foster Theory, as well as one of the premiere experts on Asgard. She found Thor after he was banished from Asgard and fell to Earth while she and her team were in New Mexico studying astronomical anomalies. She helped him in his mission to return to Asgard, eventually falling in love with him along the way. They were separated due to the temporary destruction of the Rainbow Bridge. During Loki's assault on Earth, S.H.I.E.L.D. kept her out of harms way by transferring her to a remote observatory where Loki could not find her.
Foster found out of Thor's return through the footage of the Battle of New York; this left her disappointed and angry that Thor didn't attempt contacting her. During the Convergence, she became host to the Aether and helped Thor defeat Malekith during the Battle of Greenwich. Once free of the Aether, Foster returned to work and Thor had decided to remain on Earth with her. Due to her work studying of the Convergence, Foster was being considered for the Noble Prize in astrophysics. Following the Ultron Offensive, Foster's relationship with Thor turned sour, leading her to dump him.
In 2018, Foster was amongst the victims when Thanos wiped out half the life in the universe with the Infinity Stones. Resurrected five years later by the Avengers, Foster learned that she had stage IV cancer, seeking chemotherapy by 2024. She visited New Asgard, where the broken pieces of Mjølnir reassembled themselves and presented itself to her, granting her superhuman abilities. Operating as the Mighty Thor, she befriended King Valkyrie and defended New Asgard from Gorr the God Butcher, reuniting with Thor in the process. However, continued use of Mjølnir greatly weakened her body, and as a result of her decision to join the final fight against Gorr, she succumbed to her cancer. Having died a warrior's death, her soul went to Valhalla, an Asgardian afterlife, where she was greeted by Heimdall.
