The original Nova, Richard Rider, ran in Spider-Man's New York in the late 1970s and guest-starred alongside him against a common foe. Rider went on to co-found the New Warriors and eventually became one of Marvel's biggest cosmic heroes, but that early friendly-rival dynamic with Spidey never really faded.
The modern Nova, teenager Sam Alexander, connects to a different Spider-Man: Miles Morales. The two are founding members of the Champions, a team of young heroes who decided to do good on their own terms. Whether it is Richard trading quips with Peter or Sam standing beside Miles, the Nova-and-Spider-Man pairing is always about two young heroes who make each other braver.
Peter Parker and the original Nova, Richard Rider, both got their start as teenage heroes in New York, and they crossed paths early: Nova guest-starred alongside Spider-Man in Amazing Spider-Man #171 (1977), two rookies bouncing off each other while trading punches with a super-villain. Years later a second, younger Nova arrived: high schooler Sam Alexander, who inherited a Nova Corps helmet from his father. Sam would end up shoulder to shoulder with a Spider-Man too, standing beside Miles Morales as founding members of the Champions.
Both Novas remain part of the Marvel universe. Richard Rider, long a major cosmic hero, has returned to Earth's stories after his time lost in deep space, while Sam Alexander continues as a young hero closely linked to the Champions and Spider-Man Miles Morales. The two Novas have even appeared together, treating the Nova legacy as something passed between generations rather than owned by one person.
Nova is Marvel's Human Rocket, a hero powered by the Nova Force, the cosmic energy of the Nova Corps of the planet Xandar. The first Nova was Richard Rider, an ordinary Long Island teenager chosen by a dying Xandarian centurion to inherit his powers. Rider grew from a nervous rookie into a co-founder of the New Warriors and one of Marvel's most important cosmic heroes.
The second Nova is Sam Alexander, a high schooler from Arizona whose father had secretly been a member of the Nova Corps. Using his dad's helmet, Sam gained the power to fly, fire cosmic energy, and hold his own in outer space. He joined a new generation of young heroes as a founding member of the Champions, standing beside Spider-Man Miles Morales.