Challenges Faced by Thor Alone

Despite Thor's considerable powers, several factors would have made it difficult for him to handle the Chitauri invasion alone:

Numbers

Given the vastness of the Chitauri army, taking on a large number of foes simultaneously would be extremely challenging even for Thor. His lightning, while formidable, would likely cause significant collateral damage, making the battlefield less advantageous for him.

Leadership and Strategy

The Avengers worked together to strategize and coordinate their efforts. Thor, alone, would have struggled to effectively manage the battlefield without the teamwork and diverse skills brought by the other Avengers. The combination of their unique abilities was crucial in coordinating a successful defense against the invaders.

Loki's Manipulation

Thor's brother, Loki, was orchestrating the invasion. While Thor could confront Loki, the emotional and strategic complexities of their relationship would have made a solo effort highly complicated. Loki's manipulation and chaotic influence would have added significant challenges.

Comparing Thor and Captain Marvel for Space-Based Destruction

As far as fighting the ground troops, it is highly improbable that any single character could take on all the Chitauri and Leviathans simultaneously. Even if Thor tried, his lightning would likely cause significant collateral damage. Moving to the more complex task of destroying the Chitauri mothership, the situation is equally uncertain.

Captain Marvel's Advantage

When it comes to comparing Thor and Captain Marvel in terms of their ability to destroy a spaceship, Captain Marvel has two significant advantages:

Thor's Versatility in Space

Thor's biggest power that Captain Marvel does not possess is his ability to summon lightning. While Thor can indeed produce a significant amount of energy, even his most powerful blasts have been shown to come from external sources; the lighting he summoned in Wakanda and the energy he pulled from the sky in the first Avengers movie. This suggests that Thor's ability to harness and use his powers in the vacuum of space is quite limited.

Conclusion

While Awakened Thor could have taken on many elements of the Chitauri invasion, the sheer numbers of the Chitauri forces, the lack of teamwork and strategic coordination, and the presence of Loki's manipulation all argue against his ability to handle the entire invasion on his own. Given these factors, it is unlikely that Thor could have performed the same mother ship-busting feat as Captain Marvel or the nuke without significant advantages in space adaptability and independent flight.

T-LDR: Can Thor Destroy a Mothership Alone in the First Avengers?

TL;DR: Based on his lack of versatility in space and the need for weapon assistance, it is unlikely that Thor could have destroyed a mothership alone in the first Avengers movie. With Stormbreaker, it might have been possible given his demonstrated powers, but even then, the limitations in space would have been a significant challenge.