'Alien' spotted at International Space Station as stranded NASA astronauts get ready to come back to Earth

Sunita 'Suni' Williams and Barry 'Butch' Wilmore have been stranded in space for nine months, and now they've been joined by an 'alien'.

The NASA astronauts were only supposed to be in space for a little over a week, but the pair were forced to settle in for the long haul on the International Space Station after their mission met a hitch when the Boeing spacecraft was found to be unsafe to use to bring them home.

That’s when SpaceX's Falcon 9 ship was put on the back burner as an option to retrieve them from the ISS.

Sunita 'Suni' Williams and Barry 'Butch' Wilmore have been in space for months (NASA)

It was only yesterday (March 15) that the launch had been confirmed, and Wilmore and Williams could hope to be home in a matter of days.

Elon Musk’s company sent up four astronauts to the International Space Station: Anne McClain, Nichole Ayers, Takuya Onishi, and Kirill Peskov.

Now, in an update shared by the National Aeronautics and Space Administration (NASA), the NASA astronauts have arrived at the International Space Station.

"The SpaceX Dragon spacecraft docked to the orbiting complex at 12:04 a.m. EDT, while the station was roughly 260 statute miles over the Atlantic Ocean," it detailed.

Another update revealed the hatches were opened between the space station and the SpaceX Dragon spacecraft at 1:35am EDT to allow the group to meet each other.

"McClain, Ayers, Onishi, and Peskov were welcomed by the Expedition 72 crew, including NASA astronauts Nick Hague, Don Petitt, Suni Williams, and Butch Wilmore, as well as Roscosmos cosmonauts Aleksandr Gorbunov, Alexey Ovchinin, and Ivan Vagner," it said.

However, something odd happened just before the SpaceX craft docked… an ‘alien’ was spotted on an official live feed.

An alien was seen on the ISS (NASA)

But, if you thought Wilmore and Williams had invited an extra-terrestrial on board for a spot of tea, that’s not quite what happened.

As it turns out it, was Crew-9 commander Nick Hague wearing a gray alien mask as his crew awaited the arrival of Crew-10 to take over.

Hague can be seen floating around in a black hoodie and his mask.

People on Twitter reacted to the alien mask, and they seemed to love it.

One person wrote: "Haha that would be trippy, I would've laughed so hard."

Someone else said: "Funny and fitting space missions need some humor too!"

Another commented: "That’s next level hospitality! But real question If aliens were watchingg do you think they’d be amused or offended?"

After Crew-10 got there, the live stream showed the crew members embracing in zero gravity.

McClain said: "Crew-10 has had a great journey up here and I cannot tell you the immense joy of our crew when we looked out the window and we saw the space station for the first time. That is such an amazing journey. You can hardly even put it into words."

Williams went on to tell Mission Control: "It was a wonderful day. Great to see our friends arrive."