Footage has emerged of the Populous-designed MSG Sphere in Las Vegas lit up with cascading red and yellow lights and the greeting "Hello World" on its LED screen.

The sphere, which is being designed by stadium specialist Populous for the company behind New York's Madison Square Garden (MSG), will be the world's largest spherical structure when it opens in September.

On social media platform Twitter, films and photos show the 34-metre-high and 157-metre-wide sphere covered in moving lights as its LED displays were tested. Covering nearly 54,000 square metres, they form the largest LED screen in the world.

Swirling yellow and red lights lit up the screen, creating a lava-like effect that made the building look as though it was covered in fire.

The Death Star has some fancy new lights. ✨ pic.twitter.com/hipiKXUNj5

— Las Vegas Issues (@VegasIssues) July 1, 2023

Videos shared on social media show the sphere lit up

The tests were carried out as the building prepares to be fully lit up for the first time tomorrow in time for the 4th of July.

The words "Hello World" greeted viewers, who described the MSG Sphere Las Vegas as a "Death Star" and "otherworldly".

The Sphere Thingy just got a lot more interesting pic.twitter.com/GZSf9jbXjK

— Las Vegas Locally 🌴 (@LasVegasLocally) July 2, 2023

It was compared to the Death Star

The panels of the sphere, which viewers have also likened to "the Eye of Sauron", were visible "several miles away" according to one commenter.

Once complete, MSG Sphere Las Vegas will host "multi-sensory live entertainment" and concerts, with U2 set to be the first band to play there when it opens in September.

It will have a capacity of 20,000 people, including 17,600 seats and a further 2,400 standing spaces.

"This vivid canvas will display stunning and dynamic imagery unlike anything ever seen before – all at an unparalleled scale," MSG Sphere said of the Independence Day event.

The Sphere at The Venetian Resort in Paradise, Nevada, has an exosphere made of LED light panels which is visible from several miles away. It was tested on July 1st, 2023

[read more: https://t.co/VViYhUIx3G]pic.twitter.com/5aP1zZYiJs

— Massimo (@Rainmaker1973) July 3, 2023

It is the first of two spheres to open

MSG Sphere Las Vegas is one of two spheres designed by Populous, with the second planned for Stratford, east London. However, this venue was placed on hold by UK housing secretary Michael Gove, who issued an Article 31 holding directive for the building earlier this year.

The London sphere has been divisive, with author Anna Minton saying "the red flags raised by the MSG Sphere relate to democratic failure".

The video is by JoyVegas.