When Worlds Collide (1951)

In producer George Pal's sci-fi disaster picture - a follow-up to Destination Moon (1950), and typical of 50's apocalyptic, doomsday disaster films - with a mediocre story that had spectacular special effects (Films with a similar plot included Deep Impact (1998) and Melancholia (2011):

• the film's prologue quoted the Book of Genesis in the Bible - specifying God's punishment upon the corrupted people of Earth by destruction ("the end of all flesh"), and the saving of the faithful Noah with an Ark.
• it told about the imminent destruction of the Earth (in six to eight months in the future) by a rogue star named Bellus that was on a collision-course with the planet. [Note: Since the threatening object was a 'star' - then the title was inaccurate. It wasn't a "world" that was about to collide with Earth.] The first threat was Bellus' single orbiting satellite known as Zyra that would pass close to Earth, 19 days before Bellus would crash into the planet.
• to save the human race from extinction, there were desperate efforts to build a space ark to transport a group of men and women to Zyra. As time ticked away and the 'day of doom' approached, Zyra as predicted came close to Earth (on Z-day) and caused massive earthquakes, volcanic eruptions, forest fires, floods and tsunamis that wreaked havoc around the world. Fires threatened to destroy the 'ark' spacecraft set to take off in a few weeks.

The Hour of Doom - Zyra's Z-Day

• the rocket-propelled 'ark' spaceship that was built on a ramp, was stocked with food, medicine, microfilmed books, equipment, livestock and animals, and was ready to depart
• in the improbable happy ending, the spaceship launched with about 45 passengers (selected by lottery) off the curved ramp, as they watched Bellus crash into the Earth on a viewing screen. The 'ark' craft safely entered Zyra's atmosphere and landed with a gliding free-fall and belly-flop since the fuel had already been depleted. When the crew disembarked into a deep snow field, they found that Zyra was habitable with fresh air, and would be greener and more lush further away at lower elevations
• some of the best examples of visual effects were a great fireball - a sun-sized body called Bellus - hurtling toward earth, the rocket-propelled spaceship built on a curved ramp, and a view of the sunrise landscape on Zyra (a color sketch/drawing).

Ending Views of Zyra's Landscape (A Sketch Drawing)