Deep Impact (1998)

Plot
On May 10, 1998, teenage amateur astronomer Leo Biederman discovers an unusual object near the stars at a  in  with his school's astronomy club. His teacher informs astronomer Dr. Marcus Wolf, who realizes that the object is a comet, heading for a collision course with Earth. Wolf dies in a car accident trying to alert the world.

One year later, journalist Jenny Lerner investigates the sudden resignation of  Alan Rittenhouse and his connection to "Ellie", supposedly a mistress. After interviewing Rittenhouse, she is intercepted by the and brought before President Tom Beck. Lerner realizes that Ellie is not a mistress but an acronym: "E.L.E.", for. Due to Lerner's investigation, President Beck makes an announcement earlier than planned: the comet named Wolf-Biederman (named after Wolf and Biederman, mistakenly assuming Leo Biederman was killed along with Professor Wolf) is headed for Earth. It is 7 miles (11 km) long, large enough to cause a mass extinction, and possibly wipe out humanity, if it hits the Earth. He also reveals that the United States and Russia have been constructing an called Messiah in orbit that will transport a team led by Oren Monash and including veteran astronaut Spurgeon Tanner to the comet, so that its path toward Earth may be diverted using nuclear weapons. After his name is mentioned on TV, Leo speaks to the town about the discovery and how the White House thought he died alongside Wolf.

After landing on the comet, the crew members plant nuclear bombs beneath the surface, but are delayed and caught in outgassing explosions when sunlight hits the comet surface. While fleeing to the space vehicle, Monash is blinded due to direct unfiltered sunlight and suffers severe facial burns, while Gus Partenza is lost, ejected from the surface by an outflow of cold gas. When the bombs detonate, the ship is damaged from the blast and the team loses contact with Earth. President Beck announces the crew's failure; the nukes did not divert the comet, but split it into two smaller rocks nicknamed "Biederman" (1.5 miles (2.4 km) long) and "Wolf" (6 miles (9.7 km) long), both heading for Earth.

After President Beck announces the Messiah crew's failure, he declares martial law and reveals that governments worldwide have been building underground shelters. The United States' shelter is in the. The US government conducts a lottery to select 800,000 Americans under age 50 to join 200,000 pre-selected individuals as well as a massive supply of food, genetically viable populations of significant animals and the seeds of every species of plants. Lerner and the Biederman family are pre-selected, but Leo's girlfriend Sarah Hotchner and her family are not. Leo marries Sarah to save her family, but they are left off the evacuee list. Sarah refuses to leave without her parents.

A last-ditch effort to use Earth's to deflect the comets fails. President Beck reports on this and reveals the final trajectories of the two comets. The Biederman fragment will impact the off, which will generate megatsunamis up to 3,500 feet (1,100 m) high. The people who would be in its way are immediately advised to evacuate. The Wolf fragment will impact western Canada, creating a huge cloud of dust and molten particles that will block out the Sun for two years, killing all present life on the surface of the planet in a matter of weeks. Leo returns home looking for Sarah, but her family has left for the and is caught in a traffic jam. Leo catches up to the family using a motorcycle from their garage. Sarah's parents instruct Leo to take Sarah and her baby brother to high ground. Lerner gives up her seat in the last evacuation helicopter to her friend Beth and Beth's young daughter. She joins her estranged father Jason at their beach house, where they reconcile.

The Biederman fragment enters the planet and makes impact off Cape Hatteras, creating megatsunamis that devastate the Atlantic coasts of the Americas, Europe, and Africa. Too low on fuel and life support to be able to safely attempt a second landing, the crew of Messiah decides that their only chance to destroy Wolf and save the world is to undertake a suicide mission, with the remaining nuclear warheads to obliterate the Wolf fragment. After they say goodbye to their loved ones via video conference, the ship reaches the Wolf fragment and enters a fissure to blow itself up, which blows the comet into smaller pieces that burn up in Earth's atmosphere. Leo, Sarah and her baby brother successfully make it to safety.

After the waters recede, President Beck speaks to a large crowd, encouraging them to remember and honor the heroes for their sacrifice that saved the world, as he believes they've been blessed with a second chance to call Earth their home and urging the nations of the world to continue their recovery.