Captured Science History

The long-term damage from an accident at the Chernobyl nuclear power plant more than 30 years ago is still unknown. When explosions ripped through the reactor in rural Ukraine, then part of the Soviet Union, they spewed huge amounts of radioactive material into the atmosphere and caused the worst nuclear disaster in history. About 10,000 people have died or will die because of their exposure to radiation, and experts worry about the children born to parents who were living near the disaster area. With international help, Ukraine has enclosed the damaged reactor, giving scientists time to figure out what the future holds.

To the untrained eye, Photo 51 was simply a grainy black and white image of dark marks scattered in a rough cross shape. But to the eye of a trained scientist, it was a clear portrait of a DNA fiber taken with X-rays. And to young scientists James Watson and Francis Crick, it confirmed their guess of deoxyribonucleic acid's structure. In 1953, the pair was racing toward solving the mystery of DNA's structure before other scientists could beat them to it. They and others believed that finding the simple structure of the DNA molecule would answer a great mystery, how do organisms live, grow, develop, and survive, generation after generation? Photo 51 and subsequent models based on the photo would prove to be the key to unlocking the secret of life.

Weighing as much as a small car, a rover named Curiosity rolls quietly around Mars. Scientific instruments pack its body and cluster at the end of a mechanical arm. An arrangement of lenses and instruments tops its mast, like a face. To the many NASA workers involved in Curiosity's mission on Mars, the rover is not simply a robot, but an astronaut bravely exploring an alien place. Curiosity's instruments collect data and its cameras take images of the Mars landscape, including self-portraits, in vivid color and detail. As it roams and explores, Curiosity will help find the answers to such age-old questions as has there ever been life on Mars? Could there be one day?

On the night of April 14, 1912, as it made its first voyage, the luxury steamship Titanic struck an iceberg. Then, a few hours after midnight on April 15, the ship sank thousands of feet before settling on the ocean floor. And that's where it stayed, whereabouts unknown, for the next 73 years until it was discovered by oceanographer Robert Ballard and his crew. The pictures and video Ballard brought back from the 1985 discovery helped stir new interest in the Titanic's voyage and its resting spot.

The biggest oil spill in U.S. history that polluted the pristine waters of Alaska decades ago and killed thousands of birds, mammals, and fish, still haunts the people who are living with its aftermath. On Good Friday 1989, the huge oil tanker, Exxon Valdez, ran aground in Prince William Sound, spilling millions of gallons of crude oil into the water-oil that would eventually cover more than 1,000 miles of shoreline. Cleanup began immediately but there is still oil in the sound and Alaskans say life will never be the same.

Millions of tons of plastic slip into oceans every year. Some floats and travels slowly with the currents, endangering the health of marine animals. The rest is hardly visible but is far more dangerous. Tiny bits of plastic sprinkle the ocean's surface or mix into the sandy seafloor and beaches. It ends up inside birds, fish, and other animals, harming them-and ultimately humans. Experts struggle with fear and hope as they work to stop the flood of plastic threatening living organisms across the globe.

A series of photos taken from space more than 20 years ago revealed thousands of unknown galaxies in a tiny patch of "empty" space. Called the Hubble Deep Field, the amazing image is made up of hundreds of photos combined into one. It was taken over the course of 10 days from the Hubble Space Telescope and has prompted astronomers and other scientists to speculate about universe's size, shape, and age. How long ago did the first galaxies appear? Have they always looked like they do today, or have their shapes evolved over time? And will they, along with the universe itself, go on expanding forever? The Hubble Deep Field has helped to answer some of these questions.

A massive tsunami caused by the strongest earthquake to ever hit Japan triggered the world's worst nuclear crisis since the Chernobyl accident 25 years earlier. The monster waves that crashed into the Fukushima Daiichi nuclear plant in March 2011 killed 15,000 people and caused nuclear reactor meltdowns that threatened the lives of thousands more. The waves receded long ago, but the devastating effects of the nuclear accident still linger.