Unearthly salad on the International Space Station

Photo: NASA/HANDOUT/EPA-EFE/REX/Shutterstock

At least one of the great mysteries of the universe has finally been solved: The crew of the International Space Station (ISS) reports that a tomato thought lost has reappeared.

The cosmic vegetable is a tomato that the US astronaut Francisco "Frank" Rubio grew from seeds as part of an agricultural experiment in microgravity, as reported by the Guardian, among others.

Rubio has long been accused of eating the fruit when it mysteriously disappeared more than eight months ago. However, the tiny specimen, or at least its remains, have now been found, members of the seven-man crew announced this week in a live stream to mark the outpost's 25th anniversary in orbit.

They did not reveal where and in what condition they found the dwarf tomato, which is about 2.5 centimeters in size, in the space station.

But not a tomato thief

Rubio, who returned to Earth in September after spending more days in space than any other U.S. astronaut with a record time of 371, may have been relieved by the news of the find. After landing, he said that he feared being branded a tomato thief forever.

"Hopefully someday someone will find her, this little shriveled thing," he told reporters, claiming to have searched for her for up to 20 hours when she disappeared during his harvest. "I was pretty sure I'd hooked it up in the right place. But when I came back, she was gone."

One of only twelve successfully germinated tomatoes

The project, to which the tomato belongs, is officially known as Veg-05. The abbreviation stands for: "Investigating the Productivity, Nutritional Value and Acceptance of Lettuce Plants to Supplement the ISS Food System". The lettuce cultivation experiment in space is intended to expand knowledge about the nutrition of astronauts during long missions.

In addition to assessing the viability and impact of space travel on the growth of edible plants under different lighting conditions, the experiment will also provide astronauts with taste tests and a survey to determine whether interacting with plants in the space environment has positive psychological effects or otherwise affects their mood.

The Rubio tomato was one of only 05 red dwarfs successfully germinated and brought to maturity in space as part of the Veg-100 project, compared to more than <> in a parallel experiment on Earth, according to Nasa.