For the first time in history, a flower has bloomed in space. Can this imply a possible sign of life?

The historic news that the zinnia flower aboard the International Space Station has bloomed, according to US astronaut Scott Kelly via his official Twitter account. Kelly posted a photo of an orange flower with 13 petals.

"First ever flower grown in space makes its debut! #SpaceFlower #zinnia #YearInSpace," he tweeted, adding: "Yes, there are other life forms in space!"

In a blog posted by NASA, it claimed that zinnias, a native flower from the Southwestern part of the USA, chosen not only for its beauty but also to aid researchers understand plants' ability to flower and grow in microgravity. Although the plants did not grow perfectly, it has allowed researchers to gain some insights both from plants and fluid and how to manage between ground and station.

Zinnia's sensitivity to environmental parameters and light characteristics make it a lot different from other plants like lettuce, according to Trent Smith, International Space Station "Veggie" plant growth facility project manager. With its longer growth duration of 60 to 80 days, zinnias can flower and can also be a good precursor to tomatoes.

There have been other plants grown in space including lettuce and wheat, but no flower has ever bloomed. Aside from helping researchers figuring out how to garden on space, flowers are also uplifting for the crew.

While not all crew members are up for some space gardening, Alexandra Whitmire, Behavioral Health and Performance in the NASA Human Research Program deputy element scientist, said it might be valuable. Totally surrounded in an artificial environment, plants can boost long-term missions.

Although this notion is without concrete basis, effort exerted in the Veggie project can otherwise help in preparing for the Mars mission. "In future missions, the importance of plants will likely increase given the crews' limited connection to Earth," Whitmire said.