Space Friday: A Flower, Neighbors, and Star Formation

A Beautiful Space Flower, but Not the First

On January 16, astronaut Scott Kelly tweeted a beautiful image of a bright orange zinnia flower, proudly, declaring: “First ever flower grown in space makes its debut!” While Kelly certainly deserves to be proud of his first bloom on the International Space Station (ISS), it was not the first flower to bloom in space or even on the ISS. More on that in a moment though.

Using the same process that was used grow the first space lettuce earlier this year, the Veggie Plant Growth System (or Veg-01), astronauts aboard the ISS have been monitoring the growth of the current floral crop, specifically selected to help understand how flowers bloom in microgravity. Though zinnias are actually an edible flower, these will not be consumed. They are intended as a test run for attempts to grow a tomato plant on the ISS in 2017, well after Kelly will have returned to Earth. However, not all has gone smoothly in the process.

In December, issues with humidity and potential over-watering lead to mold on the young sprouts, which Kelly tweeted images of. By the end of the month, Kelly became so concerned for the plants that he request permission from ground support team to adjust the water schedule based on what the plants themselves seemed to need. Permission was granted, and Kelly became the ISS’s “autonomous gardener” and, as he put it, began to “channel Mark Watney.”

Eventually, the plants turned around and Kelly and the Veggie team created “the Zinnia Care Guide for the On-Orbit Gardener,” which contains basic guidelines for zinnia care while leaving judgment capabilities into the hands of the astronaut who actually has the plants in front of him/her rather than relying on a step by step operational guide. This kind of autonomy could be critical in future, longer duration missions.

Why do we care so much about growing plants, especially flowers in space?

"The farther and longer that humans go away from Earth, the greater the need to be able to grow plants for food, atmosphere recycling and psychological benefits," says Gioia Massa, science lead for Veg-01 at NASA. "I think that plant systems will become important components of any long-duration exploration scenario."

While the psychological benefits are not as tangible, they are still of significant value, as Alexandra Whitmire with NASA’s Behavioral Health and Performance notes: “Plants can indeed enhance long duration missions in isolated, confined and extreme environments—environments that are artificial and deprived of nature. Studies from other isolated and confined environments, such as Antarctic stations, demonstrate the importance of plants in confinement, and how much more salient fresh food becomes psychologically, when there is little stimuli around.”

As a result, plants have become an important part of space experiments—again, this was not the first time plants have bloomed off-Earth. Plenty of plant experiments have been conducted both on the ISS and other spacecraft in decades past. In 2012, as part of what NASA called a “personal biology experiment” (meaning it was done on his own free time rather than being an official NASA experiment) ISS astronaut Don Pettit attempted to grow a sunflower, which succumbed to fungus shortly after blooming, but does count as the first flower to bloom on the ISS. More successfully, Pettit also a grew a zucchini plant which flowered. He documented the growth of the latter in a fantastic NASA blog, from the perspective of the confused zucchini plant. (It is worth noting no zucchinis actually grew, since it was a male plant).

In the 1990’s, Russian cosmonauts experimented with wheat growth on the Mir station, which did flower as part of their life cycle. Even prior to that, the Guinness Book of World Records credits the Arabidopsis (related to the mustard plant) as the first plant species to flower in space on board the Soviet Salyut-7 station in 1982. The distinction of first space gardeners went to Viktor Patsayev and Vladislav Volkov on Salyut 1 in 1971, who also wrote about the psychological benefits of tending plants during space travel. And while they were not flowering, plants actually have been among the first living things sent into space—specifically, along with two dogs, a variety of plants were onboard Cosmos 110 for a 22-day mission that returned to Earth in 1966. –Elise Ricard

Is There Anybody Out There?

One of the great unknowns in science is whether or not humanity is alone in the Universe. Some astronomers reason that if the Universe is so vast, containing billions upon billions of stars like our own sun, then surely there must be another world out there—if not many of them—where the same long, complex set of circumstances that led to intelligent life on Earth may also have occurred. On the other hand, the fact that it was such a long, complex set of circumstances makes duplication of the same random chain of events unlikely.

Several years ago, Dimitar Sasselov of Harvard University suggested that we might just be a bit early to the party, being perhaps the first civilization to develop once the Universe built up the right recipe of heavy elements to produce environments stable enough to support life.

In a more recent paper submitted to the monthly journal Astrobiology, a team of researchers at the Australian National University’s Research School of Earth Sciences in Canberra went further, suggesting that it wouldn’t have been much of a party, anyway. They propose that the reason we haven’t found extraterrestrial life is that we’re the only ones who have evolved, all others having suffered early extinction. According to Aditya Chopra and Charles Lineweaver, most emerging life never has much of a chance, its development stopping at what they call the “Gaian Bottleneck.” Applying the analogy of trying to ride a wild bull, they posit that most life falls off. The Universe defaults to extinction, and only rarely, they suggest, would rapid evolution occur after the first billion years of a planet’s existence, enabling life to regulate the atmosphere enough to maintain global habitability for several billion more years—sufficient time for life to take hold and sustain itself on the planet, as it has here on Earth. In Chopra and Lineweaver’s words, “…life must exist for a planet to remain habitable,” making the existence of life on a planet’s surface a greater factor for the maintenance and sustainability of life than the planet’s distance from its star or the star’s luminosity.

According to Lineweaver, “One intriguing prediction of the Gaian Bottleneck model is that the vast majority of fossils in the universe will be from extinct microbial life, not from multicellular species such as dinosaurs or humanoids that take billions of years to evolve.” By that line of thinking, bones or other fossils of complex life may not even exist, as those more complex forms of life might not have had time to evolve at all—making human existence the result of an incredible stroke of luck.

Feeling lonely? –Bing Quock

Young Stars in Globular Clusters

Globular clusters, “dense, spherical collections of hundreds of thousands to millions of stars tightly bound together by gravity,” as Elise Ricard wrote here a few weeks ago, are great places to study star formation. While originally thought to form in a single burst from a common cloud of gas, old globular clusters—those with ages greater than 10 billion years—often have populations of younger stars, indicating that more than one generation of stars may form.

Using observations from the Hubble Space Telescope, a team of researchers discovered young populations of stars within globular clusters that apparently developed courtesy of star-forming gas flowing in from outside the clusters themselves. This method stands in contrast to the conventional idea of the clusters’ initial stars shedding gas as they age in order to spark future rounds of star birth.

While the Milky Way hosts hundreds of older globular clusters, the scientists observed three young to middle-age clusters in nearby dwarf galaxies. The team proposes that these clusters can sweep up stray gas and dust they encounter while moving about their respective host galaxies. This theory of newborn stars arising in clusters as they “adopt” interstellar gases actually dates back to a 1952 paper, but now, more than a half-century later, this once speculative idea suddenly has key evidence to support it.

“We have now finally shown that this idea of clusters forming new stars with accreted gas might actually work,” says Richard de Grijs of the Kavli Institute for Astronomy and Astrophysics (KIAA) at Peking University. “And not just for the three clusters we observed for this study, but possibly for a whole slew of them.”

The research was published this week in Nature. –Molly Michelson

​Image: ESA/Hubble & NASA