The dingy classroom at Cadi Ayyad University in Marrakech reminds me that there was a time when astronomers charted the skies with little more than math and passion. Sophisticated computer models have been developed to catalog pulsars and probe dark matter, but here in Morocco, in a dark room devoid of high-tech gadgetry, Khalid Barkaoui, a 25-year-old doctoral student, distilled data captured by the TRAPPIST-North telescope at the Oukaimeden Observatory that helped paint a picture of three of seven previously unidentified exoplanets. With this discovery of planets that may very well be habitable, Barkaoui is inching closer to answering one of our most persistent questions: Are we alone in the universe?
An exoplanet, or extrasolar planet, is any planet that orbits a star other than the sun. Scientists like Michaël Gillon from the University of Liège in Belgium are obsessed with determining whether or not these planets support life. In Gillon’s opinion, Barkaoui’s work marks a new era of exploration that could eventually result in humans becoming an interstellar species. “I’m certain of it,” Gillon says.
When NASA announced in February the discovery of seven rocky planets orbiting a single dwarf star called TRAPPIST-1, the first known grouping of its kind outside our solar system, the report was picked up by virtually every mainstream publication in the world. But few mentioned Morocco’s role in the project. Thirty scientists, including Barkaoui and his mentor, Zouhair Benkhaldoun, contributed to an article in Nature chronicling the science behind the discovery. According to Benkhaldoun, who heads the astrophysics department at Cadi Ayyad and is president of the Arab Astronomical Society in Marrakech, without the Oukaimeden telescope and Barkaoui’s data reduction, crucial details about three of the seven planets would’ve been missed. We would not know, for example, their radius, temperature, orbiting period, mass or density — all essential to supporting the conclusion that they are the most likely to harbor life. Gillon, who led the discovery, says the Moroccan team made an important contribution to characterizing the TRAPPIST-1 system, and he is optimistic about Barkoui’s future as an astrophysicist.
Khalid Barkaoui is a shy Amazigh man from a desert city 122 miles south of Marrakech. His mother stayed home to care for six children; his father ran a drugstore. According to Barkaoui, his first year of university was marked by chronic homesickness and lack of direction. Then he met Benkhaldoun, and his inner telescope has been fixed on the skies ever since.
IT SHOWS THAT PLANETS WITH HABITABLE CONDITIONS EXIST ELSEWHERE IN OUR GALAXY, AND EVEN BEYOND.
ESSAM HEGGY, SPACE SCIENTIST, NASA JET PROPULSION LABORATORY
The telescope in Morocco was deployed after Gillon and his team discovered TRAPPIST-1 in Chile, in 2015. At the time, they knew of only three exoplanetsand published an initial Nature article to that effect. But, according to Gillon, their ground telescopes received so many signals, they couldn’t make sense of the system. “So, we had to go to space,” he says. Gillon approached NASA for three weeks’ access to Spitzer, a space-based infrared telescope. It worked: The telescope not only confirmed ground-based observations but also discovered two new planets. “It resolved completely the system,” Gillon says.
In the meantime, Morocco’s observatory in the Atlas Mountains was due to receive a new telescope. According to Benkhaldoun, the call for intensive observation of the TRAPPIST (Transiting Planets and Planetesimals Small Telescope) system warranted an expedited push. Funding was approved, and that same month Gillon’s team sent urgent requests to the global scientific community, from Hawaii to South Africa, to get several telescopes on deck to “target the star,” says Benkhaldoun, including the world’s largest — the European Extremely Large Telescope in Chile’s Atacama Desert. The ground observations culminated with the start of Spitzer’s 20-day continuous observation, in September 2016. Barkaoui’s contribution to the resulting Naturearticle, along with Benkhaldoun’s, showed there had to be more than the original three exoplanets and that three of the seven exoplanets may support life. Essam Heggy, a space scientist working with NASA’s Jet Propulsion Laboratory, said theirs was a great discovery: “It shows that planets with habitable conditions exist elsewhere in our galaxy, and even beyond.”
Krisztián Vida from Konkoly Observatory in Hungary is not so sure. His research, based on data from NASA’s space-based Kepler telescope and published in October 2016, shows the exoplanets are under constant bombardment by stellar flares, which would make life as we know it unbearable. While Benkhaldoun acknowledges that Vida’s study is worthy of interest, he says that more technological progress will be required to determine the prevailing atmospheric conditions.
For his part, Barkaoui remains optimistic. “The discovery opens the door [here in Morocco] for finding more planets … and Oukaimeden is now known throughout the world,” he says, stretching his stiff limbs and taking a sip of cold coffee. He may be bleary-eyed from staring at charts and “too busy” for anything except making the occasional tagine at home, but his commitment to the study is unwavering. Somewhat ironic, considering he was a poor student without any focus until Benkhaldoun recognized his potential. “Khalid has a speech impediment,” Benkhaldoun says. “But I’ve known him for four years, and I felt [in him] a serious behavior and willingness to learn, doubled with unfailing diligence.” Life for the protégé isn’t easy: He and his older brother are hacking single life in a small apartment, while Benkhaldoun and Gillon work to source funds that will further Barkaoui’s dreams of uncovering new worlds.
Barkaoui is completing a one-year study at the University of Liège, where he is designing a program of nightly targets for TRAPPIST-North. He’s also dipping into a new study led by Gillon called Speculoos, searching for more terrestrial planets transiting nearby ultracool stars. Obstacles remain, of course. The universities in Belgium and Marrakech are hampered by red tape, and Gillon says that Barkaoui needs to build his scientific knowledge before completing his Ph.D. Barkaoui predicts it’ll take another two years and then, “I want to study the atmosphere of exoplanets using the Kepler telescope.” But first he has to improve his English, he says. His dissertation — and all that follows — depends on it.
Quelle: ZY