THIS DAY IN SPACE

TRAPPIST-1 Planets Announced
On February 22, 2017, NASA announced the discovery of seven Earth-sized planets orbiting a single star—TRAPPIST-1—located about 39 light-years away in the constellation Aquarius. This extraordinary find, made using the Spitzer Space Telescope and ground-based observatories, marked a milestone in the search for potentially habitable exoplanets. The TRAPPIST-1 system stood out not just for the number of planets but also because three of them lie within the star’s habitable zone, where temperatures could allow liquid water to exist. The planets are similar in size and mass to Earth and likely rocky. Their tight orbits around the ultra-cool dwarf star mean a year on some of them lasts just a few days. The discovery fueled excitement and inspired numerous follow-up studies, as astronomers began to assess atmospheres, orbital dynamics, and the possibility of biosignatures. TRAPPIST-1 remains one of the best-studied planetary systems outside our solar system and is a prime target for the James Webb Space Telescope, which aims to probe their atmospheric compositions in unprecedented detail.

Soviet Luna 9's Final Transmission
Luna 9, the first spacecraft to achieve a soft landing on the Moon and transmit photographic data back to Earth, completed its mission on February 22, 1966, after sending several panoramic images from the lunar surface. Launched by the Soviet Union earlier that month, Luna 9 successfully landed in the Oceanus Procellarum region on February 3. It sent back critical data that confirmed the Moon's surface could support landers, alleviating fears that a thick layer of dust would engulf spacecraft. The images, first received by Jodrell Bank Observatory in England due to their open radio transmission, revealed a relatively flat terrain with small rocks and a clear horizon. Luna 9’s success was a pivotal moment in the space race, demonstrating Soviet technological leadership and paving the way for future lunar missions, including human landings. Its final transmission marked the end of a historic mission, one that helped change how humanity viewed the Moon—not just as a distant celestial body, but as a place that could be reached, studied, and possibly even visited.