THIS DAY IN SPACE

Discovery of Pluto
On February 18, 1930, astronomer Clyde Tombaugh discovered Pluto at the Lowell Observatory in Flagstaff, Arizona. Tombaugh was tasked with searching for a ninth planet—then known as 'Planet X'—hypothesized to exist beyond Neptune. Using a 13-inch astrograph and a technique called ‘blink comparison,’ he detected a faint moving object across photographic plates taken days apart. This object, later named Pluto, was announced to the world on March 13, 1930. Though its classification changed decades later, this discovery marked a triumph in planetary astronomy and inspired generations of astronomers. Pluto’s eccentric orbit and diminutive size puzzled scientists, and by the early 21st century, it was reclassified as a ‘dwarf planet’ by the International Astronomical Union. Despite the controversy, Tombaugh’s achievement remains historic. The discovery extended humanity’s known solar system and symbolized the ingenuity of observational astronomy. In a poetic tribute, the ashes of Tombaugh were carried aboard NASA’s New Horizons spacecraft, which conducted a flyby of Pluto in July 2015—offering humanity its first close-up images of the distant world he discovered. Pluto continues to captivate the public imagination and remains a cultural and scientific icon of the outer solar system, a testament to human curiosity and persistence.

Perseverance Rover Lands on Mars
On February 18, 2021, NASA’s Perseverance rover successfully landed on Mars in the Jezero Crater, kicking off one of the most ambitious astrobiology missions in history. Launched in July 2020, the rover touched down with unprecedented precision using a complex sky crane system. Its primary mission was to search for signs of ancient microbial life, collect rock and soil samples, and test new technologies that could aid future human missions. Perseverance carried the Ingenuity helicopter—the first aircraft to fly on another planet—and a suite of scientific instruments including SHERLOC, PIXL, and MOXIE. The mission marked NASA’s ninth landing on Mars and built upon the legacy of its predecessors like Curiosity and Opportunity. Jezero Crater was chosen for its ancient river delta, believed to be a prime site for preserving biosignatures. Within weeks, Perseverance began relaying high-resolution images, conducting laser spectroscopy, and testing oxygen generation from the Martian atmosphere. The mission received global acclaim for its technological achievement and scientific potential. It also symbolized international cooperation and public engagement, with millions watching the landing live. Perseverance’s success not only advanced Mars exploration but laid the groundwork for sample-return missions and, eventually, human exploration. It was a giant leap in our ongoing search for life beyond Earth.