1410day.year
The first known mention of the Prague astronomical clock.
The Prague astronomical clock appears in historical records for the first time, foreshadowing a medieval marvel of horology.
In 1410, the Prague astronomical clock, mounted on the Old Town Hall, is recorded in documents for the first time. Crafted by clockmaker Mikuláš of Kadaň and astronomer Jan Šindel, the clock combined mechanical innovation with celestial observations, displaying the positions of the sun, moon, and zodiac. It featured animated figures that captivated medieval onlookers and demonstrated the era’s technological prowess. Over subsequent centuries, the clock underwent enhancements and restorations while maintaining its original 15th-century core. Its enduring operation makes it one of the oldest functioning astronomical clocks in the world. Today, it stands as an iconic symbol of Prague’s cultural and scientific heritage.
1410
Prague astronomical clock
1604day.year
Kepler's Supernova is the most recent supernova to be observed within the Milky Way.
Johannes Kepler observes a bright new star in the Milky Way, later known as Kepler’s Supernova (SN 1604).
In 1604, renowned astronomer Johannes Kepler documented a brilliant transient object in the constellation Ophiuchus, now identified as Kepler’s Supernova. It was the last supernova visible to the naked eye within our galaxy, sparking widespread interest across Europe. Kepler’s precise measurements of its luminosity and position advanced contemporary understanding of stellar phenomena. His observations challenged prevailing Aristotelian notions of unchangeable heavens and contributed to the scientific revolution. Remnants of SN 1604 continue to be studied by modern astronomers exploring supernova evolution. The event remains a landmark in the history of observational astronomy.
1604
Kepler's Supernova
Milky Way
2009day.year
First lunar impact of NASA's Lunar Precursor Robotic Program.
In 2009, NASA's LCROSS mission completed the first intentional lunar impact to search for water ice in a permanently shadowed crater.
On October 9, 2009, NASA's Lunar Crater Observation and Sensing Satellite (LCROSS) executed the first deliberate impact on the Moon's surface.
As part of the Lunar Precursor Robotic Program, LCROSS targeted the Cabeus crater to search for water ice.
The mission design included a direct impactor and an observing spacecraft to analyze the resulting plume.
High-speed cameras and spectrometers detected water molecules and other volatiles ejected by the collision.
This groundbreaking experiment provided the first definitive evidence of water ice in permanently shadowed lunar craters.
The findings have since shaped plans for future crewed and robotic missions to utilize lunar resources.
2009
Lunar Precursor Robotic Program