1803day.year
Thousands of meteor fragments fall from the skies of L'Aigle, France; the event convinces European scientists that meteors exist.
In 1803, thousands of meteor fragments fell over L’Aigle, France, providing decisive proof of the extraterrestrial origin of meteors.
On April 26, 1803, residents of L’Aigle witnessed a spectacular shower of stones that rained from a clear sky.
Physicist Jean-Baptiste Biot was dispatched to investigate and compiled a detailed report confirming the stones came from space.
His findings convinced the scientific community of the reality of meteors, settling a longstanding debate.
The event marks a foundational moment in the science of meteoritics and the study of planetary materials.
Museums today display fragments from L’Aigle as tangible links to this cosmic encounter.
This incident opened new chapters in astronomy and geology by expanding our understanding of the solar system.
1803
meteor fragments fall
L'Aigle
1954day.year
The first clinical trials of Jonas Salk's polio vaccine begin in Fairfax County, Virginia.
On April 26, 1954, the first public clinical trials of Jonas Salk's polio vaccine commenced in Fairfax County, Virginia, launching a historic medical campaign.
Following years of laboratory research, Dr. Jonas Salk began field testing his inactivated poliovirus vaccine with schoolchildren in Virginia. The double-blind trials involved thousands of participants and marked one of history's largest medical experiments. Health workers administered placebo and vaccine doses under strict protocols to assess safety and efficacy. Early results generated cautious optimism as antibody levels rose among vaccinated subjects. The trial process laid the foundation for the National Foundation for Infantile Paralysis' widespread immunization program. By eliminating polio cases in trial towns, the vaccine's success became increasingly apparent. Public enthusiasm soared, and fundraising efforts expanded nationwide. The 1954 trials ultimately led to vaccine approval and a dramatic decline in polio incidence. Salk's work inspired subsequent advances in virology and immunology.
Jonas Salk
polio vaccine
Fairfax County, Virginia
1962day.year
NASA's Ranger 4 spacecraft crashes into the Moon.
NASA's Ranger 4 mission ends in a crash on the lunar surface, marking the first U.S. spacecraft to impact the Moon.
Part of NASA's Ranger program aimed at studying the Moon, Ranger 4 launched on April 23, 1962, to transmit data and images.
A series of system failures prevented the probe from returning scientific information during its flight.
On April 26, 1962, Ranger 4 became the first American spacecraft to strike the lunar surface, impacting the far side of the Moon.
Despite the lack of data return, the mission provided valuable lessons that informed subsequent lunar exploration efforts.
It marked a significant early milestone in the U.S. space program and the space race era.
1962
NASA
Ranger 4
Moon
1962day.year
The British space programme launches its first satellite, the Ariel 1.
The British space programme achieves its first orbital satellite launch with Ariel 1, in partnership with NASA.
Ariel 1, developed by the United Kingdom in collaboration with NASA, lifted off on a Thor Delta rocket on April 26, 1962.
It carried experiments to study the ionosphere and cosmic rays, marking the UK’s first successful foray into space.
The satellite transmitted valuable data back to Earth for ten months before its power systems failed.
Ariel 1’s launch demonstrated the feasibility of international cooperation in space research.
This milestone established the foundation for the UK’s continued contributions to space science.
British space programme
Ariel 1
1981day.year
Dr. Michael R. Harrison of the University of California, San Francisco Medical Center performs the world's first human open fetal surgery.
Surgeon Michael R. Harrison performs the world's first human open fetal surgery at UCSF, pioneering prenatal medical intervention.
On April 26, 1981, Dr. Michael R. Harrison led the first open fetal surgery at UCSF Medical Center.
The groundbreaking procedure involved operating on a fetus diagnosed with a life-threatening congenital condition.
Harrison’s team developed specialized techniques and equipment to access the womb safely.
This milestone opened a new frontier in prenatal medicine and improved outcomes for unborn patients.
The success of the operation catalyzed advances in fetal diagnosis and surgical intervention.
1981
Michael R. Harrison
University of California, San Francisco Medical Center
fetal surgery
1993day.year
The Space Shuttle Columbia is launched on mission STS-55 to conduct experiments aboard the Spacelab module.
Space Shuttle Columbia launches on mission STS-55 to conduct scientific experiments aboard the Spacelab module.
On April 26, 1993, Space Shuttle Columbia lifted off from Kennedy Space Center on mission STS-55.
The flight carried the German-sponsored Spacelab D-2 module, hosting over 90 experiments in microgravity.
Research spanned materials science, life sciences, and astronomy, involving international scientific teams.
Crew members collaborated closely with ground controllers to operate experimental apparatus and record data.
STS-55 highlighted the shuttle program's role in fostering multinational cooperation and advancing space science.
After 10 days in orbit, Columbia landed successfully, returning valuable findings to Earth.
1993
Space Shuttle Columbia
STS-55
Spacelab