| NAME OF ASTRONOMER | |
| JAN OORT | JAN OORT WAS A DUTCH ASTRONOMER WHO RESHAPED OUR UNDERSTANDING OF THE COSMOS IN SEVERAL PROFOUND WAYS . HERE’S WHAT MADE HIM LEGENDARY: MAJOR CONTRIBUTIONS MILKY WAY ROTATION: HE CONFIRMED THAT THE MILKY WAY ROTATES AND SHOWED THAT THE SUN IS NOT AT ITS CENTER. THIS OVERTURNED LONG-HELD ASSUMPTIONS AND HELPED MAP OUR GALAXY’S STRUCTURE. OORT CONSTANTS: HE DEVELOPED MATHEMATICAL CONSTANTS THAT DESCRIBE THE ROTATION OF THE MILKY WAY, STILL USED IN GALACTIC ASTRONOMY TODAY. DARK MATTER PIONEER: IN 1932, OORT NOTICED THAT STARS WERE MOVING IN WAYS THAT COULDN’T BE EXPLAINED BY VISIBLE MATTER ALONE. HE PROPOSED THE EXISTENCE OF “INVISIBLE MATTER,” A CONCEPT THAT LAID THE GROUNDWORK FOR WHAT WE NOW CALL DARK MATTER. OORT CLOUD: HE THEORIZED THE EXISTENCE OF A VAST, DISTANT CLOUD OF ICY BODIES SURROUNDING THE SOLAR SYSTEM, WHICH IS BELIEVED TO BE THE SOURCE OF LONG-PERIOD COMETS. THIS REGION IS NOW NAMED THE OORT CLOUD IN HIS HONOR. RADIO ASTRONOMY: OORT WAS A PIONEER IN USING RADIO WAVES TO STUDY SPACE. HE HELPED MAP THE SPIRAL ARMS OF THE MILKY WAY USING HYDROGEN’S 21-CM RADIO EMISSIONS. |
| NAME | DESCRIPTION | CITY | STATE/COUNTRY |
| BIRTHPLACE ( HOUSE) | HOUSE – VOORSTRAAT 35 FRANKER | FRANEKER , FRIESLAND | NETHERLANDS |
| MUSEUM | RIJKSMUSEUM BOERHAAVE | LEIDEN | NETHERLANDS |
| ALMA MATER – PRIMARY SCHOOL | DALTONSCHOOL OEGSTGEEST | OEGSTGEEST | NETHERLANDS |
| ALMA MATER – SECONDARY SCHOOL | HOGERE BURGERSCHOOL – BURGGRAVENLAAN 2 | LEIDEN | NETHERLANDS |
| ALMA MATER- UNIVERSITY | UNIVERSITY OF LEIDEN – LEIDEN GYMNASIUM | LEIDEN | NETHERLANDS |
| OBSERVATORY – HE CONFIRMED THE DIFFERENTIAL ROTATION GALAXY DISCOVERED THE GALACTIC HALO , AND THE GROUNDWORK FOR RADIO ASTRONOMY. | LEIDEN OBSERVATORY | LEIDEN | NETHERLANDS |
| ALMA MATER | UNIVERSITY OF GRONINGEN | GRONINGEN | NETHERLANDS |
| DEATHPLACE | HOUSE – STERREWACHTLAAN 5 – RIGHT NEXT TO OBSERVATORY | LIEDEN | NETHERLANDS |
| BURIAL | GROTEKERK -UNMARKED GRAVE | HAGUE | NETHERLANDS |