Nepedia
Back to Discover
Advanced Reader
🚀

Vesto Slipher

space Maturity 7-9 death dying Next article →

This article covers sensitive topics: death_dying. Parents can manage visibility in Parental Controls.

Vesto Melvin Slipher was a pioneering American astronomer. He changed how we view the entire universe. His work provided the first evidence that the universe is expanding. Slipher focused on measuring how fast distant objects move through space. He used light to uncover these hidden speeds. This work laid the foundation for modern cosmology.

Slipher's most important tool was spectroscopy. Spectroscopy is the study of light broken into its different colors. By looking at these colors, scientists can see specific patterns called absorption lines. Slipher used these lines to study the composition of planetary atmospheres. He identified ammonia and methane in the atmospheres of major planets. He also used spectroscopy to measure how fast planets rotate. For example, he showed that Uranus rotates much faster than Earth.

Slipher is most famous for discovering galactic redshifts. He applied the Doppler effect to the light from spiral nebulae. A spiral nebula is a large collection of stars, now known as a galaxy. The Doppler effect causes light to change color based on motion. If an object moves away, its light shifts toward the red end of the spectrum. This is called a redshift. In 1912, Slipher observed the Andromeda Nebula. He found it had a velocity of -300 km/s. This was a massive speed for that time.

His research progressed rapidly through the early 20th century. By 1914, he discovered the rotation of spiral galaxies. By 1917, he had measured the radial velocities of 25 different spiral nebulae. Radial velocity is the speed at which an object moves toward or away from an observer. Slipher found that almost all of these galaxies were moving away from us. Only three of the 25 showed different motions. This discovery suggested that these nebulae were not part of our own Milky Way galaxy.

Slipher's career was centered at the Lowell Observatory in Flagstaff, Arizona. He arrived there in 1901 as an assistant. His professor, William Cogshall, helped him secure this position. Slipher worked as an assistant until 1915. After the death of Percival Lowell, Slipher served as acting director for ten years. He was officially named director in 1926. He led the observatory for 28 years until his retirement in 1954. During his time there, he also supervised the work that led to the discovery of Pluto in 1930.

His data was vital for the work of Edwin Hubble. Slipher provided the measurements of how fast galaxies move. Hubble later combined these speeds with his own measurements of galaxy distances. This combination helped formulate the Hubble–Lemaître law. This law describes the relationship between a galaxy's distance and its redshift. It became the basis for the modern model of an expanding universe. Slipher's early observations provided the empirical evidence needed for this massive scientific leap.

Slipher's legacy is preserved throughout our solar system and beyond. Scientists have named a crater Slipher on the Moon. There is also a crater named Slipher on Mars. In 1962, astronomers discovered the asteroid 1766 Slipher. He received many prestigious honors during his life. These include the Henry Draper Medal and the Gold Medal of the Royal Astronomical Society. He was a member of the United States National Academy of Sciences. His life of discovery began in Mulberry, Indiana, and ended in Flagstaff in 1969.

551 words

Where will your curiosity go next?

Keep exploring at your chosen reading level.

🖼️ Images & Media (1)
File:Delegates to the Fourth Conference International Union for Cooperation in Solar Research at Mount Wilson Observatory.jpg
Delegates to the Fourth Conference...
More to explore

What is Nepedia?

A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.