This day in New Mexico History: January 24, 1930 - While a young researcher working for the
Lowell Observatory in
Flagstaff, Arizona, Clyde Tombaugh was given the job to perform a systematic search for
Planet X predicted by
Percival Lowell. It was hard work. Tombaugh used the observatory's 13-inch
astrograph to take photographs of the same section of sky several nights apart. It was an unheated observatory in the dead of winter. He then used a
blink comparator to compare the different images. He went grid by grid looking at every point of light. When he shifted between the two images, a moving object, such as a planet, would appear to jump from one position to another, while the more distant objects such as stars would appear stationary. Tombaugh
noticed such a moving object in his search, near the place predicted by Lowell, and subsequent observations showed it to have an orbit beyond that of Neptune. This ruled out classification as an asteroid, and they decided this was the ninth planet that Lowell had predicted. The official discovery was made on Tuesday, February 18, 1930, using images taken this day in 1930. The name "Pluto" won out over numerous other names suggestions partly because it was named after the
Roman god of the underworld because he was able to render himself invisible and partly because
Percival Lowell's initials PL formed the first 2 letters. Lowell had died 14 years earlier. The name Pluto was officially adopted on May 1, 1930. On August 24, 2006 the
International Astronomical Union reclassified Pluto, grouping it with two similarly sized "
dwarf planets" rather than with the eight "
classical planets". Tombaugh Elementary in Las Cruces is named in his honor. I still call Pluto a planet and you can, too.
This day in New Mexico History - January 24
This day in New Mexico History: January 24, 1930 - While a young researcher working for the Lowell Observatory in Flagstaff, Arizona, Clyde Tombaugh was given the job to perform a systematic search for Planet X predicted by Percival Lowell. It was hard work. Tombaugh used the observatory's 13-inch astrograph to take photographs of the same section of sky several nights apart. It was an unheated observatory in the dead of winter. He then used a blink comparator to compare the different images. He went grid by grid looking at every point of light. When he shifted between the two images, a moving object, such as a planet, would appear to jump from one position to another, while the more distant objects such as stars would appear stationary. Tombaugh 
noticed such a moving object in his search, near the place predicted by Lowell, and subsequent observations showed it to have an orbit beyond that of Neptune. This ruled out classification as an asteroid, and they decided this was the ninth planet that Lowell had predicted. The official discovery was made on Tuesday, February 18, 1930, using images taken this day in 1930. The name "Pluto" won out over numerous other names suggestions partly because it was named after the Roman god of the underworld because he was able to render himself invisible and partly because Percival Lowell's initials PL formed the first 2 letters. Lowell had died 14 years earlier. The name Pluto was officially adopted on May 1, 1930. On August 24, 2006 the International Astronomical Union reclassified Pluto, grouping it with two similarly sized "dwarf planets" rather than with the eight "classical planets". Tombaugh Elementary in Las Cruces is named in his honor. I still call Pluto a planet and you can, too.
Posts
1 comments:
Kudos to you for not blindly accepting the controversial IAU ruling. Pluto is still a planet, as are Ceres, Haumea, Makemake, and Eris. Only four percent of the IAU voted on this, and most are not planetary scientists. Their decision was immediately opposed in a formal petition by hundreds of professional astronomers led by Dr. Alan Stern, Principal Investigator of NASA’s New Horizons mission to Pluto. Stern and like-minded scientists favor a broader planet definition that includes any non-self-luminous spheroidal body in orbit around a star. The spherical part is important because objects become spherical when they attain a state known as hydrostatic equilibrium, meaning they are large enough for their own gravity to pull them into a round shape. This is a characteristic of planets and not of shapeless asteroids and Kuiper Belt Objects. Pluto meets this criterion and is therefore a planet. Under this definition, our solar system has 13 planets and counting: Mercury, Venus, Earth, Mars, Ceres, Jupiter, Saturn, Uranus, Neptune, Pluto, Haumea, Makemake, and Eris.
Post a Comment