Stargazer: Planet Neptune was discovered 1 Neptunian year ago
PAUL DERRICK Stargazer
Can you believe it’s been nearly a year since the planet Neptune was discovered? My, how the time flies. OK, so it’s been 164 Earth years, but it’s but only been one Neptunian year.
When Neptune was discovered in 1846, it was located just inside the western border of the constellation Aquarius.
Now after making one orbit around the sun — one Neptunian year — it’s back near where it was when discovered.
Longtime readers of this column with exceptional memories — Hello, anyone out there? — might recall reading about Neptune’s discovery in a 1993 Stargazer. It’s an interesting story worth retelling.
If planets could talk, surely Neptune was shouting out, “Will someone please discover me?” Yet, given the many missed opportunities, it seemed no one wanted to.
In 1781, Uranus was discovered by astronomer William Herschel from his home observatory in Bath, England. During the following years, studies of Uranus’ orbit suggested the existence of yet another more distant planet.
* First miss: In 1795, Frenchman Joseph Lalande actually stumbled across Neptune as he was making star maps. Upon checking his map later, he noticed one “star” wasn’t where he had mapped it. Rather than realizing he had found a new planet, he assumed he had made a mapping error and merely corrected his “error.”
* Second miss: In 1834, amateur astronomer the Rev. J.T. Hussey produced evidence that something was disturbing Uranus’ orbit. He wrote George Airy, prominent British astronomer and director of the Greenwich Observatory, who replied that the evidence was interesting but impractical. Hussey’s idea was dismissed.
* Third miss: Seven years later, Cambridge astronomy student John Couch Adams calculated a location for the suspected planet and sent it to Airy. Inexplicably, Airy didn’t encourage a search.
* Fourth miss: Unaware of Adams’ work, French astronomer Urbain Jean Joseph Leverrier made calculations for the suspected planet that were very close to Adams’. When these were sent to Airy, he finally commissioned a search, but, incredibly, the searchers did not focus on the spot suggested by both Adams and Leverrier.
* Fifth miss: Leverrier tried unsuccessfully to interest astronomers at the Paris Observatory to search for the planet.
Finally, he got the attention of German astronomer Johann Galle of the Berlin Observatory. On Sept. 23, 1846, after searching only a few hours, Galle and his assistant, Heinrich d’Arrest, found the planet that it seemed no one wanted to discover.
Neptune will be in our evening sky the rest of the year, yet it’s too faint and tiny to see with the naked eye.
So, the next time you’re at a star party, ask to see Neptune. And listen carefully — you might hear George Airy, who blew three chances to discover a planet, still kicking himself from his grave.
* Next two weeks: Average sunrise: 7:02 a.m.; average sunset: 7:57 p.m. Early Tuesday evening, the star Spica is just above Venus with fainter Mars to their right low in the west at dusk. Wednesday, the moon is at third quarter. The moon is new Sept. 8. The evening of Sept. 10, the crescent moon is below Venus (left), Mars (higher above) and Spica (just above) low in the west-southwest at dusk.
* Naked-eye planets: In the early evening, Venus, Saturn, and Mars are low in the west. Bright Jupiter rises soon after dark and by morning is high in the southwest.
* Star parties: The Central Texas Astronomical Society’s free monthly star parties begin at 8 tonight at the Lake Waco Wetlands and Belton Overlook Park on Stillhouse Lake. For more information, see www.centexastronomy.org.
Stargazer appears every other Saturday. Paul Derrick is an amateur astronomer who lives in Waco. Contact him at 918 N. 30th St., Waco 76707; (254) 753-6920: or paulderrickwaco@aol.com. See the Stargazer Web site at stargazerpaul.com.
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