Neptune Discovered One Neptunian Year Ago
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.
Long-time 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.
Stargazer by Paul Derrick
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, Over 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 realize 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 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 which 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 September 23, 1846, after searching only a few hours, Galle and his assistant Heinrich d’Arrest found the planet which 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 as you might hear George Airy, who blew three chances to discover a planet, still kicking himself from his grave.
Sky Calendar.
* Aug. 24 Tue.: The full Moon is called the Grain Moon and Green Corn Moon.
* 26 Thu.: The bright gibbous Moon and Jupiter rise an hour after dark and then travel across the sky together all night.
* 31 Tue. evening: Venus is just below the star Spica with Mars to their right low in the west at dusk.
* Sep. 1 Wed.: The Moon is at 3rd quarter.
* 8 Wed.: The Moon is new.
* 10 Fri. evening: 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 Party. The Central Texas Astronomical Society’s simultaneous free monthly star parties are Aug. 28 at the Lake Waco Wetlands and Belton’s Overlook Park on Stillhouse Hollow Lake beginning at 8 p.m. For more information see www.centexastronomy.org.
Stargazer appears every other week. Paul Derrick is an amateur astronomer who lives in Waco. Contact him at 918 N. 30th, Waco, 76707, (254) 753-6920 or paulderrickwaco@aol.com. See the Stargazer Web site at stargazerpaul.com.
