Researcher Finds a New Moon Around Neptune in Hubble Data

By Nancy Atkinson - July 15, 2013 at 5:52 PM UTC | Planetary Science
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It took sharp and patient eyes, but researcher Mark Showalter of the SETI Institute has found a tiny moon orbiting Neptune that's never been seen before. Showalter used archival data from the Hubble Space Telescope to find the moon, designated S/2004 N 1, which is estimated to be no more than 19 km (12 miles) across, making it the smallest known moon in the Neptunian system. This is the 14th known moon of Neptune.

S/2004 N 1 is so small and dim that it is roughly 100 million times fainter than the faintest star that can be seen with the naked eye, NASA said. Even Voyager 2 --which flew past Neptune in 1989 to survey planet's system of moons and rings – didn't catch a view of this moon, even though data from Voyager 2 revealed several other moons.

[caption id="attachment_87394" align="aligncenter" width="580"]

Neptune photographed by Voyager 2. Image credit: NASA/JPL[/caption]

Showalter was studying the faint arcs, or segments of rings, around Neptune earlier this month.

"The moons and arcs orbit very quickly, so we had to devise a way to follow their motion in order to bring out the details of the system," he said. "It's the same reason a sports photographer tracks a running athlete — the athlete stays in focus, but the background blurs."

The method involved tracking the movement of a white dot that appears over and over again in more than 150 archival Neptune photographs taken by Hubble from 2004 to 2009.

Showalter noticed the white dot about 100,000 km (65,400 miles) from Neptune, located between the orbits of the Neptunian moons Larissa and Proteus. Showalter plotted a circular orbit for the moon, which completes one revolution around Neptune every 23 hours.

Showalter should get the "Eagle Eyes" award for 2013!

Source:

HubbleSite

Nancy Atkinson

Nancy Atkinson

Nancy Atkinson is a space journalist and author with a passion for telling the stories of people involved in space exploration and astronomy. She is currently retired from daily writing, but worked at Universe Today for 20 years as a writer and editor. She also contributed articles to The Planetary Society, Ad Astra (National Space Society), New Scientist and many other online outlets.

Her 2019 book, "Eight Years to the Moon: The History of the Apollo Missions,” shares the untold stories of engineers and scientists who worked behind the scenes to make the Apollo program so successful, despite the daunting odds against it. Her first book “Incredible Stories From Space: A Behind-the-Scenes Look at the Missions Changing Our View of the Cosmos” (2016) tells the stories of 37 scientists and engineers that work on several current NASA robotic missions to explore the solar system and beyond.

Nancy is also a NASA/JPL Solar System Ambassador, and through this program, she has the opportunity to share her passion of space and astronomy with children and adults through presentations and programs. Nancy's personal website is nancyatkinson.com